BTR Hydratrak oil

[Flyinghorse]

I was looking at proactively changing my BTR Hydratrak oil as I don't know what's in there or how long its been in.
   Incidentally the chassis manual suggest change at 500miles run in.
   
   The CRS Chassis manual states a mobilube SHC 80w-140D API GL5
   
   This seems to be an Australian blend and I cant find it in the UK.
   
   I have asked mobil uk  for the equivalent They have a HD 80-140, and some say SHELL SPIRAX S6 AXME 80W/140 is equivalanet
   I have also seen a redline oil claiming to be API GL5 80-140 equivalent.
   
   I was keen to know what others are using.
   Graham

[Mark IV]

In the US the spec is 1.64 Quarts of GM #89021809 as used in the Pontiac GTO. Also 1 ounce of GM additive #89021958.
   
   This is for the BTR Hydratrak diff unit as used in the Aussie cars and the US cars as well as by Superformance in the MK III "Cobras" and the Daytona Coupe chassis.
   
   Perhaps this is available in the UK also?

[jbottini]

Rick, there are several gear lubes and modifiers for the hydra tac available.jbo

[Flyinghorse]

Mobil came back saying to use:
   http://www.mobil.com/UK-English/Lubes/PDS/GLXXENCVLMOMobil_Delvac_Synthetic_Gear_Oil_75W-140.aspx
   
   The 80w-140 has been discontinued for 10 years.
   
   Millers also have a similar product  CRX LS 75w140 NT
   
   The Hydratrak is a ATB (Automatic torque biasing) ,it looks like the sealed bit is actually the centre that's welded together after assembly, and the oil gets to all parts (ie not 2 oils).
   They don't seem rebuildable/worth rebuilding.
   Morgan/TVR owners have BTR's and seem to replace them with Quaife QDH4M or QDH6M  depending on whether its a BTR M80 or M77 Hydratrak
   The other option is Eaton truetrac.
   Graham