Changing Diff Oil.

[Wildfire]

I want to change the Diff oil. How does one do this for a Griff/Chim and what oil should I be using?

[mongoose]

Your diff should be a GKN type i think.Theres a drain plug(at the bottom) and a filler plug(on the side),just like on most gearboxes.You drain,then refill until oil just starts to trickle out through the filler plug hole,then you know you have the correct amount in.Its best done when the diff is warm,just like engine oil.Always do this on the level btw.I think tvr reccomend mobil 80/140id in the diff,but there are others you could use.I put Redline heavy shockproof in mine for instance.

[tvrbob]

LSD's are very sensitive to oil grade. Be absolutely sure the new oil is right for your diff.

[tvrolet]

tvrbob said:

LSD's are very sensitive to oil grade. Be absolutely sure the new oil is right for your diff.

unless of course its a hydratrak unit, as per later TVRs, where the LS part of the D is in a sealed unit and never gets in contact with the diff oil, so the diff oil has no impact or otherwise on the performance of the LS bit.

[griffter]

Undo the filler plug before the drain plug. The last thing you want is to find the filler plug is seized or rounded, so it can't be reomoved, and no means of refilling the diff to take the car somewhere to get it sorted.

[chassis 33]

griffter said:

Undo the filler plug before the drain plug. The last thing you want is to find the filler plug is seized or rounded, so it can't be reomoved, and no means of refilling the diff to take the car somewhere to get it sorted.

Ah, that sounds like the voice of experience!!!

Regards
Iain Who's also been there and done that, the solution was g'box out and plug weld a 19mm nut onto the filler plug

[pupp]

Think the recommendation for the later fitted BTR diffs is Mobil SHC 80W-140(ID)... when I last did this, I couldn't find any so with the help of Teeside Autotech who were prepared to decant small quantities and mail order, I obtained a near equivalent, Mobil Gearlube VS500 (SAE 75W-140) which is a fully synthetic product of pretty much identical spec. From memory, the drain plug was not that obvious, it pretty much looked like the lowest of the housing bolts and only close inspection revealed it was a drain. The filler is a pain to get to but a long pipe and flexi-funnel through the wheel arch assist.