SJ Rockcrawler Noise...

[Big Jim]

So I took the Jimny for a spin today to test my rebuilt SJ transfer box with low ratio gears. Driving in 2H there is a pretty noisy whirring sound coming from the box.

Back at home I took off the rear shaft and ran it again in the garage in gear and the noise was there.

So I've eliminated the shafts themselves (the front is fine).

There are new gears through out and new bearings where required (not all). I don't have any experience with the SJ transfer case but I would be surprised if they're this loud! Does anyone know if it's the new gears bedding in, or something wrong - or is this normal?

Cheers

[QUADRACER]

what brand, calmini are really noisey.
is it under load.
or when you let your foot off the gas.

[Big Jim]

Thanks for the reply quadracer.

it's from Low Range Offroad.

It is louder with the foot off the gas

[UBZ]

did you shim the input and output shafts properly when the transfer was reassembled with the new gears ?

[Big Jim]

yes, I spent some time with the dial gauge getting that set up to within tolerances. A good thought though.

[BlakeJ]

what do you mean "shim them properly" chirs? i also have a slight, faint wine which is noticeable at speeds above 50kmph or when i just come off the gas. i wasnt going to worry about it as it isnt that loud but dont wanna f*#k it. I just used all the old shims in the same order as when they came out (the gold ones) as mine was a rocklobster not new gears.

[UBZ]

what do you mean "shim them properly" chirs? i also have a slight, faint wine which is noticeable at speeds above 50kmph or when i just come off the gas. i wasnt going to worry about it as it isnt that loud but dont wanna f*#k it. I just used all the old shims in the same order as when they came out (the gold ones) as mine was a rocklobster not new gears.

In the FSM is a procedure for shiming the Input and Output shafts . This sets the gear mesh up properly .
Basically you assembly the case with the gaskets and measure gap between the case half's . then add / remove shims to get the right clearance .

The last Rocklobster i did, diddn't need any extra shims from the factory setup .
A bit of nosie is normal as you asking allready worn gears to re-mesh with other allready worn gears .

yes, I spent some time with the dial gauge getting that set up to within tolerances. A good thought though.

Don't mind my dumb questions , they are a pretty simple transfercase.
What gear-set did you install? anything other than a 6.5 set uses existing gears . Might be a well worn gear not meshing well with the new ones .
Did you check / replace the roller bearings / spigot bearing on the counter shaft / output shaft?
other things i would check ,
Same noise in 2wd/4wd - Hi/Low range/ Neutral?
Does it rotate by hand with out binding / rumbling ?
In 2wd does the front drive shaft rotate freely ? the selector roll pins can bend and allow the 4wd dog gear to drag on the front output shaft .
Transfercase mounted handbreak setup dragging ?
Did you use the correct paired speedo drive gear set? there are several different ratios

other than that its pull it out and open it up for a look see.

[Big Jim]

I don't mind the "dumb" questions at all, it makes sure I haven't missed anything, umm, dumb..!

What gear-set did you install?
4.16:1 so it could be an interface

Did you check / replace the roller bearings / spigot bearing on the counter shaft / output shaft?
Yes - replaced those bearings.

Same noise in 2wd/4wd - Hi/Low range/ Neutral?
I'm going out there now to bend the selector lever so I can try the other ratios (just 2H at the moment)

Does it rotate by hand with out binding / rumbling ?
Yes, felt fine on the bench.

In 2wd does the front drive shaft rotate freely ? the selector roll pins can bend and allow the 4wd dog gear to drag on the front output shaft .
I'll check this, not sure - good call

Transfercase mounted handbreak setup dragging ?
Not applicable on this

Did you use the correct paired speedo drive gear set? there are several different ratios
Not applicable - took out the drive and blanked off.

Thanks, again.