LT77 Gearbox - What Oil?

[v8s4me]

I have heard this stuff is supposed to be the mut's nuts for the LT77. Has anyone any experience of it and how it compares to a semi-synthetic 75w/90?

[v8s4me]

TV8 said:

..... Synchro crunch when very hot without it and not afterwards.

I get occasional synchro "notchiness" from 4th to 5th when very hot and high revs, so this is good to hear. Thanks.

Is it possible to drain the gearbox without a ramp, and am I going to need one of those big syringe things?

[v8s4me]

bluezeeland said:

I got this, works a treat;

http://www.amazon.co.uk/TRIXES-Siphon-Water-Liquid... £55, damn you

If that is what a decent one costs, I might as well pay a garage half an hour's labour. After I've changed the oil it will just sit in the garage cluttering up space for a couple of years until the next change, and then I won't be able to find it

Thanks for the tips gents

Next question then; the Steve Heath book states the oil capacity of the LT77 as 2.5pts (1.42lts), but on the back of the Difflock bottle is says 3lts, over twice as much. So which is it?

Edited by v8s4me on Thursday 18th February 19:38

[v8s4me]

The Steve Heath book states the oil capacity of the LT77 as 2.5pts (1.42lts), but on the back of the Difflock bottle is says 3lts, over twice as much. So does any one which it is?

At those prices, I don't want to over order.

[v8s4me]

stevoj said:

...Whichever way you go its is recommended to flush out after dropping the old oil with a mixture of engine oil and white spirit/paraffin.

What about diesel?

[v8s4me]

I've bought one of the Screwfix enema kits and the Difflock is on order. There is a large hex-head plug at the bottom of the gearbox casing; can i use this to drain, or is this holding something important in place? It seems a bit big just to be a drain plug.

[v8s4me]

carsy said:

.... Make sure you can get the filler plug off first though.

It's putting up a fight!

[v8s4me]

Number 7 said:

Should only be done up to 26 lbf ft - and its a taper fit.

It seemed to be much tighter than that! I finally got it out with a 1/2" - 3/4" adapter and a big spanner. The drain plug was OK so now just wait for the oil to turn up.

Edited by v8s4me on Saturday 5th March 15:31

[v8s4me]

honestjohntoo said:

Don't forget the radical flushing process:

• With the car on axle stands and the back wheels off the ground drain the box and re-fill it with a flushing mixture of 2:1 White Spirit and ATF.

Many thanks for the tips, very helpful. I don't have any ATF in the garage but I do have plenty of semi-synthetic 75W90. Can I use that to flush instead? And just to clarify, you mean 2 parts white spirit to 1 part oil?

Do you know if I can I add Molyslip Gearbox Treatment to the Didfflock?

Thanks

Edited by v8s4me on Sunday 6th March 10:44

[v8s4me]

Gearbox oil.

I've just replaced the speedo sender/transducer and it seems to have the same issue as the old one ie no reading until the gearbox oil gets good and hot. I thought the problem lay with the sender so I replaced that. I've also repaired a wiring fault and re-routed the wires to keep them away from the worst of the heat from the exhaust and sharp edges on the casing. Still the problem persists though. Any ideas?

[v8s4me]

The gearbox has been flushed and refilled with the new Difflock. On a short 12 mile drive today the first few shifts from 1st to 2nd happened without any of the usual baulking and crunching, and only a little bit of stiffness, which went once the oil got warm. Shifting through the ‘box seemed smoother as well and I got the impression that this will improve as things get hotter on a longer run. So all in all, a worthwhile improvement.

However, the speedostill won’t read until the oil in the ‘box is hot! I've fitted a new speedo sender (probably unnecessarily), thoroughly checked wiring up to where if goes behind the dash (I’m not taking that off again!) and fitted new connectors. So what is going on here then?

[v8s4me]

This is a very old thread and there is much more up to date information on here if you search. But to save you the bother, get that ATF dog pss out of there as quickly as possible and replace it with DiffLock

[v8s4me]

If you run a search on the 'S' Forum you'll find some good alternatives to Difflock. But what's the problem with a two week order time? You won't be doing that many miles between then and now will you?

All I can tell you is that when I changed to Difflock it was like having a different gearbox, and a much nicer one too.

[v8s4me]

Belle427 said:

Difflock Oil turned up today and what surprised me is that it’s in a re labelled Fuchs lubricants bottle and is red in colour. Looks like ATF to me. I doubt this stuff is blended especially for them but may be wrong.

Don't be fooled by the colour; it's not ATF.

[v8s4me]

Did you use it for long enough to get the 'box good and hot?

[v8s4me]

How many miles had you done on the ATF?