700R4 Rebuild PT4: Pump, Servo, 1-2 Acc and Reverse Input Drum + Solving Rev Input Clearance Problem
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- เผยแพร่เมื่อ 26 ส.ค. 2024
- I put together the 700R4 the front pump, servo, 1-2 accumulator, run into a clutch clearance problem with the reverse input drum and come up with a solution on the spot. I also discuss various applicable rebuilding considerations and offer tips and tricks for assembly.
Rebuild Video Series Publication Schedule
3/19 - Overview
3/21 - Bushing R&R
3/23 - Measuring Pump Clearances
3/25 - Sub-Assemblies (Pump, Servo, 1-2 Accumulator, Rev. Input Drum)
3/27 - Forward Drum and Clutch Clearance Measurements
3/29 - Case Assembly
3/31 - Belly Components and Shift Calibration
4/1 - Final Assembly & Build Summary
I was working on installing forward reverse piston in yesterday and y’all know how much of a pain that is to put in. I discovered a very easy and cheap way to do it. I cut the top off of a small water bottle for the middle seal and then for the outside I used a very cheap and thin sports cone. You can get 10 or so of these things for 5 bucks. You should slide it in beside it and roll it around. I was dreading this but this worked great. I thought I would share this because you Nick and others have helped me learn how to work on something that I was always very intimidated by. This was the 2nd transmission I rebuilt. I have also rebuilt 2 4r70w’s and I am about to do another. Thank all of you so much!
Hi Tim, thank you for sharing that tip! I'll try that out next time I have one in the shop. Appreciate the views and kind words.
With regards to your other question below (or above), I don't believe either of those other two things would have triggered a 3-4 clutch pack failure so soon after rebuild...The sun gear bushing walking is relatively common and I've gone over to the Sonnax wide bushing for all 700R4s and 4L60Es and use red Loctite on the bushing's OD as an extra security measure to hold it in place...When they walk, they will restrict the lube circuit, as you have observed. Putting the accumulator piston in the housing first then the spring a la a 700R4 wouldn't result in 3-4 failure, just shift irregularities with the 1-2 upshift and 3-2 downshift. It is possible, metal from one failure migrated to the 2-3 feed and partially restricted it or began to cut the sealing surface of the 3-4 apply piston (one of my '4L60E Autopsy videos shows a similar failure, but to the forward piston).
How did you set up the 3-4 clutch pack? Factory stack-up or aftermarket/a la carte?
What was the clearance?
Did you install the load release springs or leave them out?
I'd pressure test the drum and do a leak down test on the 3rd accumulator check ball capsule in the case. Do a line pressure test and take a bi-directional scan tool with you on the first test drive to make sure everything is functioning as it should.
I also did a wet test on input shaft to drum . It was cold when I done it though. There were no bubbles when I applied air.
I also have a question about the pump . It was in great shape the first time around but now has a tiny groove about 2 inches long that I can barely hang my fingernail on. I would like to understand better how to tell how bad is too bad. I know it could be sanded or turned. What do you suggest?
I forgot to tell you that the reverse input drum had some pretty bad dents in the teeth I’m guessing from the hard shifts. I think that is where most of the bigger metal is from. Do you think the accumulator being put in upside down could have indirectly caused all of this. A piece of metal like you said getting into something.
It is the pump body that has the issue
I'd test that drum hot as well as do a leak down test of the third accumulator check ball capsule in the case.
Resurface the pump if you need to but doesn't sound like the pump was behind the 3-4 failure, at least not based on what you've told me so far.
In the event you're not able to positively identify the cause of the 3-4 clutch pack failure, replace the forward drum with a known good one before you go back together with everything.
Never ceases to amaze me how much I learn from these in depth transmission videos ! Thanks for the information and easy to follow step by step.
Thanks, man - appreciate the views!
This is a trick an old timer showed me to align the pump halves. Take an empty case and put pump in upside down with bolts loosely installed. take a pick or small punch to line up holes for feeds, Philips screwdriver works too, the put Philips into one of the pump to case holes to keep it from spinning, and torque bolts.
Yep, it's a great tip...I do that with E4OD, 4R100s, etc...Im so used to using the band alignment tool w/4T65 sunshell i never do it, haha...i'll do a video on the subject as it's worth showing how to do it as most folks probably spend $$ on alignment tools that they may not need to...Thanks for watch as always, Peter!
@@nickstransmissions When you are first starting out you don't always have the tools or money. I used banding that you would use to tie things down on a skid, or pallet. to align the pump . You can use the extension housing bolts to pull the pump from the case with a prybar since they are 3/8 x 16, same as a slap hammer
@@monkeywrenchization yep, i know…improv is the name of the game when it comes to tools in those early months/years.
Another great and very informative video. You definitely have the knowledge and it's greatly appreciated that you share with us new builders! Can't thank you enough good sir!
I appreciate that! Thanks as always, Jordan!
Well Nick old 6c trans done good. Shifts beautifully up and down LOL most of all no leaks. Thanks so much for the detail on this trans I learn so much. Thanks again
You're welcome and great to hear, Steve! nice job.
Another great video. I hate clearance problems! I usually have issues with either the forwards or the 3/4 stack. I've started keeping different thicknesses of steels on hand just in case.
Thanks, Kevin and yes, I can't stand when clearance is off, haha. I always recommend folks have extra selectives (any part inside a transmission where different thicknesses or sizes are available) for units they build frequently. For 700R4s, the backing plates in the 3-4 pack are selective as well (the support rings w/the legs are all the same thickness); I have also seen differences in the 3-4 clutch pack snap rings from early to late and into the 4L60Es.
I am rebuilding a 2005 4l60e for the 2nd time. After getting on it pretty hard one day it within a couple of drives stopped shifting into 3rd gear. I took pan off and seen few small pieces of metal and a lot of fine metal. I took it apart and found that I had turned 1-2 accumulator upside down with stock springs and the new sun gear bushing I had installed had turned loose and was riding up on reaction shaft covering feed hole. The 3-4 clutches were cooked. Could either one of these have caused this?
Awesome man!! Great video.
Thanks again HMG!
First...thanks for the very informative videos on the 700r4. Also, do you use any pump rotor kits? Iam trying to find a new 10 vane and only find no name cheap ones that ive heard can fail quickly.
Thanks for kind words, HomeCNCStuff - appreciate it...Aftermarket pump rotor/slide kits can be hit and miss...Generally, I only use them as a last resort and have had decent luck with the ones from Transstar but the majority of the time, the existing factory set is ok to re-use. You can always use outside and depth micrometers to determine if any given set out of a pump is still good...As long as the rotor and slide are of the exact same thickness and clearances are within spec, it's fine to run them...You can also simply have the pump cover and body machined as required to get them within spec if need be.
What direction does the lip seal face in the center of the drum.
All lip seals face the direction of apply fluid. So if the apply fluid is coming up from the bottom of the drum, from where it enters via a shaft or feed passage in the case, the lip seals would face down into the drum - facing the on-coming fluid. The lip sealing surfaces are pressed against the inner diameter of the drum to seal off the circuit.
Hope that helps with determining which way to orient the lip seal in any given transmission.
Thank you for watching!
Didn't I hear you say not to use the orange spring in the transgo boost valve kit on one of your videos?
You may have - let me know which one....The 700R4 Transgo shift kits don't come with an orange boost or PR spring - those springs are green.
I may have been referring to the 4L80E or TH400 PR springs in those kits as they can be overly aggressive (TH400s, specifically) and if measures aren't taken to offset the converter charge orifice, you could get converter ballooning in some instances.
@nickstransmissions oh okay I may have it mixed up with a 4l80e video then. I'm working on a 4l60e and have 2 orange springs in the transgo .500 boost valve kit. I immediately stopped and remembered one of your videos. Figured I would come here to ask a question. Thank you sir.
You're welcome, man.
Hi Nick, I'm putting together my 2-4 servo and it appears mine has the corvette 2nd apply piston and some sort of aftermarket 4th apply piston and cover. the 4th apply piston has a rubber lip seal on it, is this common? my gasket kit doesn't have that seal in it so should I reuse the old seal or use what is supplied in my kit? Thanks again for all these videos, they have been extremely helpful.
Hi Kevin, I'm guessing you have the Superior Tech 4th gear billet servo kit...If so, this replacement seal kit should work: globaltransmissionparts.com/gm-700r4-4l60e-4th-apply-piston-and-servo-cover-replacement-seal-kit-by-superior-seals-only/
@@nickstransmissionsAwesome, Thank you!
You're welcome, Kevin.
So I have another question for you Nick. Years ago when I first worked on a 700R4 I remember it was common to drill the oil drain back hole to a larger diameter to in theory help prevent converter seal “blow out”! I do remember this happening often on the very early models, especially after overhaul. Now that I am doing this work much more often I don’t see that modification being called for in the shift correction kits. I do add a bit of Locktight to the converter bushing/seal and always use the seal retention clip/clamp. Has that modification been omitted on purpose? As in it’s not suggested to do that for x reason? I have seen you do that on the 4L80 but I don’t recall seeing you do it on the 4L60.
You can drill it 5/16", helps with drain back in high-rpm applications...I do mention it in my 700R4 stock to mild performance video as well as my 4L60E high performance series.
Okay I just missed it then. Just wanted to make sure that it wasn’t something that had turned into a “do not do this” issue. Thank you as always! Your response is very much appreciated!
Nah, should be fine...It's not super necessary unless you're doing HP or extreme HD.
Which assembly lube do you use through out the transmission build? Excellent videos!
It's called 'Assembly Goo' - search it on Amazon and buy a bucket of the blue lube and green lube. The green lube is thicker for holding check balls, bearings, washers, etc in place while the blue lube is used on everything else that you see me use it on.
Thanks!
I could really use some information. Can't seem to find anything that pertains to the pump housings. It seems the 700R4 labelled "Pumps" cost twice as much as a 4L60-4L80E for a rebuildable core. I need one for my '92 "K" MD8 case as mine was destroyed(Non-Rebuildable). I primarily just need to know what newer Stator/Pump housing is interchangeable with the older 700R4/4L60 case. I really would appreciate any information that you may have. Thank you.
Hi, thank you for watching. No stator/pump cover from a 4L60e will retro to any 700r4 however you can retro a 92-94 4l60e pump body to an 88-92 700r4.
Additionally none of the early non-aux valve body 700r4 pumps will work in yours so you need an 88-92 pump cover/stator assembly and either a pump body from a 88-92 700r4 or 92-94 4L60e.
Check with your local salvage yards or pick a parts. You may be able to find a pump cheap ($25-30) and spend another $50 to get the two halves remachined, making the pump new again with new vanes, rotor guide, etc. The existing rotor/slide from the salvage yard pump should still be reusable.
I really appreciate the helpful information! I was able to buy a "Core" transmission for parts. However, the 2nd pump housing isn't in great condition either.
As for machining the area where the pump actually sits in, back to a smooth/flat surface, how much material can actually be removed before the entire housing is unusable?
It literally took me a week and a half of searching for the 2nd transmission I just bought. It's slim picking in my area for these "Older" 700/4L60 transmissions.
When I separated the pump halves on both units, the inside of the housing where the stator bolts to, has a slight depression(that I can feel with my fingers) where the pump vanes have dug into the housing.
Wondering if I am able to machine it a little to just make the surface smooth or if I should just leave it alone and just put the new pump in it "As Is". Please advise.
You're welcome, man...Have the pump halves fully machined. What's typically done is the pump cover is put on a lathe and resurfaced. The pump body is either also put on a lathe or set into a vertical mill so the deck and rotor/slide pocket can be milled to the correct depth after the deck surface is machined. The machinist will shoot for .0015" clearance between rotor and slide vs pump body deck surface. When combined with the freshly machined pump cover, you'll have a brand new pump.
Excellent! I'll pull the stator shaft out of both pumps and try to find a shop that's able to machine them to specifications. Thank you again for all the helpful information! Best wishes.
So, in your opinion is the 10 or 13 vane pump better in a performance build in a 700r4?
Either is fine but 10-vane rotor/slide combos are stronger due to less vane slits cut into the rotor...The 4L60Es were designed to take a 13 -vane pump, not the 700R4s...Ive built full race transmissions that used 10 vane pumps with no issues.
thanks@@nickstransmissions
Dang, I am about start putting the 700r4 together and I see a small circular springs that I do not know where it goes or where it came from, it looks like o-ring but metal spring about 2 inches. Anyway I can send picture of it. I dont know how to identify it.
Hey man, that's your pivot pin return spring - watch the rest of the vid to see where it goes, assuming you havent already done so.
@@nickstransmissions It cant be that it's, this is round oval not really a spring but spring look a like. not sure how to describe it
Ok, i think i skipped right over the "2 inches in diameter" part of your question, lol...sounds like you're describing pump rings. One goes on the bottom of the pump body's working surface while the other one goes on top of the rotor once all the vanes are in...If that's what you're referring to and you cant find them, no biggie...grab Transgo's unbreakable pump ring kit ($20 or so) and install the rings and priming spring that comes in the kit.
@@nickstransmissions Does fit there very well, going to leave it there and hope for the best.
Took me for ever to grind down that part for the pump. After I broke that snap ring on the pump I noticed my snap pliers were not even the correct size for the holes, glad the kit comes with one. Waiting on one more package. Thank you for great videos and reply.
You're welcome but I'm still not sure exactly what you're referring to as there's nothing you should have to grind on that would go into the pump. If you're still needing help and want to send me a picture so I know what you're talking about, go to the TahoeYukon.com forum, open an account and send me a direct message there w/a picture.
Can I put a 10 vain rotor in my 7 vain housing? Or will I need to do modifications?
Yes, you can retro a 10 vane rotor into a pump that orginally took a 7 vane.
@@nickstransmissions awesome thank you! Also kinda a dumb question is it possible to install the low reverse sprag wrong in a 700r4 or does it only go in one way?
Watch my 700r4 or 4l60e rebuild vids or the Sonnax smart shell video - it breaks everything down for you...
Can you measure the depth of your cavity in your pump and get the right thickness rotor for your pump? if so, can you supply a link or any email or phone number even thank you enjoy your videos
Yep, simply use a depth micrometer that's capable of .0001 resolution to remove any uncertainty then mic your rotor and slide...I actually perform this procedure in my 200-4R Rebuild Series, PT3 (Pump and Overdrive Section): th-cam.com/video/9mPiYouEsPI/w-d-xo.html
So you like to use TRANS GO parts also? 👍 so I can measure my depth and contact them and let them know what I have and they can send me the correct pieces?
Transgo parts are great but they don't sell pump rotors or slides to my knowledge...Your best bet is to measure the existing pump rotor, slide and depth of your pocket in multiple places to determine if your existing parts are within the spec limits for the rotor and slide to deck surface clearance. My above linked video will walk you though the procedure...
You can purchase new pump rotor/slide kits on the internet or from your local transmission parts supplier but if you do, I'd have your pump castings machined so they are 100% true and meet clearance..Your machinist will need the new rotor and slide so he can set the pocket depth to ensure clearances are met.
so bought a 1991 chevy g20, mechanic said someone put wrong dip stick and so another mechanic put too much fluid, which he said caused the pump to go bad. I have taken it apart and the pump rotor and the rotor guide were in pieces. I don't know where to stop the rebuilding process. I do not see it worth putting it back into that van if I keep rebuilding, like down to bushings. Trying to decide to just rebuild the pump and put it back together or keep rebuilding and just buy another one from junk yard for that van.
Hi @shvilible1767, if you have gone in as far as taking the pump apart, I'd just go through the entire unit. This way you know it's done correctly and what parts went into it that should have. Thank you for watching!
@@nickstransmissions Great videos, so I bought,
74006B_L2 - 700R4 4L60 Transmission Master Rebuild Kit 1987-1993 GM Chevy Level 2 + Band etc,
74531AK- GM Chevy 700R4/4L60/4L60E Rotor Kit (10 Vane) (.7074") (Rotor, Guide, O-Ring, Rings, Vanes, Slide) 1981-96
and TransGo Shift kit-Jr.
Hopefully it's enough
Putting it back together is going to be very tricky for me.
Looks like a good start.
You will want to pick up three (3) large-hole accumulator pistons as the pre-existing ones are worn. You should also grab 97+ 4L60E bonded steel/rubber pistons along with the corresponding return spring. The 700R4/92-96 4L60E aluminum apply pistons in the forward drum like to crack once they have 100k + miles on them.
Also make sure you have a rubber/Viton seal for the input shaft-output shaft junction, deep inside the forward drum.
@@nickstransmissions Everything like you did in the video - 4L60E High Performance PT3 - Sonnax Super Hold Servos