Loss Of Power After Transmission Rebuilt.

[Evictor306]

Hey guys, I Just had my transmission rebuilt at a local shop. It was a complete rebuild. I get the truck back and it does shift better in general. Better shifting at light throttle. Doesn't hang between gears. BUT, I have noticed a loss of power throughout the whole range while at WOT. To the point where my 0-60 is almost a full second slower???
And the other issue is, say when I'm pulling into a parking lot at very light throttle, and right when its about to shift into second I let off the gas. Sometimes it'll stay in first, other times it will shift into 2nd and there will be a clank sound. That is if I let off the gas.
Any info on whats going on is very much appreciated. And btw, when it comes to transmissions, I know NOTHING...

 

[NSDQ]

the 1st to 2nd thing sounds like the notorious "hunting" problem that the 48RE has. Even though the shop replaced the big components like the bands and steels and things like that, they may not have replaced the governor pressure solenoid. the GPS gets clogged, causing it to "hunt" for what gear it's in, notoriously between 1st and 2nd gears. Most guys do a GM solenoid conversion. It's supposed to be a better solenoid and usually does the trick. The clank sound and the loss of power I'm not sure what that is all about.

 

[Evictor306]

Yeah I bought an upgrade governor pressure solenoid kit from one of the supporting vendors here. But who knows if the shop actually installed it or not. I also bought the shift kit for them to install.

 

[NSDQ]

I'm sure they installed it. Not sure what the problem is then.

 

[yellowfever#154]

Sounds like you better go back and talk with the guys who rebuilt it.

 

[dcapita]

Sounds like you better go back and talk with the guys who rebuilt it.

absolutely

 

[phxpoolguy]

Did they replace torque converter or at least flush the old one?

 

[Evictor306]

A quick update. Sorry it took almost a month to respond back. Work, roof damage and life all got in the way. Anyways, I kept having issues with the transmission. I'd check the fluid and it would be crazy low on the dipstick. I'd take it back the shop and they would refill it, scratch their heads and say there you go. A few days later I'd check it again, and still low. Still acting squarely. Take it back and same thing. Well eventually it got to where i couldn't even get out of the damn driveway with it. Had it towed the the shop where they admitted they might not of filled it up completely the first time. So the rebuilt the whole thing, again. Just got it back today. We'll see how it does. Oh, and I found out that they first time they filled the transmission with that auto zone fluid. It has Royal Purple in it now...They said it took only 12 quarts. I thought it was 14?

 

[VENOMOUS1 RACING]

A quick update. Sorry it took almost a month to respond back. Work, roof damage and life all got in the way. Anyways, I kept having issues with the transmission. I'd check the fluid and it would be crazy low on the dipstick. I'd take it back the shop and they would refill it, scratch their heads and say there you go. A few days later I'd check it again, and still low. Still acting squarely. Take it back and same thing. Well eventually it got to where i couldn't even get out of the damn driveway with it. Had it towed the the shop where they admitted they might not of filled it up completely the first time. So the rebuilt the whole thing, again. Just got it back today. We'll see how it does. Oh, and I found out that they first time they filled the transmission with that auto zone fluid. It has Royal Purple in it now...They said it took only 12 quarts. I thought it was 14?

Sounds like torque converter clutches slipping maybe? Something ain't right. Are they familiar with the 48re?

 

[SlvrSnake]

Sounds like they never filled the TQ with fluid when you had it done the first time. If it wasn't leaking that is the only place the fluid could've been going that I can think of.