Tailshaft to diff - Bolts will not stay tight!

[Jxfwsf]

A lot of the old British cars used to have these special little stamped washers on the tail shaft uni's. There are 2 holes in each washer with a stem in between to connect two bolts and on the outer end of each hole there was a steel tab. After the 2 bolts had been torqued up you bend the tabs up against a flat side of the nut so neither nut could turn.
Hope that makes sense.

Much like the earlier vehicles used to hold the rackend in the rack, or what's used on the v6 exhaust nuts....

Not used on on these final drive bolts.

Tbh the flats on the flange aren't for locking, more of a convenience thing to do them up using 1 tool instead of 2 and trying to hold the nut in place to torque to spec.

So if they're undoing the nuts aren't doing their job.
Doesn't need split washers, welding, thread locker or lock washers.... need to be replaced.

 

[HarryHoudini]

Tailshaft probably needs a Balance,even if its not severe vibrations at weird harmonics loosen bolts.

 

[Blester]

I had this problem with my VK but not my VL and if anything the VL had been taken apart more. Wanting to go club racing the next day and no where to get correct bolts I went down to the local hardware place and got some low (or medium) strength loctite. put just a drop on each bolt and it never came loose. I did have to undo these bolts later and they were no harder to undo than they were originally. I do this to all my cars now and have never had any come loose or be able to be undone even when dirt rallying.

 

[Mudgy]

I'd do 2 x things.
1. Pull the shaft from the car, and have it checked. If it's got high km's it's pretty cheap to have the unis and centre bearing replaced.
Vibrations as said can be a cause here.

2. New nuts & bolts. So cheap, versus running the risk of disaster. Nylocks or torque lock nuts (no nylon insert, used on Jag rear hub to disc/axle) https://www.nutty.com/Grade-8-Torque-Lock-Nuts_c_57.html

Also you might want to use some nord-lock washers.

Nord-Lock wedge-locking washers | Secure your critical bolted joints with the original lock washer from the bolting experts


These, and also Schnorr washers make star washers and spring washers a part of the stone age.

Cheers, Mudgy