Why oh why?? Help before I lose all my hair!!! Tranny issues!!!

[Dznutz70]

Why oh why? I think that this problem is giving me a brain anurism. Now here's whats happening. 89 Blazer 700R4, the tranny pan seemed to be leaking so I replaced the gasket that lasted a couple 100 miles and started again.

I figure ohh the pan must be warped. So new derail pan put it on drive it around still leaking. It seems to be only after driving and put under load and heat and ya. I let it idle in the driveway for 10 mins and no leak.

It is coming from the back of the pan by the driveshaft. And by the front of the pan. Please oh please help me. It is not coming from the pump seal. Pulled the cover and its dry.

Please give me any ideas I don't care, it could be anything even swap in a SM465 I just need some answers to why.

I would like to express my deepest apologies for not making any sense in this post.

Thank you, Danny

 

[WhiteWhomper]

Are you sure that it is comming from the pan and not from the tranny cooler lines? When they leak at the tranny, the leaking fluid will run from the edge of the pan appearing to be comming from the pan.

 

[Dznutz70]

I took a good look at the lines and they seem to be fine. I cleaned them off with brake cleaner and they stayed clean for a while. I am going to take a look at them again just to make sure.

 

[YtseJam]

You didn't put RTV on the gasket did you?? Make sure you didn't over tighten it either. It's not over full and venting is it? If you are sure it is the pan try a cork/rubber gasket

 

[BILLY RAY]

Hey man make sure it's not coming from the vent tube on top of the trans. My buddy have a trans (700r4) that leaked out of the vent hole while driving only with a load but not at idle. The problem was the torque conv.

Hope this helps /forums/images/icons/tongue.gif /forums/images/icons/grin.gif

 

[95 Silverado]

if the tranny cooler is plugged it will build pressure and force the fluid out the breather or maybe the fill tube, if the breather is plugged it can build pressure inside the case and force it out the gaskets or seals. some 4x4's have a hose on the breather that is attached to the firewall to keep it from getting water in it, be sure it is not pinched.

 

[Grim-Reaper]

Pull the inspection cover off the bell housing. Look around and see if you got any fluid in there. Might be the seal for the pump went. It will dribble right down the front of the tranny under the bell housing and look like the front of the pan is leaking. It could follow the pan lip all the way around and give you a few drips at the back. While idiling the fuid level in the pan drops. when you shut it down some of the fluid comes back out of the converter and the level raises. It gets highening in there that it is deeper than the pan and part way up the back side of the pump . If it leaks over night that would be my guess. Also the pressure under load and the pressure at idle are two different things. THe seal may hold pressure idling but once your under load the pressure might be pushing past the seal. It's not uncommon for the bolts that hold the pump on to strip out the threads into the aluminum housing. A good tranny shop will helicoil any questioanble threads (and there is usualy one or two that will be bad when it comes time fore a rebuild). The pump could be coming out if the threads are stripping.

 

[Dznutz70]

Just got back from picking up dinner and it seemed to be dry under there. I tightened the pan bolts more before I left. I already dropped the inspection cover and it was dry.

So I hope it is fixed. I inspected the seal for the filler tube and that seemed to be okay. All above the pan looks to be dry so I am ruling out the overflow tube. The truck only leaks after being driven. Not a drip if I dry it off and then let it sit overnight only after I have driven it and everything warms up.

 

[newyorkin]

Check your dipstick tube seal, too. I drove 150 miles on the truck and spent a gas stop underneath tightening the pan because it looked so much like it was leaking. It turned out to be the grommet on the dipstick tube, when it finally got real bad it became obvious whee it was coming from. If my site ever comes back, I have pictures there.