Thread: Defender gearbox oil.

Yep it does depend on your driving...
i had a Volvo with a Chev V8 and Volvo 4 speed.
smashed 6 boxes, then worked out why i was killing them. adjusted by driving and they survived.

I was just investigating the whole gear oil thing this week as I'm rebuilding the LT77.

Castrol make an MTF suited to the R380 for Land Rovers and MGs. Penrite also make a Manual Gear Oil 75 (75-80Wsynthetic fortified) specifically for the same application. I just bought 2.5 litres of the Penrite oil for $16.

Heavier oils don't flow well through the oil pump and galleries in the gearbox.

In the past I had tried the Penrite Light Gear Oil (80W) and even driving Melb-Perth, the box still felt sticky and the oil was too thick. Since then I've run on Synthetic ATF, but I'll now be trying the specifically made Manual Gear Oil 75.

Information on this oil is available on the Penrite web site.

Penrite always had 2 MTFs lite and xtra lite, 75 is what used to be called extra lite, works fine in these boxes

Originally posted by Michael2
I was just investigating the whole gear oil thing this week as I'm rebuilding the LT77.

Castrol make an MTF suited to the R380 for Land Rovers and MGs. Penrite also make a Manual Gear Oil 75 (75-80Wsynthetic fortified) specifically for the same application. I just bought 2.5 litres of the Penrite oil for $16.

Heavier oils don't flow well through the oil pump and galleries in the gearbox.

In the past I had tried the Penrite Light Gear Oil (80W) and even driving Melb-Perth, the box still felt sticky and the oil was too thick. Since then I've run on Synthetic ATF, but I'll now be trying the specifically made Manual Gear Oil 75.

Information on this oil is available on the Penrite web site.

The MTF94 is easily obtained through caltex/ampol servos etc (although you may have to push them a bit to look it up on their system) I bought a drum late last year @ $120 for 20 litres it was delivered to the servo within an hour.


Bushie

Just thru in some Redline MTL and went for a quick drive, 2nd seems a bit worse when cold but otherwise the rest seems as good if not better, will see how it feels when I get a few more miles on it with the MTL in it.

Well with a few more miles on the box with MTL, I`ve come to the conclussion that 1-2nd is definately worse when cold, but the same as it was when hot, and all other changes are definately quite a bit better hot and cold.

We`re off in it for a couple of weeks on a decent trip and hope with a few thousand more clicks on the clock 2nd might improve a bit more.

Well after clocking up 5000 kms with MTL in the box its all still the same 1-2 is worse when cold but otherwise it is an improvement everywhere else, nothing radical just a bit smother in the change.

All in all, after spending $35lt I dont think I could justify the money for the slight improvement in change, but I do hope it helps preserve the life of the box in the long term.

Hi Col,

just copied this from a Redline brochure.....

<div class='quotetop'>QUOTE</div><div class='quotemain'>In transmissions which recommend Dexron
or Mercon fluids we recommend our D4 ATF which is
very similar to the MTL, being a GL-4 Gear Oil also. The
D4 ATF will provide better low-temperature shiftability,
and the MTL would provide better wear protection for
racing use. [/b][/quote]

Note that most nearly all other ATF's don't meet SAE GL4 gear oil specs, so you should be improving the life of the trans dramatically.

I've had a few mornings where the 1-2 shift has baulked badly with my MTL/MT90 brew, to the extent I've had to stop and start over. Never had this happen, IIRC with Syntrans.