Recently rebuilt a th350 for a guy I work with.
It's the original trans in the '73 buick it's in. The symtoms were slipping in all gears, evenually it stopped moving.
He pulled it. I rebuilt it, Found burnt but not worn clutches.
Replaced all clutches with B/W tan, specs are: Forward-.010, Int-.055, Direct-.045, Low/Rev .130, end play-.005. Also replaced all bushings, washers, rings. pretty much all the common rebuild parts. Plus the roller assemblies, the intermediate roller had collapsed springs.
I also put in a Superior Products 350HP kit. Had to change the governor from a big spring type to the small spring type. I air checked everything during assembly.
The converter was only flushed. I recommended he get a cooler and not use the one in the radiator, he did that.
He put the trans back in, and it wouldn't move.
I came over and found the converter bolted to the flexplate the same way he took it out but it wasn't driving the pump. He said there were no washers between the converter and flexplate, the bolts were short stock ones so I believe it.
I put 1/8" washers between the tc and flexplate. I also pulled the pan and all was ok there.
That worked and it ran fine for the 20 miles I drove it.

Next time he got in it he says it drove for about 5 miles, slipped a few times, then sounded like the engine was straining, then it stopped moving.

I came over, put the converter in the trans as far as it would go, and used 3/8" of washers to bolt it up and still nothing. With it running I pulled a cooler line off and nothing came out. I told him to pull the trans again.

Now he calls me and tells me he drove it about a 1/2 mile and was asking if it's ok to drive it. I can't believe it drove again.
Any ideas whats going on here?

 

Well it definitly sounds like you are loosing the sump. At first I was woundering if the tc was junk but no cooler flow. You put a sk in it so I know that you put a new pr spring in. Are you sure that you put the pr spring in the right way. This I believe will cause a problem like you described. Did you change any hard parts..pump, seperator plate,etc? There is a check ball or check valve in the pump that might be sticking or missing. I have seen missing springs or broken springs in this location. Also you could have a broken spring in the valve body for the detent that I've seen do some weird stuff as well. Sounds like you need to disect this thing. I'm heading the the shop in a bit I'll take a peak at an oil diagram to see if there is anything I didn't cover here. Sorry that I couldn't be of more help here. Vince

 

Any help is good help Vince, thanks.
It does have a pump with the check ball and spring but that was fine.
Pretty sure I put everything in the VB right, it did get totally disassembled also.
He's actually bringing it over right now, he pulled it already.
I didn't change any hard parts, just inspected them real good since there was no definate reason for failure. Thats whats got me, it seems to be doing the same thing it was doing before.
It is the original trans and his dad bought the car new, the trans was worked on once about 20 years ago he says. All hardparts looked real good except for the int roller which I replaced.
Just thought of one thing, during the air test there did seem to be more than usual leaking from between the input shaft and drum.
I may replace the input but I don't think thats the problem.
I somehow got a pretty good stock of th350 parts from the pump to the direct drum, I'm hoping it's the pump cause by the converter engagement.
I'll check back. Thanks again.

 

Well it looks like ANOTHER improper converter installation.
Never seen one this bad, the pump cover has at least a .050 deep wear groove in it.
I remember that gear looked perfect too. UGH, now i got to dig one out of my garage.

 

Hi since he put it in im assuming you werent there , and this may sound like a dumb question but I have sen it done many times , Is it possible he bolted the converter to the engine first , then the trans ?

 

No, at least I hope not.
He did tell me he took the trans out with the converter on the engine.
I told him several times that the converter stays in the trans at all times. I told him several times, I think he was starting to get offened actually lol.
Something else I thought of....when I was there I noticed he was missing a block dowel pin. Maybe it wasn't on center. I'm going to give him one to put in it.

 

yes that dowl pin is a must it not only aligns the tranny it supports it and keeps it from twisting on the block , The bolts do nothing but hold the tranny to the block

 

Which of the those gears was installed into that pump? The one on the right looks factory however the one on the left looks like an after market gear. Look at how much shorter the lugs look. I was woundering if that was the gear that was originally installed. I did read about the missing dowel pin. How did the pump bushing look?

 

Do you have any pictures of those gears from the other side , Just curious to se im assuming the one on the right is new or from another unit ,

 

The gear on the right is from another pump, the one on the left used to look the same but in even better condition.
The one on the right is now in the trans. I can get a pic of the other side of the torn up gear. What are you looking for on the other side?

The bushing looked ok.

 

The lugs for the tc hub on the gear look much shorter than the gear on the right. I was woundering if it was an after market gear. It just doesn't look factory to me in the picture. Well it looks like you got the trans problem figured out. Now just gotta get all that metal out of that unit. Also did it hurt the tc hub at all? Might be a good idea to start with a different tc. It looks like it might have some metal in it as well.

 

just wanted to see where it was rubbing the pump face was curious and the gears do look quite diferent as vince said

 

They did look identical, apparently the TC somehow machined the ID of the old inner gear out and took the lugs out also. The lugs on the left gear used to be the same thickness as the lugs on the right gear, now on the old gear the lugs are almost completely gone. The TC is kind of grinded up too so I'm going to give him another one out of a good trans that got a high stall converter.

 

I actually reused the pump body, it wasn't bad at all, I just replaced the rear part shown in the pic and the gears, converter, bushing and seal.