One of the FIrst places fluid is pumped in the T-350 is into the converter. As a transmission sits, the fluid in the converter will drain down

If you think the fluid level is low : Add more fluid. If the dip stick is wrong , it likely reads incorrectly as you mention.

If the T-350 does not function after more fluid is added... Likely needs to be removed for reapir

Are you moving the shifter thru each position? P R N D 2 1 ... ?

If the fluid looks and smells burned, the T-350 may be in need of repair?

 

Ok, I was vague on if a converter loses fluid overtime or if its build to be a one way oil in; no oil comes out. I have seen some oil drippage on the pan if i recall correctly. which could indicate the converter has emptied itsself on the floor. Adding a single quart of oil then likely just all went straight into the converter, and didnt fill the transmission at all.

The dipstick is cut and then another piece is welded on. No clue why, just gonna steal a proper one from another car to check fluid. To read oil warm, how long do i need to let the engine run? 5 min fine, or too short?

 

If you think the trans fluid is low , add more fluid. Run the shifter up and down to all gears. Does the T-350 respond? Warm or not, the trans should respond with proper fluid levle and the trans is in decent condition.

Checking fluid with dipstick... Look at both sides of stick. Pushing stick in and out of the tube will pickup some residual oil from filling thru the tube.

 

Trans doesnt respond at the moment, i am not with the car so cant check it out rn. i just checked cold dipstick levels of the same trans + converter, and i know my cold level. This indicates that it needs way more fluid. I actually got a little drive out of the trans with this fluid level, which might also explain why it smells burnt.
Thanks for the help, i will update tomorrow.

 

Add 1 quart, and start the thing up, and try to move it up and down the driveway. If that does not cure it put it up on jackstands and pull the pan. If there is a fair amount of fabric in the pan that will be your answer.

Put a piece of tape over the gear selector indicator at this point, and shift the thing by feel of the shifter between clicks.

 

in the case of there being fabric this means...? Worn friction plates i assume? Thanks! Since it DOES move currently, just at wrong RPM levels. And it also already moved before adding that 1 quart of oil (i already added a quart)

 

Some fabric is ok. If ya swipe your finger through the pan and your finger comes back with a "gob on it" the fabric is all worn off the clutches, and it will never be right. The top side of the filter could be clogged too.

Thomas, I am beginning to think you are headed to pulling it, and taking it in for a rebuild. You may find some hard parts in the thing that need replaced too.

Where in the world are you? Ya know, states are big places.... At this rate no one can even refer you to a club member, or a shop they had good luck with.

 

I am from the Netherlands, so pretty far out of generally, I presume, everyone's reach here. But that is no problem! Together well get there. Ill pull the pan tomorrow as well as check the oil levels when warm. That ought to give some clarity to the story!

 

1- Over 10 years, it's very likely that there was a fair amount of condensation inside the case, which settled to the bottom. That could have been sucked up into the pump and made a pink milkshake = toasted transmission. It could also have turned the screen on the filter pickup into corn flakes and more or less stopped flow.
2- The o-ring around the pickup could have dry rotted and you're picking up more air than fluid.
3- Unlikely that it's an empty TC. They fill first, and they fill quickly
4- After 10 years, you could have any one of a dozen valves or check balls in the valve body that are gummed up and stuck.

Check the obvious things. Pink milkshake? toast. Check filter o-ring. Check filter quality/dirt. If those check out ok, you'll likely need to pull it.

 

Thanks for the clear breakdown, I will get right to checking this tomorrow. I will update!

 

Update: I pulled the pan + inspected filter. There were some flakes in the mesh filter, so definitively the friction plates going out. Besides that there was some form of sludge at the bottom of the pan, not metallic; though grey. Colour of the oil was also more orange than it was red. Definitely a burned transmission, so ill go and rebuild it. Seems the only way right now.

I have the choice of several kits, and i was wondering if thrust washers often go bad/need replacing?

 

I'd get the thrust washer kit. Some of them see more abuse than others.

As far as kits go in general plain steels and OEM Borg-Warner clutches are cost effective and all you'll ever need in a TH350. Ideally you would be well served to disassemble first and order parts after. Get some information on the web about checking endplay. Doing that before things come apart is useful as a starting point for adjustments when things go back together.

 

Go to the web site and purchase the medium that suits your reading habits, being an old guy I prefer books over digital forms. ATSG is the definitive information source.

3-speed - Page 1 - ATSG Bookstore

atsgbookstore.com

Bogie

 

Hey, sounds like you’ve got an interesting project on your hands with that TH350! Here’s what might be going on and some things you can try before pulling the transmission.
1. Fluid Level and Condition
It’s a good starting point to check the fluid level, but if the dipstick has been modified, it might not be giving you an accurate reading. You mentioned that it was sitting for about 10 years, so there's a good chance it's low, or the fluid has degraded quite a bit.

• Check the fluid level properly: Warm up the engine, then check the fluid level while the car is idling in Park. If it’s still low, try adding more fluid slowly to bring it up to the correct level.
• Burnt fluid smell: If the fluid smells burnt, that’s a sign the transmission could’ve overheated at some point. You may want to consider a fluid and filter change if the transmission fluid looks dark or smells off. That might help improve performance, especially after sitting for so long.

2. Torque Converter
It’s possible the torque converter drained while sitting for so long. If the fluid is too low, the transmission won’t be able to build enough pressure to engage gears properly, which could explain why it only moves under higher RPMs.

• Top off the fluid: If the converter has drained, it may need more than a liter to refill. Add fluid in increments while checking the dipstick, making sure not to overfill. It may take a bit of running the engine for the converter to fully fill up and start functioning correctly.

3. Seals and Gaskets
After sitting for 10 years, it’s very possible that seals and gaskets have dried out and hardened, which can cause pressure loss. Without enough pressure, the transmission may not engage the gears properly, especially at lower RPMs.

• Try cycling the transmission: You might try letting the engine run and shifting through all the gears while parked. This can help get the fluid moving and start rehydrating any dried-out seals. Sometimes, seals will soften up again after absorbing fluid, but this is hit or miss depending on their condition.

4. Valve Body Issues
The valve body could be sticking or gummed up from sitting for so long. If the valves aren’t moving freely, they might not be directing fluid where it needs to go, which can cause delayed engagement or require higher RPMs to move.

• Transmission cleaner additive: You could try using a transmission cleaner or conditioner that’s designed to clean the internals and help free up sticky valves. Add it to the fluid and drive the car gently to see if it improves performance.

5. Possibly More Fluid Needed
Since you’ve only added about a liter and the dipstick may not be accurate, it could simply need more fluid to get everything working properly. A TH350 typically holds about 10-12 quarts (around 9-11 liters) of transmission fluid, including the torque converter, so you might still be well below the proper level.
6. Final Step – Rebuild or Replace
If none of the above steps improve the situation, it could be that the transmission’s internals have deteriorated, and you may need to look at a rebuild or replacement. But before going that route, I’d try the easier fixes like fluid, seals, and cleaner additives.