Worn out yolk?
- Thread starter mbaird
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dano
Evil Handy Man
Mine wore out around the seal. But if there is any slop at all I'd replace it or you might have a pinion bearing issues if there is slop at all.
The new one I got from Dr Diff slid on real tight and no play. This was a 7290 10 Spline one onto Yukon 3.91:1 gears.
The new one I got from Dr Diff slid on real tight and no play. This was a 7290 10 Spline one onto Yukon 3.91:1 gears.
Should be zero play between splines and yoke. Do you have the U joint C clips on the u joint that centers the joint on the yoke?
I should have mentioned this is the trany yoke ...904 Torqueflite.
The vibration is a slight pulsating one around 3400+ rpm. I have had the driveline balanced and pinion angle checked/corrected by the drivleine shop . Installed a new tailshaft bushing etc... when I grab the front ujoint/yoke it seems to have excess play in it .
The vibration is a slight pulsating one around 3400+ rpm. I have had the driveline balanced and pinion angle checked/corrected by the drivleine shop . Installed a new tailshaft bushing etc... when I grab the front ujoint/yoke it seems to have excess play in it .
Then yes that is a good place to try. It won't cost much to see if that fixes it. Are you sure it's not in the engine? does it vibrate in neutral at 3400?
furyus2
Well-Known Member
I don't mean to egg you on, cause this issue is no yolk, and it could scramble your brain.
Sorry. I had to do it. I hope you get your yoke issue resolved.
Sorry. I had to do it. I hope you get your yoke issue resolved.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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At the front, because the angle is constantly changing with changes in ride height, and sliding back and forth; it does tend to wear out the yoke..
But
3400 on the engine is never 3400 out the A904, unless you have installed a lock-up.
And so, by 3400 rpm, the driveshaft, at the front, is likely to be fully stabilized, unless if the driveshaft is too short; then it tends to flail about. Or if the angle is too shallow to properly lube the needle rollers, and they hammer out the U-joint trunnions.
I can also tell you that absolutely everything can be in perfect balance, yet if a tire is out of round or has a high-spot, or a heavy spot not properly compensated for, any one of those will still cause a vibration,once the tire is on the road;
as will a perfectly balanced but bent driveshaft, or one with improperly phased yoke saddles..
As will a rim not mounted hub-centric.
I once spent a great deal of time, chasing a small but annoying vibration. Off came the tires,out came the axles, then I dicked with the pinion angles, finally with nothing left, I sent the driveshaft away for the third time and when it came back, just a lil longer, it was almost quiet enough to ignore.
Finally; swapping out the 4.30s for 3.55s put the vibration out of cruising speed. It's still there, just at a much higher mph, where I almost never drive.
Good Luck man, I know your frustration.
But
3400 on the engine is never 3400 out the A904, unless you have installed a lock-up.
And so, by 3400 rpm, the driveshaft, at the front, is likely to be fully stabilized, unless if the driveshaft is too short; then it tends to flail about. Or if the angle is too shallow to properly lube the needle rollers, and they hammer out the U-joint trunnions.
I can also tell you that absolutely everything can be in perfect balance, yet if a tire is out of round or has a high-spot, or a heavy spot not properly compensated for, any one of those will still cause a vibration,once the tire is on the road;
as will a perfectly balanced but bent driveshaft, or one with improperly phased yoke saddles..
As will a rim not mounted hub-centric.
I once spent a great deal of time, chasing a small but annoying vibration. Off came the tires,out came the axles, then I dicked with the pinion angles, finally with nothing left, I sent the driveshaft away for the third time and when it came back, just a lil longer, it was almost quiet enough to ignore.
Finally; swapping out the 4.30s for 3.55s put the vibration out of cruising speed. It's still there, just at a much higher mph, where I almost never drive.
Good Luck man, I know your frustration.
Dont notice any engine vibration while revng in nuetral . Wish I could say the same for idle ...lol
I have run several different rear ratios . Still has throbbing vibration in 3rd around 3200 rpm.
Entirely possible that Jim my driveline guy got the balance wrong but I had him check it out again a few months ago . Thats when he shimmed to correct pinion angle and installed new tail housing bushing .
I have run several different rear ratios . Still has throbbing vibration in 3rd around 3200 rpm.
Entirely possible that Jim my driveline guy got the balance wrong but I had him check it out again a few months ago . Thats when he shimmed to correct pinion angle and installed new tail housing bushing .
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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When you had the tailhouse off, did you notice the ballbearing rear stabilizer, I mean you had to have ,lol. And my guess is that you tested it before reusing it.
BTW, I had a local trany shop install another tailshaft bushing . They installed at an 8 Oclock position . When I pointed this out they insisted it didnt matter. I know the owner ...he didnt charge me. So I will just pay another shop to do it right .
I CAN **** STUFF UP FOR FREE ! Why hire someone else to **** things up !
Lol
Maybe the same case with my driveline shop but he has done my drivelines for 35 years ....
I CAN **** STUFF UP FOR FREE ! Why hire someone else to **** things up !
Lol
Maybe the same case with my driveline shop but he has done my drivelines for 35 years ....
CudaFactHackJob
Well-Known Member
It's not spoached to move back and forth a lot, so it could be a fried yolk, but omelet a driveline expert chime in here.
TrailBeast
AKA Mopars4us on Youtube
How much yoke tube is not inside the tailshaft seal?
More than 1 inch or so can let a yoke with worn splines move off center.
There should be literally zero side to side or up and down movement that you can feel by hand.
furyus2
Well-Known Member
I had a new converter cause vibration. If it vibrates at idle, like you said, you should consider bad engine balance, or the converter.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I install my bushings lined up with the oil drainback groove, but honestly, I also really don't think it matters; I just do it cuz that's the way I was taught it.
I have pressed hundreds upon hundreds of those out, back in the 70s and 80s, and I found many of them installed in no particular place, and still looking good.
I sure wouldn't press a brand new bushing out for orientation.
As to the ball-bearing still on the shaft; it should have no radial play in it.Nor play of any kind.
wash it out, right where it is. Then grab the outter race, at just one point/any point, and push/pull it in the fore and aft direction. There should be little to no movement.
Next spin it up a lil, 2 or 3k is lots enough. and it should remain pretty quiet, even dry.
Next; put some pressure on the outter ring, all around and rotate it back and forth, it should feel super smooth.The inner ring should not rotate with the balls, and should be a slip-fit tight on the shaft.
Finally, oil it up.
This bearing together with the rear bushing, stabilizes that output shaft, and everything mounted to it.
I would not be overly concerned with clearance between the bushing and the yoke. Once that shaft is spinning it is gonna want to self-center in the bushing, and I have seen those bushings come out like new, on beat tochit cores.
But play between the splines, yeah you don't want too much going on there. I Lube mine up with that black Molybdenum grease. It stays on there a long time.And so also it will stick to your fingers and clothes.
I have pressed hundreds upon hundreds of those out, back in the 70s and 80s, and I found many of them installed in no particular place, and still looking good.
I sure wouldn't press a brand new bushing out for orientation.
As to the ball-bearing still on the shaft; it should have no radial play in it.Nor play of any kind.
wash it out, right where it is. Then grab the outter race, at just one point/any point, and push/pull it in the fore and aft direction. There should be little to no movement.
Next spin it up a lil, 2 or 3k is lots enough. and it should remain pretty quiet, even dry.
Next; put some pressure on the outter ring, all around and rotate it back and forth, it should feel super smooth.The inner ring should not rotate with the balls, and should be a slip-fit tight on the shaft.
Finally, oil it up.
This bearing together with the rear bushing, stabilizes that output shaft, and everything mounted to it.
I would not be overly concerned with clearance between the bushing and the yoke. Once that shaft is spinning it is gonna want to self-center in the bushing, and I have seen those bushings come out like new, on beat tochit cores.
But play between the splines, yeah you don't want too much going on there. I Lube mine up with that black Molybdenum grease. It stays on there a long time.And so also it will stick to your fingers and clothes.
I think I will order a new yoke just to be sure . There is enough play in the yoke that I can see it . I will also pack the yoke with moly .. thanks AJ
jbc426
Well-Known Member
I've suffered from a similar vibration for a long time. Be careful using moly on the splines/inside the yoke. That grease can wash out into your transmission and lead to problems. ATF is a very efficient detergent type liquid.
My trans yoke is a new forged unit from Mark Williams. The outside diameter of the barrel is 1.505". Even with a brand new bronze bushing installed, it would wobble back and forth .030" at the u-joint, which I can feel is way to sloppy for new parts and the likely source of vibration /rumble when the driveline is between acceleration and deceleration or coasting in other words.
After years of suffering from this, I installed a teflon coated bushing from a GM 4L60 extension housing. It's a steel backed bushing with a single linear split and a white teflon or delrin inner surface. Ford C4's & C6's also have the same size bushings, but are harder to find the teflon/delrin coated bushings for.
I was about to have my yoke hard chromed to reduce the clearance, when the shop manager squeezed the GM bushing with his fingers onto the barrel of my yoke to simulate what it would fit like installed. There was virtually no detectable play, but it spun and slide beautifully on the yoke's barrel.
I installed the bushing yesterday. It slide in just like the stock one does. I put my yoke back on my driveshaft and installed it. It fit, slide and turned beautifully with absolutely no more side to side play. Problem solved.
I called my friend to tell him about my find, and he is going to install one on his car. He is a machinist and actually made an oversized bushing which still had a touch of play.
I now believe this is a solution for a problem that has plagued many of us Mopar guys for years. The new bushing and seal was less than $20 and it took a matter of minutes to replace in the car with a simple tool designed for the job.
Often times a man's life in these parts depends upon a mere scrap of information.
Very interesting ...
I would think the yoke splines should have very little play on the output shaft splines . I would prefer not to order a not yoke only to find the same amount of play . I would like to hear how this bushing of yours wears after some mileage . Does it have a lubrication hole to line up with the factory one ?
I would think the yoke splines should have very little play on the output shaft splines . I would prefer not to order a not yoke only to find the same amount of play . I would like to hear how this bushing of yours wears after some mileage . Does it have a lubrication hole to line up with the factory one ?
jbc426
Well-Known Member
No lube hole, but one just needs to be drilled and deburred to match the one on the bushing you take out.
Do you see or feel visible wear on your yoke?
An old timer at the transmission parts & shop where I grabbed the bushing said they wear a long time. I sure hope so.
He also said GM switched over to this material, and it solved a lot of problems for them. He's used them in C4 & C6's for years to resolve the slop issue, as they are a bit tighter than the babbit or bronze bushings.
jbc426
Well-Known Member
No, the inner liner is teflon or delrin. It's white or light gray with a steel backing. We test fit it onto my yoke barrel prior to installation and squeezed it closed with our hands to verify it fit correctly. I verified the fit once again after it was installed and lubricated with transmission fluid. It fit perfect with no detectable wobble.
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