I have seen posts where someone says the spindle (side yoke) has become mushroomed over. If the snap ring keeps the spindle from pulling out, what stops the spindle from pushing in to much and causing the mushroom problem? PG.

 

Nothing other than the hardness of the metal.

 

The snap ring captures the stub axle in one direction and the carrier cross pin captures it in the other. There will generally be a little play in the stub axle and over time after banging back and forth the stub axle starts to wear and mushroom.

 

IMO it not the banging as much as its the spinning of the cross shaft on the end of a poorly hardened yoke that creates the mushrooming.One wheel smoky burnouts dont help much either(bad posi clutches).

 

The only picture that I have of the differential is on page 9-12 in the 66-82 Corvette Shop manual, are you saying that the spindle (yoke #13) rubs on the differential pinion shaft (# 16) while we drive the car? PG.

 

I dont have that picture. Its the shaft that goes through the spider gears.

 

OK in the 73 shop manual they DO refer to it as the pinion shaft and what I refer to as the spiders they call the pinion gears.

 

Pete take a look at all my threads on the diff and you'll see everything in there.
The system is basic. The axles(side yokes) is splined to mate with the posi side gear, the snap ring is .187 from the end of the yoke. Endplay is a result of the yoke rubbing against the cross shaft and grinding it away. The 74?-79 yokes were total crap, someone forgot to harden them or costs were cut, who knows,other then those years are bad. The cross shaft is about a 55-60 rockwell and the yokes much less. Another reason for endplay is sloppy posi clutch setup, typical with production or quick rebulds. I've had 40-year old yokes with only a few thousands wear but the endplay was 025+". The play wasn't in the yoke but in the crappy posi setup. Once I tuned the posi and test fit the same yokes, I had to face grind them to set them up to 005 endplay.
The rebuilt or new yokes should be in the 55-60 rockwell range- although I have had new yokes that were soft and wore very quickly.

I've seen some shim the yokes under the snap ring, not the way to do it but it's done anyway. If you have more then 045-050" endplay and it's not in the posi then you need new yokes. If there is nothing else wrong with the diff,watch them until you can replace them.

I've read on some of these forums where people were told by their rebuilder that up to .125 endplay is normal, time to find a new rebuilder.
Good luck

 

Thanks everyone for taking the time to explain how that works. Now I understand what goes on inside there. PG.