Transmission Question

[Adam76wag]

Hi just bought my first Wagoneer and am new to the board. I just wonder if anyone has experience with this problem.

I have a '76 Wagoneer with a TH400 auto transmission. It will not shift out of 1st while in drive or by putting it in D or 2. When I back out of the driveway it shifts smootly into R and then smoothly into D and seems normal until RPMs build and no shift occurs. The fluid is full and bright red (previous owner swapped the transfer case from a high/low to high range only recently). There are no sounds or vibrations. I drove over 100 miles with no problem when I picked it up. When the problem happened I was cruising on the interstate at around 70mph and started to decelerate like I was coasting and pushed the gas pedal and the engine revved but had no effect on speed. When I slowed to first gear speed it would accelerate but not shift.


Thanks,
Adam
Weatherford TX

[Lindel]

Sounds to me like you've got a leak at the vacuum modulator. Should be on the passenger side of the vehicle with a hose that goes between the modulator and a steel tube, eventually to a vacuum port on the engine. My bet would be that the hose has rotted, or been chewed by critters.

[Adam76wag]

Thanks Lindel

Sounds like it is definately worth a try. I know I have vac leaks and I am still hunting them down. I was planning to replace all the vac lines anyway as soon as I stop procrastinating.

Adam
Weatherford TX

[Adam76wag]

Got the tranny workin now. Turned out it was the governer. $4 part