Thread: Th350 experts needed....help!!!

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We know very little about automatic transmissions and have a problem we need help with. The TH350 in my Son Dan's 30 rpu is a BOP pattern that we bought from Jacksons Racing Transmissions about 4 years ago. The car has yet to move an inch under power and has been filled the entire time we broke in the engine with Dextron III.

I've been a little nervous because even after running a bunch of times there was never any fluid in the lines to the cooler, not a drop. I kept thinking it was because the trans had only been run in park, but I had a talk with a rep from ATI at the drags Sunday and he said there should be fluid pumping even in park.

The driveshaft is still not in the car, so last night we took an extra yoke and inserted it into the tailshaft and started the car. When Dan put it in gear nothing happened, the yoke didn't move in any gear. Even though it was full of fluid we put in two extra quarts and when Dan revved it up the yoke did start to spin, however, it went the same direction even in reverse. And after a while it stopped spinning at all.

Just to try the simple things, tonight we pulled the pan and replaced the filter and made sure all the bolts on the valve body were tight, they were. Fired it up and it doesn't move at all now. I'm a little upset with Jackson because, while I don't expect them to warranty it after 4 years....even though it is still undriven, I can't even reach them via phone. The phone goes right to voice mail and the message says the box is full. We have bought 4 transmissions from Jackson and this is the first real problem.

I see two possibilities:

Something in the trans is screwed up, or, the torque convertor is bad (B and M Holeshot 2800 stall.) However, the fact the trans would only turn one direction, even in reverse, makes me think the torque convertor is not the problem.

Here is the real problem...........the body will have to come back off to access the transmission. The 455 Olds and TH350 are really tight in there and the only way to get the trans out without beating up everything is to pull the body off. Dan doesn't even want to look at the damn car right now, and I know how he feels.

Any suggestions will be appreciated.

Don

Oh, just some addtional info:

This is a 1970's style th350, no electronics or anything. Also, we pulled the pan and the linkage IS moving everything inside like it should, even the plunger is going in and out.

This may sound stuiped but is the converter bolted to the flywheel????? I know I'd never get that lucky

Actually, that is a good suggestion, Charlie, but yes it is. I looked at that. I also wondered if we forgot the input shaft, but since the yoke did spin for a short time I kinda ruled that out.

You're thinking though, and I thank you for that.

I should mention that the fluid is like brand new, no evidence of burning or particles in it. I thought if the front pump was out it would fry the torque convertor, that is what happened to the TCI C4 in Don's T.

Don

sounds like the converter is not driving the front pump converter not in to the pump or the front pump was broke drive lugs were busted off ,spool valve stuck .will it move the car in REV .i would have to go threw the flow charts of the 350 and that book is at the shop

Don, Remove the torque converter to flex plate bolts. See if the converter moves fore and aft a bit. If it won't move at all, then it is likely the converter is not seated in the front pump.

Pat, thanks for the suggestions. We haven't installed the driveshaft yet because the center section of the 9 inch rear is in Pennsylvania right now to correct a drip out of the seal (another long story ) But we slipped a dummy yoke in and finally got it to spin for a while, but only in one direction. The way it was spinning was the same rotation as the engine, so I take that to be forward. When you put it in reverse it still went that same direction, and the same in neutral. But it stopped spinning again althogether now.

Don

Originally Posted by Bobw

Don, Remove the torque converter to flex plate bolts. See if the converter moves fore and aft a bit. If it won't move at all, then it is likely the converter is not seated in the front pump.

Bob, good idea. When we were putting this thing together 4 years ago, we had an issue where the B and M torque convertor would not match up with the Olds flexplate that I had bought new. So we ordered a B and M SFI flexplate and it went together well. As I remember, we were able to seat the torque convertor back a short distance from the flexplate and then move it up to it's final position before putting in the bolts and nuts. But I will check that tomorrow.

Thanks.

Don

Bob, thinking about this a bit I do recall we had to spin the TC until it dropped into the transmission, like you always have to do, so I do think it seated ok.

look at the governor pop the cover off see if you have one ? can you get low 1

Question. What is the purpose of the modulator? Reason I ask is that we didn't have a line to it at first, but then we added one while trying different things last night.

Don

Originally Posted by pat mccarthy

look at the governor pop the cover off see if you have one ? can you get low 1

Where is the governor, Pat? About the low question you had, the yoke moved the same regardless of position, except for park, and it locked up there like it should.

Don

I will just reiterate what has been said. Take the TC bolts out, make absolutely sure the TC is mated to the pump drive lugs. Once that's been done slide the TC back up against the flex plate and bolt down. Next I would pull the pan and make sure the trans filter is installed with a seal (can't remember if the TH350 has one) installed. The modulator is for shifting the trans. If you don't hook it up it won't shift. If these things have been satisfied, I would say something in the trans is afoul.
Good luck, keep us informed!

Keith

low1 froward clutch is on low cluch is locked so if you had rev you could get L1 ??governer is in back drivers side has a cap over it with a wire clip over it like a master . could be just some junk in the valve body or shifter is not adjusted try unhooking the shifter and trying the shift points by moving by hand

Keith, yes, I will do that tomorrow night. My Son Don was helping us last night and he suggested the same thing about the filter, so tonight we bought a new one and pulled the old one. It was like brand new, the gasket was in place, and the screws were tight. Just for giggles we installed the new one and it made no difference.

I'm also not very happy with Jackson Racing right now because they are being non responsive. I'm not looking for a warranty after 4 years (even though the trans has zero miles on it) all I want is some suggestions, since they built it. I won't be recommending them in the future, and I hope the other TH 350 I have and the C6 are ok when I need to use them. I would put my TH350 or the B and M TH 350 I have in Dan's car, but it is not the BOP bolt pattern. I know we could get an adapter plate, but he is just fed up with this whole thing.

Don

Originally Posted by pat mccarthy

low1 froward clutch is on low cluch is locked so if you had rev you could get L1 ??governer is in back drivers side has a cap over it with a wire clip over it like a master . could be just some junk in the valve body or shifter is not adjusted try unhooking the shifter and trying the shift points by moving by hand

Oh yeah. Pat, I know where you mean.........that domed deal on the drivers side. Ok, will do. Yes, the detents are in the right places, we have a Gennie shifter and watched it go through the detents and they line up perfectly.

I'll try that governor tomorrow night too. What still has me puzzled is that no fluid is coming out of the cooling lines at all, bone dry.

Don

Originally Posted by Itoldyouso

Oh yeah. Pat, I know where you mean.........that domed deal on the drivers side. Ok, will do. Yes, the detents are in the right places, we have a Gennie shifter and watched it go through the detents and they line up perfectly.

I'll try that governor tomorrow night too. What still has me puzzled is that no fluid is coming out of the cooling lines at all, bone dry.

Don

there is a line psi port that can be check if pump is working . governor and modulator control shift points by psi. a spool valve hanging open or no governor woud dump all line psi .but if you not pumping any trans oil then filter or front pump?