Gear box oil 1986 350i

[dukeenfield]

Hi, What the best gear box oil,says in Rover manual ATF-G automatic oil or should it be TQF automatic oil.

[wedg1e]

Yeah, ATF-G should be fine. If it's red and oily, it'll do...

[350matt]

I use a the 75-90W semi synthetic castrol stuff gives much better protection than ATF without being too thick to slow the shift down.

Matt

[paul gotts]

Don't use ATF - its too thin and was apparently only recommended by Rover because the thicker gear oil intially specified was causing crunching problems when cold. RPI strongly recommend Castrol SMX. Some people also used engine oil. I'm using up my Mobil 1 5-50 in the box at the moment, still need to be careful when cold, shifting 1 straight to 3 does the trick.

[wedg1e]

You can't use anything too thick otherwise the LT77's internal oil pump won't be able to pump it fast enough - especially when cold.
I find that the box drags anyway even with ATF in.

[adam quantrill]

DON'T USE ENGINE OIL!!!

Sorry for shouting but I had the following experience puting 20W50 in a rover 4-speed box: initially everything seemed fine, the gearchange was slick, etc. However after about 500 miles the gearbox broke. Completely.

Engine oil doesn't have an EP rating which means that while its OK on relatively smooth surfaces such as bearing shells, it doesn't stop gears grinding together.

I currently use ATF (current box has done maybe 30k miles on it and getting a little tired) but was thinking of switching to the castrol or even doing a blend of the two.

- Adam

[dukeenfield]

So ATF-G is ok to use in gearbox?,this is getting as bad as trying to sort out which oil to put as in engine.

[19560]

dukeenfield said:

So ATF-G is ok to use in gearbox?

Yes. It leaks out and sprays all over the chassis but that's good for rust protection. Remember:-

wedg1e said:

You can't use anything too thick otherwise the LT77's internal oil pump won't be able to pump it fast enough - especially when cold. I find that the box drags anyway even with ATF in.

[grahamw48]

TVR 350i owners handbook (1984) gives manual and auto gearbox oil as ATF.

(Now I just need to save up for the car )

[paul gotts]

Thanks for the tip Adam. The reason that I've used engine oil in the gearbox for the past couple of years is that was what the company that re-built it suggested. Now a cynic like me might think that this would just generate them more business when the box goes again, but having known and used this company for more than 10 years, I rely on their judgment. I also seem to remember that Richard Thorpe has suggested engine oil for the Rover box in the past. I can only re-iterate what RPI say on their website about ATF - its use will eventually lead to gearbox failure. Its too thin and I dont think it can take the heat generated. It is after all, hydraulic fluid, not gear oil. On the subject of EP additives, I'm more confused after a quick trawl on the web - some of these additives are actually corrosive to synchros, and should not be used. I think a chat with someone at CTS might be in order just to clarify things.

www.rpiv8.com/transmission-3.htm

[dukeenfield]

Thanks for imformation,so it looks like Castrol SMX is the best oil to put in gearbox,did all the 350i have LT77 gearboxe's,thanks Ken.

[shpub]

dukeenfield said:

Thanks for imformation,so it looks like Castrol SMX is the best oil to put in gearbox,did all the 350i have LT77 gearboxe's,thanks Ken.

Yes but there are about 10 or s0 LT77 varients with the later ones being a lot better than the earlier one.

I use ATF. Not had a problem.

[paul gotts]

Spoke to Bernie at CTS yesterday about oil for the LT77 box. His recommendation is to use ATF, although when I said I was using Mobil 1 engine oil, he said that as long as it wasn't giving any problems, stick with it. The main thing is not to use anything too thick, as the pump is fairly puny. So, contradictory opinions from two experts, I guess you pay your money and take your choice.

Paul.