Allison 5sp: Build 2.0

[DAVe3283]

same thing i learned long ago. i thought a hard 3-4th shift at WOT was normal in a built trans and it was really pissing me off. i have threads from 2010ish IIRC that ask about the bad shift i was getting. never got them fully fixed and shifting butter smooth till mike refreshed the trans the first time and steve tuned the truck. i was so damn giddy from the smooth shifts i had a really hard time staying off the throttle . its a great feelin aint it

Yes, I'm loving the smooth shifts again! It is hard to stay out of the throttle on the freeway, I just want to click off another gear. The problem is my 3->4 shift is north of 70 MPH, and my 4->5 is at almost 100 if I'm standing on it, and the cops don't like that so much

 

[04LB7yz]

I have a suncoast g max 5 kit with a precison converter with about 20,000 and at WOT it shifts really nice and smooth. But if i get on the throttle hard let off and then hit the breaks hard, the down shifts are pretty violent. Is this normal with a built trans or do i have something wrong?

Also i am running built trans tuning by duramaxtuner

 

[Chevy1925]

Yes, I'm loving the smooth shifts again! It is hard to stay out of the throttle on the freeway, I just want to click off another gear. The problem is my 3->4 shift is north of 70 MPH, and my 4->5 is at almost 100 if I'm standing on it, and the cops don't like that so much

lots of highway pulls :rofl: :angel:

 

[Duramax One]

i thought a hard 3-4th shift at WOT was normal in a built trans and it was really pissing me off. i have threads from 2010ish IIRC that ask about the bad shift i was getting. never got them fully fixed and shifting butter smooth till mike refreshed the trans the first time and steve tuned the truck. i was so damn giddy from the smooth shifts i had a really hard time staying off the throttle . its a great feelin aint it

This right here has me worried. My truck isn't liking the 3-4 shift every couple of times it goes through that range. Other times it flares the shifts. I had assumed it was something a built transmission does because it's been doing it since I started making some power ~1000 miles after the built trans. I've only got 7,000 miles on the build, so I'm hoping it's something as simple as the trim springs.

 

[SmokeShow]

Stupid question I suppose but how is a built trans supposed to feel/shift in normal, everyday part-throttle driving? Like stock or different? Mine pretty much clicks them off pretty good at WOT but it can be finicky at part throttle. Its a Merchant-built SCIII from probably around 2005/06. I'd guess it has about 75K-100K miles on it? It no longer has the SC converter though, it went tit's up maybe 15K miles ago. So I put a [loud ass] rebuilt ATS 5 star converter in it b/c the price was right. Its as loud as a dual disc clutch in a manual transmission. Knowing my luck, the rattling is probably from the converter being facocked or the flexplate cracked ain't it?

 

[Chevy1925]

Stupid question I suppose but how is a built trans supposed to feel/shift in normal, everyday part-throttle driving? Like stock or different? Mine pretty much clicks them off pretty good at WOT but it can be finicky at part throttle. Its a Merchant-built SCIII from probably around 2005/06. I'd guess it has about 75K-100K miles on it? It no longer has the SC converter though, it went tit's up maybe 15K miles ago. So I put a [loud ass] rebuilt ATS 5 star converter in it b/c the price was right. Its as loud as a dual disc clutch in a manual transmission. Knowing my luck, the rattling is probably from the converter being facocked or the flexplate cracked ain't it?

it ought to feel like stock. if you rode in my truck, you would never know its built for 800hp till the converter locks up (doesnt hit hard but definitely more than a stock converter). shifts before and after lock up are smooth and quick though. being your converter died, did you inspect the internal filter? that can hurt the clutches if the converter plugged the filter (done that myself). Mikes springs helped the part throttle shifts smooth out even more but as im told by him, they wont affect WOT shifts unless there is something really wrong with them due to their spring rate.

yeah the rattle could be either. the ats converters arent nice to stock flex plates

 

[MAXX IT OUT]

Since we are talking builds, bad shifts and stuff here, I have a question. I am getting ready to put in a set off Mikes trim and shift springs in, and replace both filters. Should I replace anything else while I have the pan down. Is it worth doing a flush or just refilling the fluid?

 

[Mike L.]

Check internal harness for leaks at the connector. Eventually it will leak and cause weird problems.

 

[Yellow Jacket]

This right here has me worried. My truck isn't liking the 3-4 shift every couple of times it goes through that range. Other times it flares the shifts. I had assumed it was something a built transmission does because it's been doing it since I started making some power ~1000 miles after the built trans. I've only got 7,000 miles on the build, so I'm hoping it's something as simple as the trim springs.

Change Fuel filters too.