Oil leak between transmission and transfer case

Anyone replace the transmission output shaft seal and the transfer case input seal? Is this something that I can do myself or is it a difficult task?

 

We’ve got the same issue on a 1994 K2500 Suburban Diesel. Seal between transmission and transfer case is leaking. Both use the same ATF and the transmission pushes ATF into the transfer case. Diagnosed by pulling the fill plug and fluid will gush out.

I have a spare NP 241-C transfer case which I will rebuild and throw in when I pull the other case. The rebuild is rather simple and will include the leaking seal. So when I drop the case from the truck, I just throw the rebuilt one in. This is a back up vehicle, not a primary driver, so no rush to get the job done. Swapping the transfer cases will take about 2 hours. Rebuilding the replacement will take about 2 hours.

 

I hope this doesn’t end up being a big deal! If you have the means and willingness, it might be nice to try it yourself…and post the details of the job for when anybody else has to deal with this

Hopefully the only heavy lift will be the transfer case. Don’t think I would try if the transmission had to come down.

 

Took it into the dealer for service and they spotted this leak but they want $1200 to fix it. Wanted to see if it’s something I could do myself or if it’s something to just let them do.

 

Doesn’t look like a fun job.

 

Don’t know your mechanic abilities, but for $1200 I can do a whole lot stuff. The mechs at the dealers are not neurosurgeons.

 

I’ll crawl under my wife’s 4Runner tomorrow and assess the difficulty of the job.

 

Video on transfer case removal on an older gen 4Runner:

https://youtu.be/oZDSjlxl2Q4

 

I’m pretty mechanically inclined, I can usually do most of my work myself. Don’t really like paying someone to do what I can possibly do and maybe even better.

 

While I was at the dealer waiting for my T4R I saw a tech change a clutch in a Toyota 86 in 15 minutes. I assume they can change the seal in a T4R in less than a hour but will charge a higher flat rate.

 

I'd see if you can find some YouTube videos. Are you leaking transmission fluid, or gear oil? That could be a determining factor on how much fun it's going to be.

Being mechanically inclined, I'd say go for it. But, leave the weekend open, start Friday after work. If it goes well, you're back on the road Saturday. Otherwise, you have Sunday as a buffer. Make sure you have everything you know you need, and everything you think you might need.

Let us know if you tackle it, and then we'll all know better the next time someone asks.

 

Get assistance too. I’m guessing that transfer case is heavy. I had a friend years ago lose a finger when he was pulling a transmission out of a vehicle. It slipped or he couldn’t support the weight and it landed on his hand.

 

This is good advice! Losing a finger to save some cash is a bad deal.

 

Exactly!

 

Hmmm. Figuring out at what point a leak is a problem would be something I’d ask. My 2006 sienna had a some seepage on the transmission case…. I never even took it to the dealer under warranty because i was afraid they would butcher the thing and it woukd never be the same. I sold it 16 years later. Never any drips, just an area of seepage that stayed a little oily.

 

yeah fingers are expensive. Really though...I work with a therapist who specializes in hand therapy, I overhear a fair number of patient stories that start with either woodworking or mechanical projects. Best of luck. I'm pretty mechanically inclined too but not sure I'd tackle that.