Correct gearbox oil for 4.2 manual.

[johnben]

Changed my gearbox oil some days ago but now not sure whether this is the best oil for my 47 year old car.
What I have put in is a part synthetic EP 75W/90 GL-5 multi-grade gear oil.
Does it stay or should I change it?
My fears revolve around reading somewhere that the GL-5 formula overtime it detrimental to non-ferrous metals. The more I read the more confused I get.


John

1967 Ser 1 2 + 2

[christopher storey]

I have just read that GL5 spec oils are specifically for hypoid axles ONLY, so you are probably correct, and you should use a GL4 spec oil

[tim wood]

By coincidence I was going to drop a note to the forum tonight re this.
I have just changed my gear oil on my 4.2. I bit the bullet and used Redline as has been mentioned before on here.

The result is a very significant improvement in shift quality and noise reduction. OK - the old stuff looked very suspicious but the result is great.

A bit more expensive but in my opinion well worth the extra.

Regards
Tim

[daykrolik]

I concur with Tim that the appropriate Redline oil is well worth the money. It is MT 90. There is another thread on the subject, I believe. Redline 75W90 GL 5 is for your rear axle and does not require a limited slip additive. I've had great success with Redline products for many years and assure you I have no ties to the company.

[abowie]

And another.
I put Redline MT90 in the box in my newly acquired Series 1 2 weeks ago. Shifting into second either up or down is significantly improved. This box was rebuilt about 8 years/5000 miles ago.
I have had similar improvement in the box on my Series 1.5 which I have been using MT90 in for around 3 years.
I am one who has never believed a word that oil salesmen say but I am sold on MT90.
Sadly the MT90 failed to allow my Series 1 to function in 4WD today....

[johnben]

Thanks for the advice folks will order some Redline MT90 today.

John

Ser1 2 + 2

[johnben]

Just to finish of this subject I received 2 containers of Redline MT90 each under I Litre capacity (946 ml) a bit of a panic when I noted in the manual that the gearbox requires 2.4 Litres, However, I vaguely remembered something about this being a missprint and put in what I could anyway. It started to overflow at about 1.6 Litres, will check tomorrow to see if the level is OK just in case there was a large air bubble of 0.8 Litre capacity. But this is someway off 2.4 Litres.

John

2 + 2 Ser 1

[christopher storey]

John : I don't know which manual you have, but AFAIK all of the gearboxes have a capacity of 2.5 pints = 1.4 litres . I have never yet seen a ( manual ) gearbox requiring over half a gallon of oil !

[johnben]

Hi Chris

Thanks for the response, an image of the manual and detail is below, I understand this error was carried on through several prints. I have also included an image of the Operating, Maintenance and Service Handbook which as you suggest gives the correct amount.

Regards
John Ser 1 2 + 2

[Gfhug]

Has anyone tried the Millers Oil CRX-75X90? http://www.millersoils.co.uk/automotive ... Motorsport

One of the people at Stoneleigh was recommending it as an alternative to Redline MT90.

Any thoughts or experiences? The claim is it is as good, it's British and cheaper.

Geoff

[christopher storey]

I have used a number of Miller's products and have found them to be highly satisfactory. I cannot compare shift quality with Redline as I have never tried it, but on all three of my Jaguar all synchro boxes I have found the shift quality to be very good anyway

[pmansson]

An old favourite subject on many forums. I have used the MTL oil in both all synchro boxes and Moss boxes (without OD in both cases) and find it very good. Takes some mileage to notice the benefits. I have in it Getrag boxes in my BMWs as well.
Nobody talked about the MTL in this particular topic, this time....