HZJ 79 series ute Gear box and transfer case.

Chris,

In some of the Toyota gearboxes if the seal between the gear box and the transfer box leaked, oil would be pumped from the transfer box to the gear box.

Now if you look at the transmission the transfer box is lower than the gear box and you would think that the oil would run from the gear box down to the transfer box. However it is pushed up because of pressure in the transfer box. The transfer box does not have a breather, unlike the diffs and gear box.

The transfer bow would empty and the gear box would fill.

Rather than pull the transmission out just to replace a seal, a hose was fitted to the filler plug of the gear box and also the filler plug of the transfer box. This allowed oil to flow between the boxes and even out. I got a hose from Pirtek in Penrith.They new what I wanted, had the right fittings, made it up on the spot and cost $6o.

You are saying that the oil level in the gear bow is down and the transfer box is up. This is opposite to what should happen, but the oil transfer problem that I have experience is with the 75 / 60 and some 80 series vehicles.

I would top up the gear box and drain the transfer box until you have the correct level. The transfer should be easy, just let it flow out the filler plug until is stops leaking, and fill the gear box until the oil just leaks out of the fill plug. Check the levels again in about a week. If there is a difference in the levels, one up and the other down, try the equaliser pipe.

Wayne

Like Wayne says, I wouldn't do anything yet. Just restore both to level and see what happens in 5000k or 10000k time. If there's an issue, buy one of those $50 hose setups that connect the two filler plugs.

The gearbox and transfer use the same oil - should be 75/90 or 75/85.

Ok thanks, i have topped the gear box and will check it in couple weeks. so if i just add this hose to both box and transfer case, i shouldnt have to pull down the boxes? I took it to my mechanic and he went for a drive. he said there were no signs of wining or funny noises. i dont really want to be pulling the boxes appart if i dont need to. regards
Chris

Go to Terrain Tamer or some 4x4 repairer and get the G/B Hose $65 , take out the two filler plugs and replace with the connecting hose ,It's a hose that allows the oil to circulate if that seal has leaked

I would be cautious about the above advice. This hose kit is used to allow surplus oil from the gearbox (which is higher) to drain back into the transfer (which is lower) The surplus oil gets into the gearbox through the faulty or worn seal between the transfer and gearbox via a sort of pumping effect of the mainshaft turning. What you have is low gearbox oil. How long had the vehicle stood before you checked the levels? Was it days or hours - this would give an indicator of how bad the seal is and how much oil can drain down through the seal when it is not moving. The seal may be too far gone for the hose to work which may result in gearbox damage due to lack of oil or the transfer seals may burst due to tooo much oil. I have changed this seal more than once on my old cruisers - you can buy a top quality silicone seal for extra dollars which should last longer. Fit the hose kit anyway as it is a good thing but find out what is really wrong first.

Chris, had you checked the levels before? could have been like it for a long time. Do the hose thing but make sure the hose is higher than your gear box filler or it will just drain into your transfer case. This should even out the pressure between them , no more problems. Worked with a old Hilux of mine, yonks ago.

Regards

TDB

Cobber, if you have a hdj79 the boxes are seperated and there is no way this can happen, even if it is a hzj79 the boxes are completely seperate....however, if you have a 1979 model, thats diofferent...the hose job is easiest and best...
Who has been playing with your gerarbox levels last...Toymota???

ERRR does that mean because i have a 2004 T/D troopie i won't have this problem?