Crossmember to differential

[Robert P.]

I started to reattach the rear crossmember to the differential. the AIM shows bolts with Lock washers. Mine has flat washers. Should I get lock washers or will flat washers do. Thanks bob

[Edward J.]

Re: Crossmember to differential

Bob, For safety I would install locks, once in place they cannot be seen.

[Rich P.]

Re: Crossmember to differential

What year?

Different years used different washers for specific reasons.

Rich

[Brian M.]

Re: Crossmember to differential

Don't forget the blue loctite.

[Robert P.]

Re: Crossmember to differential

It's a 71. I checked Paragon's catalog and they list a kit that has 4 flat washers and 4 lock washers. Still my 71 AIM shows Lock washers. Bob

[Edward J.]

Re: Crossmember to differential

Bob, I think that you can use flats and locks or as brian says blue loctite works also, its just a safty measure to insure the bolts don't back out over the years, its alot of work to drop the rear diff. down.

[Rich P.]

Re: Crossmember to differential

Bob,

I'm sorry I thought you were talking about the snubber bracket for some dumb reason. The crossmember to rear bolt uses flat washers with grade 8 bolts. If you use lock washers the bolts will have 1 less thread contacting the rear. I would as suggested use the flat washers and locktite.

Rich

[Robert P.]

Re: Crossmember to differential

That's what I found when I removed the crossmember ( flat washers). What through me was the 71 Assembly manual showing 4 lock washers. Thanks Bob

[Michael G.]

Re: Crossmember to differential

In almost every application, split-ring lock washers serve no practical purpose, other than to provide a hardened bearing surface. This is because the load to compress the lock washer is normally much less than the design clamp-load in the attachment, so by the time enough clamp-load is lost in the joint for the lock washer to come into play, the joint is already degraded beyond its design conditions.

Unless the particular lock washer being used was designed specifically for the joint it is being used in, and, it compresses within the design clamp load of the attachment, it provides little, if any, "safety net". An attachment that has to depend on a generic lock-washer to stay together is going to fail.

[Timothy B.]

Re: Crossmember to differential

The weight on the crossmember is pushing up so the bolts are there to locate the rear left/right and hold it there.

No need for lock washers, but definitely use grade eight bolts and the flats then torque. Going from memory, I think the bolts are 1 1/8" long and the flats are thin, probably SAE washers like we discussed on the bumper bolts some time ago.