Let's Fabricate a Panhard Rod for a Straight Front Axle
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- เผยแพร่เมื่อ 5 ต.ค. 2024
- Viewers are familiar with the 1930 Model A coupe I've featured in several previous videos. High speed steering stability has always been an issue with this car.....it tended to dart and wander, particularly at 50 mph and above. After trying several "fixes", I finally determined that the problem was caused by the front axle's ability to move laterally relative to the frame and (cross) steering tie rod. To correct this, I fabricated and installed a pivoting Panhard rod to link the front axle to the frame and eliminate any transverse motion. All aspects of design, construction, and installation are described, and we go on a test drive to fully evaluate bump steer, wandering, and high speed stability.
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The wife says if you keep talking about exposing your nuts in public, they will make you become a politician. Great info and a real learning experience. As always, thanks for bringing us along UD
It's just a fetish I have, Rick. Thanks ;)
@@uncledougshotrodgarage6049 LOL!
Your sliding pin idea at the end was used on the rear suspension of racing Alfa Romeos back in the 60s, also on a beam rear axle on a BMC Mini based kitcar (the Biota) later on.
Thanks for the info, Robin. I hope they don't charge me with a patent infringement ;)
Hi Uncle Doug, I really enjoyed this video, great job!
Glad you enjoyed it, SB :)
Excellent project and fantastic cure for a problem which probably exists for many Hot Rod owners. So entertaining to watch as well. Great video.
Thanks, Robin. I hope it rings a bell with others who are coping with steering problems.
Uncle Doug, we need to see a tube amp radio installed in this beauty! :-)
You couldn't hear the radio while driving, Ken. I have a nice stereo in my '34 Ford pickup.....and never listen to it.
@@uncledougshotrodgarage6049 Based on the headers, that's why I added the smiley! Still, you have done a thing of beauty in that auto!
Uncle Doug, as one of those Engineers, but _not_ an Automotive Engineer, it looks & sounds like your Panhard rod idea works just fine. I _do_ however, highly recommend trying to get short shoulder bolts for your pivots to minimize wear in the pivots due to the screw threads having point contacts & eating the pivots up. I also highly recommend that you frequently inspect the 3/16-in. thick parts & weldments for cracks as you put more miles on the car. If the holes start "peening" (for lack of a better word) in an elongated direction, then the Panhard bar may be seeing higher loads than you're thinking.
Thanks for the great suggestions, Bob. I will keep a close eye on the condition of the bolts and the holes they pass through.
Finally I can understand your videos D .....mechanic for 45 yrs . Bikes buses, and for the last 30 years , my own on-site hydraulic hose service :)
Glad to hear that, Stewart :)
Love the ingenuity but I wonder how the slotted idea would effect body lean/roll? Might be a lot of stress on one point in a straight axle as it becomes somewhat of a rigid form of sway bar. But a great idea to experiment with!
As for the wondering, great troubleshooting on your part and I’m pleased you found a solution. I would still want to swap springs for an overall simpler, lighter, and cleaner solution. Not criticizing as differing ideas is what this hobby is all about.
Thank you for the well done and excellently explained videos. Keep them coming!
Thanks for your courteous and helpful input, EH.
Haven’t seen any new videos on either one of your TH-cam channels I have interest in both tube amps and repair and hot rods and building them great job on your projects
A new video a Fender Bassman will be posted soon, Chris.......so stay tuned :)
Yeah, I think I saw that invention in Street Rodder Magazine a while back. Street Rodder Magazine is no longer published. Many of that magazine’s staff now publish Modern Rodding.
I talked to a guy from so-cal speed shop 2 days ago at March meets, and he said they don't sell a kit without this panhard bar. He said it's a must. My 33 Ford is so bad that it wanders all over the road. I have bias ply also, so it's not even fun to drive right now
When you said that you had made this channel at the end of the Silvertone amp video. I was elated. You spent alot of time putting this together and I want to thank you for all of the hard work. I really enjoy your work and I am always very excited when there is new content. Best wishes and I hope you have a great holiday. Be careful out there. Wear that mask. Uncle Dougs don't grow on trees.
Thanks so much, Jeff. We hope you enjoy all our videos.....on both channels. Likewise on the good wishes.
As a 50+ year professional fabricator/mechanic I think I would've used two import tie rod ends(as they are quite small) and just thread a rod to go between them. I've been enjoying all your content for many years, thank you for all of your considerable efforts. Also another solution would have been to use a central sliding bearing affair that would have no bump steer effect.
Oops! Sorry for the early comment, I typed that comment in before the end of the video. That solution has been on many production cars over the years. another solution would be a Watts linkage.
Thanks so much for your excellent comments and suggestions, Jeff.
Cross steer always needs a pan hard bar! Always! Had the same issues on my 30 coupe. Installed a Speedway Panhard kit, problem solved! Nice ride!😊
Had to come over and subscribe to your new channel. I have always been interested in Hot rods. You always have really great content.
Thanks so much, LL.
great stuff, I have a shimmy at 60 so did the panhard today out of an old tie rod. Testing tomorrow, cant wait.
You can buy shorter leaf springs ( eye to eye ). A piece of 4 x 4 and a couple big C clamps to pre load the spring and stretch it to reach the shackles and they'll sit almost level with the floor.
A nice fix to control the shimmy. Your improved solution idea was used around 1926 on a French homebuilt airplane.
Thanks, Andrew. Darn it !!! I knew someone beat me to the idea.
Really nice job on this Doug. Fabricating the parts and then hitting it on the head is always a great treat. Have fun and stay safe pal.
Thanks so much, Carl. You too :)
i done that second with the 3 inch rod welded to my axle and it works great on my 1930 tudor hotrod. Thanks for the idea.
You're welcome, Buck. Glad it was helpful.
Thanks, Uncle Doug. Another great video and very informative. Although I'd heard of Panhard Rods before, until now, I really didn't know what they are or exactly what they do.
Thanks, Bob. Glad you enjoyed it :)
I’m going to have to watch this after work, just wanted to say stay safe out there Doug!
I hope you enjoy it, Bill. We will :)
@@uncledougshotrodgarage6049 And I did enjoy it. I only ever ran a side drag link for transverse leaf front ends but this reminded me you need a panhard or watts link with cross steer cars. Or your slot and pin looks like a simple fix!
Binge watched all your videos on this channel last night and this morning. As always you get a thumbs up and a cyber pat on the back.👍. Well done good Sir.
Thanks so much, Jeb :)
I don't think the brackets pivoting is necessarily a good thing. If it loosens even the slightest bit it will rotate while driving and cause significant fatigue on the rod or bracket something will break. If there is some way to lock the bracket in place that would be good. Also on most vehicles there are rubber bushings this might not be a bad idea for a tiny bit of compliance. Finally my last thought rotating fittings on threads causes high wear usually a bolt with a non threaded section is used to hold the pivoting area.
All that said, looks really good and seems to be a major improvement.
I understand, Y, and will closely monitor the bracket for any movement. It is being held in place by a 3/4" bolt under 100+ lb/ft of torque.....and the lateral forces are not particularly large. Thanks !!
Thanks Uncle Doug, You posted this video so I guess the test drive went OK :)-
On the pan-hard bar replacement, I think it's a good idea, just needs some way to reduce wear from use. As the slot is "wallared out" it will introduce more side movement (bad given the positive-feedback effect of the steering) and probably make it a bit noisy. I would suggest a bearing on the post but, with real work environmental conditions, I don't know how long it would last.
The high speed instability is just the car hitting a harmonic I'm guessing.
Just my 0.02 as one of those damned engineers :D
Cheers,
Thanks so much for the excellent observations and suggestions, Eddy.
Aww, isn't that cute, only 2 weeks old and already these 2 bots can talk to each other.
They grow up so fast these days...
Thanks, this is the second of your videos I have watched and I want to say you do an excellent job. I learned something from both and I will recommend you to my friends. I'm working on a new T bucket right now and I'm going to try your pan hard idea. The one without the rod. The only problem I see is wear on the bracket or bolt. But that should be minimal and each part will be easily replaced. I you will be able to detect any excess wear if you develop any steering issues. Simple enough. Thanks.
I'm glad the videos are helpful, Jimmy. Best of luck with your project.
Your an engineer at heart.
Thanks, Don :)
Hello Uncle Doug, You are a great fabricator, nice job. Perhaps you may know, but, a little machinist safety tip, never wear gloves when using a pedestal type grinder, if the glove gets sucked in, your hand does to. Properly set tool rests help also. The Rod looks like fun to me. It's Custom don't ya know. Fog, clouds and light rain and 51 degrees today, typical mid November day. Lockdowns to begin in Washington and Oregon, probably most states soon. Stay safe, all the best, C.
Thanks for the helpful tip, Cass. Always good to hear from you.
Concealed nuts are a good thing....:)
That's what the police told me ;)
You nailed that UD! Nice fabrication as well! Stay safe!
Thanks, James. Will do :)
Hey uncle Doug, I enjoyed your fabrication, you do good work. The only thing you might want to add to your front end invention is maybe a wear bushing. Thank for sharing your hot rod tips. Look forward to next video. As always stay safe
Thanks so much, OG. I intend to monitor the wear on the pivot holes and switch to Heim joints if needed.
My Speedway 32 Roadster did the same thing , We just put wider front tires on it ... That worked !
I'm glad to hear you were able to resolve the problem, Lloyd.
The drawing at the end reminds me of a setup I once saw on the rear end of a large, heavy duty, straight axle work truck. I'll try to find the picture again.
I figured it had been thought of before......it's so simple and effective. Let us know if you find the photo.
Eyeball engineering at its best!
Thanks, Brian :)
Great result UD but personally I would have used shouldered bolts rather than all threaded & maybe some bushes to “spread” the load. Considering you couldn’t extend the panhard rod due to not having a frame rail to connect to, I think your idea works well. Glad you sorted the Ackerman angle out, I have seen so many cars here in the U.K. where they dissect way out behind the back axle/diff’.
Regards from the U.K.
Thanks for the excellent suggestions, Geof. I will monitor wear in the pivot holes.
Great video I may just try your new idea .
cool idea but I think your strength lies in the two bolts which will be in shear.
They are both grade 8 3/8" bolts, Rex, and the shear forces are not that great.
Great video and repair.
Thanks, Ron.
Interesting invention Doug. I think it would work fine if both wheels went up and down the same amount however if one was up or down more than the other would you not be back in the same situation with an arc being described from the end of the axle to the centre? Nice fabrication work by the way. Did you consider a Watts linkage instead if the Panhard rod which completely removes any lateral movement? Stay well. Chris 👍
Thanks, Chris. The problem with Watts linkage is it's visibility if used on a front end. Since the deviation from vertical with the Panhard is only 3/32", it really isn't significant.....and it's virtually invisible.
interesting idea. you might have to consider friction and wear...it may require a bearing.
Agreed, OB. I'll disassemble it after a month or two and evaluate the wear patterns.
What you should have had is a spherical rod end both ends of the panhard rod. The first thing that will happen is the bolts through each end will wear and need replacement in very short time.
Thanks for the helpful tip, Dale.
I'd suggest bushing inserts at the pivot points, once installed drill the pivot and bushings and install zerc fittings so they can be lubricated to reduce wear.
Thanks, Joe. I will inspect the pivots after 100 miles or so to see if wear is an issue.
I kept thinking of possible issues, but in time you thought of them as well, and did it up right....so....I guess I got nutin' (:
Thanks so much, Nick.
Hi Doug, as far as steering geometry goes, caster is what controls wandering and also brings the wheels back to center after turns. I noticed your king pins are pretty much straight up and down giving it zero caster. I would think tilting the top of the whole I-beam rearward a degree or two would also improve your steering. Just say'n. 🏎
Thanks, Ed. In person, the caster is exactly 7 degrees, as set by the wishbone brackets. It's correct and un-adjustable. Besides, the Panhard rod solved the problem, for reasons explained in the video.
Think about a Watt's Linkage on there UD. OK it won't be invisible, but it will move vertically, not through an arc. And, Ford used a Watt's Linkage on some of their rear end location issues some time ago, so it fits on your Ford!
The vertical travel of the straight axle is so limited that the arc of a Panhard rod is virtually a straight line, Geoff. People have been using them for almost 100 years with excellent results.
The Ackerman would have been the biggest cure.
Good job.
Thanks, Rich :)
Hi Uncle Doug. I am interested in your bracket mount stud idea. I have a 1937 Ford Tudor Sedan with an all stock transverse spring suspension. It would be great to have drawings with dimensions as I would like to try this option and would appreciate any assistance you can provide. PS - I appreciate you are super busy with both channels. I love them both and always look forward to your next video. Thank you for your consideration!
Sorry, Mark, but the car was sold quite a while ago and I have no access to the part you're interested in.
Hey Doug, in the absense of any of your excellent current tube amp repair videos, I've enjoyed your 'wander fix' on that special car of yours. Clever fix and even more interesting your simplified invention to address the same problem..! Meant to ask, if in the US and modifications are made to a vehicle are you obliged to inform the local Department of motor vehicles, as over here we would surely have to..Take care..Ed..U.K..:)
Thanks, Ed. No, the bureaucrats haven't inflicted that limitation on us.......yet......thank heavens.
@@uncledougshotrodgarage6049 Cool..You're lucky Doug, if you change a headlamp over here you would get 50 lashes..! Take care.
@@uncledougshotrodgarage6049 Only because they don't know about it. Yet.... I'm pissed that they want me to add seat belts to my '46 Willys CJ-2A, which obviously wasn't designed to have them. If I install them, it's not a "correct" restoration, but I probably will!
I have that exact same problem in the 20 to 30 range, similar front end.
The Panhard rod solved the problem 100%, Randy.
Brilliant !!!
Thanks, Gary !!
How about a brass shim in between the pivot point for less metal to metal wear?
I used a steel washer with a bit of lithium grease.
My front-end started to wander at about 55 too. I don't even want to talk about my back-end.
You have painted a very lurid image, Will......thanks, I guess ;)
The spring length is too long. It is for a spring over the axle type mount.
Get a shorter main leaf.
Shackles should be at 45 degrees.
Your steering arms need to he horizontal to the ground. Otherwise you get bump steer.
Then try a dead man shackle on passenger side.
Great videos, hot rods AND amps 😁
Thanks for your helpful suggestions, SB.
my spit6 got front light over 60. i put a piece of ply underneath between the rad and the front valance and it seemed to fix it....and cooling improved ....it statrted getting hot at the same time. I suspect turbulent air was getting pushed up in front of the rad disrupting cooling and increasing air pressure and lift under the front. bit different in a car with less body work i suppose.
Thanks for your input, OB.
Do you think adding front shocks would help with the front end
I cannot figure out any way to add front shocks, Greg, so I'll have to do without, I guess ;)
If you were experiencing the tires following the cracks, lines or depressions in the road, you likely have bias ply tires.
Radial tires will not do that.
Regardless, the darting and wandering ceased immediately upon installation of the Panhard rod.
I don't remember you mentioning this on your other channel, is this a newer video or an older one, I ask because I didn't see the yellow on your windows!
This is a brand new video. The yellow window tint is on a different car: the '34 pickup.
@@uncledougshotrodgarage6049 I get mixed up!
Spring is to long shackles are to straight up and down they should be stretched out farther . Panhard will help .
I seen one that used a bearing on the rod
Yes, it did.
Do you need to add the pan hard bar to the other side or is one enough
Only one is required, Craig.
Wait, bump steer? I thought those of us in cattle country called it a bum steer? Sounds like it was it handling like a buck board. Physics and geometry are a bummer.
It does ride roughly, B, largely due to the small amount of suspension travel allowed when you are so close to the ground.
What are you going to do about the shocks, or did I miss it. ?
I don't have any, and don't really seem to need them.
@@uncledougshotrodgarage6049 O..K. I was wondering. I was thinking about making my own pan hard rod mainly because I'm a cheapskate I will buy stuff if I have to but if not I'm gonna make it.
You been sitting on toilet mats? Oh Doug...
Didn't you want two rods?
Yep.....they're softer than cement.
Wouldn't more toe-in have reduced the wandering?
Nothing stopped it until the Panhard rod prevented lateral movement between the front axle and frame.
How do you keep it so clean what with all the dust and sand out there? Or is this why you have cats 🤣
It stays in a well-sealed garage, P.
the drawing at the end......isn't that how a tank pivots its wheels in pairs?
I thought tanks simply used one tread or the other to turn......?
@@uncledougshotrodgarage6049 i was talking about how the wheels pivoted(had suspension travel) inside the tread.
@@yurimodin7333 I think I understand what you're saying, Yuri, but I just don't know enough about tanks to give an intelligent reply. Sorry.
Nice gloves! How'd you get a blow out already?
Thanks, Paul. This is how new gloves generally look about 2 hours after I put them on.....especially if I'm welding.
Just started watching this video, Only 44 seconds into it I noticed your spring shackles are now vertical. In the video where you replaced the front end I commented on how your spring shackles were at the perfect angle . What happened. Did you switch out the spring for a longer one. I'll bet your shackles are making your side to side movement of the front end. I set mine up like you had in first video 5 years ago. 25,000 miles no problems. no panhard bar either. Still looks and rides like the day I built it. HOLD IT, HOLD IT STOP THE PRESES. NEWS FLASH. I went back to the other video. in that one your spring is over the axle. In this one your spring is behind the axle. by putting your spring perches in your radius rods that moved your spring shackle mount closer to the spring , there fore reducing the area between the mounts making your shackles drop to vertical or near vertical. they should be at a 45` angle.
Good analysis, Mike. When you order springs, straight axles, etc. your choices are limited to what is available and you have to "make do". In this case, the panhard bar was essential to stop the side-to-side motion of the front axle. In my other car, no panhard bar is needed.
Your spring is too long AND the swaying frame problem is common because the modern rodder community has forgotten something about 28-41 transverse spring mounting. It's a simple situation. Please note I said 28-41 only. No Ford until 42 has a Panhard rod. All have them front and rear 42-48.
When an early Ford transverse spring is mounted, one shackle is slid into place in the perch. a spring spreader is placed between the spring eyes to open the spring to allow the other shackle to be slid into the opposite perch.
The shackle bars are put in place and the spring spreader is unscrewed and removed.
This leaves the spring eyes and the perch eyes with the shackle bars parallel to the ground. When the complete frame is replaced on the spring the shackle bars will drop to a 35-45 degree angle. spring
You didn’t invent that, Boyd put that on The Varni roadster.
If I said "invent" I meant that I designed, fabricated, and installed it.
Uncle you need a shorter spring
Try and find one, Doug. With the Panhard rod, this one works just fine.....finally.
Adjust your Tow in
I did.....about 1/8" to 3/16".
I don't like my nuts showing either. In the garage or in my backyard maybe, but not in public.
Especially not in the winter ;)
@@uncledougshotrodgarage6049 No! Not good for them at all. 😉
I try hard not to drive with my nuts exposed...I'm 71 that's not something you want to see....
Agreed, Glenn. The asphalt is quite abrasive.
great job!
Thanks!