I just changed my ATF after 12,000 miles and it started leaking from somewhere around the pan area. It is a Mag-Hytec Pan, and the allen head bolts have been re-checked and re-torqued for tightness. Piping coming and going are clean. It seems to be coming more from the drivers side of the pan. Is there a vent tube on that side? Oh, yeah, I notice it only leaks on my driveway, where it slopes from the front to rear of the truck. On flat pavement, no leaks. What gives? The ATF amount has all been checked and is all good.

 

O-ring on the shifter, seal on the TV dealie, OD solenoid plug are all just above the pan rail on that side. Any chance one of those is really where the leak is coming from?

 

Not sure, Dave. I crawled under the truck this am and flashlighted my way around. No leaks from the oil/water cooler under the turbo, no leaks from the in/out piping at the tranny(including piping to and from the tranny cooler by the grill). I see moisture surrounding from the adjustment for the rear( might be mistaken for the front) band adjustment bolt and some of the electrical sensor connections above the pan, bot that could be blow over from something else. I sure hope it is not the front pump seal. I changed my flexplate out back in May 08, but never pulled the torque converter from its mounting point on the tranny. I had the TC securely rigged for the reason of affecting pump seal. And even after the flexplate job, there were no leaks after that. Does anyone know where the vent tube is located? Maybe if I knew I could check that point also.

I do see moisture directly under the utmost rear of the oil pan flange, in the crevice upwards where the bell housing connects to the engine. Been that way for a long time. No drips from that. Just bugs me. Rear main seal is brand new when flexplate was changed out. My concern is the ATF drips.

 

Go to the car wash and let it have the engine bay cleaner everywhere under the engine and the entire transmission. Then pressure rinse the stinky out of everything VERY well. Top and bottom. If you're gonna do it right, you'd best wear some eye protection and cover-alls.

Then drive it around for 15 or 20 minutes to ~
- Air dry things if you will.
- Have "The Leak" present all by itself on the now clean underside.

As has been said, there's the seals of the OD plug, shifter & TV shaft, as well as both the heater/cool plumbing for the fluid on the driver's side. That forward of the plug and shafts is the fluid outlet. That rearward of the plug and shafts is the heat/cool fluid return.





There's also an O-ring seal for the dipstick (forward corner, passenger's side. Just above the pan).





Be sure to clean and check the little clips that secure the metal trans fluid lines as they go about the engine bay. With time and vibration, it's common for a hole to be "Worried" into something. Normal wind of travel will blow the oil back and can be confusing when sorting.

Also clean well the TC cover-plate. If there's a leak with the TC seal, it should present as fluid from the cover. NOTE: If you see anything from there, sort if it's trans fluid or engine oil.





~ If my memory serves me correctly, the transmission case vent is located in the pump cover-plate.

 

Nice post Dave!

 

Dave...you show off!!Why couldn't you have shown be "before" pictures of your rig before you tricked it out? Makes mine feel like my truck soiled itself!!

Nevertheless, I will take your advice.

 

It looks as though I have the same issue. Does anyone have a positive ID on the gaskets as far as Part numbers (or know of where I might find the information)?

How about the O-Ring for the dip stick; what size? Anything special?