Water in transmission

[werewolfx13]

Just finished changing the transmission fluid in my '76 k20 due to water getting into the transmission via a broken dipstick tube. 305/th350/np203 Factory trans cooler had been bypassed in favor of a LARGE cooler by my uncle when he owned the truck, and I may eventually reconnect it. Truck would still move before draining fluid. Drained out about 6 qts of strawberry milkshake, installed new filter and pan gasket, added a gallon of fluid, started the truck and let it warm for a moment, added another roughly 1.5 qts of fluid, truck would move but shuddered hard before moving and always shuddered in reverse. Topped off the fluid and kept moving it to circulate fresh fluid so I could drain and repeat. After about 3 passes back and forth in the driveway, it would no longer move. Added a bit more fluid as the fluid now showed very low, and it moved again. 1 more pass, no movement, and trans was now overfilled  . I'm guessing the torque converter is the culprit, if you push against the tcase shifter with the truck in gear and rev it up to about 3k, you can feel a LITTLE bit of feedback in the tcase, but not enough to move.

The truck sat from about 2008 til about 2 weeks ago when we started working on it. Wasn't driven much from 2006 til it sat parked due to a carb problem. Dipstick tube had been broken for an unknown length of time, I found it when the truck wouldn't move, and we guessed the fluid had leaked out a potentially dried out seal. New dipstick tube and a gallon of transmission fluid and it would move, and I started the trip home with it. After about 5 miles I noticed it topped out about 35 mph even in high range on the tcase, got to a gas station at about the 10 mile point, and noticed the strawberry milkshake fluid. Trans had been rebuilt in 2004 with a shift kit of unknown make.

So, am I looking at torque converter failure, friction band failure, or both?

Thanks in advance.

[VileZambonie]

I highly doubt it's the torque converter. You shouldn't bypass the factory cooler. The transfer case isn't in neutral is it? Flush the cooler and lines, Make sure the filter is installed correctly and check the pressure.

[werewolfx13]

Transfer case in any range, didn't make a difference. I'll try flushing the lines and pick up another filter, didn't really like the new one I used this time anyway. If I can get the transmission functioning properly I'll flush the lines for the factory cooler and put it back in play, I wouldn't have bypassed it myself. Liquid cools the transmission fluid faster anyway.

[bake74]

Transfer case in any range, didn't make a difference. I'll try flushing the lines and pick up another filter, didn't really like the new one I used this time anyway. If I can get the transmission functioning properly I'll flush the lines for the factory cooler and put it back in play, I wouldn't have bypassed it myself. Liquid cools the transmission fluid faster anyway.

     Make sure your transfer case is shifting, if it got stuck in neutral it will not move.

[werewolfx13]

The case "feels" like its shifting, but I'll watch it and have my wife try to shift it. I soaked the linkages down with tri-flow and spent a bit of time gently shifting them back and forth til it felt relatively smooth.

What's the easiest way to check the trans fluid pressure? And should I flush the lines and coolers with the aerosol cans of cooler flush or some other solvent, or just air? In the past, I've used clean transmission fluid and air (about 35 psi) to flush lines, but the cooler in the radiator has sat open for some time, and have doubts that air and transmission fluid alone will be sufficient.

Barring bad weather, on my next day off, I intend to flush the cooler lines, or replace them and flush the coolers (old lines have some rubber lines I'm assuming are repairs, how difficult is it to get the bends just right for new lines?), install a new standard square filter, fresh fluid again, check transfer case linkages for proper movement, check trans. pressure (see above), and if the transmission comes back from the dead, I'll try to get a few pics taken and put up.

[bd]

Did you notice whether the water visibly rusted the pan or valve body?

[werewolfx13]

I did notice that it had not visibly rusted either. I cleaned and dried the pan completely on the inside with pigskin/blue shop towels and the remnants of a can of pb blaster. The valve body I carefully soaked the excess fluid off with pigskin and it looked normal to me.

[bd]

...Flush the cooler and lines.  Make sure the filter is installed correctly and check the pressure.

     ^^This^^

BTW:  Is the fluid still milky?

[werewolfx13]

a little bit, I intend to change the fluid AND filter again, and then do the fluid only again after that. If it appears to come out of it, I'm going to pick up a deep pan with a drain plug and change the fluid (and probably filter) again in a few hundred miles when I install the pan.

[werewolfx13]

Had a few minutes, so I went out and messed with the transfer case shifter..first attempt, truck moved after shifting the tcase forward and back into what should have been high loc, the truck moved but shuddered HARD. Moving forward into "high" the shudder softened and the truck still moved, but wasn't "right", same story with both low ranges, felt like it wasn't REALLY engaged. And after a little more cautious monkeying, it no longer moves again no matter what I do. So, I'm going to replan my next day off and pull the center hump pan and see if anything looks out of the ordinary first, then flush the cooler lines. The shifter moves fine, and has a nice positive "click" like a 208 does (its my first 203, don't know if they are supposed to have a mild, positive click), but you don't get the accompanying "clunk" when the truck is running and is in gear or gets put into low while in neutral and back into gear. Anyone have any REALLY nice pics of what the shift linkages should look like on a clean np203 transfer case?

[werewolfx13]

Did not get to check pressure, still need to buy a gauge. But, today I verified the transfer case IS in gear, and shifts very smoothly. I dropped the pan last night and drained the fluid out, reinstalled the pan and let it drip into the pan all night, dropped it and installed the new filter today. The felt type filter I had put on previously was 95% clogged with what looked like gray slime, dirt, and metal flecks. I went ahead and installed a square mesh type filter and a new gasket, filled it with fluid, flushed the lines (breaking my cheap 1/2" flare nut wrench in the process. Yay for a new set of crowfoot flare nut wrenches) and it moved..kinda..jerked and banged HARD in reverse, and would only move forward if you got on it hard, and moved very little, regardless whether the transfer case was in high or low, lock or not. After a little cussing and grumbling, I tried it again and the transmission and transfer case both bang REALLY hard and sorta move a little (a few inches) in reverse, and virtually nothing happens in forward. It rocks forward about half an inch if you get on it real hard. Pressure test still necessary? Or am I looking at a rebuild/pump replacement?

[bd]

Are the metal particles magnetic?  What color are they (gold or silver)?  Were there any rubber flakes/pieces?  Were there any tiny, flat, black/brown paper-like flakes?

[werewolfx13]

Yes, they were ferrous pieces, silver, no rubber that I could tell, but it looked like oily dirt with metal flakes mixed in the clumps.

[bd]

Do what you can, but it doesn't sound promising....   

[werewolfx13]

I suppose I'll go ahead and hook up the factory trans. cooler and provision it for a temp gauge, and use the gauge provision to test pressure, but I think I'll plan on ordering a rebuild kit, new pump, and one of these.
 http://www.amazon.com/Transmission-Clutch-Remover-Spring-Compressor/dp/B0031FA5DS/ref=pd_cp_hi_1
If it'll work on a th350..I've done a 350 before, and the clutch spring press I used was considerably different than that, but there's a $40 price difference. Input?

And also one of these:
http://www.amazon.com/Turbo-Hydra-Matic-350-Handbook-Sessions/dp/0895860511/ref=pd_sim_b_1