Differential info - maybe important

[peteA]

In the process of getting my diff overhauled by alan voigts (he advertises in the TVRCC Sprint magazine) - just needed bearing and seals (for info cost was £300 + VAT + carriage).

anyway - alan is a very helpful bloke and called me to arrange delivery (and ask for payment!) and he started telling me details about the diff and giving me some advice on oil.

apparently the diff is australian and is fitted to a number of cars including TVR's and Aston Martins and he mentioned a few others that I have forgotten now...anyway, the interesting and possibly important bit...

The oil in the diff should have 10% silicone by volume - something to do the limited slip bit? The only product he was aware of that met this requirement was made by 'Morris'....which just happens to be what Racetech sell on their website. Alan did say that there may be others but just that he was not aware of any...?

Just thought this would be a useful 'heads up' for anyone changing their diff oil?

[gruffalo]

Good info cheers.

[ridds]

i could have sworn someone posted on here saying the LSD is actually sealed withi the diff and not affected by the oil that the CW&P run in.

[Boosted Cerb]

The hydatrak version has a sealed unit with its own oil but the normal version (cone type) is not sealed and uses the diff oil for lubricant.

Haven't heard of the silicon content before but I know the Holden boys (same BTR diff) add friction modifier if they find their diff is too snatchy, probably silicon based.

Rich.

[ridds]

Just remembered also, silicone is very very bad for aeration so I'm not sure I'd be too keen on putting it in somewhere with fast spinning sharp things.

[v8sag]

The only approved lsd oil from BTR (now Danna Spicer) for the IRS lsd's,(not hydratrak) are Castrol SAF-XJ (SAF-XA in Aus and NZ) and Mobil SHS-ID. These contain the friction modifier "Sturaco 7098"
Saying that, I have always used "Penrite limslip 90" and added 6% Sturaco 7098, as have alot of the Holden guys down under.

[peteA]

v8sag said:

The only approved lsd oil from BTR (now Danna Spicer) for the IRS lsd's,(not hydratrak) are Castrol SAF-XJ (SAF-XA in Aus and NZ) and Mobil SHS-ID. These contain the friction modifier "Sturaco 7098"
Saying that, I have always used "Penrite limslip 90" and added 6% Sturaco 7098, as have alot of the Holden guys down under.

I know a little bit about oil, etc but starting to get a bit over my head - happy to take advice though.

Cant vouch or back up what I was told only that alan sounded very knowledgeable and its his business...

for info:-

this is the link to Racetech.

http://www.racetechdirect.co.uk/tvr-car-parts-subs...

...and this is the link to the Morris website.

http://www.morrislubricants.co.uk/scripts/prodView...

going to do a bit of checking me thinks...

Take care

[Mad Mark]

Does anyone know the exact QTY of oil the diff takes? Are the QTY's different between the types of diff and how to tell which diff you have fitted?

Cheers.

[peteA]

Mad Mark said:

Does anyone know the exact QTY of oil the diff takes? Are the QTY's different between the types of diff and how to tell which diff you have fitted?

Cheers.

My normal diff - not hydratrak - takes 1.6 litres according to my tvr owners manual. Ive been warned however that from new the diffs have known to pass oil via the overflow/vent valve on top of the diff. Im going to fill it to the drain plug level...presumably that will be around 1.6 litres?

[Brummmie]

mine puked oil out of the breather, i put a length of pipe on it, but if you have it out you could make a baffle to shield it from a direct path. I use Silkolene LSD oil BTW. I put the higher geared ratio in mine (3.08) from a Holden pick up or something?

[JensenA]

Be careful what Diff oil you use. 2 respected Indie's have warned me never ever, ever, use any oil that doesn't meet the exact spec of the original Mobil 'SHC 80W 140 ID'. The wrong oil will 'kill' the Diff.

http://www.mobil.com/Australia-English/Lubes/PDS/A...

[high52kojak]

http://www.opieoils.co.uk/c-674-75w-140.aspx


The Castrol one is what was recommended to me by Opie.

I think my diff takes just under 2 litres.

[peteA]

using morris lodexol xfs 80w/140 api gl5 as recommeded by the guy who rebuilt my diff and as sold by racetech....the bottle states fully synthetic final drive and limited slip differential oil. Its half in now so i hope its ok!

[Mad Mark]

Cheers guys
I'm thinking of doing a complete oil change in it as there are some strange things happening from my rear end, oor errr lol and I just wanna make sure the oil is correct. I have had the diff casing off a short while ago but just recycled the existing oil.

[ukkid35]

comm_SS_V8 said:

Differential

======

Any 80w/140 based product.
Note: You might require some Friction Modifier to stop diff noises after changing the oil.

• Mobil Mobilube SHC (80W-140)
• MOBIL GEARLUBE VS 500 (Synthetic) (75W-140)
• Castrol SAF-XJ (75w-140)
• RedLine 80W140 Light/Heavy Shockproof Gear Oil (80w-140) - Requires LSD Modifier
• Redline 75w90 (Includes LSD Modifier) and is suitable for 'typical road use'
• AMSOIL (FGO) Long Life Synthetic 80W-140 Gear Lube
• Morris Lodexol XFS 80W/140
• Morris Lodexol SS 80W/140
• Millers CRX LS 80w140 BM

LSD Friction Modifier

===============

• Red Line LSD Friction Modifier
• AMSOIL (ADA) Slip Lock Differential Additive
• GM Synchromesh Transmission Fluid Friction Modified: (Part #GM-12377916) [Unsure of UK stockitsts at this time]

I'm looking for a BTR Diff oil, and since MOBILUBE SHC 80W-140 ID is no longer available, I want the best possible oil. It's only 2L after all and probably only gets changed 2 or 3 times in a car's lifetime, so I don't mind paying a premium.

Current thoughts are:

Motul MOTYLGEAR 80W-140 Synthetic
Lodexol XFS 80W/140 Synthetic
RED LINE Synthetic Gear Oil 80w-140 GL5

Any suggestions?

[Tanguero]

John Reid of Readman Racing recommended the Lodexol. Given that he does more BTR diff rebuilds for TVRs than all the thoers put together, thats what I went with.

[ukkid35]

ukkid35 said:

It's only 2L after all and probably only gets changed 2 or 3 times in a car's lifetime, so I don't mind paying a premium.

Three years on and I still haven't even attempted to change the oil. Lazy.

[Mr Cerbera]

ukkid35 said:

ukkid35 said:

It's only 2L after all and probably only gets changed 2 or 3 times in a car's lifetime, so I don't mind paying a premium.

Three years on and I still haven't even attempted to change the oil. Lazy.

It's supposed to be done at the 12K service so I'm sure your service point will have done their due diligence

[Jubag]

How can you tell which diff type is fitted to a specific car?

[ukkid35]

ukkid35 said:

Three years on and I still haven't even attempted to change the oil. Lazy.

Another three years and I'm actually going to change the oil today

I'm using Lodexol XFS 80W-140 as per your recommendations

The largest spanner I have is 28mm, but fortunately my adjustable was able to loosen the 29mm fill plug

The drain plug on mine wasn't a problem