Hydratrack diff question.

[phoenix-pete]

Hi does anyone know if the hydratrack diff fitted to the Sagaris uses the same oil as the standard diff as on earlier cars, ie;mobil SHC 80W-140? and if so wonder why I have been charged for 3lts at £11.45 + vat for it at my first service?
Why would the diff oil be changed but not the gearbox?
Didn't expect either to be changed to be honest.
I will ask my dealer next week, just wanted to see if anybody else has had this with the first service.
Done 1200 miles now and car is running like a dream, starting to use a few more revs now and finding it pulls like a train, more torque than the 3.6 and feels like it will be a lot easier to handle at speed than the T350 was.

P.S. just had a look for those interested as there has been disscusion on diff ratio's,mine has a 3.73-1 diff with standard gearbox.

Cheers
Pete.

[rmc]

Hi Pete,

Good question...

I've got a hydratrak diff in my car, and the owner's manual states...

"The hydratrak coupling unit which is sealed for life, fluid filled cartridge, houses an inner rotating element which is also splined to the left hand shaft..."

Doesn't this imply that you should not need to change the oil within it? One for your dealer to answer I would presume?

Rich

[GreenV8S]

Presumably that's what the service schedule says. If you have any doubts, you can always ring the garage up and ask why they did one and not the other?

[JasperJ]

phoenix-pete said:

P.S. just had a look for those interested as there has been disscusion on diff ratio's,mine has a 3.73-1 diff with standard gearbox. Cheers Pete.

Where do you check?

[phoenix-pete]

Thanks for the replies guy's.
I did think the hydratrack was a filled for life thing,HMmmm better give them a ring.
Funny how I got charged for 3lts when the diff is 1.6lts I think and the gearbox around the same.
Pete.

[phoenix-pete]

Hi JasperJ

There is a big sticker on the off/side of the diff housing you can't miss it allthough it is only paper so may not last long. Amongst other things it says Hydratrack 3.73-1
Cheers.

[tail slide]

Think you'll find that the sealed hydratrak unit sits inside the crown and planetary wheels - which do need oil - similar to Cossie viscous diff design.

[bobd]

Had a Hydratrak fitted by factory - recommended 1000mile oil change

[smirnoff]

It can't be sealed for life, I was at London TVR a couple of months ago when a Saggy that had been on a track day stank out the whole workshop with burnt diff oil.

[GreenV8S]

The viscous unit may be sealed for life, but the diff certainly wouldn't be. The oil they're changing at 1000 miles would be the gear oil, not the slime inside the viscous unit.

[tony m]

JasperJ said:

phoenix-pete said: i rang the factory yesterday and asked them what diff should be in a saggy,they said it should be a 3.73 the same as a tuscan s,but then said it was an option when ordering the car new,i was never given the option of two different diffs,they are not a bit bothered after you have bought the car,its just an excuse for putting in a different diff P.S. just had a look for those interested as there has been disscusion on diff ratio's,mine has a 3.73-1 diff with standard gearbox. Cheers Pete. Where do you check?

[Devil's Advocate]

tony m said:

JasperJ said: phoenix-pete said: i rang the factory yesterday and asked them what diff should be in a saggy,they said it should be a 3.73 the same as a tuscan s,but then said it was an option when ordering the car new,i was never given the option of two different diffs,they are not a bit bothered after you have bought the car,its just an excuse for putting in a different diff P.S. just had a look for those interested as there has been disscusion on diff ratio's,mine has a 3.73-1 diff with standard gearbox. Cheers Pete. Where do you check?

The ratio is shown on the diff housing. The ratio is NOW the same as the Tuscan S because the Tuscan S ratio has changed as well. IMO the original homologated ratio is NOT 3.73 (for Sagaris or Tuscan S). TVR, like all manufacturers, reserve the right to change specifications but you'd like to think they do it within the scope of legislation/ homologation rules, but I'm very sceptical. Furthermore, the 0-60 and 0-100mph time claims have not been altered and I'd wager big money that they cannot be achieved with a 3.73 ratio!

As regards oil change, I agree that the diff itself has to have its oil changed whereas the hydratrak unit within is sealed for life. Where 3 litres comes from is anybody's guess!!