ISOrabbitsfoot

I installed the trans in good, everything works but 1-2 shifts hard. Is this common in a fresh rebuilt? Does it just need to be "broken in" right?

mrvedit

A hard shift indicates that either the line pressure is too high or there is a problem in the 1-2 accumulator. Was a shift kit installed?

Line pressure that is too high is often caused by a sensor problem (MAF, TPS or MAP).
The proper way to diagnose this is to hook up a scanner and a pressure gauge to the trans. The scanner will tell what pressure is commanded and the gauge will confirm or refute it. A "ATD-5550" pressure gauge is only $32 on Amazon with prime shipping.

The only way to diagnose a 1-2 accumulator problem is to remove the pan, filter and then the dome-shaped accumulator cover which has only 3 screws. Take out the internals and post a picture of it. This will tell us if a shift kit was installed and we will look closely for cracks in the piston.

ISOrabbitsfoot

I'll have to check into that this weekend but I noticed that when I was driving up a pretty steep graded highway and went into passing gear it would feel like it would slip for a second in about 5-10 second intervals but only in passing gear. It wasn't a rough kind of slip it was almost like a smooth slip I guess you would say.

ISOrabbitsfoot

So I talked to the guy that rebuilt my trans.. He said that he didn't put a shift kit in it and that he turned up the line pressure so it would last longer. That doesn't make sense to me. On a fresh rebuild like this, will it ruin the trans faster with the higher line pressure?

mrvedit

A modest/moderate increase in line pressure will reduce how long the clutches slip during a shift and therefore will increase the life of the trans. Builders typically do this by adjusting the screw in the Pressure Control Solenoid (PCS) which unfortunately increases line pressure for all throttle positions. I prefer to increase it in the tune so that I can leave it soft while driving Ms Daisy, but quickly firm up when I run with more throttle.

Camaro396

iTrader: (14)

I'd rather have a firm shift than a sloppy flare feeling shift.

mrvedit

Installing a shift kit will greatly firm up the shifts. Its all relative - by "driving Ms Daisy" I meant not chirping the tires during light throttle. The combination of a shift kit (Transgo or Sonnax) and tuning will satisfy everyone needs and preferences.

ISOrabbitsfoot

I've got a question..this is located below the throttle body, what is this and do I need to have this hooked up? I checked and there is no vacuum on it.

mrvedit

It is part of the PCV system. I don't know what the "stock" hookup is as I don't have a stock setup.

bbond105

You need some kind of PCV system. Can you post a pic of a wider angle, that pic is in too close to see what is going on with the PVC? Normally a hose would run from there to the TB on that same side. On the early LS1’s a hose from the both valve covers with a PCV valve in the line wound go to that side of the TB.

ISOrabbitsfoot

Hopefully this'll help

bbond105

I’m not sure on the truck engines. My brother has an 06 truck I will take a look when I get home this evening.

bbond105

Here is a pic of a stock 06 Truck 6.0L PCV set up. The hose runs from the back of the driver’s side valve cover to the middle top of the intake. In the pic it is the hose that plugs into the top of the intake between the V in the wiring harness.
It looks like someone has changed the valley cover or installed a different engine.

mrvedit

6.0/6.2 valley covers are available with and without that PCV hose connector. I suspect a lot of variations are possible, perhaps different for CA, etc. Therefore I wouldn't jump to the conclusion that the cover or engine was changed.