4 spd Yoke Bushing

[trim88]

Have a vibration and wondering if the yoke bushing in the rear of the Trans Extension Housing can be changed without removing the Tranny?
Checked the u-joints and seem to be tight but the drive shaft spline at the end of the extension housing has some slop in it. Don't know if that means the rear trans bearing is part of the culprit too?? I guess what I'm asking is, since there is play in the yoke bushing should I look into the main bearings, front & rear also? which means pulling the trans.
Any help would be appreciated. Thanks, not the "Ace Mechanic", trim88

 

[A31PKG]

At what speed? In all gears? Does it go away when you push the clutch in?

 

[trim88]

It starts around 40. I will make a note of the gears and try pushing the clutch in. Will try to get it out tomorrow. I have not run it much since I just acquired it, in fact only once on the road and didn't want to hurt anything with the vibration. Thanks, Jim

 

[BBillyC]

Gotta chime in on this too. When in neutral and sitting at a light I hear a grumbling noise that goes away when I put the clutch in....ta da...transmission. what would be the culprit??

 

[Big John]

It starts around 40. I will make a note of the gears and try pushing the clutch in. Will try to get it out tomorrow. I have not run it much since I just acquired it, in fact only once on the road and didn't want to hurt anything with the vibration. Thanks, Jim

If it's in the driveline, the vibration will tend to come in at one speed, then disappear, then come back at a higher speed.

Are you sure it's not the tires/wheels?

 

[moparchris]

Gotta chime in on this too. When in neutral and sitting at a light I hear a grumbling noise that goes away when I put the clutch in....ta da...transmission. what would be the culprit??

More than likely the input bearing or the cluster bearing. I would put my money on input bearing.

Trim88. Most driveshaft shops dont balance the driveshafts at high speed and this can be a problem I fight with just about every car I own (most of them have 4.10 and up gears). I put the car securely on jack stands and chock the wheels very well. Then I run it up to the speed at which it vibrates (it will be worse on jackstands), then I put a hose clamp at one end of the driveshaft and tighten. Repeat the run up process, then clock the clamp till the vibration goes away. Do this for both ends if necessary, if it gets worse and never better then take that clamp off and move it to the other end and start over. It take a little time but once its done then just remove the d-shaft and take it down to the balance shop for a permanent weight. While I am on the subject, look first at the driveshaft and see if you can see a weight that has fallen off. There will be a weld or two and no weight and a clean spot where the weight was, seen that one too. Good luck.

 

[trim88]

Ok, checked for weights, no bare spots that look like one might have fallen off. There are 3 weights, 2 forward and 1 at the rear of the driveline.
I got the car out on the road today and it doesn't matter what gear you have it in, it seems to be the speed. Doesn't feel like tires as the whole car shutters..... I've had many out of balance tires in my lifetime and I don't think that is the problem. Pushing the clutch in doesn't make any difference either, so it must be in the drive line somewhere. At the rear of the tranny there is some play....I can push the (yoke? , just in front of the forward U-joint) up and down approx 1/16". Seems like that shaft coming out of the tranny extension shouldn't have any play....maybe someone with more knowledge will have the answer??
Looking up at the driveline from underneath, there is about a 1/8" of play in the driveline at the point where it enters the differential, not up and down like the front but slop in turning it before it trys to turn the rear wheels. Don't know if this is normal.
Hope this all makes sense..... Probably more like dollars and sense, (cents). trim88

 

[69hemibeep]

Ok, checked for weights, no bare spots that look like one might have fallen off. There are 3 weights, 2 forward and 1 at the rear of the driveline.
I got the car out on the road today and it doesn't matter what gear you have it in, it seems to be the speed. Doesn't feel like tires as the whole car shutters..... I've had many out of balance tires in my lifetime and I don't think that is the problem. Pushing the clutch in doesn't make any difference either, so it must be in the drive line somewhere. At the rear of the tranny there is some play....I can push the (yoke? , just in front of the forward U-joint) up and down approx 1/16". Seems like that shaft coming out of the tranny extension shouldn't have any play....maybe someone with more knowledge will have the answer??
Looking up at the driveline from underneath, there is about a 1/8" of play in the driveline at the point where it enters the differential, not up and down like the front but slop in turning it before it trys to turn the rear wheels. Don't know if this is normal.
Hope this all makes sense..... Probably more like dollars and sense, (cents). trim88

That's the lash in the gear set and that sounds about right. I would go the route that Chris described.

 

[Big John]

I had a driveline vibration that turned out to be a twisted driveshaft. The truck driveshaft that I had shortened had about a 10° twist from one end to the other.

Replaced the shaft with another shortened truck shaft. A couple weeks later I twisted that one.

 

[69hemibeep]

I had a driveline vibration that turned out to be a twisted driveshaft. The truck driveshaft that I had shortened had about a 10° twist from one end to the other.

Replaced the shaft with another shortened truck shaft. A couple weeks later I twisted that one.

What were you doing towing houses

 

[Big John]

I had a driveline vibration that turned out to be a twisted driveshaft. The truck driveshaft that I had shortened had about a 10° twist from one end to the other.

Replaced the shaft with another shortened truck shaft. A couple weeks later I twisted that one.

What were you doing towing houses

Nope.. I know exactly where I twisted the second one. Came off the highway onto a road into town. Right under the bridge, I got on it. This particular section of road had a very agressive surface and it's hard to spin the tires. I bent it on the first to second shift. BTW, that would be with the automatic trans.

Combination of some decent torque and really good traction. I'm gonna get a shaft custom made this time.

 

[A31PKG]

Pushing the clutch in doesn't make any difference eithertrim88

How about neutral? I know you just got the car, but did this happen all of a sudden? Did you ask the prior owner? It's possible that the trans may need going through, but I agree that any driveshaft issue needs to be ruled out first (run-out, balance, u-joints)... Do you have any b-body pals close by that could let you borrow their driveshaft? Sometimes swapping known-good parts is the only way to go... I'd hate to see you spend the bucks on something that ain't broke...

 

[trim88]

Yeh, same thing in neutral.
I called a driveline place in Springfield, MO (Powertrain Industries) and they said they would balance it for $35.00......sounded kind of cheap, so I asked what speed they balanced it to and they said 3500 rpm's... should that speed do the trick? I'll take it up next Mon or Tues.
Thanks for all the responses & help for this NOT "Ace mechanic", Jim "trim88"

 

[moparchris]

Yeh, same thing in neutral.
I called a driveline place in Springfield, MO (Powertrain Industries) and they said they would balance it for $35.00......sounded kind of cheap, so I asked what speed they balanced it to and they said 3500 rpm's... should that speed do the trick? I'll take it up next Mon or Tues.
Thanks for all the responses & help for this NOT "Ace mechanic", Jim "trim88"

I would guess that most shops other than racecar shops will give you the same answer on balance speed. The driveshaft turns at the same speed as the engine in high gear. Thats why I go through the trouble of balancing them on the car, besides your driveshaft goes to the shop without the rear yoke. 1/16th play doesn't sound like a whole lot and I have never (never say never) seen a tailshaft bushing cause a vibration. The last driveshaft I bought came from Mark Williams and they spin their driveshafts to 7000. It was the smoothest driveshaft to date for me. One more thing to ponder is a bent shaft, kinda along the lines of Big Johns situation, but I have seen one balance good before and have a vibration in spite of balancing. It was bent by .100", new tube problem gone!

 

[John69RR]

Has the clutch been replaced recently? If the two bolts that hold down the tailshaft are too long the transmission will "bounce". These two bolts go through the the crossmember. See if you can push up on the tailshaft. Also, is the rear mount in good shape?

 

[A31PKG]

All good stuff.... Not sure how they will perform the balance -maybe moparchris can chime in - I've never had to have it done, I would assume that the u-jounts are removed? Either way, I would definitely replace them... Also, a sure clue as to front yoke clearance issues would be a leak at the tailshaft seal.... I find it hard to figure how this happened...Was somthing changed or repaired? What's the previous owner have to say?

 

[trim88]

Well, the previous owner is not returning my phone calls.....either he is on vacation or knows the problem and doesn't want to talk about it. When I picked the car up it was sort of a rush thing (involved a 3 way trade) on his part and I just drove it around the block and didn't give it a proper test drive. So... my fault, and didn't see it coming. Not only that but yesterday when I put it in the garage I noticed a small drop of fuel under the fuel tank. A new tank was put by the prior owner and probably is leaking around the sending unit....the fun begins. I'm not really dissappointed as this gives me a new life of "Oh Yea, What Next" :brickwall: What do expect in a 42 yr old car? Honestly, I'm thrilled that I'm able to experience a car that I owned 40 years ago. I'm a lucky guy! :grouphug:

 

[moparchris]

All good stuff.... Not sure how they will perform the balance -maybe moparchris can chime in - I've never had to have it done, I would assume that the u-jounts are removed? Either way, I would definitely replace them... Also, a sure clue as to front yoke clearance issues would be a leak at the tailshaft seal.... I find it hard to figure how this happened...Was somthing changed or repaired? What's the previous owner have to say?

The driveshafts get balanced with the u joints installed, most driveshaft shops want you to rebalance after u joints. Even though the u joint is the most precision piece in the driveshaft.

 

[rrunr69]

I had the same vibration on my RR after 37 years of hibernation. Had mechanics tell me it's in the clutch, rear end, drive shaft and transmission. Found a great mechanic and he took it for a ride and told me that it's the transmission mount. A $15 item. He replaced it and showed me how the vibration is happening. All gone now. No more vibration.

 

[69hemibeep]

I had the same vibration on my RR after 37 years of hibernation. Had mechanics tell me it's in the clutch, rear end, drive shaft and transmission. Found a great mechanic and he took it for a ride and told me that it's the transmission mount. A $15 item. He replaced it and showed me how the vibration is happening. All gone now. No more vibration.

That one gets overlooked the most and you were the first to mention it :yesnod: