Gearbox/transfer case oil levels

[Banjo57]

Hi All,
Heading down the track to Katherine next weekend to pick up a Disco and drive it back.
Put the Perentie up on the hoist to change engine oil an d have a good look before the trip.
Undid the gearbox fill plug and was covered in oil, it poured out!
I had only checked the levels (all topped up) in August before our Kununurra/ord river holiday.
My question is do the gearbox/transfer case share oil and is this normal for one side to be fuller? than the other?
Cheers

[Mick_Marsh]

Hi All,
Heading down the track to Katherine next weekend to pick up a Disco and drive it back.
Put the Perentie up on the hoist to change engine oil an d have a good look before the trip.
Undid the gearbox fill plug and was covered in oil, it poured out!
I had only checked the levels (all topped up) in August before our Kununurra/ord river holiday.
My question is do the gearbox/transfer case share oil and is this normal for one side to be fuller? than the other?
Cheers

As the seal between the transfer case and gearbox deteriorates, oil transfers between the transfer case and gearbox between the seal and the rotating shaft.
The best way to fix the problem is to rebuild the LT95.
The easiest way to make a work around is to install a balance tube between the gearbox and transfer case. I have done this on one of my LT95s.

Oh, your transfer case will be way down in oil.

[Banjo57]

Thank you Mick Marsh.
Any chance of a pic next time you are underneath?

[BEARMAN]

Hi Banjo, usually the reason you get the gearbox overfilled and the transfer case oil level low is because the transfer input gear and sleeve haven't been loctited onto the shaft when it was overhauled. The seal will most likely still be good.  Oil gets splashed inside the two holes of the sleeve and because it is not turning with the shaft, the splines of the shaft act like a vane pump and pressurise the oil inside the sleeve and it ends up in the gearbox. Using a balance pipe like Mick suggests will work but you can also fix it in situ without a box overhaul. It involves removing the rear cover and pto if you have a winch, then removing the input gear and sleeve and clean them up and loctite them onto the shaft as they should have been in the first place. Contact me if you want to do it and I can guide you through the process - all it takes is an afternoon and then you don't have to worry about that pipe between the 2 filler plugs

[Banjo57]

Thanks Bearman
I'm thinking that will be a job over the Chrissie break.

[fc101]

Thankfully I dont have the issue with my LT95 and have known about the pipe fix for a long time - however something that has not been discussed is - as both gearbox and tfr case use the same grade oil, and seem to have about the same levels - why not just remove the oil seal that separates them all together so that oil can flow back and forth like it does when the oil flows from the tfr case to the gearbox (past the oil seal) and back via the pipe modification.

Garry 

[BEARMAN]

Good question Garry, But I think the levels are different so you would end up with one higher and the other lower than they should be.

[fc101]

Yes your probably right but it clearly doesn't matter as the current work around with the joining tube basically ensures levels in both balance out and there is no evidence that lower tfr case levels causes a long term issue.

It would be interesting to hear from anyone who has done it.

Garry

[muddy]

  Brian
From memory on the civie LT95 there is a spacer on the output side in the gear box (on shaft ) that can dislodge unless pressure is applied to hold it in position (towards t/c)when removing the input gear to t/f (in t/f box )and must NOT allow the output shaft to move forward towards g/b . It is a PIA to try and reposition without taking lt95 out and stripping to relocate

[BEARMAN]

Yes, you have to select 3rd gear to hold the mainshaft from moving  forwards when you work on the output gear and spacer. A needle thrust roller bearing sits on a lip on the rear of the mainshaft with a thrust washer and it can fall off the lip if the shaft has any movement forwards when you have the gear/spacer off. You can get it back in place without dismantling the box but it can sometimes take a bit of time (5 mins - 5 hours)

[DMG]

I have found that a dab of weld in 2 places on rear end of tube to line up with splines, requires filing to fit nice does the trick.  Problem is originated by the helical gear that drives the transfer layshaft.  Thrust on power on, an backing off,  creates thrust wear on preload shims and allows tube to stay with seal as Bearman has said.  If we can keep the tube spinning with the shaft, problem is eleviated.  It seems, and is generally thought that if the tube can't spin with the mainsheet, it turns into an oil pump of sorts.  What we all really need is a a better way of holding the and output gear together firmly.   Like a nut and lock washer!!!!!

Dave