Success

[TJ 450]

Right... now I know what I need to get. Then we'll see if it still makes the noise.

Tim

[Big_Richard]

Right... now I know what I need to get. Then we'll see if it still makes the noise.

Tim

better yet its only $26 from the states

purchasing the initial fill of LSD oil from the stealership would be preferable though, as postage on that would be ludicrous

Im doubtful the additive would even work with the generic, incorrect lsx-90 you have in your diff now, so you must replace it first

[wbrian63]

All "noise reduction" additives I've ever seen for LSD's are to quiet the clutches - they're techincally a friction modifier that prevents the grab-release-grab-release clunking noise that can appear during low-speed tight turning manuvers.

Obviously, if you can get an additive that quiets the noise, that would be nice. However, if the problem is caused by (as RonB and I suspect) an improperly pre-loaded pinion bearing, or a worn pinion bearing, getting rid of the noise doesn't get rid of the problem, and eventually, you'll do serious damage to the diff.

The diff's are very expensive to replace, but once set up right, are very durable.

I still vote for disassembly to check wear points on the gear faces, along with a check to see if the pinon bearing crush sleeve is properly set (it's a once-and-done affair - I think you can crush it further if it wasn't done enough, but if it gets over-crushed, your only option is to replace it). As for how this is done, I don't know, but if I remember correctly, shims are used between the pinon and the gear to set its position relative to the ring gear, and then the crush sleeve is installed to a certain torque value??? Then the ring gear/pinion gear relationship is further tuned with shims between the carrier bearings and the case, moving it to the left or right as needed to get the proper wear location on the face of the gears. Too high or too low on the face of the gears will mean a noisy and short-lived rear-gear.

You've worked really hard on this car. Now is not the time to try shortcuts.

Just my 2 cents...

[Big_Richard]

the setup proceedure is within the service manual on this site It could be printed and handed off to a differentil specialist and along with the diff to be setup for next to nothing.

Are you suggesting that a 6.9's diff should be completly silent? I've driven Tj's car and its barely audiable, I think he's making a mountain out of a molehill.

mine makes exactly the same noise, if not louder, but i have no back seat installed at the moment and mine has about 100,000k's more on the clock. It only started making it when i dumped the genuine oil and filled with LSX-90. Perhaps its a coincidence but i for one would rather put in the correct oil and see what happens first, rather than remove the diff yet again on a car thats rarely ever driven.

[TJ 450]

I'll certainly remove the diff again if it is required, but I will try the correct oil and additive first.

The only reason I didn't go down the path of rebuilding the diff was that the car has only done 224,000km and the internals looked excellent visually.

There was also no play at the input flange.

Tim

[Big_Richard]

you could always swap the diff out from nathans w114 250 and have a 3 second zero to 100 time, but redline at 120km/h

[nathan]

or i can give you a 4.88:1 rear G wagen diff...you will also be able to lock this, enabling 8 second quarter mile times!

[TJ 450]

That would be neck snapping!

Tim

[Big_Richard]

yeah, i can see this 5 litre g wagen project being the pinnacle of fuel economy.