T-400 behind a 6.2 diesel CUCV military blazer
Having a few issues with this 1984 blazer. One of the Military M1009 CUCV jobbys with the 6.2 diesel and a TH400 trans.
It has a engine mounted vacuum pump and it's sole purpose is to operate the trans modulator valve through a 'vacuum valve' deal that is basically a throttle position sensor which is mounted on the injection pump and follows the movement of the throttle shaft.
Vac pump is working good, the 'TPS valve' is good and the modulator valve holds vacuum.
One problem is that is will not automatically shift into 1st in 'D' range but will if you select L1 range.
Another problem, auto upshifts in 'D' range is not good, it winds 1st too long and will finally shift into 2nd when you back out of the throttle a little. If you havn't wound up 1st enough it will just free wheel and not go into second remaining in first.
Manually moving the shifter it will shift ok with 1 to 2 a nice quick shift. 2 to 3 is better but still soft.
2 to 3 is very soft and will sometimes sound like it slipping.
Around a 100k miles, fluid is nice and red with a normal smell.