Mechanics

TRANSMISSION LEAK

1991 Ford Ranger • 3.0L V6 2WD Automatic • 63,000 miles

Background: This truck sat for 5 years in a garage with absolutely no movement. I have serviced everything because of that. The truck runs & drives great under normal driving. I have put 10,000 miles on it since I purchased it & did that full service. Even in town & hills the trams temp never gets over 180 degrees typically running around 145 degrees in 60 degree weather. The other week when trying to pull an unloaded 6x9 utility trailer in mildly hilly area of southwest GA; 10-15 miles down the road from where I borrowed the trailer, the truck began to smoke & leak profusely from the bell housing. I had someone come w fluid & to pull the trailer back. After topping off the fluid & driving similarly as to how I drove with the trailer there was no more leaking. I have since tried to reproduce the problem with a transmission temp gauge installed thinking as light as it is the transmission was overloaded with the trailer. I have always driven it in overdrive; with the temp gauge I verified that it runs cooler in overdrive but builds heat fast when pulling the trailer & it downshifts for slight grades. When attempting the same rolling hills w the trailer in tow everything was fine until powering uphill and trans temp reached 195 degrees at which point the fluid began to pour out of the bell housing again. I know 195 is getting to the high end of acceptable temperatures but I don't think it should pour fluid out at that temp. After topping off the fluid and continuing to drive normally in lesser hills it was fine staying around 180 degrees. At home I verified that there was proper coolant & the radiator & trams fluid cooler were not filled with debris.
Please help?
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Clete43
January 4, 2014.




So no more leak now and you cant reproduce the leak?It was coming from the bell housing and not the dipstick tube where you fill it up?

Saturntech9
Jan 4, 2014.
With normal driving there is no leakage. When it happened the first time, after topping of the fluid, sitting there 30 minutes or so for someone to bring me transmission fluid, & unhooking the trailer, it took about 2 miles before all the fluid smoke stopped ( I think it was just the remaining fluid from before I shut it off). When I got home 30-40 miles later the fluid level seemed unchanged.
I was able to reproduce the leak & smoke but only by pulling the trailer up a 2 mile grade just steep enough the truck downshifted to 3rd while holding the throttle steady and getting trans temp to 195 degrees.
I was able to top the hill, let the truck up-shift back to overdrive, temp fall back to 180 and finish the 8 mile trip back home without any more smoke or fluid loss.
I have checked closely and the fluid is coming from inside the bell housing. It is not coming from a trans vent or the dipstick tube.

Tiny
Clete43
Jan 4, 2014.
Then the leak wasnt caused by the fluid getting too hot if the fluid isnt leaking from the dipstick tube. From what your saying sounds like the front seal on the transmission is leaking. Without getting in there its hard to say for sure.

Saturntech9
Jan 4, 2014.
Do you have any ideas as to why it hasn't lost a drop of fluid in 10,000 miles, or any more fluid since the two incidents. I put 800 miles on it yesterday & today with no more fluid leak at all. It only leaks when it reaches 195 and only leaks from the front.
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Tiny
Clete43
Jan 4, 2014.
Because the hotter the fluid gets the thinner it gets so that would make perfect sense why it would leak like that. The reason why it would only leak from the front seal is because the seal is bad.

Saturntech9
Jan 4, 2014.

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