Side Yokes Again
Thread Starter
4th Gear
Joined: Sep 2004
Posts: 4
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Side Yokes Again
I recently purchased a 76 Vette in very good condition but in need of some suspension work. The rear spring was flat and the shocks leaking.
Talking to a guy at MuskegonBrake, he told me to check the yokes as they could make a spring flatter also. Recommended no more than 1/8" play. Checking them shows about an 1/8" a side. The flange on the yoke that butts up against the side of the differential does not come in contact with the side surface. If wear was 1/8"-1/4" as posted in some of these threads wouldn't that flange on the yoke wear down against the side of the differential? There is no contact between these surfaces on my car. Also I am checking this with the spring and shocks removed and am not sure if that affects it or not. I am a newby to Corvettes but think my yokes are fine. The guy at MuskegonBrake also recommended a composite sping but I am now worried about the height problems everyone seems to talk about. Final note, my tires do not look cambered in when on the ground and the height difference is about 3/8"-1/2" lower in the back
Talking to a guy at MuskegonBrake, he told me to check the yokes as they could make a spring flatter also. Recommended no more than 1/8" play. Checking them shows about an 1/8" a side. The flange on the yoke that butts up against the side of the differential does not come in contact with the side surface. If wear was 1/8"-1/4" as posted in some of these threads wouldn't that flange on the yoke wear down against the side of the differential? There is no contact between these surfaces on my car. Also I am checking this with the spring and shocks removed and am not sure if that affects it or not. I am a newby to Corvettes but think my yokes are fine. The guy at MuskegonBrake also recommended a composite sping but I am now worried about the height problems everyone seems to talk about. Final note, my tires do not look cambered in when on the ground and the height difference is about 3/8"-1/2" lower in the back
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
I like steel springs better than glass. I couldn't get the glass springs to stop bouncing. Currently running a late C3 2.5" wide spring. They were stiffer than the earlier steel springs but ride real well.
On to your stub axles: 1/8" is way past worn out. Ideally you would like to see 0.005"! You should consider them worn out at 0.040-0.050" play. 1/8" is 0.125" (I'm sure you know...).
If you let it go further the stub axle will contact the diff and soon damage it to the point you need an all new diff rather than just new stub axles.
Worn posi clutches also increase play so you probably want to pick up a new set of clutches while you're ordering stuff.
I'm doing my diff later this month. Got my parts from fastcorvette and found them extremely friendly and had good prices.
On to your stub axles: 1/8" is way past worn out. Ideally you would like to see 0.005"! You should consider them worn out at 0.040-0.050" play. 1/8" is 0.125" (I'm sure you know...).
If you let it go further the stub axle will contact the diff and soon damage it to the point you need an all new diff rather than just new stub axles.
Worn posi clutches also increase play so you probably want to pick up a new set of clutches while you're ordering stuff.
I'm doing my diff later this month. Got my parts from fastcorvette and found them extremely friendly and had good prices.
Drifting
Joined: Oct 2003
Posts: 1,426
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From: VetteMOD
St. Jude Donor '05-'07
Originally Posted by Kid Vette
I woudn't beleive anything Muskegon Brakes says, nor would I buy anything from them. Talk to VBP, they actually know what they are talking about.
I agree BIG TIME with Kid Vette. Look at previous posts about the Muskegon Brakes spring. There is a problem there that they have been unable to identify (it's been many months since they were supposed to be figuring this out). I was in your position a few months back and decided to go with a steel spring. If I were to go with a composite, I would only buy a VBP spring and it would probably be a dual mount. Keep in mind, you will need shocks for a "bouncy" composite spring.
As far a the play in the side yokes, .125 is a lot. You have two options, fix your side yokes or convert to 6-link. There have been many posts about the 6-link conversion and machining the side yokes to reduce play. Both of these are attributed to Norval Wilhelm.
Since you are new to C3 ownership, I would just do a search for topics by Norval Wilhelm and that volume of information will keep you busy for a year!
Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
By the time the flange contacts the case you're really in trouble. The end of the stub axle rides against the pinion bolt inside the diff. The flange has plenty of room before it would contact the case. Also think of all the play you suspension has now. You can pull the top of the wheel in and out changing the angle quite a bit. Not good for handling.
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Yes. But what you call a flange really is just a "dirt deflector". It is thin metal and is only there to keep dirt away from the seal. If this piece of metal would actually touch the case it would be ripped apart.
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Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
Note the dust/dirt deflector. Also note that there isn't much more than 1/8" on the end of the stub axle until you get to the snap ring. Once you get to the snap ring nothing is holding the axle in anymore and it can slide out when you take a hard turn.
Drifting
Joined: Jul 1999
Posts: 1,542
Likes: 43
From: Plano TX
Markus is right what you see is just a dust collector.
Many years ago while still learning about corvettes a friend of mine bought a 79. I thought the camber on the rear looked excessive so when time allowed we jacked it up and found that the u-joint strap was actually cutting into the diff housing.
Based on our finding we pulled the rear to put in new stub axles. Luckily there was still enough material on the housing to still accept a seal, but it was close.
20 years later another friend of ours has the car and the thing is still like we put it back together. Was a great way to learn since we were rushed to get it back together. Back then the vettes were our only cars.
Also, on a car that gets as bad as my friends the axle usually will mushroom in side which made getting it out the biggest pain of the entire job. The shaft that separates the two axles will wear some and should be replaced.
From what you describe it appears it will be a straight forward replace axles and center shaft.
Dave
Many years ago while still learning about corvettes a friend of mine bought a 79. I thought the camber on the rear looked excessive so when time allowed we jacked it up and found that the u-joint strap was actually cutting into the diff housing.
Based on our finding we pulled the rear to put in new stub axles. Luckily there was still enough material on the housing to still accept a seal, but it was close.
20 years later another friend of ours has the car and the thing is still like we put it back together. Was a great way to learn since we were rushed to get it back together. Back then the vettes were our only cars.
Also, on a car that gets as bad as my friends the axle usually will mushroom in side which made getting it out the biggest pain of the entire job. The shaft that separates the two axles will wear some and should be replaced.
From what you describe it appears it will be a straight forward replace axles and center shaft.
Dave
Racer
Joined: Mar 2003
Posts: 268
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From: Mechanicsville VA
Norval's and Gary's information is gospel, as far as I am concerned.
The problem as I see it is that once the yokes have worn just a little, they are past any hardening and wear that much more/faster. Either need to rebuild the yoke the right way, or purchase a new/properly rebuilt one. (and that may elicit more recommendations for or against vendors of all types...)
The problem as I see it is that once the yokes have worn just a little, they are past any hardening and wear that much more/faster. Either need to rebuild the yoke the right way, or purchase a new/properly rebuilt one. (and that may elicit more recommendations for or against vendors of all types...)
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
I was told the following:
Early stub axles were hardened to rockwell 16
Late C3 axles were rockwell 12 and wore extremely quickly.
The GM replacement axles are rockwell 20 and last a long time.
Early stub axles were hardened to rockwell 16
Late C3 axles were rockwell 12 and wore extremely quickly.
The GM replacement axles are rockwell 20 and last a long time.
Thread Starter
4th Gear
Joined: Sep 2004
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Thanks for the indulgence
Thanks so much for indulging my ignorance as I am knew and sending me the pic. What I am really getting at is if the stubs are that bad shouldn't the dust collectors have been rubbing away on the sides of the differential? Also, is the wear a sign of hard use?