What's everyone think of these CV axle flange bolts in the FWD E-body cars with the TH425? The originals are 3/8"-24 with a 12pt head on them that accepts a 7/16" socket and they're pretty much unobtainable as originals.

I've been doing a bit of digging around online and lot's of people claim that these are one time use, torque to yield, bolts. The manuals, however, do not mention this in any of the CSM's or Service Guilds I've seen at least. I question the ability of these to actually be "torque to yield" bolts considering the big hefty split washer GM installed on the originals. How could you even meet TTY numbers with a split washer like that? I had mine out last year and I re-used them with a bit of orange loctite and everything has been fine so far. What do you think? Is this one time use stuff hogwash?

In any case, I have been looking around for alternatives for when I replace my CV axle and have found a few options. I actually ordered up a set of 5 ARP 3/8-24 bolts with a 12pt head but the head was a little too big to fit on the flange as they took a 7/16" socket. Even though the originals take a 7/16" socket, the overall head design is smaller so they fit while the ARP ones, which are larger, don't. You can actually get ARP 3/8"-24 bolts that have a 3/8" head on them rather than the 7/16" which is quite a bit smaller so I bet these would be great substitutes. I may order up a set just to check em out. You can also get 3/8"-24 hex cap screws which would also work pretty good, I think. As long as they're good quality, say grade 8 equivalent with a lockwasher and some orange loctite I think you could get by just fine? Applied GMC sells them for the motorhome as well but they appear to just be ARP bolts to my eye......at least, very similar.

These pictures below are internet pics for reference, not mine.





Looks like someone had to double up on the washers with this one.

 

Took a big risk on this purchase. Will it fit correctly? Who knows, but I'll find out. I would imagine these PN's are "technically" for later era Toronados and not specifically for a '66 but will see.

Anyone have any thoughts on those bolts I mentioned earlier?

 

If the manual says nothing about one time use, as long as they are in good condition I’d reuse them.

A bit of blue loctite wouldn’t be a bad idea. I’d be willing to bet the factory used some kind of thread locker.

 

Yeah, that's what I figured as well. Last time I had the passenger side axle out, I used orange loctite on the bolts and it's held up just fine. This is one of those things though that may have been updated through a service bulletin or tech bulletin years later that I don't know about. I wonder what the '69 or '70 CSM's say about axle replacement?

 

Those bolts are not torque-to-yield, they're not even Torque-Angle.

Reusable provided they're not damaged, rusted, bent, stretched, etc. In other words, can they be cleaned-up and look OK?

 

I just got some 3/8 x 16 ARP bolts Friday with a 7/16 12 point head but they were threaded the full length so I am sure they have something BUT .........
I would not think twice about reusing the ones you have. I have had the axles out of my Wife's Riviera at least three times and reused them every time. Just over 300K miles and they are fine.

 

Just curious, what was the actual GM part number on the box ?

 

Yep, the ones I have are in good shape except for one that I stripped a little when taking it out. I replaced it with a used bolt from a '67 Toronado axle that a guy sent me. The '67 bolt was about 1/4" longer so I had to cut it.

 

The only part number on the box was GM-8111. There's a few companies selling these things and I'm sure they're all the same ones but god knows if it'll work on a '66.