LT77 output flange + oil query

sowen · Post by **sowen** » Mon May 14, 2007 8:45 pm

Does anyone know of a torque figure for a 2wd lt77 output flange nut? and should there be a seal between the splines and the nut/washer? The nut was quite loose when I took it off and there was no seal in the back of it. I was thinking of doing it up proper tight with a little sealant on the washer.

Would EP90 be fine to put back into it, as I've got lots of the stuff lying around for my landy. The box stank of EP90 when I pulled it all apart to clean it. If not I'll go on the hunt for some Castrol SMX or whatever its called.

Simon

Post by **katanaman** » Mon May 14, 2007 9:08 pm

My Haynes says 66lbf, EP90 isnt the right oil you can use ATF or or better use Castrol SMX. I would advise you to flush the box out before re-filling.

sowen · Post by **sowen** » Mon May 14, 2007 9:19 pm

I'm not going to use ATF as thats about as good as filling it up with water in my opinion. The box was cheap on Ebay because it crunched in 4th and 5th, turned out part of the input shaft to mainshaft bearing was lying in the bottom of the casing.

£10 worth of bearing and gasket later it feels excellent. I flushed everything out with avgas, inside and out to remove all traces of EP90 and bearing off the casing and gears. I'll try Halfrauds for some Castrol SMX, as thats what the guy I bought it off put into his replacement box.

The nut was definitely not half 66lb ft, as my monkey wrench made light work of it

Simon

ian.stewart · Post by **ian.stewart** » Mon May 14, 2007 9:51 pm

Assuming this is the right thing, "Driving flange to mainshaft" according to the Factory manual, and I quote,-----200nm---------20.4 kgf,m--------150ft/lbs

sidecar · Post by **sidecar** » Tue May 15, 2007 6:05 am

I use Redline MTL in my LT77, it seems very good. (Not the heavy shock oil). Their website has some interesting gumph on it

I agree about ATF

Pete

sowen · Post by **sowen** » Wed May 16, 2007 7:32 pm

I'm confused now, which is right, 66 or 150lb ft? What is the factory manual you've got Ian?

It may be worthwhile me buying a decent manual that covers the lt77 now, any suggestions on good-uns from anybody? I know theres a few variants of the box, as I've got 17a, 19a and 30a boxes stacked up in my garage, and certain parts are not interchangeable between them.

Simon

Geoff King · Post by **Geoff King** » Thu May 17, 2007 4:07 pm

This says 120ft/lbs http://www.landrover.ee/est/files/manua ... x/lt77.pdf

sowen · Post by **sowen** » Thu May 17, 2007 9:00 pm

Cheers for that Geoff. Thats exactly what I wanted, 120lb ft is what I'll go with, and I cleared the shelf of my local Halfrauds.............. of its single 1ltr can of SMX

Just gonna hunt for a 5ltr can of SMX to top up the little'un for filling my boxes with.

Simon

ppyvabw · Post by **ppyvabw** » Thu May 17, 2007 11:02 pm

sowen wrote:I'm not going to use ATF as thats about as good as filling it up with water in my opinion.
Simon

I may be wrong, but I think the reason why ATF is used is because the LT77 has a rudimentary oil pump. EP90 is too thick for it to work properly.

I don't know where I have heard that, but I know it should be ATF or similar. I haven't actually ever seen the insides of one, or studied the haynes manual in any depth either.

Am I right guys?

sowen · Post by **sowen** » Fri May 18, 2007 7:25 am

I guess you're right about EP90 being too thick for the pump to work, makes sense to me. I believe ATF was only specified for people who were having trouble with selecting gears when the gearbox is cold. The oil does get hot quick, and anyway, I drive slower for a few miles to let everything warm up before using the loud pedal, so that shouldn't be too much of a problem for me

I was thinking of EP90 because the gearbox I will be using is old, has an unknown mileage, and the guy I bought it off was getting 14 second 1/4 mile times, so its bound to need something a bit thicker between the gears to keep it quiet and help take up a little slack, not that it has much now

Post by **katanaman** » Fri May 18, 2007 8:19 am

EP90 will kill the syncro's of your box. It has stuff in it that attacks the brass they are made of. very old boxes that are supposed to use it are made to take account for this. EP is also completely the wrong lubricant for a gear box and doesn't help anything. Its meant for diffs and the like that has a different gear mesh system. If you want to use thick oil (not recommended) use a heavy single grade engine oil.

sowen · Post by **sowen** » Fri May 18, 2007 5:43 pm

Point taken Marki. That explains why my 4 speed rover box takes engine oil, while my land rover box takes ep90

I remember doing an emergency gearbox rebuild on my landy in the carpark at work a few years ago, got it all back together, before I realised that I had no ep90 to put back into it. All I had was a few litres of gtx in the back, so in they went.

The gearbox was howling away on the 10 mile run

to get some ep90 for it, but once switched back, hardly whines at all now

. Since then I've always kept a few cans of the stuff lying around.

Just need some more SMX to go into the box, and waiting for the new clutch plate to come through the post so that the box can at last go into my rover.

Thanks for all the input guys!

Simon