Loctite on CV/Axle bolts?
 

I'm getting ready to put my passanger side axle back into the 951 and a friend of mine said i should use a type of loctite on the bolts. Anyone have any input on this? I haven't found any info about using it with the search feature. TIA

Absolutely not, torque them correctly, and you will be fine.

Doc, do you drill and safety wire for a track car?

Thanks for the response Doc!

You can use loctite blue if you want, but if they are in good shape and torqued well then it shouldn't be necessary.

Dal.

Yes sir, the wire is a lot easier to cut off than it is to get out a stripped cheesehead that was locked in place with loctite :)

btw, with our 800hp 996TT, we didn't ever do anything but properly torque the CV bolts, no loctite or safety wire. We ripped the flywheel off the crank on the track, and the CV bolts were all still in place. The flywheel bolts are torque to 66ft/lbs and blue loctite, while the CV axles are only torqued to 36ft/lbs.

Having had a half-shaft go "clunk" on me (fortunately I was only going slowly at the time) I would most certainly say to Locktite them. Mine have been all changed from triple-squares to allen type and Locktited. Not a problem since. At some point I'll drill the heads and safety wire them too.

Here's why I'm so paranoid about it:

1. It's not something you normally check often (although now I do)
2. The tow truck guy with the flatbed who got my car home after the "clunk" (I couldn't fix it on the roadside due to lack of a cheesehead wrench) mentioned that he'd seen this happen on a couple of other 944s too. He also said that in one particularly bad case, the CV bolts came out while the guy was on the highway doing about 70. The halfshaft (spinning rapidly) flailed around briefly and then stuck into the pavement, pole-vaulting the ass end of the car and literally tearing part of the back half of the driver's side suspension off. Obviously the guy lost control of the car and it spun out into a guardrail. Now granted this was a "told-to-me"/"I'm hearing it second-hand" story, but it's believable enough to either (1) check those bolts REGULARLY (like, at least every oil change, preferably every fill-up with gas), (2) Locktite 'em or (3) safety wire 'em. I'll be doing all three thanks much.

I also opted to switch to the allen-head type bolts rather than the triple-squares, since basic allen size wrenches are part of the standard tool kit. Triple-squares aren't. They're also much harder to source in a pinch.

After having them come loose twice at the track (and sheared off 4 of the bolts), its Loctite AND safety wire for me. Probably not necessary for a street car.
Also, replace any bolt whose threads look worn. Thoroughly clean the threads on the bolts and the hubs, and make sure there's no grease in the CV's bolt holes.

Jon.

and make sure there's no grease in the CV's bolt holes.

And just how do you do that???? I have never been able to keep the grease off my threads!!

I am with doc. I have raced and DE'd for may years. I lost a driveshaft once, which was only torqued. Ever since then, I have torqued and wire locked and never had a problem. If you get the thread holes clean enough for the loctite to take then it complicates disassembly, and there's a risk of stripping the bolt centers. I have lost count of the number of times I have removed driveshafts for various reasons. Wirelockings a pain but at least you don't strip heads, or break bolts.

Twist up some strips of paper towel and run them through the CV's bolt holes. Then wipe the grease off the surfaces that will mate to the hubs. Use degreaser if necessary.
There's not a lot of thickness to the trans and wheel hubs, so there's not a lot of threads for the loctite to work on. I've never had any difficulty removing the bolts. Make sure the heads are clean andthe tool is sharp. Replace any bolt that looks worn.

I would be one to discouraged loctight on the CV bolts. I've had numerous CV bolts break off in the hub. It they are not treated they easily unscrew and can be replaced. I have had to drill out a bolt tip that was treated with blue loctight and to do that you have to remove the hub. After drilling and using a bolt remover to get the tip out, the main nut holding on the hub needs to be retorqued to I believe 360 ft/lbs . The entire procedure is a real PITA. I haven't had any more issues once I replace all the CV bolts with new ones however I always check them w/ every oil change as mentioned. Safety wire would be a good idea as these bolts inevitably come loose over time and unwired need to be retorqued regularly.

Proper use of locktite requires absolutley clean thread surfaces. I have a hard time buying that you'll get them clean enough just running a rag or paper towels through the holes. You'd need to actually clean them with a solvent 'til NO grease residue was left in order for the locktite to be truly effective. Caution, use of locktite in this scenario may be giving you a false sense of security. Safety wire gets another nod here.

I picked up some 12.9 grade bolts for the CV and when I looked they were a tad longer so I have enough clearance to use lockwashers and mine are holding strong.

I was thinking hex heads and those saftey wire star washers would be good for this application.