TH400 and 6.2

[ctmpwrdcamry]

I went and drove a friends m1008 tonight, thinking about purchasing it. The only thing i didn't like was the transmission shifted hard and late(30mph out of first) Upon returning I spoke with the owner and he said it was recently rebuilt, but the issue is new. The fluid looks great, nice and red. Could it be the vacuum actuator that is creating the problem?


Thanks

Sean

[NH2112]

I can't remember driving a single CUCV during my 12 years in the army that didn't shift into 3rd late and hard. Typically what I'd do is get it up to about 30-35, let off the throttle, and then step on it again and it'd shift. If I owned one with a TH400 now, the first thing I'd do is adjust the VRV (Vacuum Regulator Valve) to specs, then mess with the modulator. Different years of trucks had different procedures for adjusting the VRV, and with CUCVs being built in a certain model year doesn't necessarily mean they're the same as civilian vehicles from the same year. You may end up just having to "trial and error" it till you get it the way you want it to feel, regardless of what the manuals tell you to do.

[packmaster2r]

In case you haven't already done so, be sure the vacuum pump is working. Many moons ago I had a failure of the vac pump on my '89 sub 6.2, which caused the defrost door to quit working. These engines have very little manifold vacuum, thus an auxilliary vac pump rides in place of a distributor.

[ctmpwrdcamry]

Alright, thanks guys! Well, it appears i am not going to be able to get the truck, no place to put it. Thanks for your help anyway, hopefully another time another truck.

[quadquazy]

Hey check your vacuum line and replace it if necessary. I replaced a TH400 because it was shifting hard into 2nd and 3rd and the new one did the same. Figured out my vacuum line was the original from 1985 and was cracked all over. Replaced it and it worked fine. Wish I had known that before I'd spent $500 for another tranny. I guess that's what I get for being a Ford man and thinking the vacuum line was only a kickdown (no wise cracks from the peanut gallery please). I still had to adjust the vacuum module to get the right firmness of shifts. Good luck