Vibration problem

-
gunmetal72

gunmetal72

Life is a dark ride
Joined
Jan 5, 2010
Messages
550
Reaction score
53
Location
Sicamous B.C
I recently had my 340 Duster 4 sp tuned. The guy needed to put it on a dyno but said the rear yoke on an 8 3/4 diff needed to be changed because it was showing some some wear and it was unsafe to dyno it. I had it changed but now I have a vibration at about 60 mph. I checked the universal joints and they all seem ok. The tail shaft on the trans does have some wear but I don't think it is overly lose, I have seen worse. Is it possible that when the yoke was changed it was put on to tight or too lose? I am not sure if it needs to be tightned to a specific torque. Hoping someone might have any suggestions.
 
gunmetal72 said:
Is it possible that when the yoke was changed it was put on to tight or too lose? I am not sure if it needs to be tightned to a specific torque. Hoping someone might have any suggestions.
Click to expand...

YES!!!!

Anything is possible. Yoke could be damage, this a new yoke?

The pinion uses a "crush sleeve" to set pinion bearing preload. Pinion bearings work sortof just like front wheel bearings, that is you have two tapered bearings and the yoke nut pulls them together just like the spindle nut.

But in BETWEEN this is a crush sleeve, and if that nut is not tightened enough, the bearings are loose, sloppy, don't have proper preload

Too tight, and you will damage or destroy the bearings.

You have a shop manual?
 
Unbolt the drive-line at the rear end, turn it 180 degrees, bolt it down and take it for a drive.

Check your tires for lumps and bumps, an indication of belt separation.

I recommend these two things first because they are free.
 
'n make darn sure the rear clips are properly installed in the joint
 
67Dart273 said:
YES!!!!

Anything is possible. Yoke could be damage, this a new yoke?

The pinion uses a "crush sleeve" to set pinion bearing preload. Pinion bearings work sortof just like front wheel bearings, that is you have two tapered bearings and the yoke nut pulls them together just like the spindle nut.

But in BETWEEN this is a crush sleeve, and if that nut is not tightened enough, the bearings are loose, sloppy, don't have proper preload

Too tight, and you will damage or destroy the bearings.

You have a shop manual?
Click to expand...

Yoke was replaced with a used one and no i do not have a shop manual, but I think I can get a hold of one. I will also give the rotate the drive shaft a try. The rear tires are on so no seperation of the belts that I can see. I will also check the universal joints again
 
Make sure the u joint caps are the same depth in the driveline yoke when you look at it again.
Also if anyone recently changed or disassembled the front joint they might have rotated the front yoke 180 without knowing you can't do that.
The go ONE way for life, unless it has been rebalanced.
 
What, for the record, is the year of your car? There are several manuals you can download for free
 
its a 72. I managed to find a manual and I read that "under no circumstances should the pinion nut be backed off, If this happenes a new collapsibale spacer needs to be installed". So, because the yoke was changed, does that mean I need to take the diff apart and install a new collapsibale spacer?
 
You should, you should see the shop you were at and let them handle it, you could have put a different series end yoke on and doesn't meet the series joint you're using, and you could have to much or not enough pre-load on the pin.

You could do more damage then what you are saving doing this yourself.
 
Supershafts said:
You should, you should see the shop you were at and let them handle it, you could have put a different series end yoke on and doesn't meet the series joint you're using, and you could have to much or not enough pre-load on the pin.

You could do more damage then what you are saving doing this yourself.
Click to expand...

How would I know what series of yoke I need?
 
You have to know what series joint you have and then measure the yoke and see, you either have 2.125" or 2.625" wide at the inside of the yoke where the joint sits.

Then see which joint you have, again measured at the clips on the outside edge which are on the joint
 
Supershafts said:
You have to know what series joint you have and then measure the yoke and see, you either have 2.125" or 2.625" wide at the inside of the yoke where the joint sits.

Then see which joint you have, again measured at the clips on the outside edge which are on the joint
Click to expand...

So as long as the yoke and joint are the same series, it does not matter which yoke is used, is that correct? And if they do match, then I will need to check the preload on the pinion? does that make sence?
 
If the yoke matches the series joint you are using then it's the same, there are 2 styles that can be used, and actually 4 if it's different than the detroit series yokes.
You would re-set the preload also, lighter than the factory spec since the bearings are used so you want to be in the 6 to 10 area, anything between not less or more
 
Here is what I did. I checked the wheel bearings, greesed and reset them as one seemed to be a little tight because it had no end play and I believe they should have a little according to the manual. The vibration is now gone but I have a bit of a whining noise coming from the rear. I am thinking that could be the wheel bearing so I might replace both of them to be sure. But before I do that I thought I would get some advice. The u-joints were replaced by the guy that did the tune up but I am not totally sure if they are correct so I have posted some pics in the hopes of someone telling if they are correct.
The u-joints messure 3 1/4",
the front and rear yoke on the shaft is 2 7/8",
the front yoke on the trans messures 3"
yoke on the diff messures 3 3/8".

1st pic is the shaft attached at the diff
2nd pic is rear of shaft
3rd pic is front of shaft with front yoke attached
Please take a look at the pics and tell me if you think they are correct.
 

Attachments

  • rear of shaft on car.jpg
    103.7 KB · Views: 201
  • rear of shaft.jpg
    96 KB · Views: 191
  • front of shaft.jpg
    112.4 KB · Views: 199
Do all those caps have a clip on the inside of the yokes holding them in?
If so, everything looks ok.
I can see three of them in the second to last picture, and maybe the fourth on the cap on the right.

Also, does the yoke on the rear end move AT ALL besides turning in a circle?
 
Yes all caps have clips on the inside and no there is no movement it just moves in a circle
 
That joint isn't installed correctly, or it's so piss poorly made it's not right, but it surely has something wrong as it looks so off centered
 
Are all the clips the same thickness ? or did/are the clips able to move side to side on the cap in it's groove
 
In the second picture,, the clips on the driveshaft side appear to be around the cap,, but not actually in a groove,, is that so??? Check that all clips are in fact in a groove..

It looks weird,, like caps are not all the way in, or needle brg fell over not allowing caps to seat...
 
All the clips are the same thickness and there is no side to side movement. All joints are tight with no movement. Both u-joints are all the same size but the yoke sizes are different if that makes a difference? I listed the sizes of the yokes.
 
Is the joint seated correctly at the end yoke you just changed ? is the end yoke new ? look at the end yoke where the clips lock up to center the joint and see if there is a wear groove in that area.
 
Supershafts said:
Is the joint seated correctly at the end yoke you just changed ? is the end yoke new ? look at the end yoke where the clips lock up to center the joint and see if there is a wear groove in that area.
Click to expand...

You did see this in post 15 right?
"The vibration is now gone but I have a bit of a whining noise coming from the rear."
 
You must log in or register to reply here.
-

Back
Top