HZJ 75 gearbox noise, help...?

[billaloo]

Can anyone help. New to the forum and have a gearbox noise question. I have a 1990 HZJ 75 Troopy. Love it, had it for 10 years, wouldnt be without it. I recently had the gearbox rebuilt by a mechanic I trust. The issue with the original was a worn main shaft(?) Hell noisy 3rd gear. ( though still ran fine) I Got the troopy back after the rebuild. It Was like a brand new vehicle for about a week. Luxury! Smooth and quiet. Then 3rd gear became sticky, nothing major, just notchy. It didnt get any better so I Took it back, he dropped the box inspected it, played around. Said he couldnt find anything wrong, everything looked fine and the way it should but fine tuned it a bit. Reassured me that all bearings, seals etc had been replaced. I Got it back again, ran like new for a lot longer. I Trust his work and don't doubt him at all but I am now in Perth and my mechanic is 2600 ks from here. The problem now is that the gearbox is still fine when she's cold. But as soon as she's warm the gears are notchy. Especially 3rd. also at this time the whole box feels generally sloppy in 1st and 2nd and is noticeably noisy, Except when Im at cruising speed and I back off the excelerator ever so slightly. When its cold the box is quiet and smooth. On a really hot day after a big run i also find the clutch shudders a little, mostly in reverse. ( the clutch was obviously replaced at gearbox rebuild and with a heavy duty clutch) . My question is this : Is there a thicker oil I could use in the box that might help with the issue?
Any advice on the drama would be most welcome!
cheers
Billaloo

 

[Radd Cruisers]

Is your transfer case in 4WD or are your hubs locked and sticking?

Clutch shudder happens, but with freshly machined parts is should not be.

Cold, damp weather can lead to a bit of shudder until the clutch/flywheel warms up.

Are you engine or transmission mounts old? The "mostly in reverse" statement makes me think you should be checking them.

Thicker oil may actually make things worse. Stick with the factory spec. or use a synthetic for best results.

~John

PS: please update your profile with things like your location. It's helpful when pointing you towards help or others in your area who might offer assistance.

 

[alpinemechanic]

I agree thicker oil will dampen noise but will make notchy changes notchier! Tough call.
With regards to clutch shudder and gears hard to engage, this may just need to wear in especially if a real heavy duty clutch and very well machined gears

 

[billaloo]

Thanks for your thoughts guys, much appreciated!

 

[roscoFJ73]

Castrol VMX 80 is what I have used for for years with no shifting problems,so it should work in any H55F.

I dont know whats wrong with your box but Im guessing it will have to come out again.
It could be in the shifting mechanism in the top cover.

I use these guys,I think they are the best rebuilders and the most honest,
Belmont Gearbox and Differential at U 6, 89 Windsor Rd
WANGARA, WA, 6065
9408 0366

NOTE they are not in Belmont which is 20 klms from Wangara