Major TH350 problems

[fostrem]

So after a long haul of tracing my fuel lines, checking pressure and compression, and timing i finally got my old 76 shortbox to hold a solid idle. Now, unfortunately when the truck is in park and i rev the engine, it drives! I can only shift into park and neutral, or at least thats what I think I am in. I can dabble with a simple engine like my 350SBC but when it comes to transmissions I'm lost. Its got a TH350 in it. My plan is to drop the pan and see if theres any metal in it. What exactly should I be looking for? The fluid does look low and old so i will replace that. Does it sound like i should be in the market for a used replacement, or a rebuild? Any thoughts would be incredibly helpful.
Thanks a lot!

[mopar346]

What is the fluid like, color and smell mainly. It will tell you what you need to know with out wasting the money on a gasket, filter and fluid if a build is in the future. I would also make sure the shifter linkage is adjusted and operating correctly.

[fostrem]

Thanks for the response. Well I checked the fluid about a month ago and it was black, smelled burnt and was low. I took it to the shop for a dizzy replacement, which they installed 180 out, and they put more fluid in it. I haven't really driven it since so the fluid is red but smells a little funny. I went under the truck and took a look at the linkage. Not really sure how to adjust it. When i move my shifter I get a lot of play. Park is at the very top and then it shifts into another gear close to the bottom. How do I know if it is working properly?
Thanks again

[king-918]

Either shift linkage is off or your parking pawl is not engaged
Posted via Mobile Device

[mopar346]

Welcome to the forum.

I typically will adjust it in neutral. Secure the truck from rolling, either by putting it on jack stands or blocking the tires on both sides. Disconnect the linkage at the tranny, shift the lever on the tranny to park, verify park by rocking the truck, shift the lever 2 clicks in the only direction is will shift, start the truck to verify neutral, have someone hold shifter in the correct neutral position and adjust the linkage so that it slips in and out of the lever with no bind, secure the linkage. Start it up and shift it into drive and reverse to verify engagement and proper shifter position. Test drive the truck, with no shift kits I would expect it to shift into 2nd at 18+/- mph and 3rd at 28+/-.

It goes without saying but I will say it anyway, DO NOT START THE TRUCK WHILE YOU ARE UNDER IT.

[mopar346]

There is a failure that will make it drive in park, I think it may be the sprag coming apart or 2 drums welding together, I cant remember but it can happen.

[motornut]

any chance the indicater is out of alignment too
do you feel notches for gears or just putting it in P N D

[fostrem]

Thanks for the tips on adjusting the linkage! I will give it a try in the morning. As of now, I it shifts into two gears, one at the top of the shifter, and one at the bottom. If starts in both and will not roll in the top one, I will check the other gear tomorrow. It seems as though it is skipping reverse? not sure but I will adjust the linkage and go from there. Thanks for the welcome and thanks for the help guys!

[mopar346]

Make sure you report back. The strength of a thread in helping others in the future is to close the loop, too many people don't.

[fostrem]

Well when I get under the truck it seems as though the transmission can only go into two positions yet it wants to drive and will start in both. This seems wrong right off the bat
Posted via Mobile Device

[rs72z]

Originally Posted by fostrem

Well when I get under the truck it seems as though the transmission can only go into two positions yet it wants to drive and will start in both. This seems wrong right off the bat
Posted via Mobile Device

The nut has come off the selector shaft inside the trans. Drop the pan and look where the shaft goes through the trans.

[fostrem]

Thanks for the tip. I dropped the pan and the nut was loose you were right. There was also a bolt in the pan which fit into a hole right close to the selector. I'll take a picture in a few minutes and post it. Also the tranny will only shift into the first two positions. Is this normal while the car is off? Just want to make sure before I slap the pan back on.
Thanks,

Finn
Posted via Mobile Device

[rs72z]

No, that's not normal. Make sure that the the park rod didn't get jammed behind the pawl at the back of the trans. Also make sure that the little rod that goes to the manaul valve on the valve body is still hooked up.

[fostrem]

Sorry that I'm asking so many questions but what exactly do those parts look like. Also there is an s shaped piece of metal that is only connected on one side. It is connected to what seems like a little pump. When I pulled it, more fluid drained out. Should this be connected to something?

[fostrem]

ok so i attached the manual valve where it is supposed to be attached and i cannot see anything getting jammed yet still it will only shift between park and reverse. When i first dropped the pan when the selector was still loose, i believe i shifted through all the gears on the rooster. all i did was tighten the selector and attach the manual valve. is there any way i could have cause this by tightening the selector?
thanks
finn

[fostrem]

could this be because the fluid is drained out?

[rs72z]

Check the big rod. Coming off of the rooster and make sure that its not stuck behind the packing pawl at the rear of the trans.
Posted via Mobile Device

[fostrem]

you were right, it is getting stuck behind the pawl. How do i fix this?

[rs72z]

There is two bolts that you will an remove, that will let the rod come out from behind the pawl . Then just reinstall the bracket and bolts that you took out.
Posted via Mobile Device

[fostrem]

I tried that and it still seems to be getting stuck on the last part of the rod. how is the pawl supposed to move to clear this part of the rod?

is there a trick to reinstalling that im looking over?

[rs72z]

When you have the bracket down push the lever in toward the trans and then push the tapered part of the rod between the lever and the case bolt the bracket back in.
Posted via Mobile Device

[fostrem]

by lever do you mean the pawl? i feel like no matter how i install it, the notch at the end of the rod will always catch the pawl if that makes sense. If It install it while the tranny is in 1 or 2, it will cycle through the rooster then catch again on reverse.

[rs72z]

Can you get a pic of it?
Posted via Mobile Device

[fostrem]

Attached is a picture of how it sits in reverse. I removed the bracket but this is how it sits with the bracket on I believe, because when i try to move it past reverse with the bracket on, the parking pawl moves a little like the rod is getting stuck on it.

[rs72z]

Looks like the rod is broke where it goes past the pawl.
Posted via Mobile Device