LT77 gearbox

Johnny Rotton · Post by **Johnny Rotton** » Tue Dec 02, 2014 1:58 pm

Have LT77 gearbox in my Seight and this year it has started to develop a harsh grinding type noise in 5th gear. It is the kind of noise you get when the propshaft is out of balance. The harshness is only prevalent in 5th gear. Anyone else experienced this and know what is causing it ?

v8250 · Post by **v8250** » Tue Dec 02, 2014 6:23 pm

It's doubtful it's the prop', more like 5th gear issue. The easy way to determine is to remove the prop' from the gearbox end. Fire up car, go through each gear and listen carefully. Hopefully it will only be noise in 5th which means you can drop the 'box and get repaired.

Seight-V8 · Post by **Seight-V8** » Sat Jan 24, 2015 1:49 pm

The LT77 gearbox in my seight hasn't been much good even when I bought it reconditioned from rimmer bros many years back.

Second & fifth always whined......but 10 years later it still driver, was always noisy driving, so I fitted a small piece of rubber under the gearbox mount to stop the noise transferring to the chassis....

Been great ever since.....still don't like my the way my LT77 though.

I should think though grinding noises are not good from any gearbox, and it needs looking at.

As already mentioned drop the prop and put your car on axle stands then run the engine & gearbox and listen for any grinding.....if so looks like one for a reconditioning.

scott

DaveEFI · Post by **DaveEFI** » Sat Jan 24, 2015 3:40 pm

Big snag with some reconditioned boxes is they may just replace damaged parts. Sometimes with used but good from another box. And gears tend to sort of wear themselves in as a pair. So if one needs replacing because of damage they all have to be new to get a quiet box. Which makes for a very expensive re-con box.

SuperV8 · Post by **SuperV8** » Tue Feb 03, 2015 9:00 am

I have an LT77 taking up garage space. Took it out of My Dax Rush when I fitted a 4.6 and T5 Tremac. Let me know if your interested.

Tom.

bodger · Post by **bodger** » Thu Feb 05, 2015 10:05 am

I had a similar noise coming from mine a while back ...
Sounds like the circlip has come off and the 5th gear has moved off the shaft and being held on by the rear case ..
It stays there but makes a right mess of the oil pump

Seight-V8 · Post by **Seight-V8** » Sat Feb 07, 2015 9:15 am

My LT77 was like that from new....that was 14 years ago....just had enough of it and want something better....my blocks also cracked so new top hat liners for me.

So while engines out I want to change the gearbox, R380 is the easiest option, and T5 the most expensive and most work.

I was wondering if the daf/Sherpa/pilot R380 could have the ratios changed to the V8 at a reasonable cost.....anyone done this...

There's more daf/pilot ones knocking about than V8 ones, so would be easier to get one and convert it.

cheers

scott