Best way to address 1/2 shift problem
06-15-2011 | 11:25 PM
#21
The input housing had a billet shaft from RPM pressed into it along with the collar that Sonnax sells. I remember my builder remarking on how hard it was to press the shaft in. He said it went in much harder then the shafts he usually presses in. Also, there was no master spline so they had to be careful to line up the oil holes. I could swear he mentioned something about the check ball (not the one in the end of the input shaft for TCC) but not 100%. I can find out if you think that is something.....?
06-16-2011 | 10:56 AM
#22
Teching In
Joined: Jul 2009
Posts: 25
Likes: 0
This will be my last post for awhile as I am getting ready to head out for a week.
I agree, going back to the vette is your best bet at this point. I would rather have you do that than run your shift pressures lower that stock. Also, the Sonnax performance Pack calibration kit does not include accumulator valve springs and the original kit/mods you had may have changed this spring. The Sonnax kits shims the original spring and builds off that original calibration. We do this because there are way too many original springs and the T-Go etc springs cover the range with a broad stroke IMO. So there is a chance you have the Sonnax accumulator valve spring combined with an SK spring. This will contribute to a harder 1-2. The only way to get around this is to go back to an original spring from a trans with your exact model code. This can be a PITA. Far easier at this point is to swap back to the Vette servo. Hopefully your builder can work with you on that.
Gregg Nader
Sonnax Tech
I agree, going back to the vette is your best bet at this point. I would rather have you do that than run your shift pressures lower that stock. Also, the Sonnax performance Pack calibration kit does not include accumulator valve springs and the original kit/mods you had may have changed this spring. The Sonnax kits shims the original spring and builds off that original calibration. We do this because there are way too many original springs and the T-Go etc springs cover the range with a broad stroke IMO. So there is a chance you have the Sonnax accumulator valve spring combined with an SK spring. This will contribute to a harder 1-2. The only way to get around this is to go back to an original spring from a trans with your exact model code. This can be a PITA. Far easier at this point is to swap back to the Vette servo. Hopefully your builder can work with you on that.
Gregg Nader
Sonnax Tech
06-18-2011 | 10:13 PM
#23
Thread Starter
TECH Apprentice
Joined: Jul 2005
Posts: 375
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From: Utica, MI
He did install the shaft first before installing the collar.
The billet shafts always go in harder than the factory shafts IMO. Also if there is a sleeve on the drum before pressing the shaft in this might add to the resistance some. I personally always install the shaft first and then install the sleeve. Not sure what Gregg is thinking about with the input drum here unless he is looking at converter charge effecting the stall.
06-18-2011 | 10:17 PM
#24
Thread Starter
TECH Apprentice
Joined: Jul 2005
Posts: 375
Likes: 0
From: Utica, MI
Thanks Greg (and Vince), I believe he went back to the original, but not sure. I know he did a lot of checking, etc to ensure there wasn't old mods (springs, bigger holes, passages plugged, etc) that would intefere with this build. I'll let him know and we'll see if any of that is working against us here. Sounds like a vette servo swap at this point though. Thank you for your help and I'll be sure to post up my changes. Take care. 
This will be my last post for awhile as I am getting ready to head out for a week.
I agree, going back to the vette is your best bet at this point. I would rather have you do that than run your shift pressures lower that stock. Also, the Sonnax performance Pack calibration kit does not include accumulator valve springs and the original kit/mods you had may have changed this spring. The Sonnax kits shims the original spring and builds off that original calibration. We do this because there are way too many original springs and the T-Go etc springs cover the range with a broad stroke IMO. So there is a chance you have the Sonnax accumulator valve spring combined with an SK spring. This will contribute to a harder 1-2. The only way to get around this is to go back to an original spring from a trans with your exact model code. This can be a PITA. Far easier at this point is to swap back to the Vette servo. Hopefully your builder can work with you on that.
Gregg Nader
Sonnax Tech
I agree, going back to the vette is your best bet at this point. I would rather have you do that than run your shift pressures lower that stock. Also, the Sonnax performance Pack calibration kit does not include accumulator valve springs and the original kit/mods you had may have changed this spring. The Sonnax kits shims the original spring and builds off that original calibration. We do this because there are way too many original springs and the T-Go etc springs cover the range with a broad stroke IMO. So there is a chance you have the Sonnax accumulator valve spring combined with an SK spring. This will contribute to a harder 1-2. The only way to get around this is to go back to an original spring from a trans with your exact model code. This can be a PITA. Far easier at this point is to swap back to the Vette servo. Hopefully your builder can work with you on that.
Gregg Nader
Sonnax Tech
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