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Egan
07-05-2012, 03:33 AM
Installing the Corvette Servo in the H2 tranny:

The idea behind this part is that it firms up the 1-2 shift in our transmissions. For $18 shipped, I figured what the heck and ordered it from: http://www.oregonperformancetransmission.com/mm5/merchant.mvc?Store_Code=OPTI&Screen=PROD&Category_Code=4L60E&Product_Code=NTP-K51828C

The installation itself is easy enough and took about an hour.

Step 1: Remove the heatshield between the cat and the side of the tranny.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01956.jpg

Once removed, you?ll see the servo:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01957.jpg

Egan
07-05-2012, 03:34 AM
Step 2: Push in the servo cover, compressing the spring, and remove the clip that holds the cover in. I used the wonder bar:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01958.jpg

With the clip out, you can use pliers to pull the cover out. It will likely get stuck on the blue seal. The kit comes with a new blue seal, so I cut the old one out:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01960.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01961.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01962.jpg

Egan
07-05-2012, 03:35 AM
Step 3: Pull the cover out, exposing the 4th apply piston

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01963.jpg

Pull the 4th apply piston out, exposing the servo assembly:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01964.jpg

Egan
07-05-2012, 03:35 AM
Step 4: Pull the servo assembly out. There is a spring on the back side that will likely fall out:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01965.jpg

That spring was resting on the protrusion seen here. Make sure you put it back on before sliding the new servo back in:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01966.jpg

Egan
07-05-2012, 03:36 AM
Step 5: Remove the clip, washer, and spring from the 2nd apply piston. Simply push down on the washer and spring and pop the clip out:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01967.jpg

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01968.jpg

Then simply slide the shaft out:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01969.jpg

Egan
07-05-2012, 03:37 AM
Step 6: Disassemble the 2nd apply piston assembly. Start by compressing the cover (I used a c-clamp):

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01970.jpg

Once compressed, remove the circlip and uncompress the cover:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01971.jpg

Take the spring out of the existing servo housing and move it over to the new one:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01972.jpg

Egan
07-05-2012, 03:38 AM
Step 7: Reassemble the servo. Start by compressing the housing cover again and reinstalling the existing circlip.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01973.jpg

Unfortunately, I was only born with 2 hands, so I had to get some help:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01974.jpg

Next reinstall the shaft:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01975.jpg

And then slide the new housing over the piston. Make sure the seal is lubricated and fully seated:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01976.jpg

Next install the new red seal on the piston and reinstall the spring, washer, and clip to hold it all together:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01977.jpg

Egan
07-05-2012, 03:39 AM
Step 8: Reinsert the servo assembly into the transmission – make sure that spring that fell out in the beginning is in:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01978.jpg

Step 9: : Reinstall the 4th apply piston:

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01979.jpg

Install the new blue seal on the cover and push the cover in place. Again compress the cover and reinstall the original clip. I need an extra hand to do this. I also had to reseat the assembly a couple of times to get it to fully seat.

http://img.photobucket.com/albums/v482/Egan70/H2/DSC01980.jpg

Don’t forget to reinstall the heat shield after you check for leaks and proper operation.

Egan
07-05-2012, 03:41 AM
First impressions are a much longer, smoother shift between 1 and 2. I'll reassess after the 12 mile drive to work tomorrow.

[__--MUD--__]
07-05-2012, 04:15 AM
These guys have some pretty good **** for our trannies...few other things you can do w/ out yanking it out for 2-3 & OD. Plus 4l80 conversion kits if you realy want to say screw it.

http://www.transmissioncenter.net/4l60e.htm

pdxrealtor
07-05-2012, 07:37 AM
Another great write up! This , to me, was worth paying 45.00 to have done.

Much firmer shifts. 1st lasts much longer.

jsbihn
07-05-2012, 10:55 AM
MUD
There is alot of good stuff on there and most of it is surprisingly inexpensive

I assume when you refer to the 2-3 & OD, you are talking about overdrive billet servo?

Hellz
07-05-2012, 05:26 PM
well i tried to give a shot at this today, and i am stuck at step 1...well i dont have a heatshield to remove...

i can not get the housing to compress to remove the clip.
when you compress it, is the amountit compresses noticable, or are we talking thousandths of a inch here?

i tried using a pry bar.. that wasnt working and moved up to a crowbar.
i can get leverage on it, it just is not moving at all.

any thoughts?

Egan
07-05-2012, 07:24 PM
well i tried to give a shot at this today, and i am stuck at step 1...well i dont have a heatshield to remove...

i can not get the housing to compress to remove the clip.
when you compress it, is the amountit compresses noticable, or are we talking thousandths of a inch here?

i tried using a pry bar.. that wasnt working and moved up to a crowbar.
i can get leverage on it, it just is not moving at all.

any thoughts?

It moved a good 1/8 inch at least, if not 1/4 inch.

Hellz
07-05-2012, 08:17 PM
ya, its not moving at all.

i tried putting a socket in there and trying that route... no luck

i have an open shot at it from the wheel well, and tried using a hammers handle and slapping it to break it free.. still no luck..


going to drown it in some WD40 and let that sit for awhile

Egan
07-05-2012, 09:09 PM
ya, its not moving at all.

i tried putting a socket in there and trying that route... no luck

i have an open shot at it from the wheel well, and tried using a hammers handle and slapping it to break it free.. still no luck..


going to drown it in some WD40 and let that sit for awhile

This servo is pretty far from the wheel well. I was standing in between the arms of my lift when I was directly underneath it, and the forward arm is behind the front wheel by at least two feet.

pdxrealtor
07-05-2012, 09:18 PM
I was thinking the same thing, Egan. I actually went outside to check it out and it seems possible with the front wheel and fender well shroud off.

However, it doesn't look easy. With your second guessing combined with the fact there was no heat shield... Hellz.. are you sure you're in the right spot?

Hellz
07-05-2012, 09:51 PM
well it is some distance away.. but i do have clear access to it fromt eh wheel well.. i just wont have any leverage and would most likely need a 2nd person to help with it.

this is fromt the passenger side.

pdxrealtor
07-06-2012, 04:42 AM
Well goddamn.,.

Can you use a pipe, like a breaker bar, to get a good seat around the hump then tap it loose with a heavy hammer?

Sounds like it just needs to be loosened up and then you'd be good to go.

glennf1
07-09-2012, 03:44 AM
Glad to see this write up that is Hummer specific! Thanks!

guruerror
09-21-2012, 07:11 PM
Installing the Corvette Servo in the H2 tranny:

The idea behind this part is that it firms up the 1-2 shift in our transmissions. For $18 shipped, I figured what the heck and ordered it...

...The installation itself is easy enough and took about an hour....

Egan:

How much tranny fluid did you loose when you popped the servo out?

I guess I'm going to tackle this on Sunday or the next weekend, but wanted to verify how big of a mess it was going to make.

Thanks in advance.

Hellz
09-21-2012, 08:19 PM
i havent tried since my first attempt at installing this.

let me know how this goes for you. i couldnt get the lid to push in enough to dig the ring out. i figured there has to be years of grime built up around it.

Egan
09-21-2012, 08:30 PM
Egan:

How much tranny fluid did you loose when you popped the servo out?

I guess I'm going to tackle this on Sunday or the next weekend, but wanted to verify how big of a mess it was going to make.

Thanks in advance.

It was just a few drops, maybe a slight dribble for 30 seconds. Not enough that I needed to add any fluid.

guruerror
09-21-2012, 08:41 PM
It was just a few drops, maybe a slight dribble for 30 seconds. Not enough that I needed to add any fluid.
Sweet...thanks for the quick response.

i havent tried since my first attempt at installing this.

let me know how this goes for you. i couldnt get the lid to push in enough to dig the ring out. i figured there has to be years of grime built up around it.
I'll definitely post back results.

guruerror
09-21-2012, 08:49 PM
First impressions are a much longer, smoother shift between 1 and 2. I'll reassess after the 12 mile drive to work tomorrow.
What's your long term impressions?

Egan
09-22-2012, 06:51 PM
What's your long term impressions?

It's definitely worth the money. With the right amount of throttle the first gear pulls well and shifts smoothly.