350i - gearbox oil

[tvrtim50]

Anyone know what should be used? - my gearbox feels a bit notchy when its cold - wondered whether the viscosity was wrong???

[350zwelgje]

When cold that is normal.... I change from 1 to 3 until warm, then it is fine. But I have standard gearbox oil. It can be improved by using Castrol SMX, and plan to do so when I change it next time. ATF can be used, but it can leak out as the seals (especially at the back - even no seal) are not designed for it. And low level will cause gearbox failure (once bought a car with LT77 box and it was gone due to running a few 100 miles on low level of ATF). Some people even use a mix of ATF and gearbox oil. In case of no gearbox oil, I use temporary engine oil (15W40 used several times also in a Rover with same box for thousands of miles and no problems). When you do a search many threads will come up and without one solution, besides that SMX is probably the best way to go.

Rob

[number 7]

As 350zwelje says, SMX is the way to go, avoid ATF.

7.

[Jon S]

I m a SMX convert too

JS

[honourablepickle]

where did you all buy the castrol from ?
i had trouble getting some last year

[dw350i]

I think I have atx in the moment (red thin stuff) the gear change and general operation is excellent, however, the box does leak quite a bit of oil from the upper regions somewhere at the rear, will changing to the castrol stuff help to reduce this leakage?

[number 7]

dw350i said:

I think I have atx in the moment (red thin stuff) the gear change and general operation is excellent, however, the box does leak quite a bit of oil from the upper regions somewhere at the rear, will changing to the castrol stuff help to reduce this leakage?

It comes along the selector rod. SMX is a bit thicker, so will help, but ATF is not what you want to be using. There is a very small O ring which wears, and can only be replaced by stripping the box, so not worth doing as long as you keep checking the level.I had a proper oil seal fitted into a machined groove when the box was rebuilt, which cured the problem.

7.

[adam quantrill]

The place next to the MG owners club do the castrol stuff. It's on the web.

I got some LSD oil from there last year for the 400SX.

www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9002097&contentId=7003933