My T-case just let go of a heap of oil, advice plz.

[Lugnutt]

I could use some advice on a transfer case/transmission problem that I experienced recently, thanks in advance for any help.

I've got a stock 1972 chevy 1/2 ton, short bed, 4x4 pick-up with the 350 auto trans and a 205 T-case. I had both of them rebuilt a year ago and then parked the truck and covered it with a truck cover.

This last month I found a guy who I wanted to drive the truck to for some bodywork and paint. It was a long drive, so with my wife following me in my jeep, we headed down the freeway. I only got about 20 miles when my wife called me to tell me there was smoke coming out from the bottom of my truck. When I pulled over I found the smoke coming from my oil soaked mufflers and oil leaking from the output shaft of my transfer case. I limped back home and when I parked it and turned the engine off, oil gushed out of the transfer case from the same rear output shaft.

I'm thinking that it must be a tranny/transfer case seal, but why would it gush out so badly when I shut the engine off? Do these transfer cases have breather vents that might be plugged? It was almost like it was being forced out under pressure.

The worst part is that the tranny shop that did the work last year (top rated guy, highly recommended), is now out of business. Another question is, once the seals are fixed, how do you get rid of all the cross contamination of the oils (auto trans fluid/90 wt gear oil)?

I hope some of you guys can advise me on the best thing to do and what to watch out for.

Thanks,

[71swb4x4]

It does sound like it was coming from the trans but have you confirmed that? Who filled them, is it possible the transfer case was overfilled and this drive it finally let loose through the rear seal?
Have you confirmed that it's trans fluid and gear oil mixed? Did you check the transmission fluid level?
Had you driven the truck before this time?

[SWB4x4]

My truck leaks all the Transmission fluid out too if it doesnt get driven for a long while as long as I drive it daily it doesnt leak I wonder if we have same thing wrong?how long did u say it sat for?

[Lugnutt]

It appears that the tranny fluid level is normal. I did check it while cool, but it was running and the fluid look and smelled normal. I pulled the plug on the T-case and nothing came out. I stuck my finger in itand down and couldn't find the oil level so it's low. There was a little left-over oil from the gush on the outside and it was clear/amber, though it seemed a little thin. It sure didn't look like 90w gear oil, though it's hard to say from just a drop. Also, when I backed the truck up so I could get under it, it had a slight growl to it that wasn't there before.

I'm thinking now that maybe the shop put the wrong weight oil in it when they overhauled it. It also sounds like I may have some damage inside the box. If I smoked the box, what would be a reasonable charge for another tranny shop to repair the damage to one of these?

Thanks for the responses

[Chevy1TonFun]

Someone correct me if I'm wrong, but if you are moving your truck with little to no gear oil in the t case then it should make some noise. NP205 t case are pretty tough and handle quite a bit of abuse. Try adding some fluid and see if the noise goes away. Replacing seal on a 205 are pretty simple.

[Lugnutt]

Well, I ended up towing my truck to a shop that specializes in trans, t-cases, and diffs. After removing the t-case he confirmed that it was originally filled with the correct gear oil (though I can't tell if it was over-filled) and the main problem was a failed rear seal. The rubber seal material completely seperated from the metal. I do remember, after the rebuild, driving the truck on one camping trip with friends that added about 500 miles, but then parked it for about a year; maybe the seal stuck to the shaft during the idle time.

The good thing is that the tranny apears to be fine and the t-case gears seem to be ok so with some new seals and new gear oil, i'll be good-to-go. I'm also taking this opportunity to have them change-out the rear diff carrier that's pretty much worn-out.

Thanks again to the three of you for your helpful comments and suggestions.

[Chevy1TonFun]

Awesome! I happy it was an easy and cheap fix for you!

[67chevy1series]

my dads 70 leaked ever since we got it in 02 and this year it did the same thing. it was the seal for the tranny and transfer case if a remember correctly. no leaks at all now