Gearbox fluid

[burnhampm]

I have a 2004 LR Defender 110 and need to replace the gearbox fluid - I have the workshop manual but cannot figure out the exact technique for refilling the oil once I have drained it. Any and all help is greatly welcomed

[antichrist]

Manual or automatic?

[burnhampm]

its a 5-speed manual

[antichrist]

Originally Posted by burnhampm

its a 5-speed manual

If I'm not mistaken that would be an R380 in the 2004 Defender. The fill plug is on the right side of the housing, about 1/2-2/3 the way up. It's a Torx 55. Just remove that then remove the drain plug. Let it drain, refit the drain plug, then fill it until fluid starts to run out of the fill plug. Refit the plug.
Make sure there isn't any gunk in the fill plug socket so that your Torx bit fully seats.

Land Rover orginally spec'd ATF for the R380, but later released a TSB stating to use Manual Transmission Fluid (which is a lighter weight than typical gear oil). I've been using Redline MTL. Whatever you use, make sure it's only GL4, not GL5.
A lot of people use it and swear by it.

[TerryS]

Originally Posted by Disco Mike

Something in the 75W to 90W range unless you want to go H.D. and use the 85W/140 which could also be used in both diffs.

NEVER use gear oil in either an LT77 or R380. The internal oil pumps can not pump the stuff and the drive is fragile enough, it will likely break in very cold weather. I swithched to MTF, and went back to synthetic ATF, because the first/second shift got clumsy again.

[burnhampm]

Thanks - have been trying to track down the right gearbox oil. the manual stipulate MTF-94 but that is hard to find. Just a few minutes ago, I found another site that stated "synthetic MT75D" was a better oil to use in the gearbox. Lately on both of my defenders (2004 90 & 110) the transmissions have been making strange sounds - much like some type of hydraulic pump that is running dry. It is bad on startup but goes away when the vehicles are warmed up. Also, on my 90, there is a problem with the gearbox/clutch. I will put the vehicle in reverse and then for some reason the clutch seems to fail. I have to take my foot completely of the clutch and then and only then will it work. I am feraful that there is a problem with the clutch. ANy thoughts?

Thanks

[TerryS]

Originally Posted by burnhampm

Just a few minutes ago, I found another site that stated "synthetic MT75D" was a better oil to use in the gearbox.

Was this a Land Rover site, making a reccomendation specifically for the R380?

Originally Posted by burnhampm

Lately on both of my defenders (2004 90 & 110) the transmissions have been making strange sounds - much like some type of hydraulic pump that is running dry. It is bad on startup but goes away when the vehicles are warmed up.

That is just what happens, especially in cold weather when an oil with too high a viscosity is used. The pump is cavitating, trying to pull an oil to thick. Either that or you're very low on fluid, but I don't think that's the case as you say it goes away when the gearbox warms up.

Originally Posted by burnhampm

Also, on my 90, there is a problem with the gearbox/clutch. I will put the vehicle in reverse and then for some reason the clutch seems to fail. I have to take my foot completely of the clutch and then and only then will it work. I am feraful that there is a problem with the clutch. ANy thoughts?

Thanks

I am not entirely certain I understand what you're describing. It could be a hydraulic problem in your clutch master/slave system, or possibly a clutch disc problem. It doesn't sound like a gearbox issue though.