H55F Tranny / T-case troubles

[Malahki]

Having an issue with my 1989 BJ74 manual Transmission pushing it's oil out and into my T-case and then out the T-case breather.

Discovered the problem when I seen an oil spot on the driveway after a long drive on a hot day. After pulling the fill plug on the T-case almost 2 liters of oil poured out before leveling off. Of course this meant the transmission oil was way low.

I've only ever been aware of the opposite problem where the oil goes from the T-case into the transmission and eventually overflows out the shifter housing. I had that issue when I first bought the truck and rebuilt the T-case and replaced the seal between the two cases. I also used the Terrain Tamer kit that connects the two fill plugs with fittings and a piece of hose, which allows any excess oil in the transmission to drain back down into the lower T-case fill hole via the connecting hose

So that was 50,000km ago and like I said its the T-case is overfilling.
Not the transmisiin. Has anybody experienced this? What's causing it? And what's it going to take to fix it?

 

[auclair]

check your t-case breather it is plugged

 

[Malahki]

As mentioned in the first sentence the oil is coming out my T-case breather so i am pretty sure it's not plugged. If it was I'd think it would pressure up and force the oil into the transmission

 

[roscoFJ73]

As mentioned in the first sentence the oil is coming out my T-case breather so i am pretty sure it's not plugged. If it was I'd think it would pressure up and force the oil into the transmission

Sometimes the oil travels downhill to the t/case,we've had a few do this on this forum. I havent seen a plausible reason why yet.

 

[crushers]

there is no rhyme or reason, the oil can flow either way.
the seal is gone again.

 

[Malahki]

Obviously I have no idea how long it took for that much oil to transfer over and it sucks that it's going that direction.

I'm thinking all switch to a clear hose on the filler plugs, so it'll be easy to keep an eye on the T-case oil level and just keep running it for a while.

Does anybody make a seal upgrade for it? Like Marlin Crawler does for the axles. I really don't want to keep dealing with this issue

 

[crushers]

more installation issue, i would say, you could run an equalizer hose and forget all about it.

 

[Malahki]

Equalizer hose as in between the two cases fill plugs like I already have as mentioned above?? Or are you talking about something else??

 

[roscoFJ73]

Does anybody make a seal upgrade for it? Like Marlin Crawler does for the axles. I really don't want to keep dealing with this issue

I think you've just had bad luck. Ive 4 H55F and never had a problem with the seal.

Ive had good luck with other seals by adding some auto trans reconditioning fluid to the oil. It softens the rubber but takes a 1000klms or so to work

 

[Malahki]

Thanks for the tip Rosco, I may try that in the future

more installation issue, i would say, you could run an equalizer hose and forget all about it.

And Crushers if we are talking about the same thing here, it's not so much of an equalizer as a tranny overflow line because it doesn't work when its the T-case overfilling like in my situation.

 

[crushers]

yah, i missed that in your original post. if it is over flowing at the t/case then you would think it would be at the tranny since it is supposed to work to equalize the levels ...
no advice now, sorry i can't help.

 

[Bluegrass40]

@Malahki ever figure this out? Was the seal damaged? I just rebuilt my xfer case and used a terrain tamer kit from cruiser brothers. Only have 500 miles on the truck. That seal seems really hard to instal incorrectly (other than installing backwards). Curious if you found the root cause in your case. Thx.

 

[Bluegrass40]

Oh. Btw. Mine is on a ‘78 40 series with stock cases so it could be a different setup. You probably have a split case. Mine is not.