It’s a brand new loaded drum straight from GM. I assume it’s a sealing ring issue. Probably just ask them to swap in a new updated pump cover at this rate even if I have to pay for it.
It’s a risk for sure, but I like to know what’s really going on. I was hopeful it was just a misassembly of the valve body, and I could correct it myself.
It was at one of the more reputable shops in my area, and it was my original trans that was rebuilt. $4k with several Sonnax upgraded parts included. I wish I could have done it myself, but the right shoulder isn't what it used to be.
You Bet. $3100 + 7.75% tax my cost with a $2000 core for a SRTA unit. I wouldn't have gotten the piston that helps prevent 4/5/6 clutch coning and a few other minor upgrades. I would still have needed to get it installed which runs about $1200 in my area. The warranty would have been better no doubt, but with the wife and I working different schedules, this shop being 4 blocks from work was very convenient. They have also been very good to work with so far.
A GM reman won't have the Sonnax upgrade parts just like a Ford reman won't have them.
Not sure what those are, but the original lasted him over 200K and AC Delco does include improvements as they come along. Plus the independent shops don't have the advanced equipment for rebuilding and testing that a re-manufacturer does. If they did, they would have caught the issues OP is experiencing BEFORE the transmission was installed back in the vehicle. Now they will have to R&R it all over again and eat those costs plus the fix it's needs. I'm sure they will try and do it as quick as possible and probably take some short cuts along the way. Not a good situation for both parties.
I nursed it to get there. It had a broken wave plate in the 2/6 clutch pack for some time, and the 4/5/6 clutches were coned significantly and completely used up. I do agree with your points presented, especially catching it before it left, though a vacuum tester and simple blow gun for air checking are not expensive, and any reputable shop should invest in the tools to prevent comebacks.
You really need a transmission dyno to test the rebuild in simulated on-road conditions. Not sure what they cost, 6 figures?, so few independent shops will have one. 15 years ago my 94 Cadillac Fleetwood needed a transmission. I was going take it and put it back in to save as much money as possible. The local shops wanted $800 to $1200 to rebuild it, but what happens if it doesn't work right? Even if they repair it, I would still have to take it out and put it back in. Not fun with car on jack stands in my driveway. Got an AC Delco for $1250 instead knowing it would be fully tested before leaving the factory. Been fine ever since.
I've been on both sides. I've rebuilt quite a few for myself and others, and had shops do the rebuild with my installation. A lot of Turbo 350s and 400s from a local shop back in the day when we actually had a 1/4 mile track here, to the 200-4R I got from Bowtie Overdrives that I currently run in the Nova now. I wanted more than just a stock rebuild configured to the original factory specifications, with the factory weaknesses. Honestly I believe these transmissions have a lot to be desired in the shift quality department. Even the 6L90 in my work truck is too soft and sometimes erratic. Once the cross leak is fixed, I will dial it in with HP Tuners and be on my way. If it blows up, I'll just fix it again. A waste of money? Sure. But if I've got to have a vice, this is it.
Would I be correct to assume there should be zero leakage through the 1/2/3/4 feed port when air is aplied to 3/5/R circuit?
You heard correct. There is a minor leak at the 1/2/3/4, and air bleeds into the 1/2/3/4 from the 3/5/R initially, and it seals up with a little pop after a second or two. They did put a Sonnax billet 1/2/3/4 piston in at my request. Do you think it more likely a sealing ring issue causing a cross leak, or the swapping of the piston?
And now you get to see another. I figured you would get it right, without even seeing the unit.
