unckybob

I am hoping to switch out my automatic to a manual transmission. Has anyone seen a good thread on this?

The hard part seems to be getting the clutch pedal/linkage installed. Can anyone help?

Squigie

I considered swapping my TH400 out for a manual tranny, while the engine and tranny were out. So, I dug up everything I could find. It wasn't very helpful, of course.

There's also an old thread (or two) over on the vannin.com forums.

Basic theory:
You're pretty much guaranteed not to find a donor that allows a straight-forward swap. You'll probably have to bit-and-piece it together.

You need everything from the flywheel, back - including a driveshaft, with some trannies. (Pilot bearing, thrust bearing, clutch, pressure plate, flywheel, bell housing, tranny, tail housing, driveshaft, shift linkage, cross member, tranny mount, etc.)

You'll need clutch linkage and brackets for your engine family and the transmission you're using. (Not necessarily from a van, but you have to make sure your chassis has enough clearance for what you do find.)

You need not just the clutch pedal, linkage, and mount bracket; but also the proper brake pedal for a manual transmission. (Brake pedal for automatics doesn't clear the clutch pedal.)

And, swapping column-shifter parts over is generally more headache than it's worth (if you can even find a donor). So, most people that have done it ended up going with a floor shifter, with separate linkage running to the tranny. Going with a shifter lever brought straight through the floor ends up with a massive lever throw for gear changes, due to the angle required to get to the driver's seat.
Certain '79(?) and up manual trannies had a factory floor shifter. It's the best choice.

If you have cruise control, you'll have to figure out how to tie the clutch pedal switch into the system. Some years just had it piggy-backed on the brake switch to kill the cruise; some years had a separate circuit. Later models ('84-87?) just required the cruise control harness to be plugged into the switch harness, then a jumper wire cut on the control box.


The reasons I decided not to do it....
1. I couldn't find a donor vehicle with most of the vital van-specific parts.
2. Column-shift actually made more sense for me (even with potential problems), but I couldn't find ANY donor that still had the column-shifter parts in usable condition.
3. I decided a different approach would be better:

...Going to a 4L80E with a full-lockup torque converter, a stand-alone controller, and a speedo cable drive unit. Cruise would still work. Speedo would still work. I'd have an extra gear. I wouldn't be wasting as much power in the torque converter. I could tune the shift points, lockup, line pressure, etc. And, I could even tune the controller to allow manual shifting, if desired.
Right now, it's on the back burner. But when I run into a good deal on a decent 4L80E, I may start picking up the other parts.

unckybob

It turns out that the van has to have an automatic otherwise the computer won't be able to run the vehicle. Thanks.

Squigie

Certain years, yes.
Older models, no.

unckybob

I believe the 1991 (my year) has to take an automatic.