Broke another trans...what's going on?
 

I have gone through a Th350, 2 Th400's, and now a well built PG....all in about 1 year. I don't think I am doing anything different than any of the other turbo guys to build boost. I broke another pump. It has been the pump on all of the them. Not sure exactly if its the pump or pump gear, drive, etc.. don't really no anything about the trans department. Just repeating what I am being told.

The good news is my current PG builder said to pull it and bring to him tomorrow and he will fix it for free while I wait. He and the other trans builders believe that when I build the rpms up on the foot brake and then bump the foot brake in and set the trans that is where I am braking stuff. However, if I try and only build boost on the transbrake I am not able to build much boost at all. I have to get some boost built on the foot brake first.

What am I doing wrong or what is it you guys are doing? Should I be able to go in and set both set of beams, set the transbrake and build enough boost without using the footbrake first?

I posted in the trans section but got no responses.

Bumping in on the footbrake is done everyday. I would get a better trans builder.

^ Could be this.

I am wondering if you are having issues with the converter ballooning. Do the converters you use have a balloon plate? That is the only way I can see to break the pump. I have built a few transmission but not for a living. Will your builder let you have the broken pieces? If so maybe post a pic. Who made your converter?

Have the correct distance between the converter and flexplate(as in you don't pull the converter towards the engine a bunch)?

The convertor is a PTC. This is the third trans builder. This guy has plenty of cars that don't break.

The convertor pulls just over a 1/4" to the flywheel when I tighten it down. My PTC was spec'd for a turbo.

FWIW. My car does do something I haven't seen any of the other cars do. You can see it on the videos. My car raises waaaaay up when I am building boost on the foot brake. Then when I set the trans brake it squats waaaay down like a sprinter getting in the blocks. Any chance the stress from the two positions is doing something?

I can't believe three different really good trans builders would all keep screwing up the same thing. It has to be what I am doing or something the car is doing.

Here is a video of it. You have to watch it on big screen to see what I am talking about.

Do you run a after market ultra bell housing or after market case on your PG? No mid plate right? I have seen issues with mid plates where the chassis starts twisting a little and the mid plate breaks tha case. I wondered if you maybe distorting the case but not breaking giving a slighjt mis alignment. The reason I ask about the ultra bell is that you would have the top bolt that is not on a standard case which may help plus much stronger. Solid transmission mount is another thing that I have personal bad experience with causing internal binding in the trans when the chassis twisted slightly.

That is a big heavy car for a 350

just over a 1/4" of an inch from seated to pulled forward to the flex plate? Does that seem a little far? When you add in the converter moving forward? When the pump breaks, whats happening to it?

Quick question, do you shim your converter out any? or do you bolt it straight to flex plate?

I bolt it straight to the flexplate. You got me thinking that maybe I need to shim it. I am using a polyurethane mount and it is a stock bell housing. I thought a 1/4" was fine but maybe the flexing is causing it to pull out more than it needs to. When you shim, can you just use washers for the shims so it doesn't pull the convertor out as far? I am thinking this must be what is happening. Again, a th350, 2 th400's and now the PG all built by different people and all considered good trans builders.

I don't know enough about transmissions to know what is exactly breaking in it. Tomorrow when he pulls it apart I will take pictures of the broken parts. The good news is if I pull it in the morning and bring it to him he is going to fix it for me for free while I wait. I am thinking I need to use some washers and shim it some.

It is a big heavy car and its a Power glide. I am not sure it is better but my car sure picked up a bunch of ET with the change.

Yes you can use just a standard washer. What distance did the shops say was fine? 1/4" is a little more than you should have but idk if that's causing it. Normal 1/16"-1/8" is recommended and a standard washer is 1/8" thick so you could put one in there
As for it squatting on the brake that's normal don't worry about that.

I use washers, nothing wrong with that. I always go 1/8". making sure their is room for the pilot to extend into the crank. im thinking .200 for some reason rings a bell

Dave used to always say, no more the 3/16" and no less then 3/32"

Don't feel so bad. I broke my trans on Saturday morning. Made the 2-3 shift and lost the snap ring in the intermediate clutch pack. Took out the case, the direct drum and the intermediate clutches. Whoops.

I was never told anything. lol I guess you live and you learn. I just figured it had to not be butted against the fly wheel and not too far out to pull off the shaft. So I measured it and it was just a tad over a 1/4". So if I shim it with a washer or two to get it to 1/16" of an inch, it should be fine....or correct anyways? I am really thinking this is what is causing this issue now.

Maybe they assumed I knew and I shouldn't have assumed the way I did what was a correct distance.

Yeah, that does make me feel a little better. lol

Added a degree of timing, leaned it out a touch, and turned the meth on. It was a cool morning, car made 13psi of boost in second gear and when I grabbed third all hell broke loose. Smoke from the center console area. Then the stinky burned trans fluid smell. I got it apart and found the carnage. Probably about $500 or so worth of damage.

I work at a Trans shop and put trannys in every day. 1/4 inch is too far bud. Add in when your loading the converter up ie foot brake or Trans brake the converter is pushing towards the motor so figure it's already 1/4 inch out of the pump gears then how ever much it's flexing forward. Almost garentee your breaking the pump gears apart. That would be my guess with no pics. I mean come on a th3nhalf 2 400 now a power glide. And every one a pump? Either your your making more power then every other guy on earth or the converter is pulling to far out. Looks like its time to go to a lenco lol jk Space it out with washers you'll be good to go