Problem with torqueing the rear half shaft

[Michael L.]

Guys,

I'm trying to install the rear half shafts on the chassis and I'm having trouble torqueing the half shafts down. When I torque down the outer half shaft bolts onto the trailing arm I'm tearing up the French locks due to friction between the bolt and lock. It just keeps twisting up and mauling the lock. I thought about putting a little oil on them to lube them up but I'm afraid of corrupting the torque specs. On the inner portion of the half shaft, cannot reach the u-joint nuts in order to torque them down. I can only get a wrench on them. Should I just use a wrench and guess at the torque spec??? Thanks for your help.

Mike

[Joe L.]

Re: Problem with torqueing the rear half shaft

Guys,

I'm trying to install the rear half shafts on the chassis and I'm having trouble torqueing the half shafts down. When I torque down the outer half shaft bolts onto the trailing arm I'm tearing up the French locks due to friction between the bolt and lock. It just keeps twisting up and mauling the lock. I thought about putting a little oil on them to lube them up but I'm afraid of corrupting the torque specs. On the inner portion of the half shaft, cannot reach the u-joint nuts in order to torque them down. I can only get a wrench on them. Should I just use a wrench and guess at the torque spec??? Thanks for your help.

Mike

Mike------


Your problem with the french locks is VERY common. I've never installed them without having this problem. However, if you use stainless steel french locks, the problem is lessened because the material is harder. However, I still apply "Never Seize" to the interface between the lock and the bolt. Yes, that does affect the torque specs but so be it.

Getting at the nuts on the inner u-bolts with a torque wrench is impossible unless you use a crow's foot wrench. Even then, it's very tough. This is one application that absent assembly line special equipment, you pretty much have to do by "feel". You also need to go back and forth between the nuts on each u-bolt to ensure that they are both tight.

[Gary R.]

Re: Problem with torqueing the rear half shaft

As Joe mentions and you found out, the steel locks easy. I think I recall at about 45-50ft/lbs they twist. I stopped using them years ago and use the SS ones. Those I lube under the bolt head and bend the lock down flat so the bolt won't catch it. I can step them up to 70 ft/lb no problem, then bend the link of lock back up and check for clearance. With high HP builds, 450-900hp. I use 31 spline axles and Loctite and lockwashers.

[Joe L.]

Re: Problem with torqueing the rear half shaft

As Joe mentions and you found out, the steel locks easy. I think I recall at about 45-50ft/lbs they twist. I stopped using them years ago and use the SS ones. Those I lube under the bolt head and bend the lock down flat so the bolt won't catch it. I can step them up to 70 ft/lb no problem, then bend the link of lock back up and check for clearance. With high HP builds, 450-900hp. I use 31 spline axles and Loctite and lockwashers.

Gary------


....and one can use the Locktite even if one also uses the french locks. I think GM might have used it for this application instead of the french locks IF it had been invented then.

[Sal C.]

Re: Problem with torqueing the rear half shaft

Are you sure you are torquing the the half shaft and not the axle shaft?