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... Still no idea why Porsche used the stupid hex key design...
I suspect they used these things to help improve working clearance when removing/installing. I use a half inch square drive extended impact socket i purchased specifically to do this job- worked perfectly- no issue removing or installing.
When I had to replace CV boot it looked from paint marks as if all the bolts were original. They all came out fine with 1/2" breaker, but next time I'll use impact wrench to save repeatedly crawling out from car to release parking brake, rotate wheel to another accessible position for couple of bolts, then re-apply brake. I replaced all the bolts with new allens - maybe Porsche used Allen bolts because depending on how the axle is hanging, the inner boot can block a socket from getting square on the bolt head?
On #30, I used a 1/2" breaker bar, app 18" long, and an Allen socket. I used a strap wrench around the mating hub for counterforce, they came loose after a little grunting....
May sound silly, but use a high quality allen head socket, as low-quality sockets very often are not made with correct clearances, and any looseness between tool and fastener will result in a buggered fastener. Also, the allen recess in the fastener needs to be dead clean. Then, it's really just a matter of torque. If the fastener still gets buggered, these can save the day:
I'll share my casual dislike for using hi-power impact guns on loaded driveline bolts. Between the potential damage to bearings to potential damage to ring & pinion plus spider gears in the differential, for me anyway the long lever arm and the correct driver is the best solution. For the bolts through the inner CV joints into the drive flanges, I typically use a couple long 1/2"-drive extensions with an impact-rated hex driver to bring the actual wrench work out into the wheelhouse area. I leave the differential free (gearbox in neutral) and set the parking brake. If the bolts are stubborn I'll recruit an assistant to stand on the brake pedal. I suppose that an impact gun could be safely used with the same protocol, but so far anyway that hasn't been necessary.
The bolts go in with something like 65 lbs/ft torque dry. No Loctite, no anti-seize. I do add witness marks with a paint pen or nail polish to each bolt so I can see if they move over time. So far so good: none broken or head-stripped, none so stubborn they wouldn't come out.
Serious racers like to drill the ends of the socket capscrews for safety wire. There may be pre-drilled bolts available for this purpose. I'm a much bigger fan of safety-wiring the bolts vs. adding Loctite to the threads, if there's a serious risk of them backing out. There are some not-quite-horror stories from folks who have been stranded when the bolts were not tightened correctly. Doing these "by feel" or " 'that's not going anywhere' plus a little more" methods risk too much. Use a torque wrench, so you can decide when they come out next.
We used the Stage 8 bolts on my sons 944, they're great going in the first time but not really made for reuse. He had a bad top trans mount and kept snapping axles, after one use most of the Stage 8 bolt heads were worn or stripped. Good thing is even with stripped heads they come out easy.
The most interesting part of this whole CV joint thing has been that the original boots lasted 27 years and 65k miles while the replacement boots only lasted 5 years and 15k miles. I read that there were some poorly crafted boots kicking around europe for a while that people only got a year out of, I'd have to look to see where I bought these boots from but I bet they're from the same batch as they look well worn for only 5 years old.
I had the same problem while racing recently at Spa Francorchamps - both outer CV gaiters split during qualifying. Managed to drop one driveshaft in 10mins, swapped a spare one and then tried the driver's side. 3 bolts would not budge and began to round off. Patched the hole with duck tape and electrical loom tape. Went out, raced 2 x 40mins races and finished 3d in class, and 25 overall out of 74 starters.
Anyway, when back at the base, with the help of a proper ramp, we managed to get the nasty bolts out. Swapped them for proper 13mm hex heads bolts. Now I can get a proper socket on them and swap driveshafts in minutes if I need to. Still no idea why Porsche used the stupid hex key design...
Do you remember where you found the proper length hex head bolts = 57mm?
Do you remember where you found the proper length hex head bolts = 57mm?
Yes. That would be great to know.
Must be a custom bolt maker, with a 13mm head on a 10mm bolt of 12.9 hardness, 57mm long.
I've used C/V bolts from 996 Cup Cars (possibly also in 996 street cars...I don't know what is used in street cars.)
These have a 12 point cheese head, which can be tightened and loosened multiple times.
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
id try some heat. i don't believe they did come with locktite.....
Normally they did not come Loctited, BUT, a previous owner/shop might have used Loctite on installation.
Most Loctite will fail at 300 degrees F. Heat the bolt with a small diameter torch, use an aluminum or brass head hammer, give it a sharp rap and it should break free.
May sound silly, but use a high quality allen head socket, as low-quality sockets very often are not made with correct clearances, and any looseness between tool and fastener will result in a buggered fastener. Also, the allen recess in the fastener needs to be dead clean. Then, it's really just a matter of torque. If the fastener still gets buggered, these can save the day:
07-03-2017, 07:35 PM
