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Bottom diff mount hole, should this be elongated?
Kriss - 19/11/10 at 12:15 PM

When removing my diff for a rebuild (Big up to the Phil @ Road and race Transmission brap brap brap yacka yall!) my bottom diff mount with the thread bar was very loose. Nylocks may be a bit knackered but they should have only been used once ever!

Anyway, when reinstalling, we noticed that the diff could pivot ont he top mount threaded bar, as the lower seemed to have larger holes int he chassis mounts.

Any ideas or things to be carefull about here?


stevegough - 19/11/10 at 12:30 PM

The diff should not be able to swivel - neither hole should be elongated at all. Sounds like it has worn like this?


MikeR - 19/11/10 at 12:38 PM

may explain the noise you got when going on / off the power.

The diff should be a nice tight solid fit and should not move. Possibly the nylocs were at the end of the thread and therefore tight - but nuts weren't pulling the mounts tight. Potentially you need new diff mounts. If there like the haynes roadster you could just buy new mountings. If they're welded on you potentially need new mounts welding on. Get some photos and post them on here. If possible measure the bolt you're using and the hole (measure the hole in 3 or 4 places to prove its round and not deformed from round).

A bodge that is acceptable (others will need to confirm) would be to weld some 3mm thick washers onto the existing mounts with the right sized hole in them. then tighten up the bolt onto the new welded in washers.


Bluemoon - 19/11/10 at 04:42 PM

Use shims (thin metal sheet with a hole to take up the space between the chassis and the diff, on both sides of the mount I think I used some thin washers). On reassembly you will want a washer over the oval hole (and use new a nyloc).. This should be o.k if the hole is not too elongated. Never worked out why the build manual does not specify shims here. On reasembly mark with a line of white paint on the bolt/diff so you can see if it moves again.

Dan

[Edited on 19/11/10 by Bluemoon]


Kriss - 19/11/10 at 04:45 PM

the hoelf or the treaded bar at the bottom mount is larger than the bar.

i have done it up barstid tight and used nylocks and loctite. Have also marked the diff bolts with a marker line to detect movement


James - 19/11/10 at 04:48 PM

When you say threaded bar...

Are you using just normal studding or something rated 8.8 or higher?

Most threaded bar is basically made of cheese and is not really safe to use.

Cheers,
James


MikeR - 19/11/10 at 05:08 PM

i think we may have two issues here. Can you take the measurements i suggested and include the bolt / threaded bar + take some pictures. We'll be able to 'see' the problem then and not risk getting confused over terminology.


MikeRJ - 19/11/10 at 08:31 PM

quote:
Originally posted by James

Most threaded bar is basically made of cheese and is not really safe to use.



Sounds like the nuts and bolts that B&Q sell, made from something resembling ripe brie.