I have this '97 Jimmy, 4 wheel drive, 4.3 engine, automatic trans. This thing is going thru tranny fluid as if there is a leaky modulator. I see no leaks under it, though, and looked today at Advance for a modulator, and it says this doesn't use one!!!

Anybody familiar with this problem or a possible cause of this massive amount of consumption? It gets to the point that it is causing the engine to run rough so it's got to be getting sucked into the engine thru some means??

Thanks for all your ideas.
Mike

 

Check the coolent for color. Also look at the color of your trany fluid (smell, color, thickness).
also check the fill plug for the T-Case. If the rear trany seal is bad it will pass into the T-Case.
If you are leaking via the trany cooler (runs threw the radiator) then you should have discolored coolent.

easy fix, cap off the trany cooler at the radiator, install an external trany cooler.
recomended fix, replace the radiator.
T-Case
Drop the T-Case and replace rear seal for trany.

 

Actually the rear of the trans has no seal, the t-case has the seal on the input shaft. Otherwise MNHawk hit it right on the head!! Korey.

 

Check your engine oil too.

If it is leaking into the radiator, You may need a new radiator.

I would install a new radiator, and not use the tranny cooler in it. Instead, I would use an aux cooler and cap off the tranny cooler in the new rad. Get the tranny flushed and the engine coolant flushed.

I have anaux tranny cooler in front of my rad inline w/ the factory system. Swartkk invited me over last winter and we installed it in his dads' heated barn.

 

If none of the above find the missing fluid. You may ahve a leaky gasket. Look for tranny fluid on the bottom side of the truck.

Word of caution, when you take out that top plug in the t-case, have a catch can ready. If your fluid is going into the t-case it will gush big time. Hopefully the fluid has backed into your vacuum lines, and then into your HVAC controls. that gets to be a mess to fix.