Pushing Oil from TCase to Tranny

[98 HOO]

1982 109"

The truck is pushing gear oil from the transfer case to the transmission. I can level them both, drive 100 miles and the transfer case will be low and the transmission overfull. I am thinking this is leading to the bigger oil spot on the garage floor as well. Just wanted to see if there is any suggestion on the simplest first attempt to repair. Do I need to pull the whole tranfer case, or can I replace the tranmission output seal with the t-case in place?
Thanks!

[mearstrae]

Check your vents on the trans and transfer, you may be building up pressure and forcing oil from one to the other and also causing an outside leak.

'95 R.R. Classic LWB
'76 Series III Hybrid 109
'70 Rover 3500S

[LaneRover]

we should swap either trannies or transfer cases because mine sends it from the transmission to the transfer case.

[TedW]

we should swap either trannies or transfer cases because mine sends it from the transmission to the transfer case.

Mine goes straight to the overdrive........I've never had to add to it.

[98 HOO]

Mine goes straight to the overdrive........I've never had to add to it.

You guys aren't giving me much hope... I will look for the vent lines. I pulled the drive shafts, the e-brake drum, and the bottom cover. Started to look a little intimidating after that.....

[TedW]

Make sure everything is vented - gearbox, t-case, and OD - that should stop most of the outside leakage, and then you are at least keeping your 90wt. on the inside...

[98 HOO]

I only see a vent for the overdrive. Are there vents already on the t-case and transmission that I am just not seeing, or should I install some? The vent on the OD is a simple hole drilled in the top cover. Can I do something similar with the t-case and tranny? Still think I have some issues with seals. When I dropped the front driveshaft, the space between the shaft and flange was full of gear oil. I can also see where it is leaking out the weep hold by the emergency brake.....Thanks again for the help.

[mearstrae]

There should be little 1/8 NPT fittings that look like buttons on top of the trans and transfer [the overdrive should have some sort of vent also]. There shouldn't be any holes open to the outside of anything [oil can get out/water and dirt can get in]. There may still may be seal problems, but the vents are essential. I have three on my LT95, trans/transfer/OD, that have long hoses leading up to the firewall, so water and dust won't get in.

'95 R.R. Classic LWB
'76 Series III Hybrid 109
'70 Rover 3500S

[98 HOO]

I don't see any vents. Picture of my setup attached - The yellow arrow shows the hole in the OD. It was there when I bought/installed the OD. I put a small hose to extend it up to the underside of the body. I don't see anything on the t-case. There is one bolt (red arrow) on the top - could this be it and someone has plugged it?

[TedW]

I installed Defender axle vents (the ones with the hoses) on the access plates of all 3: box, tcase, and OD.

On the OD I Drilled out the hole that the cotter pin goes into, and used the vent with the hose that exits from the side (so it doesn't interfere with the parking brake.

After you do this you will be able to clear that mung off and it won't come back (well, not quickly, anyway).

Just my solution to the problem - I'm sure others have successfully done things differently.

[luckyjoe]

I ran all three vents in series, so only one common line is routed to the engine bay. I also made baffles to sit below each vent opening (deflects oil in the OD and t-case). In ten years not a drop of oil has made it into the vent lines.

[98 HOO]

Excellent - Thanks for the advice - maybe this is good news. I will certainly try installing the vents before I pull the whole case. Might try to replace the front and back output seals while the shafts and brake is off.