3rd Gear Wall at WOT, Clutch Hydraulics, and Drill Mod
06-13-2018, 06:39 PM
#1
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3rd Gear Wall at WOT, Clutch Hydraulics, and Drill Mod
At wide open throttle I cannot get my 96 LT1 w/ T56 into 3rd gear. It is like hitting a wall and I am blocked out. Under normal driving it is fine. I have a LE 223/231 112 lsa cam car with 1.6 RR, a PCMforless tune, and a Ram HDX clutch.
I just purchased a new ACdelco master and slave cylinder to see if it is the clutch hydraulics. I am thinking the clutch is not disengaging fast enough during my 2nd to 3rd gear shift at wide open throttle. The hydraulics are original and 22 years old at this point.
Should I do the drill mod while I am at it? I read about the drill mod and saw some claim its only for the LS1 cars with an internal slave T56.
I just purchased a new ACdelco master and slave cylinder to see if it is the clutch hydraulics. I am thinking the clutch is not disengaging fast enough during my 2nd to 3rd gear shift at wide open throttle. The hydraulics are original and 22 years old at this point.
Should I do the drill mod while I am at it? I read about the drill mod and saw some claim its only for the LS1 cars with an internal slave T56.
06-14-2018, 10:54 AM
#2
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Location: Las Vegas
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Re: 3rd Gear Wall at WOT, Clutch Hydraulics, and Drill Mod
It sounds more like an internal issue to the transmission versus the hydraulics. If the hydraulics were the issue, you would expect to see the issue with all of the gears, all of the time. Since you already bought the parts, you can give it a whirl. Most of the issues I have read about that relate to the master/slave cylinders are in regard to hard shifting to 1st.
The T56 in the 4th gen fbody did have a known issue with the 3rd/4th shift fork being too soft a material. Replacement forks are made of steel to resolve the issue.
I would try the master/slave (be sure the system is bled properly), and if the issue persists, take it to a transmission shop for evaluation.
Another option for the master cylinder that fixes all of the complaints about the stocker: http://www.hawksmotorsports.com/93-9...-cylinder-kit/
The T56 in the 4th gen fbody did have a known issue with the 3rd/4th shift fork being too soft a material. Replacement forks are made of steel to resolve the issue.
I would try the master/slave (be sure the system is bled properly), and if the issue persists, take it to a transmission shop for evaluation.
Another option for the master cylinder that fixes all of the complaints about the stocker: http://www.hawksmotorsports.com/93-9...-cylinder-kit/
Last edited by DrewHMS97SS; 06-14-2018 at 10:58 AM.
06-14-2018, 06:17 PM
#3
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Location: Hell was full so they sent me to NJ
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Re: 3rd Gear Wall at WOT, Clutch Hydraulics, and Drill Mod
Look at the troubleshooting section of the T56 factory manual, courtesy of Shoebox:
http://shbox.com/1/t56_service_manual.pdf
http://shbox.com/1/t56_service_manual.pdf
06-20-2018, 02:33 PM
#4
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Join Date: Jun 2003
Posts: 1,083
Re: 3rd Gear Wall at WOT, Clutch Hydraulics, and Drill Mod
OP
if you have not yet swapped in the new hydraulics, 1st determine if you have a disengagement issue. Typically this occurs in 1st & reverse vs the 2-3 shift.
Just jack up rear end, start car, push clutch in and hold to floor and put in gear....do the rear tires move?
If they do you have a disengagement issue which is failing hydraulics. The LT1 hydraulics come as a sealed system so replace if the issue is "disengagement"
As mentioned the 3-4 shift fork (stock) is aluminum which has been known to bend so a replacement steel fork is recommended if that is the case. IDK if the 3-4 fork is used in the 2-3 shift though
There are other issues causing shifting issues (syncros)...but 1st confirm if you have a hydraulic issue
if your stock 20+ year old hydraulics are in fact good the fluid in them if it has never been replaced is long done. You can do the "ranger" method of flushing the fluid by using a suction device (turkey baster, plastic syringe) to remove the fluid in reservoir and replacing with new. Drive a little and repeat until the fluid becomes amber clear again.....or just replace the sealed hydraulics as a unit
no drill mods for LT1 hydraulics
if you have not yet swapped in the new hydraulics, 1st determine if you have a disengagement issue. Typically this occurs in 1st & reverse vs the 2-3 shift.
Just jack up rear end, start car, push clutch in and hold to floor and put in gear....do the rear tires move?
If they do you have a disengagement issue which is failing hydraulics. The LT1 hydraulics come as a sealed system so replace if the issue is "disengagement"
As mentioned the 3-4 shift fork (stock) is aluminum which has been known to bend so a replacement steel fork is recommended if that is the case. IDK if the 3-4 fork is used in the 2-3 shift though
There are other issues causing shifting issues (syncros)...but 1st confirm if you have a hydraulic issue
if your stock 20+ year old hydraulics are in fact good the fluid in them if it has never been replaced is long done. You can do the "ranger" method of flushing the fluid by using a suction device (turkey baster, plastic syringe) to remove the fluid in reservoir and replacing with new. Drive a little and repeat until the fluid becomes amber clear again.....or just replace the sealed hydraulics as a unit
no drill mods for LT1 hydraulics
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