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Bag Envy
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2,247 Posts
Discussion Starter · #1 ·
Ok so I searched through all the threads about this stuff and it really didn't make sense to me. I understand it's a cheap mod that's easy to do. But I'm curious why would you want firmer shifts? To me my truck shifts pretty smooth right now and I haven't re-geared or tuned it yet. And when someone says they have a "built" tranny is the servo(s) and the shift kit what they are talking about? I realize these might be real dumb questions..so I apologize in advance. I just wanna make sure my trans lasts as long as it possibly can so that's why I'm looking into all this.
 

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is Bi-Winning and a
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8,241 Posts
A tranny that shifts too smoothly is actually allowing some slippage to occur. This is bad for your tranny in the long run since it builds heat and excessive heat kills a transmission. The servo helps to firm and tighten the 2nd gear shift eliminating some of the slipping.
 

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GMFS Member
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1,034 Posts
Servo: the servo simply put: cleans up the shifting from 1-2 and 2-3, most feel like it slips going into 2nd and the servo helps to make it a firmer shift by having more apply pressure between the shifts.
 

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I don't have a truck
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10,439 Posts
A tranny that shifts too smoothly is actually allowing some slippage to occur. This is bad for your tranny in the long run since it builds heat and excessive heat kills a transmission. The servo helps to firm and tighten the 2nd gear shift eliminating some of the slipping.
Yes, it is better for the bands. Really though, a $20 servo is not going to make much of a difference, it's not the end all of transmission mods. If you want it to last you need to re-gear
 

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is Bi-Winning and a
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8,241 Posts
Yes, it is better for the bands. Really though, a $20 servo is not going to make much of a difference, it's not the end all of transmission mods. If you want it to last you need to re-gear
:shake: It just helps. I could feel a difference in my 2 gear shifts after the install though.
 

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Bag Envy
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2,247 Posts
Discussion Starter · #7 ·
OK now THAT makes sense to me. Luckily for me I don't drive my truck but maybe once or twice a week cause I have a DD. I knew re-gearing would save the trans but wasn't clear on all the servo stuff. I hate to ask this but could someone point me in the right direction of what to order? Would this be what I need? Or is there something better out there?
http://www.sonnax.com/part_summary.php?id=4757&pl=3
 

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Registered
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1,270 Posts
OK now THAT makes sense to me. Luckily for me I don't drive my truck but maybe once or twice a week cause I have a DD. I knew re-gearing would save the trans but wasn't clear on all the servo stuff. I hate to ask this but could someone point me in the right direction of what to order? Would this be what I need? Or is there something better out there?
http://www.sonnax.com/part_summary.php?id=4757&pl=3
I have a brand new one if you wanna buy it. I never got around to installing it. PM me a price and its yours.
 

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HOT AIR BALLOON OWNER
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14,932 Posts
Really though, a $20 servo is not going to make much of a difference, it's not the end all of transmission mods.
Exactly, it just doesn't do much. A bit firmer is all you get, mix w/ a TransGo and the 2-3 becomes quite a bit tighter as you stuff another accumulator spring in there to resist softening of the shifts as well as opening the fluid flow for the 2-3 and the boost valve.



Your going to want a corvette servo over the billet. I heard that the billet servo is more harsh on your tranny.
Trucks have different line pressure tables than the cars (5.7 stuff) with the 60E. Check it out in EFI live and shit. They have less pressure as they have the larger holding capacity so if they had both, you can induce banging. BTDT.

I spent a lot of time fucking with that to get nice shifts and once I started doing my own tuning with help, I found out the pressure differences...

That's why I love the TransGo vac modulated kit, takes the PCM out of the loop for line pressure. High vac = softer shifts, low/no vac = firm shifts

I would NOT build one of these units w/o the vac mod kit. $100 WELL spent.
 
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