Allison 6sp: built trans poor shifting

[disposablehero]

Revmax built trans with stage 5 TC. She shifts really slow and soft on big tunes. Tried relearn but it still acts the same. Especially with a boosted launch. It seems to really hang during the 3-4 shift. Ar least I think its that shift. Am i missing something? In the tuning maybe? Tried a bt lockup bud but no improvement.

 

[plowboy_lbz]

Did you do a full relearn? Unless they have a tech II you would have to take it to a dealer.

 

[disposablehero]

Yes. Did a full relearn. Dave at draconian diesel had the stuff. Also tried with the cts.

 

[disposablehero]

Oh. And stock tune shifts fast and firm. And lowered throttle positions shift faster than big tune at wot.

 

[boominator]

Change your fuel filter

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[dmax711]

Oh. And stock tune shifts fast and firm. And lowered throttle positions shift faster than big tune at wot.

I'd work on tuning.

 

[duramaxdiesel]

I'm thinking tuning also.

 

[disposablehero]

What in the tune would cause that? Was thinking higher power making it blow past the shift point to where there isn't fueled? I'm trying to tune my own stuff. Fixed my lack of boost at low rpm. New fuel filter and brand new lift pump on the truck.

 

[LWATSON]

Sometimes you can drop rail preasure enough to draw out a shift and it wont drop quite enough to code and go into limp mode.

 

[disposablehero]

Plenty of fuel. Over 25k and holds. Lowest I've gotten it is to a 24.8 for barely a sec. So that shouldn't be an issue.

 

[Mike L.]

I think your problem is your own tuning. I don't think the big tuners here are going to help you with this.

 

[hondarider552]

If it shifts great with a stock tune, may want to go back to a stock tune and go back from square one. I wouldn't mess with the defuel tables.

 

[disposablehero]

So it's in the tuning. I've come to a few different avenues with tuning issues. I've heard rpm vs speed. Heard something about blowing past the shift point and there not being fuel tuned in at the higher rpm. Some say to avoid trying to tune the trans too much as well. Just played with the TC lock points to mimic th mode more. I guess I understand the big tuners not wanting to give out their tips and secrets. I know there are several ways to tune a truck. Maybe someone can point me in the right direction or name a table I can look at harder.

 

[xtremebikr04]

You could always post the tune up for people to look at and help point you in the right direction.

 

[dmax711]

Honestly I'd let someone that knows what their doing tune it. No offense to you, but nothing will kill a trans faster then shitty tuning.

 

[02CCSB]

I'll throw you a bone...bigger tires? Is your speedo correct (GPS'd)?

 

[Mike L.]

Honestly I'd let someone that knows what their doing tune it. No offense to you, but nothing will kill a trans faster then shitty tuning.

Amen to that.

 

[paint94979]

Take a log and post it... Should be pretty easy to see if its tune related

 

[disposablehero]

OK. I'll log it tomorrow. I was thinking the speed vs rpm thing. My speed is like 3% off.

 

[hondarider552]

Why do you need to mess with shift speeds?