Turbodan

got my car back from mini resto. took it for a few track days. went to a small track called Toronto Motorsports Park and the car stepped out a few times and I thrashed it a little.
anyways on the weekend the axle bolts came out and disconnected the axle on drivers side.
I bought new bolts (twice actually, once from dealer and then got black bolts with allen heads on recommendation from friend said black bolts are better.
Anyway went to install and only 3 of the bolts would go into the threads. I tried turning the bolts while pressing on the socket but would not grab.
I should have moved the axle over to test the threads without the axle. my guess is the holes in the axle got damaged as one of the original bolts was bent. any thoughts? new axle needed?

Turbodan

I ordered a new axle will arrive tomorrow and will remove the old one maybe later today and test the threads with axle out of way.
it has been really hot here so crazy working in this heat. rain today may cool things a bit.

walfreyydo

The CV joint itself could have been slightly misaligned, not letting the bolts to thread into the threads in the stub. The CV joints shouldn't have threads, just the axle stubs, so ordering a new axle wouldn't solve your issue.

Also, you are using the cv bolt locks right? Make sure you have them torqued correctly (35lbs IIRC) and using the locks. Should have no issues with the bolts working themselves out.

Turbodan

I did order a new axle for $90 CDN here tomorrow. I need to go in there again but i had some of the bolts in and others would not thread. could the slot where the bolts go bend?

Turbodan

So the part that the bolts go into, the threads are damaged. A shop is trying to clen the threads with a thread tool. Otherwise I would need to swap out his part. It is like a hub on the side of the transaxle and I assume there is a seal and swap out the fluid (was just changed). I assume a used one will suffice?

Turbodan

turns out the threads on 3 of the holes were damaged. we cleaned them with a thread tool and every thing went back together, repacked grease in the bearings and used some blue loctite and marked the bolts. gonna try it at Mosport on Sunday I think.

Oddjob

Just an FYI for those having problems with CV bolts coming loose (there have been various threads over the years where some have chronic issues with the bolts):

In the manuals for newer factory race cars, I've seen a numbered diagram showing the recommended tightening pattern and a 3 stage torque sequence for the CVs. So common practice should be to torque the CV bolts in a star pattern, like wheel nuts. And go around twice to make sure they are tight.

walfreyydo

Did you use the CV locks (axle bolt plates) I linked above? Those are OEM and must be installed...they act like a lock washer but also link adjacent bolts together.

Threadlocker shouldnt be necessary.

Turbodan

yes we used those but only two were present.
locking nuts would be my next step if it comes loose.

Droops83

The 951 CV axle bolts are same as the NA 944, and are undersized for the amount of torque the engine generates, especially if the transaxle has a LSD; they are 8mm, should be 10mm like Porsche used on any and all higher torque platforms since then. The CV bolts need to be re-torqued before and after every track event, during the 10+ years that I did a lot of track events, I would always get a bit of a turn from many of the bolts each time I checked. I never had an axle shaft come loose because I always checked them!

I did eventually install the Stage 8 CV bolt locks, which do their job. You should do the same, because I don't trust compromised threaded holes in a system that already is insufficiently sized for the task at hand . . . .

Another pro tip after replacing CV boots is to use non-marring pliers to squeeze down the caps (thin metal part the boots are clamped to, insert a few bolts to ensure the holes are aligned) all the way onto the CV joints before installing the axle onto the car. This will ensure that none of the torque force from tightening the fasteners is used to squeeze the caps onto the CV joints---this has been the cause of many cases of CV bolts coming loose after being "torqued to spec." A re-torque after the first drive is always a good idea.

Turbodan

we marked them with paint so can visually check on them.