48re shift issue

[dangerous06]

I've had this issue since it was built and only when floored going thru the gears. 1-2 shift is flawless 2-3 has a hesitation that will actually throw you forward in the seat and then throw you back. This is really enoying it's a second but that's to long when floored! Then 3-4 is to short as in it shifts to O.D. to fast and can seem to bog it some when it locks up. Under normal driving it's fine only when floored does it do this! Any ideas?! I'm running a Goerend Constant pressure valve body.

[Purn1973]

Mine had similar symptoms, the 2nd gear ridged band that I got from Suncoast had slipped on the drum and burnt, also fried most of my clutches and steels.
Went back to HD fiber clutches and HD flex band to cure the problem.

[YOUNG GUNS15]

I'm having the exact same problem with the 05 in my sig with the 2-3 shift, I've tried all sorts of adjustments on the front band but nothing has cleared it up. What Purn is saying makes sense. Unfortunately.

[Toby Cashion]

stock servo? I put a sonnex in mine and it did this, i think it has something to do with the aftermarket servo having to have more fluid to fill to release the 2nd gear band. I went back with a stock servo and shifts are perfectly smooth with no binding.

[YOUNG GUNS15]

Originally Posted by Toby Cashion

stock servo? I put a sonnex in mine and it did this, i think it has something to do with the aftermarket servo having to have more fluid to fill to release the 2nd gear band. I went back with a stock servo and shifts are perfectly smooth with no binding.

Ours is a sonnax.... huh maybe it could be those

[LAmiller]

If you have a double spring in the servo, and I've seen it in a few goerend transmissions, it will release the band too quickly causing it to go to 1st for a split second before applying 3rd.

Lavon

[zstroken]

Originally Posted by LAmiller

If you have a double spring in the servo, and I've seen it in a few goerend transmissions, it will release the band too quickly causing it to go to 1st for a split second before applying 3rd.

Lavon

I was thinking all of the goerend transmissions with the constant pressure have the double spring.

[dangerous06]

Yes they do !!HUH I'll give them a call to see if there is a fix!

[zstroken]

Originally Posted by LAmiller

If you have a double spring in the servo, and I've seen it in a few goerend transmissions, it will release the band too quickly causing it to go to 1st for a split second before applying 3rd.

Lavon

Are you inferring that you will feel engine braking at this moment?

[YOUNG GUNS15]

I don't think it's engine braking. I did a few data logs and on the 2-3 shift it would slow down for a split second about .5-1.5mph with the engine at full song. Doesn't sound like much but it wants to throw you forward in your seat hard.

[dangerous06]

Originally Posted by YOUNG GUNS15

I don't think it's engine braking. I did a few data logs and on the 2-3 shift it would slow down for a split second about .5-1.5mph with the engine at full song. Doesn't sound like much but it wants to throw you forward in your seat hard.

Exactly what I'm experiencing!!!!! So it's normal that sucks! Maybe a stock servo will help i'll ask Dave or gene!

[YOUNG GUNS15]

Originally Posted by dangerous06

Exactly what I'm experiencing!!!!! So it's normal that sucks! Maybe a stock servo will help i'll ask Dave or gene!

Post up what he says cause I've been fighting this issue for a while. Finally turned the line pressure way down in 3rd to make the flare less violent. Still there but barely noticeable now.

[dangerous06]

Originally Posted by YOUNG GUNS15

Post up what he says cause I've been fighting this issue for a while. Finally turned the line pressure way down in 3rd to make the flare less violent. Still there but barely noticeable now.

Sorry got to busy today I will call on Monday and post a reply! As for
Less line pressure equals burned clutch packs!

[YOUNG GUNS15]

Originally Posted by dangerous06

Sorry got to busy today I will call on Monday and post a reply! As for
Less line pressure equals burned clutch packs!

Yeah I understand that but the truck is making less than 400hp so I'm not concerned about it yet.

[zstroken]

Originally Posted by YOUNG GUNS15

Post up what he says cause I've been fighting this issue for a while. Finally turned the line pressure way down in 3rd to make the flare less violent. Still there but barely noticeable now.

What ratio lever are you running? What are your front clutch clearances? Both of those can impact the timing, as well as the band adjustment.

[YOUNG GUNS15]

Originally Posted by zstroken

What ratio lever are you running? What are your front clutch clearances? Both of those can impact the timing, as well as the band adjustment.

4.2 and whatever the factory sets the pack up at. We chose not to rebuild the transmission just yet. I've tried 2.5, 2, 1.75, and currently it's at 1.5 turns back off. Every adjustment acted the same. Transmission has 150k miles, we've had it since brand new so it's beer been rebuilt.

[zstroken]

Originally Posted by YOUNG GUNS15

4.2 and whatever the factory sets the pack up at. We chose not to rebuild the transmission just yet. I've tried 2.5, 2, 1.75, and currently it's at 1.5 turns back off. Every adjustment acted the same. Transmission has 150k miles, we've had it since brand new so it's beer been rebuilt.

So u put in a differnt lever? Would think at 150k some clearance would be there.

[YOUNG GUNS15]

Yes, it's a billet lever. I'm leaning towards the sonnax servo since it never flared before. I might buy a TCS to try before tearing into the transmission, the TCS in my 47re works flawlessly.

[bluthndr]

Originally Posted by YOUNG GUNS15

Yes, it's a billet lever. I'm leaning towards the sonnax servo since it never flared before. I might buy a TCS to try before tearing into the transmission, the TCS in my 47re works flawlessly.

I have a TCS in mine and it has a flare 2-3 at WOT. However, mine also has a 3.8 or 5.0 lever (can't remember - it's been years since I built it). It does NOT grab 1st in between and slow down however, and it ONLY happens when it is under pretty good power.

I am building one for a guy now with a sonnax servo and 4.2 lever and a good flex band, so we will see how it goes.