Gear Oil Recs?

[AbnMike]

I can't find 80W for the gearbox or 90W for the differential anywhere (unless I order it).

Before I order and have to spend on shipping is there a crossover that is acceptable?

Thansk

 

[bavbob]

I bit the bullet and used Redline despite all the hoopla about synthetics and leaking. Been fine for 3 years. Check Amazon, often decent prices on Redline and with 2 quarts of anything you just about hit the free ship threshold of 25 bucks.

 

[Luis A.]

Many, myself included, use Redline MTL, which is a 70W80 GL-4. GL-5 (the current standard) can damage the bronze synchros in the gearbox.

 

[DerSchwede]

GL4 for gearboxes and GL5 for rear axle. I use Castrol SAF-XJ with LSD and SAF-XO for non-LSD units. TAF-X for the gearbox. Everything's fine since I started using it some 15 years ago.
Cheers
Andes

 

[AbnMike]

Many, myself included, use Redline MTL, which is a 70W80 GL-4. GL-5 (the current standard) can damage the bronze synchros in the gearbox.

Do you use the same Redline MTL (70W80) in the gearbox and the differential?

 

[sfdon]

The rule that DerSchwede is trying to explain is that Limited Slip diffs need GL5-
Using GL4 will ruin them.
Transmissions cannot use GL-5- it screws up the synchros.

Use Napa auto to order your oils.

 

[Nicad]

I have a couple of Litres of BMW limited slip that I used in my E36 M3. It was sourced at the dealer and I guess they get it from a larger tank. Would this likely meet the spec for an older LSD diff?

 

[DerSchwede]

Yes it will meet the spec. I ordered 3 bottles of Castrol Syntrax Limited Slip 75W-140 (former SAF-XJ) yesterday for €10.45 each (approx. $52/gal.)