Questions about my 4l60e transmission
09-22-2017, 05:25 PM
#1
Burning Brakes
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Questions about my 4l60e transmission
Hi guys. I have a base 95 with the 4l60e transmission. I recently changed the fluid, the magnet had probably 1/8" of very fine particles/sludge on it and the pan was otherwise clean and not discolored. I changed the fluid because I was having a little hesitation when the car shifts down from OD to third. It goes into gear without fail and shifts up trough the gears when leaving a stop without hesitation or any problems I can tell. If I am driving at 45 or so and give it some throttle, it acts like it wants to but doesn't readily shift down to third , if I give it more than part throttle, it kicks right into third. I can also down shift manually into third and it selects the gear properly.
Hopefully I've explained the problem properly.
Question is, does it sound like the transmission is on the way out? Thanks for any help.
Hopefully I've explained the problem properly.
Question is, does it sound like the transmission is on the way out? Thanks for any help.
09-23-2017, 08:06 PM
#3
Team Owner
09-23-2017, 08:27 PM
#5
Team Owner
09-23-2017, 09:06 PM
#6
Le Mans Master
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C4 of Year Finalist (appearance mods) 2019
Even though the transmission is an automatic and not a manual it still has clutch friction plates; it actually has several sets within the trans and these are wear items. If by chance you are the kind of guy who puts his foot to the floor and keeps it there every once in a while why those wear parts tend to wear a little more. It's only natural. The material could be whats making up the sludge in the pan.
At some point the thin plates with the friction material need to be replaced and you'll have to take the car to a trans shop to have these replaced. There are actually some excellent videos on the tube that show professional people taking the 4l60e completely apart and explaining how each part functions and how they wear and what the symptoms of each part wearing out are.
It doesn't sound to me like its on the way out. Sounds normal. but after watching the vids you'll be able to determine if you have other issues. (ask me how I know)
At some point the thin plates with the friction material need to be replaced and you'll have to take the car to a trans shop to have these replaced. There are actually some excellent videos on the tube that show professional people taking the 4l60e completely apart and explaining how each part functions and how they wear and what the symptoms of each part wearing out are.
It doesn't sound to me like its on the way out. Sounds normal. but after watching the vids you'll be able to determine if you have other issues. (ask me how I know)
Last edited by Mr. Peabody; 09-23-2017 at 09:09 PM.
09-24-2017, 01:40 AM
#7
Melting Slicks
The sludge on the magnet is from the friction disc in the torque converter. Perfectly normal. The only clutch in a 4L60/60e that is subject to normal wear is the 3-4. Corvettes aren't hard on the 3-4 because they don't weigh a lot, have low Cd, and don't tow anything, so the transmission can't be loaded very much because the car accelerates so easily.
09-24-2017, 01:41 PM
#8
Melting Slicks
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Maybe.. But it isn't unusual for a 4L60 with 100K on it.
Transmissions run much dirtier than engines. Gears run together. There's the TCC clutch slipping on and off. They have bushings that all wear in.
It's not as bad as it sounds provided there's no significant pieces of metal on there. (Ripped up thrusts, ground up bearings.. stuff like that.)
Transmissions run much dirtier than engines. Gears run together. There's the TCC clutch slipping on and off. They have bushings that all wear in.
It's not as bad as it sounds provided there's no significant pieces of metal on there. (Ripped up thrusts, ground up bearings.. stuff like that.)
09-24-2017, 01:44 PM
#9
Melting Slicks
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If they ever did you'd burn through the paper lining pretty quickly and have no clutch.
They ride on a microscopic layer of ATF and that is why slipping is so bad for them. You burn that layer off and you're into the clutch.. And it won't last long.
Take a razor blade and poke a clutch lining sometime. it just comes right apart like cardboard.
09-24-2017, 02:52 PM
#10
Melting Slicks
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Something else.. If you drop line pressure in a 4L60/E for any reason, the first thing you lose is the 3/4 clutch. It is the first thing to go.
It is so sensitive a misadjusted TV will burn one on the test drive. (don't ask me how I know that) It's actually better if the cable just breaks completely rather than be adjusted improperly.
So, if you are doing a patch, you will want to address any issues associated with line pressure or it will burn again. Rings.. Leaky check capsule.. ETC.
The rest of the unit can look pretty good, actually.. But still eat 3/4 clutches up in a relatively short period of time.
It is so sensitive a misadjusted TV will burn one on the test drive. (don't ask me how I know that) It's actually better if the cable just breaks completely rather than be adjusted improperly.
So, if you are doing a patch, you will want to address any issues associated with line pressure or it will burn again. Rings.. Leaky check capsule.. ETC.
The rest of the unit can look pretty good, actually.. But still eat 3/4 clutches up in a relatively short period of time.
09-24-2017, 07:33 PM
#11
Melting Slicks
Because only the 3-4 comes on and off during normal driving. Ie, there is a speed mis-match between the elements while the shift is occurring. The Forward, Lo-Reverse, and Reverse Input are generally applied when the car is not moving. So there is no wear because of speed mis-match. They just apply.
Forward Clutch is always on in forward, and is applied at a stop. You work on these too. You've seen the lettering and markings still on the lining even after 100k miles. Forward doesn't wear at all.
Lo Reverse and over run: Only applied when moving if downshifting into manual ranges, or into D1 for the lo-reverse. Sure, these may wear some, but it is rare to have a failure caused by one of these "wearing out". They can fail for other reasons, but generally don't during a normal service life.
Reverse Input: Only applied in Reverse, and while at a stop.
Band: Does not generally wear. A long-time trick experienced builders use is to save good used bands for high-performance builds where a seasoned band will have the desired shift characteristics the first time, instead of requiring numerous shifts to break it in.
Again, you work on these. You know what I meant. Only the 3-4 comes off and on at speed. Most 700 / 60 / 60e "old-age" repairs are because the 3-4 wore out. Upon tear-down, the other frictions are usually just fine.
Forward Clutch is always on in forward, and is applied at a stop. You work on these too. You've seen the lettering and markings still on the lining even after 100k miles. Forward doesn't wear at all.
Lo Reverse and over run: Only applied when moving if downshifting into manual ranges, or into D1 for the lo-reverse. Sure, these may wear some, but it is rare to have a failure caused by one of these "wearing out". They can fail for other reasons, but generally don't during a normal service life.
Reverse Input: Only applied in Reverse, and while at a stop.
Band: Does not generally wear. A long-time trick experienced builders use is to save good used bands for high-performance builds where a seasoned band will have the desired shift characteristics the first time, instead of requiring numerous shifts to break it in.
Again, you work on these. You know what I meant. Only the 3-4 comes off and on at speed. Most 700 / 60 / 60e "old-age" repairs are because the 3-4 wore out. Upon tear-down, the other frictions are usually just fine.
09-24-2017, 09:41 PM
#12
Team Owner
The OP didn't specify, but I presume this was the accumulation on the magnet itself, not in the pan itself. The magnet is about 1-1/2" square. So 2.5 square inches. When I had my Blazer I towed a lot, and serviced the 60e every 30-35K miles. The accumulation on the magnet was always about "1/8th inch". That transmission lived to 185K before the 3-4 wore out. So to me the "1/8" inch is no big deal. The more the TC comes on and off, the more dust gets on the magnet.