Chasing the rumble

[Robzilla]

Silly question but was it high range or low range in the video?

I recall reading somewhere that in high range the diffs won't fully lock up, or something like it uses the ESP system for traction (buggered if I can't find where I read that though so may be false). But that's what the video looks like, an ESP system trying brake/unbrake wheels for traction.

Or if the video was in low range, then yeh she's cooked!

Edit: was info like this (only someone else's comments from the interweb so may not be accurate)

My understanding is that as long as stability/traction control (ESP) is ON - - the brakes will intervene before the ELSD intervenes. With ESP in PARTIAL OFF, the brake portion of the traction control is less active and ELSD can actually engage while forward motion is maintained. When in 4LO, ESP is totally off and the only thing working is ELSD.
In summary...
4HI - ESP ON - Minimal impact of ELSD / Maximium impact of brake-based traction control
4HI - ESP PARTIAL OFF - Brake-based traction less active / ELSD more likely to engage
4LO - ESP OFF - ELSD only functioning traction control device

[Windex]

Yeah she was in low range, wasn't messing about on that creek bed

[Clarky]

If both are doing it I would even try another FDCM from a wreaker, they are plug and play, no programing required. I picked one up for $150 so cheap enough.

[Windex]

Originally Posted by Clarky

If both are doing it I would even try another FDCM from a wreaker, they are plug and play, no programing required. I picked one up for $150 so cheap enough.

Thanks for the replies guys, and Clarky I might just try that as who knows what trickery is going on in mine.

Well I've been able to do some diagnostics today and found a few things, firstly the rear solenoid was very gummed up, so I gave it it a good dose of brake clean and then some Inox. I was then able to cycle the solenoid duty cycle via Appcar DiagFCA (I'll post a vid late when I can get a helper), this allowed me to move the solenoid and repeat the cleaning process. Once I'd finished doing this I was able to open the solenoid with much lighter pressure (using a really small pick).

*Realized that since the video of me being stuck I'd swapped a second hand solenoid into the front diff so will have to monitor it in the future.

I took a few pics during the process just in case anyone is interested and if it helps someone in the future.








Getting back to the hunt for the rumble I think I've found it, to try and confirm the the pinion wasn't playing up I removed the rear driveshaft and have found that the front uni is loose but doesn't appear to have any play, but the rear has quite a severe notch in it like one of the needles have died. Hard to relay in video or pics but it definitely has a different feel over about 5 degrees of its movement.

[ren0vator]

Yep that uni joint is dry with flat spots
I had to get a new tail shaft manufactured for mine

You are right about the clutch pack solenoids
They are normally open i.e. let the oil drain through
Once clutch packs start to wear; time to replace the whole lot
You may be able to salvage the intermediates (steel plates)
but if there's surface erosion of dark spots pitch them out too

And remember Always put friction modifiers in LSD's.
electronic or otherwise

P.S. Rumbles are usually bearing related

[Windex]

Originally Posted by ren0vator

Yep that uni joint is dry with flat spots
I had to get a new tail shaft manufactured for mine

You are right about the clutch pack solenoids
They are normally open i.e. let the oil drain through
Once clutch packs start to wear; time to replace the whole lot
You may be able to salvage the intermediates (steel plates)
but if there's surface erosion of dark spots pitch them out too

And remember Always put friction modifiers in LSD's.
electronic or otherwise

P.S. Rumbles are usually bearing related

Thanks for the confirmation, thought I'd be up for a new one as the way they press the unis in

[Windex]

New driveshaft has been in for awhile now, had to get a new pinion flange so I could use a big serviceable Uni. Rumble is still there seems very much like a bearing rumble as many of you have suggested so I think I might bite the bullet and get the diff ratios done and new bearings throughout. Has anyone refreshed their clutch packs as seems like a good idea while its all open?