Hello all,

I have is an issue with the fluid leaking from the transmission, which I am certain is causing hesitation when first starting out. The sides of the transmission, rear of the bellhousing, are absolutely soaked in ATF. The oil pan looks wet. Everything behind the transmission is covered in ATF. But I cannot see where it is coming from. I don't have access to a frame hoist, and it's way too cold to be rolling around undernreath this thing looking for an oil leak. It must be leaking a lot of fluid, since it's gotten quite low and the truck seems to be bathed in ATF.
Also, I've been experiencing a neutral like situation when in gear when the truck is cold. I can start the truck, let it idle for a few minutes, and when I put it in gear it is almost as though the truck is in neutral. It will not move unless it revved up to about 2000 rpm. It only does this at first when it's cold, or after it has been sitting for a few hours.
I'm sure this hesitation is a product of the low fluid level due to the leak, but I thought I'd toss it out there in the event that it might be related. If anyone has any ideas as to what might be leaking that far forward and that high on the transmission, please point me in a direction to start looking.
As always, I do appreciate any and all advice.

Sean

 

The type of leak you describe is generally the main seal between the transmission and the torque converter. However, if the transmission if full and you are getting the cold start stall, and if you have been leaning on the power a bit and perhaps spinning out, etc., the OEM torque converter balloons and can crack quite easily or deform enough to blow the main seal described above.

If the transmission is low on fluid, and doing the stall, that would be expected as these units drain back into the pan and it takes a bit before they refill all the passages and the converter.

It would also be a good idea to check the transmission cooler lines and make sure none of those are leaking and blowing fluid on the transmission.

The best and easiest method to find any leaks is to have a pressure test performed.

 

The hesitation to move after sitting a long time is normal (sort of). The fluid drains out of the torque converter and needs to refill when you start to drive. If you want to test this warm the truck up in neutral. The fluid WILL be circulated in neutral but will NOT be circulated in park to fill the converter.

As for the leak - mine was leaking from the "shift shaft" where the shift linkage goes into the tranny. You might want to look there as well as the other places.

 

RCW,
I had leaned toward the torque converter/input shaft seal, i just didnt feel like pulling the inspection cover to take a look at it. I have personally never been hard on the truck (burnouts, brake stands, and the like), but I cannot speak for the previous owner. All of my problems started one day after a long hill climb in low gear and 4 wheel drive. I'll peel off the inspection cover and have a look.

Sidewinder,
The leak is located more on the passenger side than the driver's side. I also have a Transgo shift kit installed, so my converter charges in park. It was kind of neat to see on my trans temp gauge that the trans actually warms up along with the engine now while in park.

I am still open to any ideas here. I would like to get as many ideas as possible before I take it in and put it up on the hoist to poke around. Thanks again for all of your advice.

Sean

 

How many quarts low is it?

 

Without measuring it exactly... I would estimate between 3 and 5 qts. Pretty broad, I know, but I'm guestimating.

Sean

 

Check your dipstick tube where it goes in to the pan there is a rubber like bushing that the tube sticks into the tranny with. Mine came loose after a trans rebuilds and i had a bad leak for a while and thought was serious. Or second thing is you mentioned long climb in low gear up hill. The vent hole is inside of the bel houseing and if ur overheating it ir over filling it it will come out of the vent hole and leak out the inspection plate and make a mess. But that should stop and dry up if you drive it easy after that.

 

Check the lines where they go up to a cooler, under the exhaust manifold

 

Well, a tablespoon of an ATF leak goes a long way, so let us know how many quarts it's down when you refill it....

 

XLR8R,
I spent some time working with various oils and oil leaks on the sub... So, I know how a half gallon can look like 10 gallons when it's had a chance to "flow out". But, I was about 3 quarts low. I thought about it being the pan gasket, which I assume is where the question came from. But that would be way too easy, and I just replaced that. I'm going to have to put it up on the hoist and poke around a little.

On an aside; has anyone experienced a whirring noise, similar to a power steering pump, when the trans is low on fluid?

Thanks again

Sean

 

That's probably from the partially filled converter.