R151F clunk

[Belzedar]

There's a loud clunk coming from my gearbox when I take off in 1st gear. It's the r151f which I've heard isn't too strong (just found that out browsing ) and have seen a few posts saying it could be worn output shaft.
Can anyone verify that or throw in some advice?
Cheers

 

[roscoFJ73]

Are you sure its the gearbox? There is a few components that make clunks in the drivetrain. You are correct ,they are not the best. A gearbox mechanic told me usually they die in a number of places at the same time. They shift bad ,the bearings howl and they make clunks.
But i would look for other things like driveshaft spline being dry. Uni joints etc.

 

[Belzedar]

Yeah uni's are all new, driveshaft been off and is fine. All mounts are good. It's definitely inside the gearbox.
I was hoping for an easy fix (as ya do) but looks like the gearbox is coming out.

 

[876 Cruisers]

I have a kzj70 im not sure what gearbox i have but its a 5 speed. whenever i shift i usually hear a clunk sound too and im not sure where its coming from. i have all new universal joints and in order for me not to hear that clunk sound i have to ease up off the clutch very slowly. But to me it sounds as if its coming from in my gearbox as where my gearbox is, is where i usually hear it coming from.

 

[Belzedar]

I've got it down to input shaft or bearings worn. I've pulled the box out and am sending it off to get rebuilt. I'll post everything I find out on this thread ☺