Hello all,

Last November I took out my rear-end and sent it to Bairs for total rebuild. The yokes were replaced as well as the other standard rebuilt items. On Monday after having new meats put on the car I took it to a local front end shop for alignment. The shop said they could not align the car due to too much end play in the rear end yokes, yikes! I took it home and got under the car and observed about 1/16 of a inch of end play on the left side and 1/8 inch on the right. This is just a eye ball measurment but there was much more play than when I put the rear end back in the car.

I called Bairs and they said they have never had this happen in the past and believe that there must be some other problem. They suggested that I take it to anouther front end shop, do not tell them of the current situation, and see if they can align the car. They also say that the rear end has to have some end play as it is a free floating rear end.

Any ideas out there on what I should do? I live in a rural area and do not have any local Corvette experts that I can consult. The car runs great, does not pull to one side or the other. No funny noises.

Thanks

Andy Anderson
Hereford AZ.

 

Yoke end play has nothing to do with alignment. Your yokes are made to move in and out as the wheel travels up and down.

Slop in the camber strut bushings or trailing arm assemblies is a problem. I'd find another shop that is familiar with Vettes. If you don't have Smart Struts with poly ends - Go buy them :yesnod:

 

gkull, I respectfully disagree. The yokes are not supposed to move in and out. They have retaining clips to keep them seated in the differential. A very slight amount of in and out play may be acceptable, but the amount quoted is a bit more than would be normal with rebuilt parts installed.

The way that yoke play affects rear alignment is that the worn ends of the yokes effectively shorten the length of the upper "arm" of the suspension (the halfshaft). Therefore the lower "arm" (the strut rod" must be shortened as well to keep camber at spec. Once you're out of adjustment range on the camber cams, you're SOL and Bubba starts bending the strut rod itself to get more adjustment range.


[Modified by sb69coupe, 8:54 AM 2/20/2003]

 

The yokes should not move in or out more than a few thousandths. The center pin can wear along with the yokes which will cause the same problem. Some GM yokes made in the late 70's and early 80's had very poor heat treating. The remfg. ones usually have heat treated buttons that are very hard and do not wear. As for the Alignment. You can do that youself very easily with a protractor and bubble level for camber and a mearuring tape for toe. Set the camber on "0"- 1/2 deg Negitive (in at the top) set the toe in to 1/8" closer at the front.

 

So what about yokes that have no retaining clip? My yokes are both capable of being removed from the differential itself - is this a fault??? If so, I'm a bit concerned....

 

I wasn't really clear. Since it was rebuilt so recently I didn't think that the yokes were the problem. The yokes are only allowed to move in and out if there is slop in all the other parts.

If the trailing arm isn't rigid side to side your going to have movement

 

Bob Fisher - If you can pull out a yoke without removing the C clip your rearend is full of metal. It happened to my 79 by the time it had 50K miles on it. The cheap poopie factory yoke are so soft that they ware to the point the retainer clips fall off. You need to remove the rearend and see what damage has been done.

When I opened mine up it was full of oil that looked like metal mud and it was making bad noises. the passenger side yoke had started to also grind away the outside of the case. I ended up buying HD trailing arms with Stainless Steel shims, New Pumkin, Custom Hardened yokes, and new U-joints

 

Hmm, I'd been wondering about that for a while. Although it's quiet enough, I've changed the oil and additive a couple of times to try to clear up some chatter from what I thought was the positraction clutch - maybe it still is, although it looks like a full rebuild will be in order (next winter!!!). There's definitely no groove on either yoke for retainer clips, so would they both have worn out that much? There's still some adjustment on the eccentric cams for the strut rods, so I'm not that concerned about it. I only do about 2K miles a year and this is the original unit with 80K miles on it.
Bob

 

Bob I hate to tell you if the grooves for the retainer ring are gone your shafts are WAY worn. I would not wait another year. I personally would not wait another day if it was mine. When cornering the axle tube acts as the upper control arm. With nothing to hold it your alignment is moving quite a lot. This could lead to major problems while driving.

 

I agree w/Gordon. My '69 was about that bad when I purchased it. I spun it on an onramp going about 20mph when the rear camber shifted as the yoke slopped around. Drove home. cleaned out my shorts, and started tearing into the rear suspension the next day.

 

You don't have a six link suspension do you? They do not use clips and the yoles are shortened to about the groove to prevent binding.
Look if there is another strut rod about the 1/2 shaft. If not like others I would worry about any driving. The top of your wheel is free to flop in or out.

 

whoo, so I guess I will try anouther shop. Thanks for all the ideas.

 

There was a guy selling a (NO clip) set of yokes on ebay a while back, he "thought" he had (and probably still has) a special set of side yokes :lol:
...redvetracr

 

And then here I am with a perfect set of Yokes about to machine the ends off to go to a Six-link setup. :lol: Jim

 

Trade me for mine that are bad then.

 

(Maurice,Trade me for mine that are bad then.)

Sorry Maurice, but mine are the Dana 44 HD 4sp Yokes.

Why don't you just put a Six Link under the beast? Then you would have the best of both.

It's not anymore expensive to do than it is to replace your bad Yokes if the splines are good. You wouldn't have to replace the yokes maybe just have to clean up the ends. Don't forget to check the cross shaft too.

Buy the Smart Struts for the lowers and a set of Poly Struts for the uppers. I think Van Steel or VBP will supply them any length specified. Then have a couple of brackets made and you have an improvement and not just a repair.

As many people that have '63 - '79 Vettes here it does look like someone would fab up a good set of mounts for a 6-link to sell others and eliminate a lot of problems getting the spec's and having someone make them up a set.

I plan on having a couple of extra sets made when I fabricate the set for my '80. It will require a different set up for the inner mount than yours. The Dana Aluminum housing will require a 2"x2" overhead crossmember between the frame rails with a mount dropped down for the inner mount. IMHO I would prefer this type mount on all years. The T-Arm mount will still be the same though.

Go back and do a search on 6-link's and see if you can come out better doing it.

If I could have helped you out I would have been more than Happy to have.

Sometimes a repair just creates an oppertunity for a better car through upgrades, Good Luck JIM

 

I can not see making a bracket and bolting it to the rearend using the rearend bolts. You have to remove the complete rearend anyway to mount a 6 link then why not just weld a pair or easy to make mounts to the crossmember and bolt the upper strut rods to this welded mount. I made the bracket mount first, mount it to the rearend and started checking it out then thought why do it this way.
First you bolt this complicated bracket to the rearend them bolt the rearend to the crossmember. Why not eliminate the bracket and go directly off the crossmember?
A mount can be a simple say 3 inch piece of round stock with a 5/8th hole drilled and tapped in the end then weld this round stock to the crossmember. a 5/8 bolt through the end of the strut rod and into this round stock is all that is needed.
Done with a little imagination and care and it looks factory stock. My strut rods are hex aluminum with parts turned round for looks and part left hex for a wrench.
With a 6 link toe adjustments are a matter of just turning the upper and lower strut rods alike.
I can do 5 minute changes to any of the rear wheel camber toe change.

 

Great idea, I will start looking into that.

 

Norval is right. It is a much better way and easier to mount the top inner strut.

Oh Yeah, NORVAL is the one who has given me all of my Six-Link information including the idea of new 2"x2" crossmember to mount the Dana '80-'82 on.

There is a lot of information on Corvette FAQ's

JIM

 

Norval,

Have you already made an extensive post showing your handywork on the 6 link? I have long thought about doing this not only for the better geometry; but, because I hate thinking about breaking a half shaft u joint in a fast corner and losing control of the car.

Thanks,

Chuck