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#1 Gearbox and lsd oil recommendation
Posted: Sun Jul 17, 2022 7:41 pm
by Piscator
I would like advice or recommendations for suitable gearbox and lsd oil, please.
I have heard that Redline MT90 is suitable for both gearbox and lsd. I think that Castrol EP90 is a replacement for Castrol Hypoy, but presumably needs an additive for the lsd.
Can anyone please advise the capacity of the gearbox as there is an inconsistency in the handbook, which refers to a difference between 'early' and 'later' cars. If this really does relate to the S2, when did the change occur (engine/chassis no.)?
Finally, is the GL4 or GL5 classification of any significance to our cars?
Many thanks for any assistance anyone can give me.
#2 Re: Gearbox and lsd oil recommendation
Posted: Sun Jul 17, 2022 8:01 pm
by mgcjag
Yes for gearbox...not suitable for diff....look at the spec
https://www.redlineoil.com/mt-90-75w90-gl-4-gear-oil or search on the forum
#3 Re: Gearbox and lsd oil recommendation
Posted: Sun Jul 17, 2022 9:32 pm
by rswaffie
Hi
In my 63 s1, the moss box seems to like the MT90 as did a similar box in my previous Austin Healey 3000.
When Alan Slawson rebuilt my powerlok diff, he included the following info re oil:
Warning Note – Castrol ‘Axle Z90’ limited slip oil or quality equivalent oil to be used for the LSD unit.
Synthetic or semi-synthetic oils do not work in these units and MUST not be used
He supplied the Z90 oil for the diff as part of his service.
#4 Re: Gearbox and lsd oil recommendation
Posted: Mon Jul 18, 2022 7:45 am
by mgcjag
Redline have the MT90 and MTL.........have a search through the forum. ....MTL is typically refered to for the Moss box and MT90 for thr 4 syncro. .....Steve
#5 Re: Gearbox and lsd oil recommendation
Posted: Mon Jul 18, 2022 9:27 am
by mach2andy
My freshly overhauled completely leak free gearbox was a bit tight engaging 1st and 2nd gear, & to try to overcome this I drained it and refilled it with Redline MT90. It then leaked like a sieve and I had to drain it and refill it with standard EP oil.
#6 Re: Gearbox and lsd oil recommendation
Posted: Tue Jul 19, 2022 3:02 am
by johnetype
My experience with Redline MT oil in my gearbox was the same as Andy's; the gear change wasn't noticeably better and the gearbox leaked liked a sieve from the rear seal. However, others report a different experience so do a search on previous posts on the topic to help you.
GL4 and GL5.
GL5 has a sulphur based additive which is not kind to "yellow" metals, e.g. bronze and brass, so do not use GL5 in a Jaguar gearbox.
As for capacity, use the fill plug (on the RHS for later gearboxes) as the definitive level.
#7 Re: Gearbox and lsd oil recommendation
Posted: Tue Jul 19, 2022 9:02 am
by Gfhug
John, the gearbox capacity for the S2 did get wrongly converted between imperial and other measurements.
And has been pointed out the filler could be on the right with no hole in the gearbox tunnel to gain access, so it’s from underneath the car with a simple squeeze bottle with a spout to fill.
Geoff
#8 Re: Gearbox and lsd oil recommendation
Posted: Thu Jul 21, 2022 7:10 pm
by Piscator
Many thanks to everyone who replied. I now have (most of) the answers I was looking for.
I'll go with something like Castrol EP90 for the gearbox.
I now know I have the later gearbox (access hole on the left, filler plug on the right---pretty obvious really when it is pointed out!).
I am still not sure what to use for the diff. The Castrol Axle Z90 has been apparently superseded by Transmax LSD Z85w-90, which is rated GL5.
Still, I feel I have made good progress---thank you, Steve, Richard, Andy, John and Geoff for taking the trouble to assist.

#9 Re: Gearbox and lsd oil recommendation
Posted: Thu Jul 21, 2022 7:57 pm
by Gfhug
John, if that is what has taken the place of Z90 I’d go for it. You could always try asking Alan Slawson for his up to date advice.
http://www.ajsengineering.com/
Geoff
#10 Re: Gearbox and lsd oil recommendation
Posted: Thu Jul 21, 2022 8:24 pm
by mgcjag
Hi John...the diff isnt fussy....as per Jag spec EP90.....if you have lsd....then EP90 with lsd addative... you can get plenty if different oils with addative already in .....have a look at Morris.....easy to get and they have a great technical helphine if you need it......Steve
#11 Re: Gearbox and lsd oil recommendation
Posted: Tue Aug 09, 2022 9:04 pm
by colinevans
Hi John
When Alan Slawson rebuilt my diff last year he recommended Castrol Axle Z limited slip 90.
Regards Colin