May be a dumb question but have you looked at your pan, or changed the fluid and filter? I have seen a Blazer that got the pan a little banged up and it was just enough to press against the filter keeping it from circulating fluid. He had a similar problem. Blew fluid out of the vent tube and started a fire. Subsequently we changed his fluid and fixed the pan but the damage was done. His clutch plates are starting to come apart and his tranny is providing resistance from the engine to the wheels (feels like he is riding the brakes). He is already looking for another tranny and he is putting in a secondary tranny cooler when changing it.

I personally would pull the pan first and if you see **** in it then time for a rebuild or buy a reman tranny. Check all the lines to when out just to make sure there are no blockages.

 

Update to my transmission issue. I have purchased a replacement transmission and am in the process of installing it. I noticed that the fluid that I thought was coming out of the transmission breather was actually coming from the transfer case. I'm thinking that transmission fluid was being pushed back into the transfer case causing the fluid level to overflow. I should of checked it before I took it out. I'm going to replace the transfer seal while it's out. I'll keep you updated.

PS: Can anyone recommend me a good transmission temp gauge? Thanks.

 

Replacement transmission is installed and the transfer case seal has been replaced. I've just about got everything back together. I'll keep you posted.

 

I picked my trans gauge for the RX on line at bowtie overdrives - good people to work with

 

I purchased a MaxTow transmission temp gauge. I just got to get around to running the wiring and installing it after I get everything else done. I didn't realize yesterday that the gasket that goes in between the transmission and transfer case isn't available except from a dealer. I called AutoZone and the told me it wasn't available. I searched through the forum here and found a post about it. I'll be putting some RTV on it.

 

Not available? What? I just called advance auto to ask about that seal for my 97 and they said they have them in stock but there are both double and single lipped seals so I need to get mine out first to see which one I've got. (Thats just what the told me, about the input shaft seal).

Was I talking to the guy about the wrong seal? I don't see how any seal for something as common as that could be dealer-only?

 

there is a gasket between the adapter and transmission
4L60E , 4L65E, 4L70E Gaskets & O rings Transmission Parts

 

I've finally got the remanufactured transmission installed. While I had the transfer case off I replaced the transfer case input shaft seal. The original seal was hard and brittle! I test drove it this weekend and it works great! There must have been a combination of transmission and transfer case seal failure. Now I've got an auxiliary transmission cooler, inline filter, and MaxTow transmission temperature gauge.

 

OK,
I know this is a really old thread.
but i was having the same problem with the transfer case purging fluid out of the bleeder by the dipstick.
but the problem stopped, now when i'm going uphill at about 45-50 and i give it it little more gas it'll downshift then upshift almost immediately, then bog a little down to like 1,500 then back up to 2,100(normal).
then when i'm coasting to stop or slowdown the passenger side will start grinding. not sure if it's the cv axle or the transfer case itself.
it will stop grinding when i stop or if i engage 4-hi.(but i don't like to do that)
like something with the 4x4.
i'm not sure.
it also shifts hard into 2nd almost every time.
4x4 hi and low work fine with no knocking or grinding.
the first time it happened i was going about 80 on the highway and when i got off the exit, slowed down it started grinding.
hasn't purged fluid since.

need to know if a transmission replacement is the only way to go.

HELP!!