Slight gearbox noise - worrying.

congo181 · Jun 21, 2022

Driving home from a successful MOT and I noticed a slight screech coming from I think a gearbox but only when off load.
Just done a full rebuild but the boxes only had an oil change - it’s been standing since 2008.
It sounds like it could be a bush spinning. Any ideas where I should start looking? I don’t want to wreck it.
What’s would be a good sequence of things to determine the cause?
Cheers, Jim
It’s a 1987 110 with an LT77, LT230 and a 2.5NA 12J. I have fitted a LOF clutch with a new spigot bush.

Hicap phill · Jun 21, 2022

Mine was a transfer box

Check fluids

congo181 · Jun 21, 2022

Hicap phill said:
Mine was a transfer box
Check fluids

Check them for what Phil? Level and metal glitter or something else?
I used EP90 in the transfer.

tottot · Jun 21, 2022

Put the high/low in neutral and then start and run through the gears. Still a noise you then know it is not in axles, shafts and hand brake.
"Check them for what Phill " For oil I recon,

Hicap phill · Jun 21, 2022

congo181 said:
Check them for what Phil? Level and metal glitter or something else?
I used EP90 in the transfer.

Sorry check fluids could mean you need more beer….
But as it’s a landy… oil ep80 inthe transfer box.
You can drain these and take the large inspection cover off
(Mine ate the bearing race so was easily found)

Brown · Jun 22, 2022

About how many miles do you suppose the box has done? I have an R380 in mine rather than an LT77 but the noise was starting to get rather scary at 135,000 miles so I popped a reconditioned unit in. Since then it has been much quieter. The symptoms with the old one were that it was very noisy on the overrun - taking your foot off the accelerator meant that the racket increased dramatically. So much so that I got into the habit of pressing the clutch down as soon as my other foot came off the accelerator, which made it a little better. Also, if it's gearbox wear it might well be a bit quieter in 4th, because there the input and output shaft are latched together. The gears are all going round, of course, because of synchromesh, but the worn items are not taking any load. I'm pretty sure this will be the same in the LT77 as it was in the R380.

congo181 · Jun 22, 2022

Brown said:
About how many miles do you suppose the box has done? I have an R380 in mine rather than an LT77 but the noise was starting to get rather scary at 135,000 miles so I popped a reconditioned unit in. Since then it has been much quieter. The symptoms with the old one were that it was very noisy on the overrun - taking your foot off the accelerator meant that the racket increased dramatically. So much so that I got into the habit of pressing the clutch down as soon as my other foot came off the accelerator, which made it a little better. Also, if it's gearbox wear it might well be a bit quieter in 4th, because there the input and output shaft are latched together. The gears are all going round, of course, because of synchromesh, but the worn items are not taking any load. I'm pretty sure this will be the same in the LT77 as it was in the R380.

It’s done 95k miles and I’m sure both boxes are genuine.
I have a feeling the transfer may have the very low ratio gearing but I’ll have to check the serial tomorrow.
I went for another drive today and the noise seems less severe so fingers crossed. I’ll check the drain plug magnets tomorrow too.

Brown · Jun 22, 2022

congo181 said:
It’s done 95k miles and I’m sure both boxes are genuine.
I have a feeling the transfer may have the very low ratio gearing but I’ll have to check the serial tomorrow.
I went for another drive today and the noise seems less severe so fingers crossed. I’ll check the drain plug magnets tomorrow too.

Well, one would hope for a little more than that from a gearbox, but I suppose when things are nearly 100,000 miles old, there's going to be some evidence of wear and tear. If it's quieter in 4th that suggests the primary gearbox rather than the transfer box. But all kinds of things can make a difference - speed, temperature, how clean the oil is, whether you're accelerating or decelerating and so on.

payydg · Jun 23, 2022

congo181 said:
Driving home from a successful MOT and I noticed a slight screech coming from I think a gearbox but only when off load.
Just done a full rebuild but the boxes only had an oil change - it’s been standing since 2008.
It sounds like it could be a bush spinning. Any ideas where I should start looking? I don’t want to wreck it.
What’s would be a good sequence of things to determine the cause?
Cheers, Jim
It’s a 1987 110 with an LT77, LT230 and a 2.5NA 12J. I have fitted a LOF clutch with a new spigot bush.

do you have a cross drilled input gear or oil feed plate? If not definitely check the state of the input gear and main shaft splines.

congo181 · Jun 25, 2022

Well I’ve now done about 15 miles and the noise had gone.
I’ve not yet checked the transfer for a cross drilled shaft, but it’s on the list.
One thing I’ve noted though is the lack of speed! Wow it’s slow.

Brown · Jun 25, 2022

congo181 said:
Well I’ve now done about 15 miles and the noise had gone.
I’ve not yet checked the transfer for a cross drilled shaft, but it’s on the list.
One thing I’ve noted though is the lack of speed! Wow it’s slow.

Had it got slower recently or has it always been like this? If it's a recent development could this mean that something's binding?

congo181 · Jun 25, 2022

Brown said:
Had it got slower recently or has it always been like this? If it's a recent development could this mean that something's binding?

I’ve only done the 20 miles in it since I’ve had it.
I got it as a non runner (clutch) a year ago, and once I’d got the engine out I couldn’t stop myself. So not got any history to compare it with.

Hicap phill · Jun 25, 2022

congo181 said:
I’ve only done the 20 miles in it since I’ve had it.
I got it as a non runner (clutch) a year ago, and once I’d got the engine out I couldn’t stop myself. So not got any history to compare it with.

I used to always drive slowly round maidstone… I hated the 1 way route & I would always make sure I could stop at marinos chippy on way home.
Speed is not needed as your always at the front of the queue

Zed. · Jun 25, 2022

congo181 said:
One thing I’ve noted though is the lack of speed

its a Landrover....

Rich.

payydg · Jun 26, 2022

congo181 said:
Well I’ve now done about 15 miles and the noise had gone.
I’ve not yet checked the transfer for a cross drilled shaft, but it’s on the list.
One thing I’ve noted though is the lack of speed! Wow it’s slow.

Check that input gear mate. If it’s not it’s just a matter of time until the main shaft splines fail and then it’s a new gearbox. You can replace the gear or fit an oil feed plate very easily.

Slight gearbox noise - worrying.

congo181

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Hicap phill

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tottot

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