48re shift issue

dangerous06

dangerous06

diesel tech
Joined
Mar 24, 2008
Messages
3,564
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.
 
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.
 
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.
 
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.
 
Toby Cashion said:
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.
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Ours is a sonnax.... huh maybe it could be those :doh:
 
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
 
LAmiller said:
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
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I was thinking all of the goerend transmissions with the constant pressure have the double spring.
 
LAmiller said:
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
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Are you inferring that you will feel engine braking at this moment?
 
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.
 
YOUNG GUNS15 said:
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.
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Exactly what I'm experiencing!!!!! So it's normal that sucks! Maybe a stock servo will help i'll ask Dave or gene!
 
dangerous06 said:
Exactly what I'm experiencing!!!!! So it's normal that sucks! Maybe a stock servo will help i'll ask Dave or gene!
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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.
 
YOUNG GUNS15 said:
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.
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Sorry got to busy today I will call on Monday and post a reply! As for
Less line pressure equals burned clutch packs!
 
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YOUNG GUNS15 said:
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.
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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.
 
zstroken said:
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.
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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.
 
YOUNG GUNS15 said:
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.
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So u put in a differnt lever? Would think at 150k some clearance would be there.
 
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.
 
YOUNG GUNS15 said:
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.
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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.
 
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