I am in the process of replacing the bushings on the gearbox of my 1993 Plus 8. Whilst I have the gearbox exposed I thought it would be good opportunity to also change the gearbox fluid. Can anyone point me in the direction of how best to do this? Links to photos below.
FWIW, my '93 +8 has an LT77 box (actually, an LT77S - the last iteration of the LT77 box), and I believe yours is likely to be the same as mine. However, it is a Morgan.....
FWIW, my '93 +8 has an LT77 box (actually, an LT77S - the last iteration of the LT77 box), and I believe yours is likely to be the same as mine. However, it is a Morgan..... Dave
You get the prize, vbalddave!
YES, you have the last variant of the 2wd LT77, somewhat different than the more common 4wd in that the latter has a filter on a second drain. In other words their internals are the same, but the casing and draining, filtering, filling systems can vary, even within the same vehicle model as the LT77s kept changing as well. The correct choice of fluid is VITAL. LT77s have an internal pump which cannot deal with the regular manual gear oils. They quickly eat their own innards if not properly fed. (Don't ask how I know and quickly learned the importance of oil viscosity..as in 5 miles). That is why LR/Rover insisted on Dextron-3 a now discontinued (Ford) product. Dextron 3 was made for automatic transmissions, a red fluid that is much thinner than traditional gear oils, and something this internal pump can handle. Then Castrol TQF (from memory), rough shifting, then Castrol SMX-S (great!), also discontinued, and then Castrol Aircol PD 32, and then a fully synthetic Syntrans Multivehicle 75-90, most of which are not available outside the UK/EC assuming they are still available. In North America I used to use the oil specifically recommended for this box by Amsoil. But I changed my LT77s (3 +8s) to 3 2wd R380s over twenty years ago and stopped closely tracking LT77s and their recommended fluids. I am loathe to suggest anything for a sensitive box if I haven't tried it. But there are still 1000s of LT77s about on all continents.
There is no need for an elegant gear oil dispensing pump, though I can think of many other uses for it. It would actual better serve, carefully used, as a filler. Gearbox-wise such thing are they are used for single access systems. Did LR decided to block the drain by 1993? That would be sad indeed and a recipe for very Morgan and TVR dirty carpets. The LT77 casing casting came with many easy options for them to put in drainage or filling ports. I found my LT77s easy..as I do the more muscly and smoother R380s. And the 2wd LT77 is uncomplicated compared to its 4wd cousins shown above. Please note, that aside from their identical gear ratios, a 2wd LT77 and a 2wd R380, have nothing in common.
The videos are dealing with variants other than the one Morgan uses. VERY DIFFERENT. They look like earlier 4wd units from Defenders or other LR V8s. .
One first loosens the filler access (YOU DO NOT WANT TO DRAIN THE GEARBOX ONLY TO FIND YOU CANNOT OPEN THE FILLER!) then drains the box (no need to flush it) and re-fill it. Have a couple of liters on hand as it takes (again from memory) 1.6 liters, as your Handbook indicates IIRC.
It looks like my filler nut is square - see photo below. The drain nut appears to be the one with the splash of yellow paint on it. Please correct me if this is incorrect.
From memory the LT77 gearbox has reverse next to first gear, ie to the left then up. The R380 is below 5th, ie to the right then down. Easiest way to be sure but I'd bet your '93 has an LT77. I used Transmax in mine and it was fine, but then I've used standard auto trans fluid in my MGB V8 (LT77) and that was fine too. Again from memory the big hex nut is 36mm and a socket won't fit. Make sure you can open the fill BEFORE driving the oil.
2012 Plus 4 in Sport Green. Much comfier than the Plus 8!
There is no question it is a LT77, of the 2wd family and the final "S variant. That can be seen at a glance, Others have been posting pictures and videos of other earlier, [b]4wd LT77s[/b], which have been misleading for you and other moggers. The non-sd1 remotes are a give away. The R380 (a earlier version with an internal weakness only cured in 1999) only appear a year and a bit later. It looks different, , though it has the same remote, but the placement of reverse is ok if the box is not visible.
Originally Posted by David-Houston
It looks like my filler nut is square - see photo below. The drain nut appears to be the one with the splash of yellow paint on it. Please correct me if this is incorrect.
Of course, that is it. The filler nut is square on most LT77s and Allen key'ed with R380s. Nobody mentioned that?
[quote=David-Houston] I was planning on using Castrol Transmax (meets requirements for ATF+3, Dextron III H and prior). .
As I noted, I do not want to recommend a fluid without fresh research. I see nothing harmful in a Dextron compatible fluid, but that will merely produce the same notchy feeling shift, characteristic of the LT77. I am sure there are intrepid LT77 souls enjoying the much smoother feeling one of the fully synthetic M94s will provide. (the discontinued Castrol SMX-S was GREAT). So unless one knows how to read a a gearbox spec sheet and compare it....
The best in the world is Ashcroft Transmissions in the UK. I know the owner for many years, I will drop him a note to shortcut the need for direct research.
The best in the world is Ashcroft Transmissions in the UK.[i] I know the owner for many years, I will drop him a note to shortcut the need for direct research. [/i
SNIP from a personal email
Originally Posted by Dave Ashcroft
Hi Lorne, Hope you are well, We are still recommending a good ATF oil rather than the MTF94, Regards Dave Ashcroft
![[Linked Image]](https://i.ebayimg.com/images/g/tv4AAOSwhqhaDp9u/s-l1200.jpg)
That would be sad indeed and a recipe for very Morgan and TVR dirty carpets. The LT77 casing casting came with many easy options for them to put in drainage or filling ports. I found my LT77s easy..as I do the more muscly and smoother R380s. And the 2wd LT77 is uncomplicated compared to its 4wd cousins shown above. Please note, that aside from their identical gear ratios, a 2wd LT77 and a 2wd R380, have nothing in common.