Reverse input bleed holes
Thread Starter
TECH Junkie
Joined: Dec 2012
Posts: 3,605
Likes: 1,316
From: Iowa
Reverse input bleed holes I've seen lots of conflicting info out there, and would like to see it put to bed once and for all. What are peoples thoughts/beliefs/explanations for what they do with the reverse input bleed holes. Transgo has you install orafice cup plugs in oversized holes. Some install one cup and drill out the other hole. Some leave it alone. Some drill them both oversized. etc
What do you do and WHY?
What do you do and WHY?
TECH Junkie
Joined: May 2012
Posts: 3,046
Likes: 713
From: Poplarville, MS
I got this info from Dana.
Reverse/Input Drum
Do not install the restrictors in the reverse/input piston; the piston is fine "as is". I have seen and heard of reverse/input clutches glazing and clutch failures with these restrictors installed in anything that will go over 5,000 rpm.
Never use the restrictors that come in all the TransGo Shift kits for the reverse/input piston. Doing this will cause centrifuge problems if the motor goes over 5,500 rpm. If you have already installed them in the reverse/input piston, then drill "one" of the restrictors out to .065" - .070", to prevent the centrifuge problem already mentioned. I have several 700R4/4L60E's going over 8,000 rpm, and none of these have a clutch apply problem on the 2-3 shift.
Use the "waved" steel to replace the Belville steel. This will stop the metal contamination from the Belville eating the drum. Set the clutch clearance to .040" - .070". Always use the Turbulator steels as they get rid of the excess drag. The reverse apply feed hole in the separator plate should be .104".
Reverse/Input Drum
Do not install the restrictors in the reverse/input piston; the piston is fine "as is". I have seen and heard of reverse/input clutches glazing and clutch failures with these restrictors installed in anything that will go over 5,000 rpm.
Never use the restrictors that come in all the TransGo Shift kits for the reverse/input piston. Doing this will cause centrifuge problems if the motor goes over 5,500 rpm. If you have already installed them in the reverse/input piston, then drill "one" of the restrictors out to .065" - .070", to prevent the centrifuge problem already mentioned. I have several 700R4/4L60E's going over 8,000 rpm, and none of these have a clutch apply problem on the 2-3 shift.
Use the "waved" steel to replace the Belville steel. This will stop the metal contamination from the Belville eating the drum. Set the clutch clearance to .040" - .070". Always use the Turbulator steels as they get rid of the excess drag. The reverse apply feed hole in the separator plate should be .104".
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Joined: Aug 2010
Posts: 7,321
Likes: 527
From: Ann Arbor, MI
IMHO, one problem with the HD2 kit is that it was originally designed for very early 4L60E.
Due to upgrades by GM, things like modifying the Reverse piston and grinding the manual valve don't apply to '98+ units.
If Dana (PBA) says not to mess with the Reverse piston, even for early year ones, I would take that advice.
Reverse Apply Feed hole - position the separator plate so that the accumulator section is in the lower right corner. Then the Reverse feed hole is in the upper left corner near the cutout. Looks like my (handy) stock '99 separator plate is already drilled to .110".
Due to upgrades by GM, things like modifying the Reverse piston and grinding the manual valve don't apply to '98+ units.
If Dana (PBA) says not to mess with the Reverse piston, even for early year ones, I would take that advice.
Reverse Apply Feed hole - position the separator plate so that the accumulator section is in the lower right corner. Then the Reverse feed hole is in the upper left corner near the cutout. Looks like my (handy) stock '99 separator plate is already drilled to .110".