What Diff Oil To Use?? 1999 Caterham Super Seven

[Sjwarden]

Been lurking on this site and dreaming of a Caterham for years.  Finally got one a week ago.  Planning on doing some maintenance and checks over the winter, and preparing for a lot of miles come better weather.

 

My new car is a kit that was assembled here in the States in 1999, a super seven K series car with the 1.8 VVC engine and Caterham’s 6 speed gearbox from that time.  It is also fitted with an LSD.

 

I have a VIN SDKLDKANSX0010168.

 

Wondering what gear oil I should use to top off the diff in this vehicle but I cannot figure out what type of LSD it has.  Does anyone have any ideas?  Unfortunately the VIN plate has no info other than the VIN number on it.  Thank you for any help or input.  

 

[MV8]

If it were a clutch type LS, a friction modifier additive would be needed. Otherwise, you can use the normal diff oil. I'm guessing it has a Quaife ATB. You can check with a $20 usb probe camera through the filler (they have a built in adjustable brightness light).

 

They went to BMW diffs around 2010. Prior to that, all are supposed to be 7". Probably a 3.62 or 3.92 ratio but ratios from 3.14 to 4.70 are also available.

[Croc]

8 hours ago, Sjwarden said:

Wondering what gear oil I should use to top off the diff in this vehicle but I cannot figure out what type of LSD it has.  Does anyone have any ideas?  Unfortunately the VIN plate has no info other than the VIN number on it.  Thank you for any help or input.  

 

 

Congratulations on your new acquisition and welcome to USAS7.  Sadly it is a little cold right now to have a good play with it but Spring will be here shortly.  There are a number of other Rover-engined car owners on USA7s so don't think you are alone if you are confronting engine questions and need technical input. 

 

I think MV8 is right.  If original then I expect it is a Ford Sierra diff housing with Quaife internals for a 1999 car.  I assume you did the usual test to confirm LSD - on a lift, rotate one wheel, etc.?

 

I would not top off the diff oil.  I would drain/suck out what is there and give it all new fresh oil.  I have never been a fan of mixing old unknown oil with new stuff. 

 

For spec, I would look up one of the Rover assembly manuals of a year near to your build year in the library on this site and see what they recommend for diff oil spec - you can get a match to a quality brand available in the USA. 

[coffee break]

Send a sample of the oil to be analyzed and see if there any friction modifiers in it.

[Sjwarden]

Thank you all for the suggestions and advice.  I did go ahead and buy a boroscope, should come in handy.  I did also check the rover assembly manuals and they refer to the owners manuals for the oil specs.  I found an owners manual that seems close in year to mine and I think in combination with a boroscope to verify the diff type I can nail this down.

 

Also might send away for an oil analysis as coffee break suggested.

 

 

[slowdude]

As croc has mentioned. Most likely a sierra diff.

 

That k series will be a riot. I think we may have enough people now for a bulk deal on oil filters from discount mg rover spares.

 

Enjoy! (And don't forget to rev that motor out).

[jbcollier]

You just need to figure out what kind of LSD diff you have and get the oil to match.  Testing the oil you have might be useful to catch any developing issues but there is no guarantee that the PO used the right oil.  If it is a torsion diff, raising one wheel off the ground and seeing if it spins proves nothing.