Harsh downshift coming to a stop under 20 mph

[Chad]

I been driving my other truck and have had some weird down shifts. Typical example;

Coming up to a stop sign (always driving in tow/haul) as I brake truck drops down really hard into first gear. Always happens at about 15 mph. Very recent occurrence. Truck is built exactly as the truck in my signature EXCEPT the tranny is a PPE stage 4, and no lift on 285/55/20's and Caltracs.

It's harsh enough to post about, which I rarely do, and the tranny might have 35 k on it, not sure exactly on that. The tranny in my red truck, truck noted above in my sig, has 65k with absolutely no issues.

Thoughts?

 

[Dan@PPE]

Hi Chad! How you doing?


have you tried putting the trans in fast learn and resetting taps? When was the last time you changed the spin on filter? Does the trans temp have any effect on this issue?

 

[Bryce418]

I agree with Dan on the learn issue. Mine does that from time to time, but I blame that on it being purple

 

[Dirtymaxx03]

mine does it but only when cold. like sitting over night then pulling out of my neighborhood, as soon as i start to slow down it downshifts hard as hell

 

[paint94979]

reset taps, and change spin on... fixed mine

 

[D-MAX Mafia]

Can taps be reset with efilive? I havent messed with the trans side of tuning except to download a tune.

On the Droid X

 

[paint94979]

Can taps be reset with efilive? I havent messed with the trans side of tuning except to download a tune.

On the Droid X

yes sir... a Tech II+ is the only way to put our Allison's into fast learn though

 

[JoshH]

yes sir... a Tech II+ is the only way to put our Allison's into fast learn though

Snap-On scanners can do it now too. I just did mine the other day to check it out. It wouldn't work on my boss's 03 though.

 

[x MadMAX DIESEL]

How often are you supposed to change the spin on? And how would that have anything to do with it, just asking not that I know about autos... Mine does this too and everyone says its normal, which I personally think is bullshit. That has got to be doing damage!

 

[paint94979]

Snap-On scanners can do it now too. I just did mine the other day to check it out. It wouldn't work on my boss's 03 though.

interesting Josh thank you

 

[Chad]

Thanks guys. Got side tracked be back later tonight with responses!

 

[Mike L.]

Snap-On scanners can do it now too. I just did mine the other day to check it out. It wouldn't work on my boss's 03 though.

Then it doesn't work. The red brick is way behind the times.

 

[Chad]

Hi Chad! How you doing?


have you tried putting the trans in fast learn and resetting taps? When was the last time you changed the spin on filter? Does the trans temp have any effect on this issue?

Hey Dan! Doing good for the most part...I haven't put the trans in fast learn or reset the taps. I don't drive this truck hardly ever. I basically gave it to my son in law and I'll check if he has done the filter. He's usually good about maintenance, and i discussed tranny up keep recently but don't remember the outcome of the conversation. I've done my spin on a couple times...Strangely enough I think that the tranny has always run cooler than mine, but probably just the difference in the rotating mass in the wheels/tires.

I need to talk to you about some dual fuelers this year...

 

[Chad]

mine does it but only when cold. like sitting over night then pulling out of my neighborhood, as soon as i start to slow down it downshifts hard as hell

You know I think it may have only happened while it was cold. I had the truck for a week while my son in law was out of town and I was doing some work on my truck and am pretty sure it was the same as your case as I was usually only doing short runs for parts or to my production facility...

reset taps, and change spin on... fixed mine

Gonna make the boy do it, hopefully that will do it...He mentioned it a few weeks back. I'm not actually worried about the tranny to much I have faith in the build its just odd. My son in law has kept his foot out of it for a while now since getting his last (of several) ticket(s) for doing 3 HUGE burnouts with a cop right behind him. The officer was laughing as he wrote the ticket...LOL.

How often are you supposed to change the spin on? And how would that have anything to do with it, just asking not that I know about autos... Mine does this too and everyone says its normal, which I personally think is bullshit. That has got to be doing damage!

Yeah, really, how often should we be doing that?

 

[Chad]

10 posts to start a photo album??? Geez I guess I should have spend less time lurking and more time shooting my fool mouth off...anyway here's #10.

 

[Righteyeblind]

Definitely reset the taps otherwise you will not get full potential out of your trans. Mine used to do the same thing. Reset taps, changed spin on like and it was butter smooth.