C2 Rear End Yoke Balancing

[Thomas N.]

Hi:
I am tearing apart a 67 rear end, and the rear end yoke has balancing weights on it. My question is are these weights to balance the yoke only, or is it balance for the entire rear end? The reason I'm asking is if it is to balance the entire rear end, I'm replacing the ring and pinion with a new set, and putting in a stronger posi basket and gears, and if would probably be not the same balance required. I appreciate any information you can provide.

[Gene M.]

Re: C2 Rear End Yoke Balancing

I’ve not seen balance weights on the yokes on any cars worked on.

Do you have photos of these?

[Joe L.]

Re: C2 Rear End Yoke Balancing

Hi:
I am tearing apart a 67 rear end, and the rear end yoke has balancing weights on it. My question is are these weights to balance the yoke only, or is it balance for the entire rear end? The reason I'm asking is if it is to balance the entire rear end, I'm replacing the ring and pinion with a new set, and putting in a stronger posi basket and gears, and if would probably be not the same balance required. I appreciate any information you can provide.

Thomas-------

The weights are sometimes seen on the deflector attached to the pinion yoke. When present, they are usually small, rectangular metal tabs spot-welded to the deflector. Usually, only one or two tabs are present but I have seen as many as 5, as I recall. However, I have never seen such weights on GM SERVICE pinion yokes which are supplied with deflector. Unless this is only peculiar to the particular SERVICE yokes I've seen, this would lead me to believe that the balance weights were added as part of the differential carrier manufacturing process.

As far as trying to rebalance a differential after parts are replaced, I've never heard of anyone doing it and I don't think there is any capability in the field SERVICE world to do it.

[Joe L.]

Re: C2 Rear End Yoke Balancing

A described weight can be seen on the original pinion yoke on my 1969:

[Jim D.]

Re: C2 Rear End Yoke Balancing

I don't recall ever seeing an original yoke without a balance tab.

[Joe L.]

Re: C2 Rear End Yoke Balancing

I don't recall ever seeing an original yoke without a balance tab.

Jim-------


I've seen some that did not have it (or, evidence of one ever being present) but they are, by far, the minority.

[Richard G.]

Re: C2 Rear End Yoke Balancing

"is to balance the entire rear end, I'm replacing the ring and pinion with a new set, and putting in a stronger posi basket and gears, and if would probably be not the same balance required. "

Best guess is the yolk was static balanced. This would have been before it was assembled to the pinion gear.
The yolk is a forging the center of gravity will vary.
Because the input shaft is a machined part it is much easier to control the amount of unbalance.
If it was me, I would just reinstall the yolk, as it, on the new gears.
Rick

[Joe L.]

Re: C2 Rear End Yoke Balancing

"is to balance the entire rear end, I'm replacing the ring and pinion with a new set, and putting in a stronger posi basket and gears, and if would probably be not the same balance required. "

Best guess is the yolk was static balanced. This would have been before it was assembled to the pinion gear.
The yolk is a forging the center of gravity will vary.
Because the input shaft is a machined part it is much easier to control the amount of unbalance.
If it was me, I would just reinstall the yolk, as it, on the new gears.
Rick

Rick------


That's possible. However, if that were the case, I don't understand why it was not done on GM SERVICE flanges.

[Richard G.]

Re: C2 Rear End Yoke Balancing

Joe
Good point.
However, having worked for big corporations for many years I understand anything is possible.
All it takes is one retiree and good practices go out the window.

[Thomas N.]

Re: C2 Rear End Yoke Balancing

Thanks for the responses. I for some unknown reason am unable to post pics, but the above show exactly what I have. I figured the balance was for the casting only, but wanted to see if others had any insight.

[Darryl D.]

Re: C2 Rear End Yoke Balancing

"is to balance the entire rear end, I'm replacing the ring and pinion with a new set, and putting in a stronger posi basket and gears, and if would probably be not the same balance required. "

Best guess is the yolk was static balanced. This would have been before it was assembled to the pinion gear.
The yolk is a forging the center of gravity will vary.
Because the input shaft is a machined part it is much easier to control the amount of unbalance.
If it was me, I would just reinstall the yolk, as it, on the new gears.
Rick

So, does this mean you need to pay attention to the original position before disassembly so it can be re-installed in the same position?

[Joe L.]

Re: C2 Rear End Yoke Balancing

So, does this mean you need to pay attention to the original position before disassembly so it can be re-installed in the same position?

Darryl-------


Well, whether it's essential I doubt but that's what I would do if I was re-installing a pinion flange on the pinion gear shaft it was removed from.

[Perry M.]

Re: C2 Rear End Yoke Balancing

Such a small part with a small circumference, the inertia can't be much. Personally, I have never seen a weight on any of the cars I've owned, Corvettes or passenger cars. I know drive shafts are balanced but how many of you reinstall them in the exact same location on the yoke? When I had my half shafts shortened, the company that did the work said it was not worth the effort or expense to balance them because the inertia value was nearly undetectable. I realize the half shafts rotate 3 to 4 times slower than the yoke/driveshaft. If it were me, I would just reinstall the yoke.