Hi Guys
I just figured I would pass along some info on side yokes, probably many of you know this already. I hope it helps some of you.
I have found the '63- about '72 axles are pretty good, many of them I can reuse in fact. The '73-'79 however were pretty bad and there are still a lot of virgin differentials out there.
Today I got a call from my heat treater about 3 sets of axles I sent out for testing and heat treating if required.
1) New HP axles, these I know about and always treat unless it is for just a 1/4 miles car. 24 Rc scale
2) Virgin '79 GM axles, starting to roll the edges but otherwise still good- 20-21 Rc
3) Virgin '66 axles 19Rc- However since I am fitting these to a tuned posi, not a sloppy spring loaded posi, I had to dress them 025-030". I believed these were case hardened originally and that would make sense, since .030" is the limit on case hardening. They will be better then new now.
Now contrary to what someone said on another forum, these are treated by a long established heat treating company not by me with a torch! I have used them for street/strip setups up to 1000hp without any issue.
Anyway this is a subject that comes up all the time on all the forums when guys get to rebuilding or checking the differentials in these cars. If you have endplay, especially in the C3's, over 050" keep an eye on it. If the yoke is soft it is riding against the 60Rc cross shaft and grinding away. If let go it will in time grind into the housing boss and seal, then you will have more issues.
Yoke end play comes from (3) areas:
1- Worn yoke faces- as mentioned
2- Sloppy posi setup- very common in factory units and even aftermarket
3- Worn case side holes- not too common but I repaired them.
I just figured I would pass along some info on side yokes, probably many of you know this already. I hope it helps some of you.
I have found the '63- about '72 axles are pretty good, many of them I can reuse in fact. The '73-'79 however were pretty bad and there are still a lot of virgin differentials out there.
Today I got a call from my heat treater about 3 sets of axles I sent out for testing and heat treating if required.
1) New HP axles, these I know about and always treat unless it is for just a 1/4 miles car. 24 Rc scale
2) Virgin '79 GM axles, starting to roll the edges but otherwise still good- 20-21 Rc
3) Virgin '66 axles 19Rc- However since I am fitting these to a tuned posi, not a sloppy spring loaded posi, I had to dress them 025-030". I believed these were case hardened originally and that would make sense, since .030" is the limit on case hardening. They will be better then new now.
Now contrary to what someone said on another forum, these are treated by a long established heat treating company not by me with a torch! I have used them for street/strip setups up to 1000hp without any issue.
Anyway this is a subject that comes up all the time on all the forums when guys get to rebuilding or checking the differentials in these cars. If you have endplay, especially in the C3's, over 050" keep an eye on it. If the yoke is soft it is riding against the 60Rc cross shaft and grinding away. If let go it will in time grind into the housing boss and seal, then you will have more issues.
Yoke end play comes from (3) areas:
1- Worn yoke faces- as mentioned
2- Sloppy posi setup- very common in factory units and even aftermarket
3- Worn case side holes- not too common but I repaired them.
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