weird transmission noise.

[killalux]

i have a bad noise in my hilux 5 spd (g52) gearbox, it is a load knocking type of noise in every gear when under load, and when decelerating it goes to a squeling type noise in every gear. the noise doesnt change no matter what speed it is doing.
does anyone have any suggestions as to what it may be.
cheers steve

[mick!]

I could take a huge guess and say that it might be a bearing, on the input of output shaft. It is very hard to say without hearing it though.
Have you taken it to a transmission or driveline specialist?

Are you sure its in the gearbox. Maybe it is a tailshaft centre bearing (if fitted).

Mick!

[beebee]

I thought I had a gearbox noise.......it was the diff

I worked that one out when it starded to go clunk.......clunk......bang!

[killalux]

its defenitly not the diff, the noise is still there with the transfer in neutral.
the guy from the transmission shop drove it and he has no idea what it is, so it is goin back on monday to have a better look.

[Gazzaj]

tell us about your rear end set up I`m about to get a solid axle swap and get my rear end flexing I talked to some one about how many leafs I can take out they said only 2 but looks like youv`e got only 2.
drain the oil in the gear box you might have got water in it

[Area54]

Sounds like a centre bearing related problem, the sound will come up through the shift boot sounding like the box. The centre bearing has two dust covers that cover the seal lips for the bearing. These dust covers are pressed onto the main shaft from the transfer, and onto the rear of the drive flange (same front shaft). When the isolating rubber around the centre bearing fails and collapses, these dust covers can bind into the rubber and spin on the main shaft/drive flange - these will squeal like a stuck pig - as the driveshaft continues to rotate and the dust seals remain fixed/embedded in the rubber. Simple fix in this case - new centre bearing, and a shim made out of a tin can, underneath the dust cover and press it back on the shaft/drive flange. The knocking will be either the driveshaft unis not liking the imbalance of non-parallel flanges (due to lower bearing) the uni at the rear of the transfer running in excess of 7 degrees (173 degree angle) misalignment with no correction, and the now flogged centre bearing jumping around in it's housing.