Divorced Transfer Case Wanted
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- เผยแพร่เมื่อ 28 ก.ค. 2024
- Is your divorced transfer case still sitting alone at home? Send it to be a part of Seeker. There is life after divorce.
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How about just scrapping the whole boat and buying a 1980’s RV and restoring that with boat parts instead?
You should look for an underdrive unit, like a transfer case without the split to drive the front axle.
Yes. Motorhomes use these. We call that short drive shaft a jack shaft. Gear Vendor makes them, but so do other manufacturers. Check motorhome salvage. Forget the 4x4. Get a splitter. That 4x4 transfer is big and bulky. Splitters are much smaller.
What Tomm said is a much better idea than a big bulky transfer case
Gear venders are nice but also are expensive. Rick Johnson is the man to talk to if you go that route.
Today I learned.
But Doug could use the split drive as a PTO, maybe come up with some dangerous way to power bow thrusters.
On older medium duty trucks they had a auxiliary transmission that would work perfectly for what you want to do.
I believe I have one it's been probably 20 years since I put it in storage, I'll go look for it tomorrow.
They go right directly in the driveline a u-joint in the front of them and a u-joint in the back.
I am also headed to Oklahoma next week I could bring it with
Yes best way to go auxiliary or Brownie transmission, easy install no changes at 1 to 1 and if you don't like it just reinstall the drive shaft.
Look for a Spicer 6041 (4 speed) or the smaller 5831 (3 speed) Model variations on either exist with no overdrive, only direct and various under drive ratios. Other models are probably much larger than required for your application
"Brownie"
How did it go? Did you find it?
Higher RPM on the engine will smooth out the powerstroke just like driving faster across a cattleguard or washboard road smoothes the ride. If you do end up using a transfer case, maybe consider having the unused output available for PTO operations. Keep up the great work, Doug!!
PTO option sounds good.
@@olivier2553 Going to be a little hard to access it with where it will end up, but hey, an option for the future if you can swing it is always nice and you never know when a pump needs a power source.
@@KnightsWithoutATable But if you cut it off, it is not hard to access, but definitely impossible :)
with the transfer case you can use the front drive for a on demand pump
Oh. By the way. Another thing to look into. The harmonic balancer your engine has is likely a solid unit. Look into a device called a fluid damper. They work much better for smoothing out the impulse of each of the power strokes of the engine and can extend the service life of your engine as well.
yup they work! i have a cat engine in my dump truck and i discovered that the damper has a life of only 200k miles. the gel inside of them thickens and hardens.
I have a np203 it’s not divorced but you can make a yoke adapter easily or buy one. You can have it if you want it. In my opinion the np 203 has better planetary gears setup than the divorce 205. You might actually be able to remove the front output drill tap the case and make a cover. So it’s just a reduction box I have seen some old timers do this.
you need an auxilary transmission, rather then a transfer case, start haunting old truck wrecking yards, you can get em 2-4 speed, sometimes called a brownie box. Underdrive units are pretty skookum too.
And yeah, Diesels have a "power band" each motor is gonna be a little different, most like 1500, I think the 5.9 cummins is happy in the 2000rpms range.
A transfer case might be too low of a reduction, closer to 4-1 when ya need more like 2-1 ish... anyway good luck mang
the other option Ford (borg warner?) transmissions out of 70's 1/2 tons trucks? pull the input shaft and bell housing, fabricoble the u joint flange, reassemble off to da races.
All you need is the range box portion of a transfer case. There are several companies that make what you need that doesn’t have that big extra lump hanging off the side. You can also build one from a New Process 203 with a couple extra bits. You could talk to the guys at offroad design and they would be able to line you out with what you need easily enough.
What you should look for is an axillary transmission. They come in 2 to 4 speed boxes . There are some of those on marke t place.
can be air shifted too.
If you could find one, Spicer made a small 2 speed auxiliary transmission that guys were putting into 1 ton trucks back during the 70s energy crisis to get over drive. They can be mounted in reverse as well to get under drive. And they may have been available with different ratios. They are quite compact in size as well and only weigh 50 pounds. Spicer 4800 model.
You should look at using a 4 speed transmission gearbox instead. A nv465 I would think be perfect, you'd have three different reductions to choose from and 4th is 1:1 ratio of you wanted to just take it out of the equation. Plus very durable, easy to find, removable bell housing and wouldn't be hard to put a yoke on the input shaft
Yes this, the "doodlebug" homemade tractors had inline transmissions to mix and match for the right gear ratios
the problem with this is the nv465 (and pretty much every other manual trans) relies on the pilot bushing in the crankshaft to support the input shaft. Without that support then the bearings get munched in extremely short order and wipe out the input shaft, output shaft, and cluster gear.
@@MonkeyWithAWrench could Doug solve this by mounting a bearing in front of the manual trans or will it be impossible to center well enough to prevent wear
@@jonathancorbett5917 it could be done but the TIR on that would need to be about .005" to be to spec. A looser tolerance would work for a while but would eventually cause the death of the trans. there are ways to make it work but the transfer case idea is by far easier. Even then, if the transfer case is not geared low enough then a different gearset would be the next easiest. I'd personally consider it a plan c at most
You should also think about just using a standard 4 speed top loader transmission for a reduction box. It would get you the same effect but give you 4 reduction to choose from and would be normally operational conditions for that style gears. Most transfer cases are not made to run in low range for long periods of time.
Yes this, inline transmission just like the old timers did for their homemade tractors
It actually crossed my mind, that the chain in the case could come under some significant wear.
some older chev and dodge used a NP 203 transfer case. The reduction was a seperate box bolted to the front / rear output box. You might be able to use the reduction box.
Use a transmission, Granny gear, 4th direct then 3 lower gears, transfer case only gives you one low and direct.
guys, a cheaper and more tested unit would be a joey box or truck aux box with 3 or 4 speeds..There should be a heap of them in the wreckers yards..
I can't get my brain to understand why decreasing the pitch and increasing the RPM doesn't do the same thing.
With the variable propellor, he should be able to dial in any RPM he wants to work with.
Agree on the underdrive unit comment, def. a better option. If you do end up looking for a divorced transfer case, they were common on late 60's - early 70's International Harvester pickups (1200 series) and the IH Travelall. Hope this helps.
Ben at 406 Garage (who have their own TH-cam channel) has a lot of old International trucks and parts, and has just fitted a divorced transfer case to one of theirs. They could be a good source of a transfer case if you need one.
However, the comments about underdrive units seem valid.. they are designed to do exactly the job you want, and would be smaller and easier to mount.
All the best to you and ALL the crew! Thanks Doug!!!
1700 rpm is the sweet spot towing heavy with my 6.7 cummins. That's about 60mph in 5th 70 mph in 6th. She's happy there.
Saw at least one comment mentioning a 'brownie' transmission, which is a secondary, separate transmission used on older medium- and heavy-duty trucks, and that seems like it would be a perfect solution for what you want to do, instead of trying to cut up a transfer case. It would give you more gearing options as well so you could get things just right, most would have 3 or 4 gears on them. Wanted to bump this idea if I could, it's a good one!
We had a similar problem with our tmr mixer truck the pto output was to fast for the mixer ( we mixed as we drove down the road) so we spliced in a old gm. 6 speed standard transmission shifted it in to third and left it there. It worked great for years the advantage was the transmission was very stream line which we needed because it needed to fit between the frame rails and driveshaft
It was a treat being on Seeker under sail yesterday...looking forward to more today!
Like commented below, the NP203 range box might be able to be adapted to what you are looking for. Off Road Design works with them and might have an adapter plate for your transmission. The only divorced transfer case I know of is in a M135, commonly called a "Deuce and a half". Might be too big though. You might also want to look at a BlackBox planetary gear drive which is a underdrive unit which looks to be pretty compact, but costs about $2k. Even so, it might be easy to make mounting plates for it.
Deuce and a half was quite a beast.
Dana 24 was the unit the F250 "hiboy" trucks used 1960-1972. Not sure how it would handle the power of the cummins but it is an all gear drive unit, If you think thats the route you want to go i may have one that needs to be rebuilt. Adding in a "crawler box" might be a better option, they sell them for the off road jeeps, it adds a low range gear around 2.72. Check out advance adapters.
You may want to consider a Dana 20 from a 1st gen Ford bronco. Technically it is not a divorced transfer case, but due to its design it would be very easy to convert to a divorced. Importantly it is all gear driven design and with a VERY compact size ,also the High-Low shift is separate from the 4x4 shift. The ford version has its own stub adapter and low is something like 2.43-2.47:1 depending on year. It was also used in 1 ton jeep trucks for the military but has a different mount that I think be more difficult to used. Alternatively a NP 435 is a very small manual transmission that would probably fit the bill much better and be heavy duty
It's a similar issue that they had with propeller driven aircraft which gave rise to the constant speed prop. Keep the engine running in it's optimum power band and rather than adjust the throttle to increase or decrees speed, control the pitch of the prop blades instead.
Doug the rigging is looking fantastic. Also, I totally agree with the assessment on the engine rpm speed.
I have a divorced np 205 but a better option is to see if you have the space to install a 4 speed manual trans. Something like an sm420. This would give you 3 reduced gears . This way you can pick the best for your pitch and rpm.
Send me an email if you'd like to part with the NP205 but we are liking the manual trans idea too. svseeker@ymail.com
@@SVSeeker Doug, do NOT do the manual trans idea. The input shaft on pretty much every manual trans relies on the pilot bushing in the crankshaft to support the end of the input. Typically there is only a single ball bearing on the input shaft that will not handle the load without a pilot bearing supporting the end of the input. If you can come up with some sort of a carrier bearing and a plate on the bellhousing then it could be made to work, but for the input shaft and mainshaft to survive they need to be within about .005" total runout otherwise it munches the bearings. If you want to get on the phone with me for a few I'd gladly explain this in more detail, but a failed pilot bearing is a common cause of failure in manual transmissions. Its just the small little bearing or bronze bushing in the back of the engine crankshaft but its a critical part.
@@MonkeyWithAWrench Thanks and yes that makes sense. A carrier bearing would be needed.
@@SVSeeker I've been thinking of a way to build a carrier bearing. A trans like a sm465 have a front input retainer that can be removed with 4 bolts. if you build a custom retainer that is concentric, then you could add a second bearing to the input spaced out as far as possible and could get it to work. It would even be decently easy to keep the TIR within spec and not make the whole unit overly bulky. The only concern I have is making sure the unit is short enough. Doable, but the transfer case is going to be easier and probably more reliable.
@@MonkeyWithAWrench Agreed. I can be done but we like the transfer case for ease. And 2:1 is more than enough reduction.
I also have a divorce transfer case located in steelville Missouri. It's free if you want it
Usually higher RPM equals lower efficiency, but not when you're pushing it on torque like this. Probably the right call for your setup. Definitely look into the alternatives to transfer boxes that people are suggesting. Finding a divorced unit that has a low range could be tricky since they're usually found on cars with optional AWD setups.
Please consider a ZF220A. I have this transmission behind a 6BTA and its works great. I have seen these used for around $2000.00. Use a transmission that is built for marine use instead of cludging on more stuff to transmission that is not working for this applicaiton. Sometimes the best way to build a pair of pliers is to buy a pair of pliers.
With the out put shaft on the front you could probably use it to mount a shaft with a pully on it for a on board air compression setup if the one u have now fails or option to have more air . Food for thought maybe Doug 🤔 .
This is a great video for anyone interested in sailing or learning more about transfer cases!
👍💋 I really like this channel! ♥♥♥
An underdrive or brownie box is what your after. But a transfer case is awesome. But the front output with transfer case in 2wd could be used as a pto and put a water pump on that would be capable of pumping seeker dry before anything important goes under.
Something else you may want to look for is a aux. transmission. It is similar to a transfer case but it only has one input and one output. I would like to say I have both but they are not available.
i hope you find what you are looking for. thanks for the update and have a wonderful evening
great idea to use the transfer case!!!
another thing is called a underdrive gear box and is pretty much what you are wanting without any cutting or modding needed
have a look at a company called northwest fab to get an idea of what I'm talking about
they are not cheap but they do have flanges and yokes and holes to mount the unit
also there's many other company's that make them this is just one off the top of my head
4 to 1 if you go with an Atlas or Jeep Rubicon xfer. These are gear driven rather than chain drive as well.
A company called Gear Vendors makes boot on over/under drives for all sorts of off road, racing and just about anything else you'd like speed up or slow down a driveshaft on, look them up they're bullet proof systems and simple to mount and use!!
A small 3 or 4 speed manual transmission would probably be far more reliable and have more reduction ~5.5:1-1:1 in less space. Some of the 60/70's 3/4 speeds are really compact without the bell housing. Adapting a hub from a clutch disk to a u-joint would be easy, just a matter finding one that does not need a pilot bearing or doing something like using a fwd hub/wheel bearing with the hub from a clutch disk to support the input while also giving a flange to mount a u-joint.
Also forward output could be made up as a pto as well...
Given the length of the vessel at 74’ your maxim hull speed is about 11 Knots. As such balance the power band of your engine to the required prop to achieve the hull speed
Maybe hook your hydraulic pump to the second output of the transfer case, that way you can shift to turn in on and off while the engine drives the prop.
Nissan made a great divorced transfer case that was compact and great bracket attachment and they are rock solid late 70's to 80's 4wd trucks
Use the secondary output to drive a small generator AC or Dc for auxiliary purposes.
Interesting idea, id look for the new process 205 unit. There are many options available in the aftermarket as well.
Way too big
Like a lot of folks said... Range box only is the best option it seems, I think a 203 style setup would work fine in your application but their are more robust options available at corresponding price. Off-road/aftermarket fab shops and suppliers like ORD, WFO, advance adaptors, etc have a product to fit your need with minimal excess.
Have you thought about a manual gear box with just 1st and reverse maybe find one with a granny gear? I've been thinking about that during your whole build. Something with out the complication of the auto. My racing days we would pull out gears except for the ones needed for the track to decrease rotational mass. It would definitely ease the complication in your drive line and be more robust.
An external planetary gearset might be a better solution. Similar to a Gearvendors overdrive unit but in reverse. It would eliminate the forward output shaft and be more streamlined. Yet a divorced transfer case would provide excellent proof of concept.
I have zero knowledge about transfer case but I am subscribed to the channel Matt Off Road Recovery and they deal with a lot of problems of transfer cases, even special built ones for high torque.
Just put a manual transmission in there. More gears selection, and it can fit in the tighter spot.Your just going to have to build a support for the input shaft.
I think I would try to remove all transmissions, converters etc, and put 1 single reduction (incl reversal and neutral) to the desired rpm range, based on a standard calculation like they do for any ship (using power-rpm curve and prop specs).
Brilliant I had the opposite problem and had to take the reduction gearbox out
If I remember right that engine's most efficient rpm is like 1500-1800 rpm. You may take a look online at used military truck parts, something like a deuce and a half transfer case.
Your friend on boat says exhaust temp is so high , sounds like engine is lugging. Less pitch on variable pitch prop will raise engine rpm. Seems thats easier than adding something else inline.Test it , back the pitch off just a little. I think Jonnie 540 said similar.
The NP205 is what you need & comes Divorced in Chevy, Dodge & Ford. It's the strongest T-case ever put in a pickup & I run one in my 3000hp 4WD racecar. To save all the hacking & wacking wouldn't it be easier to use something like an MS465 Chevy truck trans & that will give you better ratio options rather than only one reduction ratio on a 205? Hooking a trans to the back of 545 with a floating coupler is the simplest way. Having said all that, is there a reason you don't run the 545 in 2nd or 3rd?
They make a divorce kit for ALL transfer cases. You could also use Klune reduction unit with a divorce kit. That way it is a single yoke. But do a search for transfer case divorce kit. You will be amazed. I would also suggest using a gear unit such as the dana 300 or dana 20. Just my two cents. If you get stuck hit me up. Been building 4x4's for a very long time.
To build a divorced case , check out advanced adapters, they make tons of that sort of stuff...
A lot of flat bottom jet and prop boats use Power Glide automatic transmissions. Also a bunch of New England lobster boats use complete auto power train's including the exhaust.
You can stack a manual trans behind the trans you have . I have seen this used on tractors and 4x4's.
Maybe use a 4 speed manual truck transmission if you can find one short enough? You can accommodate a small miss-alignment of driveshafts using rubber a driveshaft donut or "giubo".
Some of the old Kenworth trucks had a 5 and a 4 gearboxs. Just take the 4 speed rear gearbox and use it instead of the transfer case. The 4-speed gearbox like a Spicer series 1241D has a deep under-under-direct and a over drive Gere and would hold up better than a transfer case
The NP 205 came in some 70's to 80's 3/4 ton pickups, but they are not cheap... A Planetary tcase typically runs cooler under high load, and it has a internal lubricant pump, (NP241) you can always remove the forward output section on a NP241 and cut eh part off you don't need. It also uses ATF, so it in theory could use the same fluid as the Allison? A 4x4 case allison might be cheaper in the long run?
I know gear vendors makes an external overdrive unit maybe they have an under drive unit and I believe they are pretty compact. Basically a transfer case without the front driveshaft output.
You need to look for a Brownie Box. It's just an auxiliary underdrive transmission that has 2 or 3 gears, one of those being 1 to 1, that use to come in older big trucks.
That should work, but they are pretty rare at this point. Probably even rarer at this point but would work even better is an over/under drive unit. They were aftermarket two speeds that you bolted behind your trans in your truck or muscle car. It did the same thing as a divorced transfer case but only had one output. It gave you direct drive and a overdrive gear to get better mileage in the highway in the days of 3 speed automatics. But it could also be mounted the other way giving you direct drive an a gear reduction, so your truck would have a granny speed and could split every gear just like it has a 2 speed rear end. I think they were planatary gear sets but not sure. But unlike a transfer case, you could shift them on the fly.
An easier thing to find is a gear reduction unit off of old PTO driven farm equipment.
Datsun 740 is divorced. I got one . don't know how to get it to ya.its yours if you can ship it
You could keep the part that is meant to drive front wheels and use it as a PTO (if you get one where you can put the outputs in neutral independently)
NP 205 has PTO covers on it already
Manual transmission would also work in a pinch. You'd have like 5 options. Direct and step by step below that. L in an transfer case is approx 1/2.
Don't know what the torque or power requirements are, but you can look for used Axletech T232 or T600 transfer cases. T232 should be just right on the power rating, but the T600 are used on some MRAP vehicles and very easy to find.
They make stand alone gear reducers for rock crawlers. NF sells Black Box that is pricey, but super compact. I wonder if it is worth calling some junkyards looking for something similar.
just build a reducer its just 2 gears a tranfercase would be less reliable being more complex unless you wanted another output shaft. you can make the entire reducer yourself with the machine tools you already have going so far as to cut your own gears if you really wanted to. then you will have the optimal gearing instead of just getting close
I would suggest driving a generator with the other transferase drive output because the transfercases can drive 2wd REAR, 4wd Hi or Low, and 2wd Front. A lot of people don't know that it can drive 2wd front because the manufacturers never install the switch to use it in 2wd front. When needed you can now use the generator with 2wd front driven by the main engine.
New Process 205 is the transfer case you are looking for. The Brownie auxiliary transmissions that people are going to recommend have a very low torque rating's. The NP 205 is used by all the off guys and on the street behind custom built 5.9 Cummins trucks too. Perfect for what you need. You will want to get a twin stick rail kit for it. This way you can just shift from direct to low 2 wheel drive and not use the 4 wheel drive side. There are videos here on u-tube about this. Also, larger yokes like the 1480 size you probably have from the bus is available after market as needed.
What you want is fully gear driven unit a NP 205 Divorced transfer case. Came in Dodges and Fords. Seriously consider using a a 4 spd like the GM SM 465, it as synchros. Dodge has a NP 435 with a granny low.. The Ford & Jeep 4 spd T18 comes with a Bull Low comes with a compound low gear ratio of 4:32:1 or 6.32 : 1... To hook up conrols is easy. Can be done easily with cables eg Ag loader applications. I would recommend converting the valve body of your automatic if you keep it, to fully manual.
Fully divorced transfer cases are pretty hard to come by these days for cheap. As some have stated if you could built an adapter to use a common transfer case used on common transmissions I bet we could get one for free.
A 12v cummins will be much happier on boost at a higher RPM for sure. Ive had several 12v's in tree trucks.
Doug, if I understood his explanation, the extra output shaft/connection you're not planning to use doesn't have to be cutoff unless it's for clearance reasons ? Couldn't the output be directed to a generator for a backup charging system or the power could be used for other boat or shop tasks like air/hydraulic power apps ? Having that extra load could help keep engine being in sweet spot of power curve too...
What about a marine transmission with a built in reduction, it’s small and can be mounted to bracket/plate - wakeboard boats use a fork lift type transmission and there are manual transmissions for fork lifts
Not this but related: if it has a neutral you can let the propeller spin while sailing (engine off) and have an alternator on the propeller shaft to generate power. Like a RAT on aircrafts. To charge batteries from the wind.
Transfer case from an M211 (1953) sounds like the ticket you need.
Your comment about the transmission not getting warm...working on my RV I learned that a certain degree of heat in the transmission oil is important because it drives the moisture out of the oil. I think the recommended temperature is around 170 F. I installed a temperature-switch that doesn't turn on the transmission cooling-system until that temperature is reached. You're in a definitely humid environment. Is a cold transmission a problem? As I listen to the rest of this video I realize that knowledgeable experts can make things sound overwhelming but we can't live without them.
This seems like a really good solution to the problem. If you wanted to, could you use the second drive out of a transfer case as a PTO?
Doug maybe you should check with Gear Vendors. They make a some great rpm reduction for the Hot Rod industry. Maybe they can build what you are looking for.
A industrial gear reduction box is what you need. you can get one rated for the power of the engine whatever gear ratio you want.
Super cool info on the torque covertor
To increase engine RPM, run at a lower blade angle ie less pitch
I love when you get someone who comes in and says "here's what you need. this'll unlock all sorts of stuff for you. also I own all of these things in my other car."
You might want to look for something called a doubler. They do have some that are small and don't need a transfer case.
The model case your looking for would be a NP205, they came in both standard, and divorced.
The early Dodge Trucks from the 80's used them.
They are a 2:1 reduction in low range.
Ford F250's used them too '79 vintage
Most transfer cases use chains, that won't be good, also aren't designed for using them in low all the time
the chain is used to drive the front shaft
Build one all you are looking for is a 2 to 1 reduction split the drive shaft little sprocket on the input side big sprocket on the output side put a chain on and box it in.
I bet 10 bucks you have everything there on the boat to build it. I know for a fact you have the tools and ability
Have you considered a gear vendors overdrive? Used in drag racing often, and can be used to under drive or overdrive and wouldn't have the big offset of a transfer case that you don't need. Made for smaller applications but capable of holding over 1000hp
He needs UNDER drive not over.
SCS makes what he needs in many flavors but they are $$$$
Lenko will have a 2 speed module that should suffice. Second hand units might be around, but I’m pretty sure a singular module new wasn’t expensive enough for me to spit my food out so it might be worth a look
Hi Doug ! Just asking. Would it be a good idea to connect a permanent magnet motor to the front axle flange of the transfer case. This permanent magnet motor might be able to charge your batteries when you are sailing if you pitch your blades the right way (and leave the transmission in neutral). With the right controller (something for EV’s like from Curtis) you can also power the electric motor to turn the shaft to “help” the diesel engine in case of emergency or power the propshaft when the diesel fails. To charge the batteries you signal the controller to regenerate like regenerative braking in a car. Been following for years, i hope you can do something with this. Cheers!
Older model diesels had a recommended 1000 rpm min run for extended idle and the sweet spot running continuous load was around 1200 so I'm betting you run it so load surges doesn't knock it much below 12 a lot.
Get a over/ direct/ under drive auxiliary transmission
You could look into a "doubler" its essentially an 'extra' low gear for a transfer case, without having the front output. a transfer case with a doubler would make 4:1. simply with a doubler you can get 2:1 without extra front gears
The same thing as a Suzuki Sierra 4wd has in it. Seeya Rob... the transfer case is separate from the gearbox.
what about just using a 4 speed manual gearbox, you dont need to shift gears while driving on it so select a gear reduction and away you go, gives you multiple rev ranges to use, many years ago when i was into 4x4ing and rock crawling i bolted 2x stock 4 speed gearboxes together with to get super low crawler gear ratios