Just want your opinions until I can call Performabuilt. My transmission seems to work fine until i start putting some boost behind it. I can lock it in 2nd and but some boost behind it with no problems(no slip), same with 3rd. However when it goes to shift 2-3 under boost it slips(goes right up to rev limiter). I don't notice it doing it under part throttle. Think it could be a shift solenoid?

Oh yea, its a LVL2 still under warranty.

Thanks in advance

 

Uh oh! Sounds like the old 3-4 clutch pack! At least it's under warranty! Are you in chestertown, md? That's like 1/2 hour from me!

 

Does the 3-4 clutch pack control the 2-3 shift? 3rd gear holds just fine it just has issues shifting 2-3 under boost.

Yes, I am in Chestertown MD.

 

bump looking for some insight on this

 

Is this a new condition that has happened without any changes to the vehicle?

The 3-4 clutch is just the name of the 3rd gear clutches. The actual control of this is a little more involved then just a solenoid and a set of clutches. Circuitry in the valve body involving different valves stroking, accumulation, seals, separator plate and also the tune of the vehicle all play a role here as well.

My advise to you and I'm sure Frank is going to tell you the same thing. Is to look to see if the actual command is present when the engine starts hitting the rev limiter. In some cases you will need to tune your computer for a lower commanded shift in order to make this happen. Keep in mind that MPH and RPM are both very important here. With the added boost and HP at WOT you shift tables might not be where they really need to be. Hope this helps some to determine where you issue is. Vince

 

[QUOTE=Vince B;4757532]Is this a new condition that has happened without any changes to the vehicle?

The only thing I changed was the pulley. I was doing some gradual throttle increase logs to watch my A/F. I never went past 70% throttle so it never saw any more boost then before the pulley change and it was shifting at about 4800. Do you think that I should manually hold it in second(with HP tuners) and create a couple #'s of boost and manually change it to third to see if it still starts to slip/flash?

 

Even a seemingly minor change such as a pulley swap can indeed cause symptoms like you're experiencing. Before you try anything else, you have to verify that the shift is actually being commanded. Locking it in 2nd and then commanding the shift yourself is not a bad idea, but you need to know what the PCM is commanding first.

What is the fluid condition?

Something else, do not let it miss upshifts too many more times as the 3/4 clutches will fail in a very short period of time.

If you'd like to discuss it in detail feel free to give me a call.

g

 

The shift is being commanded. I logged it tonight. Locking it in 2nd and commanding the shift myself did nothing. Increasing the line pressure did nothing. Any other ideas?

 

Does it rev like in neutral when 3rd is commanded?

 

yes when we command 3rd gear it just revs like neutral, but we can lock it in second and it can take the power with no slip, and can do the same in third with no slip, it just cant go from second to third with out slipping