TR8 LT77 gearbox help....?
Discussion
I have just completed rebuilding a TR7 V8. Having driven the car for about 50 miles, I now have an issue with the gearbox. LT77) It goes easily into first gear, then, when 2nd is selected, it goes in gear (noisily) but if I pull the stick further down, it starts to 'crunch' , this is the same when i select 3rd, and again if I were to pull the stick down it starts to 'crunch'. 4th and 5th are fine. I've read a lot about crap LT 77 boxes.... So is it a case of bin it and start again ! ??
You probably know this already but the LT77 (somewhat unusually) needs automatic transmission fluid rather than regular manual gearbox oil. I hadn't realised this when changing the gearbox oil on mine a few years back, and in particular it was 2nd that became most difficult to engage; changed it for ATF and immediately all was well again.
The bushes on your your selector extension bolts are probably shot, or disappeared completely. When this happens pulling back firmly, or pushing down on the gearstick, will bring the extension into contact with the tail shaft, or perhaps the CV joint/UJ which ever has replaced the original, which has probable expired by now too.
Replacement poly bushes are radially available, from the usual suspects, & are a fiddly but not technically difficult job to replace from under the car. Make sure you use the steel tube spacers in from the old, in the new bushes. [Note, some prefer to come down through the tunnel, but I find under the car easier].
As long slim fingers are helpful in this job, perhaps your glamorous assistant will do the fiddly bits for you, if you ask nicely, & supply surgical gloves to keep her fingernails clean. I find a written request, wrapped around some expensive trinket often helps.
Replacement poly bushes are radially available, from the usual suspects, & are a fiddly but not technically difficult job to replace from under the car. Make sure you use the steel tube spacers in from the old, in the new bushes. [Note, some prefer to come down through the tunnel, but I find under the car easier].
As long slim fingers are helpful in this job, perhaps your glamorous assistant will do the fiddly bits for you, if you ask nicely, & supply surgical gloves to keep her fingernails clean. I find a written request, wrapped around some expensive trinket often helps.
I disagree. This gearbox has a fiber oil pump that gets all chewed up when attempting to pump thick manual gearbox oil in cold winter weather. This is the only reason that Rover switched to ATF. ATF does not protect the gears. Only manual fluid will do that. I used FULL-SYNTHETIC manual tranny fluid for 20 years and had zero gear wear. And I never missed a shift.
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