won't go into Drive?

[purple gas]

Like it says. I can shift the lever into D, but the tranny won't shift. T-350, it is. Should I swap it out for another one? Could it be a simple thing? Should I hit it with a hammer? Are any carb linkage or vacume lines involved? Could it be a pull the pan and check / change something simple? Does it have anything to do with the fact for 1 revolution of a tire, the drive shaft rotates not quite exactly 2 times? Any advice would be greatly appreciated. FINALLY bombing around in my truck is fun, but avoiding the freeways sucks!

[Karl Hoh]

Have you checked oil level, linkage connections. Does it go into reverse? If yes then the clutch pac seal failed. If no, then the pump may have failed. Either way it needs to come out and rebuilt/replaced.

[woodridge]

Probably will have to come out, what does it do if you pull the shifter to low? If it pulls out and then will shift up you may have a bad low roller clutch, if it still won't move there is a problem with the forward clutch.

[pound41]

Be you start yanking out the tranny. If it worked fine before you need to check your modulator valve its on the the back and has a vacuum line on it. My 70 wouldn't go into drive. It had been sitting for a while I drove it. The next day no Drive. My Dad said change the modulator valve first. Cost less than $ 20. Switched it haven't had a problem since. Start simple

[Longhorn Man]

That doesn't make any sence..the mod valve only controls the RPM at which to upshift... nothing else. It'll go through all 3 gear (shifting at a MUCH higher RPM) with a bad mod valve.

[purple gas]

Thanks for the tips... Oil level is ok. It goes in reverse fine. You can shift manually from 1st to 2nd, but won't go into drive when the shifter goes there. Talked to guy who sold me the van I got the motor & trany from yesturday. He said it shifted fine, but it had sat for long time before I got it. When I first drove it ( and I still haven't driven it much ) it would rev pretty high before shifting out of 1st, and my liscenced mechanic buddy tweeked some linkage or something at the back of the motor and that helped the 1st-2nd thing. I'm thinkin I'll be yarding it out for a re-build anyways.

[woodridge]

Now with more info try this.
1. Make sure you have vacume at modulator valve.
The mod valve uses engine vacume to control shift timing and quality
2. Make sure T.V. (passing gear) cable is not hung in the pulled out position.
3. If #1 and #2 are not in spec and trans will not shift after they are corrected problem is most likely internal.

[da-burb]

Modulator valve...the fact that you have 1rst and 2nd gears but doesn't shift into 3rd is a bad modulator or the vacuum hose is off.

[Longhorn Man]

With the added info here, I will say mod valve.
You should be able to get 3rd amnually too. Get it up to about 50 in second (onless that's spinnin the snot out of it then do this at 40 - 45) and manually go from 2nd to 3rd... it'll probably go.
Check all the connections on the line going from the carb (or intake) to the modulator. There should be a hard line with short rubber hoses on either end.