smitty

I have a vibration coming from the rear and at 60 to 80ish mph. I have changed wheels and replaced both u joints. Has anybody experienced this problem? Im sure its internal but if not . My suregrip does needs new clutches, its a one wheel wonder right now. If I must rebuild rebuild my rear end what gears, axles, ect should I use? I am looking for 0 to 80 power with ok highway manors it will probity never see the track. After this is resolved I will get my tranny looked at, them larger cam and roller valve train in motor.

69Ronrunner

have u checked wheel bearing play also 3.55 have always been my fav for shred / drivable gears.

smitty

Surprisingly i have frogot to check them every time I have had it in the air lol. Also Idk which rear it is, I think 8 3/4. It is smooth on the rear and you can remove the 3rd member...? I know its a dumb question.

69Ronrunner

More than likly its 8 3/4 there should b a set of casting #s u can check online. They will b on the removable 3rd member

Gorts 5th

if the rest of the rear end checks out you may have a bent drive shaft.
happened to me.
you don't need much
mine actualy had slight dents in it from where it was twisting, the tec at advance drive line showed me how it was deforming with a straight edge,
it's wild

78D200

I bent driveshaft would take out u-joints every 3-6 months. You should still have it checked/spun. Is your pinion or pinion yoke loose? What condition are the wheels and tires in? When did you notice this starting? Did you change anything right before?

smitty

Nothing has been changed except the u joints. Tires are ok I put the factory rims back on, I had fattys and thought they might be the problem. It got better. I cant remember when it started it has sat a long time. I just now got the itch to work on it again, you know how it is...LIFE. Will anything of happened if I put the driveshaft back in, 180 out? Where would I go to get the driveshaft spun?

TVLynn

I can't see the rear end causing a vibration without making some kind of noise. Firmly support it up on Jack Stands & block the front wheels.. Have someone help you. Run it in gear and watch the drive shaft for run out

smitty

Ok thank you I'm gonna try that this weekend. And I have a loud exhaust lol.

Gorts 5th

if you have a straight edge put it on the drive shaft while your under there you never know make sure your u joints are seated correctly clips in the yoke.

duster3

x2 on checking the drive shaft, had the same problem on my Duster with 8 3/4. Put it up on jackstands and just put it in drive at idle. Then look for any unbalance looking parts of the driveshaft.

TVLynn

Also the rear end will be noisy with both wheels off the ground SO don't run it too fast of a speed

78D200

Does the vibration happen all teh time between 60-80?
Does it only happen while braking, or on the gas or just cruising?
Have you checked to make sure the pinion and yoke have no play?
Have you made sure the chunk is securely tightened to the axle housing?
Do you feel the vibration in the steering wheel, in the seat or on the floor?

Chryco Psycho

What make of tires , BFG for example are not round even when balanced
or pinon angle get an angle finder usually $10 at a tool shop , the pinion should be 5-7* down from the driveshaft angle

smitty

Yes all the time between 60 and up. I can go faster than the vibration but something tells me i shouldent. its a little worse under acceleration but still present when i let off the gas. The vibration is bad enough that it shakes the whole rear of the car at its worst. After all you guys are saying im leaving towards the drive shaft but im not going to condemn it till I check it on jack stands and with a strait edge.

Gorts 5th

what the frick happened to BFG's they use to be a top tire company
what about Dunlop or Cooper?

jacilynn_s

The front yoke to driveshaft actually only goes on one way. It should always be marked when changing the u joint. That said here is a few things I have found out over the years.

A number of times the replacement u joints have the grooves in the wrong spot. They come with the really thick clips or the thin ones however with the thin ones it actually slips from side to side causing the vibration. You cant put a thick and thin as they is just as bad.

I have had to grind and measure the thick clips down (dont let them turn blue) until I get them both just right so that the u joint fits perfectly nice and tight into the yoke of the rear end. This usually solves the problem.

Have fun.

smitty

The ones I installed had the thick clips they went in tight, but my front yoke did have some play when I removed them, the cap just slipped right out and back in. but when it went back togeather it felt tight b/c of the clips. It feels like its coming from the rear of the axle if anything. I have the axle In the correct way but I may of put it in backwards on the rear yoke. so the weight on the rear of the drive shaft may be facing the wrong way.

78D200

U-joint caps should always be a press fit item, whether new or old. If old caps are sliding out, take a micrometer and measure the OD of the old cap and the OD of the new cap. If they are the same, measure the yoke openings then. You shold also measure around the hole to make sure the hole is not enlongated in one direction.

jacilynn_s

O.o the thick clips should never fit into a chrysler product since they are made for the ford. Remove driveshaft from the rear end(this one does not have a specific balance so you don't have to mark it. Only the front yoke is balanced with the driveshaft.)

Check the yoke for grooves on the inside where the clips sit against the yoke. There shouldn't be any grooves stock the inside was flat. If there is grooves you will have to either look for another one, be careful of the spines as they are different from one to another.

I have seen these grooved so bad from badly fitted u joints that one side has a big groove while the other is almost perfect. This causes the vibration you mentioned. Its something easy to check and often overlooked.

THe front yokes can usually be changed from one driveshaft to another however some are specificly balanced with a driveshaft and can cause a vibration wearing out the rear seal, bearing, and front u-joint rather well.

Driveshafts rarely going out without some reason. A wieght rusted off or broke off which is visible with a good inspection of the shaft, a big dent from a rock or something.

If everything else checks out, its a simple but good inspection, you can use a large diameter hose clamp on a section to see if it makes things worse or better to identify if that is the problem.

Other problems that could cause vibration are drivetrain alignment, specifically the front axle dip. Many people ignore this for some reason even after they jack up suspensions. There is a maximum angle that a u joint can run at.

Bent axles or bad axle bearings. This is something one can check easy enough. I have seen a bearing seised to the shaft and the race turning in the housing making a huge mess. If you got oil or grease leaking all over the rear brakes you got problems that need addressing.

Rusted rear drums where a section of rust has let go. This causes the drum to go out of balance, yes they are balanced.

Mostly just go do a good inspection of areas such as brakes for grease or oil, the driveshaft for a missing wieght, and the yoke for grooves.

The front yoke the caps should never slip in and out. If there is a hairline crack in the yoke, it happens, the cap will slip in and out. This is actually dangerous as it could let go at the worst time.

smitty

That's great info thanks

smitty

thanks to everyone for there help. I put my car on jackstands sat. morning and the driveshaft is visible bent. I have found one on ebay from a classic car salvage yard. I will let you know when i get it installed. may take a bit still waiting on refund check. :banghead:

Gorts 5th

Your welcome...thought it was a bent drive shaft, we have a local shop that manufactures and repairs em great place.

smitty

How much did they charge to fix a driveshaft?

Gorts 5th

Advance drive line is the local rebuilder
3x.065 tubing $41.85
Retube and balance $95.
spicer u-joint 2@36.22
R&R joint 2@ $20
they reused the yoke and both u-joint ends
total $205.65
took em 24 hours

78D200

I've always been skeptical of used driveshafts. Who's to say the one you are buying online won't be bent as well? I'd find a local drivline shop and have them build you one. I did for a friend's Ch*vy truck and it cost $340, from slip yoke to rear axle.

Gorts 5th

Yes have them build you one.