Ever seen a possessed 722.118?
 

My transmission is completely insane when cold. I know I don't really need this thing for long, because I am doing a drivetrain swap soon, but I thought this was at least worth discussing.

The transmission in question is in a '77 300D. No bowden cable or vacuum modulation here, folks; this just uses a simple rod driven by throttle, and of course the kickdown switch under the pedal. Fluid levels are correct, and no real indications of trouble can be seen in the pan.

Before anyone suggests it, the shift bushings are all new, and the shift detent positions are all correct as a result.

Here's the weirdness... When cold, the transmission can be in park, but it will suddenly grab and try to drive forward. It has done this to me while I was standing in front of the car, and it has done this when parked nose-to nose with other cars in parking lots. If that isn't strange enough, when reversing while cold, the transmission will occasionally and suddenly shift in to what appears to be park, stopping the car dead, and giving everyone in the car a good neck thrashing. Shifting to neutral or park and then back to reverse engages things again, and reversing is once again possible, but sometimes you have to do this eight times to make it out of a parking space.

Once a little warm, the transmission works fine. Even letting it fast idle for four minutes in neutral is enough to make the transmission behave properly. It short upshifts a bit under full throttle between 2nd and 3rd, but other than that, it works pretty well. My solution to this madness has been to let the car fast idle for several minutes in neutral while keeping my foot planted on the brake, and it seems to prevent issues.

Thoughts? Would a priest help? Heh. I just want to make sure it stays together long enough to give me the time I need to clean up and reseal the turbo drivetrain. This thing is currently my daily driver while my convertible hides for the winter.

Try a quart of transx tranny fluid additive. It solved the issue with my 722.112, it wouldnt upshift to 3rd cold by itself until it warmed up for a few min.

Got a good emergency brake? I'd make sure it's always tightly applied when parking.

My solution (as always) is take it to bits!

http://www.peachparts.com/shopforum/diesel-discussion/304903-722-118-automatic-transmission-rebuild-monster-diy.html

This might help - if you are sure park is being engaged

You've got the gear selector lever going into the valve body

http://www.peachparts.com/shopforum/...dy-removal.jpg

http://www.peachparts.com/shopforum/...valve-body.jpg

The park pawl has a return spring in the tail cone section (as I've been calling it)

http://www.peachparts.com/shopforum/...tre-casing.jpg

http://www.peachparts.com/shopforum/...mechanism1.jpg

If that spring is bust you might get some weird poo occurring...

http://www.peachparts.com/shopforum/...mechanism2.jpg

http://www.peachparts.com/shopforum/...ctor-shaft.jpg


Are you sure however park is being engaged and the brake bands (or the clutches) aren't engaging by accident?

You can quite easily check brake band operation in the car by removing valve body (see first picture - and have a look at text in thread) and then test operation with compressed air...

http://www.peachparts.com/shopforum/...clearnace1.jpg

http://www.peachparts.com/shopforum/...clearnace2.jpg

http://www.peachparts.com/shopforum/...clearnace5.jpg

Oh yeah and check the reverse band adjustment screw

http://www.peachparts.com/shopforum/...adjustment.jpg

Oh yeah and I forgot to say - good luck - and if you want to take your valve body to bits you are a bit on your own as the pictures of the valve body in the thread I posted are for a more recent 722.118... though I understand from the ATSG manual that the balls and springs "between the plates" are common to all 722.1s - the springs in the upper part of the housing seem to be different. Perhaps the earlier valve bodies are too?

If you get stuck I have a 722.112 trans and valve body here that might be a bit closer to yours as that too has the throttle modulating linkage. I can take that to bits and make photos if you've just watched parts of your valve body fly past your ears!

I actually ran some Trans-X in there for about 400 miles a few years ago, and it did improve things. I have some more I can throw in there... Maybe something is just gummed up. It really does work better each time I drive it.

Truthfully? No. With the car in drive or reverse at idle, it easily overpowers the parking break. I am working on it. I'll tackle that when i overhaul the entire brake system at once.

Thanks for the pictures and the offer, friend. I have a better idea of the exact workings now, and I might actually be able to theorise the problem after I process things for a bit. I'll investigate and report back.

That transmission was designed by Satan....

Ha!

Yesterday I tried to leave the Bellevue Square parking garage, and it tried to mount another car when I started it in park. No harm was done, but geez...

The other car was a BMW... Can you imagine my horror? At least it wasn't a Hyundai.

Honestly, if I could find a 5 speed. :D

Even a four speed. :)

But I guess I will be stuck with the auto from the '83 for a while. :uneasy:

Wow a humping car. Are you sure you want to fix that? You could make some serious money with that!

TWalgamuth (sp?) has a four-speed kit out of his 280e listed right now in the used parts for sale section. :D

Will it offset the child support payments? I have this mental image of little half Beemer, half Mercedes pedal cars. Ugly buggers.

That wouldn't bolt on, would it? Some of the bits are right, but the flywheel and bellhousing would have to be the wrong ones.