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thick vs thin powerglide clutches

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#1 ·
why would you use a thinner clutch pack vs a thicker clutch pack..if one instance you could fit 7 thinner frictions and steels or 6 thicker .i just had a trans redone the high gear had 7 clutches in it but they were really thin and with the taper on the steel hub they look to be skipping teeth it was missing a few of the cogs .the hub was replaced with another steel hub but no taper. the drum had to be machined to fit the thicker clutch pack .now only has 6 cluches ..what would the difference be and why would you use one vs the other .
6 thick vs 7 thin .
the 7steels/frictions had heat marks but im pretty sure that was due to lack of pump pressure...
 
#2 ·
More clutches will provide more holding power in high gear. Sometimes in conjunction with increased line pressure. But, you need to check as you found out when trying to run additional frictions to ensure they won't ride up onto the edge of the high gear hub. You can run 8 thin frictions in an OEM drum if you properly machine the piston. One other mistake I've seen people do is machine the piston too short and then have the first steel stacked on it get bound up in the drum at the bottom of the notches.
 
#3 ·
The use of extra clutches is said to add torque capacity to the clutch pack and shorten shift time from start to finish by reducing slip during application.There comes a point when the extra clutches burn because of the use of them in conjunction with thinner steel plates.Extra clutches with thin steels start to compromise the clutch pack because the thin steels cannot absorb and transfer the heat geberated during a ratio change.There also comes a point when extra clutches rob horsepower when they are not applied because the must be rotated when not in use and cause parasitic drag.Each application is different and every seasoned pro has his choice of what works with his combination.With a th400 you can use 6 direct clutches and stock thin steels and the clutch pack is never compromised.With a 2004r you can use 8 thin clutches and 8 thin steels and burn them everytime.However with a 2004r you can use thin clutches and oversize steels and have extremely long lasting direct clutch pack.As for a glideI have done enough to know that 6 clutches and 6 stock thickness steels will function all year at 1000 hp in a full weight car without issues.Beyond that I would go go to 7 and after that dont know.
 
#4 ·
so even if the friction mateirial is thinner it will hold more with added steels and frictions ..i figured the thicker steels and frictions would withstand the heat better ..we did pull out the old stock steels and borg warner frictions and replace them with alto/coline (sp).in the high gear and reverse ..the pump was all scored up and on the test stand was only putting out around 28-32 lbs of pressure at 4500 rpm ..then new pump is at 200 .im not a trans guy at all but im trying to get more involved in some of the parts of building that i always just relied on others for ..
 
#6 ·
If you use the nitrided (Kolene) steels make sure to give them a quick lookover. Many ship out with a gunky coating still on them. I prefer to use solvent (mineral spirits) and a Scotchbrite pad to remove that with. They'll look like a dull grey color when cleaned; not the darker black as they sometimes ship. Don't sand them; the finish needs to be smooth.