4L60 #1 dead.....
11-10-2004, 03:59 PM
#13
TECH Junkie
My Radix powered Tahoe killed 6 4L60Es before I went with a 4L80E.If you decide to build the 4L60E go with vacuum controlled line pressures,make sure the builder knows the truck is supercharged so a check can be installed in the vacuum line.It's my oppinion that the PCM's "Torque Management"reduction of line pressure does more harm than good in a high horsepower applications.
11-13-2004, 11:12 AM
#17
If you get a chance to compare design schematics of 4L6X and the 4L8X you will notice something interesting...
The 4L60/65 is really a two-speed transmission with overdrive.
-two planetaries
-overdrives low for "second"
-overdrives direct for "fourth"
-band engages overdrive
-clutch pack engages direct
The 4L80/85 is actually a 3-speed trans with overdrive.
-three planetaries
-clutch pack for forward (first)
-clutch pack for intermediate (second)
-clutch pack for direct (third)
-clutch pack for overdrive (fourth)
-has 2 bands, but they are for reverse and overrun, NOT shifting
The problem with bands used for shifting is that they cannot be overworked without becoming harsh. The band is wrapped around the reverse input clutch drum in the 4L60 and is used for second and fourth. The more pressure is put on a band the more self energizing they become, and it will start grabbing, causing jolting shifts instead of firm shifts.
The 80 uses only clutch packs to shift and each shift is a single event. It is more more precise, responds much more linearly to line pressure increases or to a shift kit, and it transfers power effortlessly.
The 80/85 is not just stronger, it's designed far better.
The 4L60/65 is really a two-speed transmission with overdrive.
-two planetaries
-overdrives low for "second"
-overdrives direct for "fourth"
-band engages overdrive
-clutch pack engages direct
The 4L80/85 is actually a 3-speed trans with overdrive.
-three planetaries
-clutch pack for forward (first)
-clutch pack for intermediate (second)
-clutch pack for direct (third)
-clutch pack for overdrive (fourth)
-has 2 bands, but they are for reverse and overrun, NOT shifting
The problem with bands used for shifting is that they cannot be overworked without becoming harsh. The band is wrapped around the reverse input clutch drum in the 4L60 and is used for second and fourth. The more pressure is put on a band the more self energizing they become, and it will start grabbing, causing jolting shifts instead of firm shifts.
The 80 uses only clutch packs to shift and each shift is a single event. It is more more precise, responds much more linearly to line pressure increases or to a shift kit, and it transfers power effortlessly.
The 80/85 is not just stronger, it's designed far better.
11-13-2004, 02:48 PM
#18
TECH Apprentice
Join Date: Aug 2003
Location: Newport News, Va
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I have blown up 2 4L65E trannys. I am on my third one at the moment. I just bought a high performance GM unit. I hope this one holds up. Its really a 4L60E. I got a one year warranty so we will see what happens.
11-13-2004, 03:07 PM
#19
Originally Posted by James B.
If you get a chance to compare design schematics of 4L6X and the 4L8X you will notice something interesting...
The 4L60/65 is really a two-speed transmission with overdrive.
-two planetaries
-overdrives low for "second"
-overdrives direct for "fourth"
-band engages overdrive
-clutch pack engages direct
The 4L80/85 is actually a 3-speed trans with overdrive.
-three planetaries
-clutch pack for forward (first)
-clutch pack for intermediate (second)
-clutch pack for direct (third)
-clutch pack for overdrive (fourth)
-has 2 bands, but they are for reverse and overrun, NOT shifting
The problem with bands used for shifting is that they cannot be overworked without becoming harsh. The band is wrapped around the reverse input clutch drum in the 4L60 and is used for second and fourth. The more pressure is put on a band the more self energizing they become, and it will start grabbing, causing jolting shifts instead of firm shifts.
The 80 uses only clutch packs to shift and each shift is a single event. It is more more precise, responds much more linearly to line pressure increases or to a shift kit, and it transfers power effortlessly.
The 80/85 is not just stronger, it's designed far better.
The 4L60/65 is really a two-speed transmission with overdrive.
-two planetaries
-overdrives low for "second"
-overdrives direct for "fourth"
-band engages overdrive
-clutch pack engages direct
The 4L80/85 is actually a 3-speed trans with overdrive.
-three planetaries
-clutch pack for forward (first)
-clutch pack for intermediate (second)
-clutch pack for direct (third)
-clutch pack for overdrive (fourth)
-has 2 bands, but they are for reverse and overrun, NOT shifting
The problem with bands used for shifting is that they cannot be overworked without becoming harsh. The band is wrapped around the reverse input clutch drum in the 4L60 and is used for second and fourth. The more pressure is put on a band the more self energizing they become, and it will start grabbing, causing jolting shifts instead of firm shifts.
The 80 uses only clutch packs to shift and each shift is a single event. It is more more precise, responds much more linearly to line pressure increases or to a shift kit, and it transfers power effortlessly.
The 80/85 is not just stronger, it's designed far better.
Same with 4l80e/4l85e.
Philip S.
