Griff diff oil

[Ozstyle]

Hi all,
the search system is down so I need some advice. I'm going to change the oil in my diff (GKN type), on finding the recommended oil, Mobil HD 90, I notice there is no recommendation on the labling that states it is suitable for limited slip differentials. The other similar products available do state they are suitable for limited slip diffs.

So now I'm not sure what is the best diff oil to use. Anyone have any experience or recommendations on the subject?

thanks

Ozstyle

[falcemob]

Comma oils now do an oil specifically for limited slip diffs or you could just add a friction modifier to the standard oil.

[steve-v8s]

The handbook for my 98 500 also says hypoid 90 ( I have the BTR Diff) But …. If you call the factory they insist that the ONLY oil that will work is some Esso stuff that they import. It seems it is not available from any supplier other than TVR dealers, and it is only available in very large drums. I did call the local dealer who said they would sell in smaller volume if I brought a container. Others recommended Millers CRX LS 80w140 BM. A call to Millers confirmed this was OK . I bought some mail order as it was a lot cheaper and less hassle than going to the not so local dealer. However… being a lazy type it is still on the shelf in the garage as the second hand Diff I bought had nice clean oil in it so I went with that.

I have since heard that the normal Hypoid 90 is used in the Hydrotrack but should not be used in the normal LSD. Apparently you can identify the diff type because the Hydrotrack has two groves machined around the flange on one of the output shafts and the normal ones don't.

[GriffOz]

I have the GKN diff in my 430. The car had been stored for a couple of years before I bought it and the clutch plates were sticking - unnerving bangs from the rear end as they released. My local diff specialist put in an additive made by Ford Performance Vehicles for their LSDs. Their clutches also stick. I've since discovered that Holden have a similar additive for their diffs as they have the same problem!

Clutch problem is solved on mine. As to longevity, I can't say but diff man says should be OK. Could be worth a try.

[chevtrev]

Any LSD diff oil should be ok,but a call to a your dealer won't go a miss.
Did you guys know that TVR f#uck around with the BTR plates,just changed mine to a 3.08 ratio and internals as in the Holden V8 racers down here,sounds like they don't trust your driving skills,hence alter how it kicks in.

[Ozstyle]

Hi all,

thanks for the replies, replaced the diff oil with SAE 90 (Valvoline LS90) that is suitalble for limited slip diffs. Good news was that when I drained the old oil there was plenty of it and it looked fairly clean.

Ozstyle

[GriffOz]

chevtrev said:

Did you guys know that TVR f#uck around with the BTR plates,just changed mine to a 3.08 ratio and internals as in the Holden V8 racers down here,sounds like they don't trust your driving skills,hence alter how it kicks in.

So how do they do that?
GriffOz