hey guys , I've got a 99 blazer and it's blowing transmission oil out the vent tube , but only at high-way speeds it seems , what would cause this, anyone else ever run into this problem any help would be great .. and no its not over full . lol checked that , thanks Dwayne.

 

is it coming out the vent line for the transfer case? if so the transfer case is overfilled, due to a bad seal on the transfer case input shaft, causes the auto trans to put oil into the transfer case. its a $12 seal, theres also a gasket between the trans and transfer case, not sure what that costs, i had to get mine from a gm dealer. when i had oil coming out of my vent tube i took out the top plug on the transfer case. (fill/level plug) 4 qts came out! over double whats supposed to even be in the transfer case, ive heard of this causing transmission failure, the trans gets too low on fluyid and causes failure. and because the vent line is tied into the 4wd front axle acutator, you can also get atf in the vaccum lines, causing all kinds of issues with the hvac stuff..... so take out that top plug on the transfer case and see if oil pours out.

 

yup! that's the problem , went out to the garage and spun the plug out and she was way over full . thanks for the info , guess I'm dropping a transfer case, any thing else I should be looking for? is this job a pain In the *** to do other then dropping the t case , thanks again.. dwayne

 

the biggest pain for it with me was putting that case back up in its place, get a helper if you can. i had mine up in the air as far as i could with 4 jack stands. if it hasnt been done in a while, now would be a good time to replace the fuel filter, its alot easier with the t/c out of the way, i happened to have one on hand and was going to change it anyhow, was nice having extra room to do that.