What broke in your 4L60E?
01-07-2006, 04:03 AM
#1
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What broke in your 4L60E?
I have been trying to come up with a list of the 4L60E's weak points, since so many of the posts here are about problems with this tranny. I am no expert in this transmission, for sure, but if enough people post with answers, we can probably get a pretty good idea of what needs to be upgraded. This would be a big help when shopping for a rebuild or if someone attempts to DIY.
If we get some decent responses, I will make this a "permanent" sticky.
Rich
If we get some decent responses, I will make this a "permanent" sticky.
Rich
01-07-2006, 04:08 AM
#2
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Join Date: Mar 2003
Location: Palm City, Florida
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Re: What broke in your 4L60E?
I don't remember the exact details....I think the 3-4 sprag was shot and the stator was worn. Hopefully Frank can chime in here and correct me.
Once again, great thread. I like the idea
Once again, great thread. I like the idea
01-07-2006, 04:12 AM
#3
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Re: What broke in your 4L60E?
Originally Posted by Cmr0z28
I don't remember the exact details....I think the 3-4 sprag was shot and the stator was worn. Hopefully Frank can chime in here and correct me.
Once again, great thread. I like the idea
Once again, great thread. I like the idea
Rich
01-07-2006, 07:05 AM
#4
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Join Date: Apr 2001
Location: Calimesa, California. US
Posts: 716
Re: What broke in your 4L60E?
The 3-4 clutch pack is the Number one problem with these units, not enough clutch area. From there the sun shell on the early 2000's were soft and would strip out the teeth. The input drum will break at the 3-4 clutch lugs, & forward lugs occasionally. Sometimes the forward aluminum piston would crack, I have these Cryoed to prevent this. Rarely, the overrun hub would shear the teeth off. Not enough line pressure, which will burn up the 3-4 clutches, and the 3rd gear feed hole in the valve body plate is way too small to keep the 3-4 clutch pack alive with anything above about 450-475 horsepower. Planetaries rarely fail. This is with 1996 & later units. As for improvements, the Borg Warner clutch material (Hi-Energy), on the 3-4 setup will work fine, but you will need to increase the count to 7 (at a bare minimum), to 8 or 9. With the "right" torque converter, they can last for quite awhile. HD sunshell from GM or the aftermarket Beast sunshell will be needed. The electronics have caused problems on occasion, that is why I use the Vacuum modulator, from Trans-Go to control WOT shift pressure. These are some of the necessary upgrades to make these units last.
01-07-2006, 10:16 AM
#5
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Join Date: Mar 2002
Location: Newark, Delaware
Posts: 3,634
Re: What broke in your 4L60E?
We've solved all the clutch pack failure problems in the '60E. For the longest time, our biggest obstacle was the output shaft being the weakest point in our high HP racing transmissions. There were signs in the few that broke that the front internal hub went first, and then took the output shaft with it. The release of the 4L65E front internal support seemed to help this. We include the 65E part in out "pro Race" build. The output shaft itself is also replaced by a '65E shaft in our "Pro Race" units. The '65E output shaft is shot peened. We also use a wider bushing in the rear sun gear to give the front internal hub more stability.
The weaker "single cage" SKF input sprags start to go when you apply too much HP. We always "update" them to the much stronger 700 style "double cage" design. GM claims they redesigned the races to help the "single cage" design, but they still fail. WE use the better 700 style in ALL of our 700 / 4L60E rebuilds. We can get away with replacing just the "single cage" elements in units that haven't already destroyed the sprag. If the sprag has already failed, it will require the inner and outer races to be replaced, also.
In stock form, the 3-4 clutches are very prone to failure. This is due to several contributing factors. First being the "load release" springs GM installs in the clutch pack itself. They were intended to push the top and bottom pressure plates apart to prevent the clutches from dragging at high RPM's. Yea, it looks good on paper...but...if you reinstall them, you'll burn up the 3-4's repeatedly. To further complicate this matter, Trans-Go missed the boat completely here, and offers STRONGER springs for the clutch pack! Then again, Trans-Go shift kits contribute to many other transmission failures. Their vacuum modulator idea for the 4L60E is among the worst things you can do to a 4L60E. We have 4L60E's being shifted at 7000 RPM's without any "load release" springs that are surviving just fine.
Another contributing factor for 3-4 burn up is pressure. Most people don't know that the 700 / 4L60E is designed to start dropping pressure at around 5000 RPM's. This was to keep the transmission from slamming on the shifts in our family cars when we were trying to merge into traffic. Unfortunately, the pressure needs to be there at high RPM's for our race cars. There's a spring that we change in the pump that fixes this problem.
The accumulator for 3rd gear is in the backside of the servo. By using a billet servo, we not only give you a better 2nd apply, we also remove the 3rd accumulator. This allows the 3-4 clutches to come on quicker, which reduces the chance of any slippage before full apply. All of our "Race", and "Pro Race" builds get a billet servo for 2nd gear. We also use a 3-4 clutch pack that is specifically designed for racing 700 / '60E's. It's made by Raybestos...Called the "Z-Pack". The Z-Pack strays away from a typical steel-clutch arrangement and uses a 1 sided clutch with alternating inside and outside splines. GM started using this design back in the mid '80's in their front wheel drive TH440 transmissions when they couldn't keep 3rds in them. The design simply works better, and holds up better. Raybestos also uses a clutch lining that is better suited for racing applications.
A common build problem among many is to try jamming as many clutches in the 3-4's as you can. Some get 9 in them. Think about this for a minute...What happens to thin metal when you heat it up? IT WARPS! To get 9 clutches in the 3-4's, you have to use .063" steels. When those .063" steels see a little heat, they turn into a wave. They then take away all the clearance in the clutch pack...it drags...and burns up.
In stock form, the '60E also has many 2-4 band issues. The stock "Corvette" servo is just not adequate to apply or hold the band. Yes, all LT1 / LS1 F-Bodies already have "Corvette" servos from the factory! The billet servo has much more apply area. This gives a better 2nd shift, and as a result of the 3rd accumulator being eliminated, it helps the 3-4 clutches, as mentioned earlier. Along with the billet 2nd servo, we also use a billet "dual piston" "Super Hold" 4th servo. It gives twice the holding power in 4th gear. We use the pair of billet servos in all of our "Race" and "Pro Race" rebuilds. The worst case scenario is if the band goes to the point where it ruins the reverse housing. The band wraps around this housing, and stops it from rotating in 2nd and 4th. If the band builds excessive heat, it will warp (dish) the band surface of the drum. If you try putting a new band on that drum, it will burn up the outside edges and not touch in the middle. If the band goes to the point where the material comes off, it will gouge the drum surface, also rendering it useless. Some builders use "cut" drums. This means the drums are turned on a lathe to make them flat again. We prefer to use new Gm drums to prevent any problems with servo pin length. If you turn the drum, you need a longer servo pin.
The band, itself has alot to do with it's lifespan. There are many different linings available for them. Alto also makes a wider band to give more surface apply area. I see the word "kevlar" thrown around alot, when talking about bands. Kevlar is just too hard of a material to hold up for a 2-4 band. The alto "red", or the "high energy" linings work much better. As far as I know, nobody makes a wide band with the "High Energy" lining. We have had them specially made, though. Stock (and many aftermarket) bands have weak anchors that are prone to ripping out. The Alto anchors are reinforced.
Some may have encountered input shaft / input drum failure. This is not the transmissions fault...It's the torque converters. Some converter manufacturers subscribe to the theory that it's OK to remove the lock-up clutch damper in the converter. Yes, this makes lock-up apply firmer, but it transfers too much stress through the input shaft / drum. I've seen the "Band-Aid on a bullet wound" fixes for this, such as a steel sleeve around the splined area of the input drum, in the over-run piston area. We just did one that had one of those drums in it. The whole center of the drum was broken out. Sure enough, we had the Art Carr converter cut, and they eliminated the damper. There's no reason to reinvent the wheel...Just put the right converter in them.
700 / 4L60E's very rarely break planetaries. There are 5 pinion planetaries available, but they're not necessary. When a planet goes, it's usually because the needle bearing under the pinion gears goes, and sheds debris through the gears. The 5 pinion uses a needle bearing in that location, also...so they're just as prone to failure as a 4 pinion. The 5 pinions are a little heavier, too. We offer 5 pinion planets as an option, but I usually warn the customers that they're not necessary.
The bushings in the pump stators have a habit of wearing. This allows contact between the input shaft and the stator, which wear out the teflon rings on the input shaft, which will cause serious crossleaks.
The aluminum input (forward) piston has a habit of cracking. We offer a late steel piston set as an update. This update replaces all 3 of the aluminum pistons in the input drum with steel replacements, as well as the 2 spring packs that are different.
Sun shells are notorious for breaking in 60E's. Strangely, we see this more in trucks, not F-Bodies. We replace the shells with "The Beast" to prevent any chance of future failure.
The low / reverse clutches had some issues in earlier units. This is because the low / rev. clutches are ON in park. They weren't releasing fast enough in early units. GM redesigned the manual valve and valve body in later units to make them release faster. We make some modifications to earlier units to fix the problem, also.
The stock design (earlier) low /reverse sprags had a habit of twisting the top and bottom cages. This would put the rollers on a semi-diagonal axis. The later design had a different spring type, which provides more support along the whole roller, as opposed to just the center. We "Update" them to the new design.
Solenoids very rarely fail in a 60E.
The valve body in later PWM units had a habit of wearing out the TCC Control valve bore. This causes a code 1870. Sonnax Ind. offers a kit that fixes this. We ream the valve body and install a new valve and sleeve.
There are many areas of failure in stock 4L60E's. Fortunately we've found ways to fix / update them all to prevent further / repeated failure.
Frank
The weaker "single cage" SKF input sprags start to go when you apply too much HP. We always "update" them to the much stronger 700 style "double cage" design. GM claims they redesigned the races to help the "single cage" design, but they still fail. WE use the better 700 style in ALL of our 700 / 4L60E rebuilds. We can get away with replacing just the "single cage" elements in units that haven't already destroyed the sprag. If the sprag has already failed, it will require the inner and outer races to be replaced, also.
In stock form, the 3-4 clutches are very prone to failure. This is due to several contributing factors. First being the "load release" springs GM installs in the clutch pack itself. They were intended to push the top and bottom pressure plates apart to prevent the clutches from dragging at high RPM's. Yea, it looks good on paper...but...if you reinstall them, you'll burn up the 3-4's repeatedly. To further complicate this matter, Trans-Go missed the boat completely here, and offers STRONGER springs for the clutch pack! Then again, Trans-Go shift kits contribute to many other transmission failures. Their vacuum modulator idea for the 4L60E is among the worst things you can do to a 4L60E. We have 4L60E's being shifted at 7000 RPM's without any "load release" springs that are surviving just fine.
Another contributing factor for 3-4 burn up is pressure. Most people don't know that the 700 / 4L60E is designed to start dropping pressure at around 5000 RPM's. This was to keep the transmission from slamming on the shifts in our family cars when we were trying to merge into traffic. Unfortunately, the pressure needs to be there at high RPM's for our race cars. There's a spring that we change in the pump that fixes this problem.
The accumulator for 3rd gear is in the backside of the servo. By using a billet servo, we not only give you a better 2nd apply, we also remove the 3rd accumulator. This allows the 3-4 clutches to come on quicker, which reduces the chance of any slippage before full apply. All of our "Race", and "Pro Race" builds get a billet servo for 2nd gear. We also use a 3-4 clutch pack that is specifically designed for racing 700 / '60E's. It's made by Raybestos...Called the "Z-Pack". The Z-Pack strays away from a typical steel-clutch arrangement and uses a 1 sided clutch with alternating inside and outside splines. GM started using this design back in the mid '80's in their front wheel drive TH440 transmissions when they couldn't keep 3rds in them. The design simply works better, and holds up better. Raybestos also uses a clutch lining that is better suited for racing applications.
A common build problem among many is to try jamming as many clutches in the 3-4's as you can. Some get 9 in them. Think about this for a minute...What happens to thin metal when you heat it up? IT WARPS! To get 9 clutches in the 3-4's, you have to use .063" steels. When those .063" steels see a little heat, they turn into a wave. They then take away all the clearance in the clutch pack...it drags...and burns up.
In stock form, the '60E also has many 2-4 band issues. The stock "Corvette" servo is just not adequate to apply or hold the band. Yes, all LT1 / LS1 F-Bodies already have "Corvette" servos from the factory! The billet servo has much more apply area. This gives a better 2nd shift, and as a result of the 3rd accumulator being eliminated, it helps the 3-4 clutches, as mentioned earlier. Along with the billet 2nd servo, we also use a billet "dual piston" "Super Hold" 4th servo. It gives twice the holding power in 4th gear. We use the pair of billet servos in all of our "Race" and "Pro Race" rebuilds. The worst case scenario is if the band goes to the point where it ruins the reverse housing. The band wraps around this housing, and stops it from rotating in 2nd and 4th. If the band builds excessive heat, it will warp (dish) the band surface of the drum. If you try putting a new band on that drum, it will burn up the outside edges and not touch in the middle. If the band goes to the point where the material comes off, it will gouge the drum surface, also rendering it useless. Some builders use "cut" drums. This means the drums are turned on a lathe to make them flat again. We prefer to use new Gm drums to prevent any problems with servo pin length. If you turn the drum, you need a longer servo pin.
The band, itself has alot to do with it's lifespan. There are many different linings available for them. Alto also makes a wider band to give more surface apply area. I see the word "kevlar" thrown around alot, when talking about bands. Kevlar is just too hard of a material to hold up for a 2-4 band. The alto "red", or the "high energy" linings work much better. As far as I know, nobody makes a wide band with the "High Energy" lining. We have had them specially made, though. Stock (and many aftermarket) bands have weak anchors that are prone to ripping out. The Alto anchors are reinforced.
Some may have encountered input shaft / input drum failure. This is not the transmissions fault...It's the torque converters. Some converter manufacturers subscribe to the theory that it's OK to remove the lock-up clutch damper in the converter. Yes, this makes lock-up apply firmer, but it transfers too much stress through the input shaft / drum. I've seen the "Band-Aid on a bullet wound" fixes for this, such as a steel sleeve around the splined area of the input drum, in the over-run piston area. We just did one that had one of those drums in it. The whole center of the drum was broken out. Sure enough, we had the Art Carr converter cut, and they eliminated the damper. There's no reason to reinvent the wheel...Just put the right converter in them.
700 / 4L60E's very rarely break planetaries. There are 5 pinion planetaries available, but they're not necessary. When a planet goes, it's usually because the needle bearing under the pinion gears goes, and sheds debris through the gears. The 5 pinion uses a needle bearing in that location, also...so they're just as prone to failure as a 4 pinion. The 5 pinions are a little heavier, too. We offer 5 pinion planets as an option, but I usually warn the customers that they're not necessary.
The bushings in the pump stators have a habit of wearing. This allows contact between the input shaft and the stator, which wear out the teflon rings on the input shaft, which will cause serious crossleaks.
The aluminum input (forward) piston has a habit of cracking. We offer a late steel piston set as an update. This update replaces all 3 of the aluminum pistons in the input drum with steel replacements, as well as the 2 spring packs that are different.
Sun shells are notorious for breaking in 60E's. Strangely, we see this more in trucks, not F-Bodies. We replace the shells with "The Beast" to prevent any chance of future failure.
The low / reverse clutches had some issues in earlier units. This is because the low / rev. clutches are ON in park. They weren't releasing fast enough in early units. GM redesigned the manual valve and valve body in later units to make them release faster. We make some modifications to earlier units to fix the problem, also.
The stock design (earlier) low /reverse sprags had a habit of twisting the top and bottom cages. This would put the rollers on a semi-diagonal axis. The later design had a different spring type, which provides more support along the whole roller, as opposed to just the center. We "Update" them to the new design.
Solenoids very rarely fail in a 60E.
The valve body in later PWM units had a habit of wearing out the TCC Control valve bore. This causes a code 1870. Sonnax Ind. offers a kit that fixes this. We ream the valve body and install a new valve and sleeve.
There are many areas of failure in stock 4L60E's. Fortunately we've found ways to fix / update them all to prevent further / repeated failure.
Frank
Last edited by 12SCNDZ; 01-07-2006 at 10:21 AM.
01-07-2006, 10:17 AM
#6
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Join Date: Mar 2002
Location: Newark, Delaware
Posts: 3,634
Re: What broke in your 4L60E?
Originally Posted by Cmr0z28
I don't remember the exact details....I think the 3-4 sprag was shot and the stator was worn. Hopefully Frank can chime in here and correct me.
Once again, great thread. I like the idea
Once again, great thread. I like the idea
01-07-2006, 02:39 PM
#8
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Join Date: Apr 2004
Location: dalton Ga.
Posts: 1,013
Re: What broke in your 4L60E?
I was going to " " you Frank and say, and this is the reason I choose YOU to build my transmission but, it would have taken a whole page to quote you. 
My transmission has been GREAT so far after you rebuilt it. Thanks! 
P.S. I know the 3-4 cluch pack went out on mine but do you remember what else you had to replace (it was rare I think).
My transmission has been GREAT so far after you rebuilt it. Thanks! P.S. I know the 3-4 cluch pack went out on mine but do you remember what else you had to replace (it was rare I think).
Last edited by 30696bird; 01-07-2006 at 02:41 PM.
01-07-2006, 02:50 PM
#9
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Join Date: Mar 2002
Location: Newark, Delaware
Posts: 3,634
Re: What broke in your 4L60E?
Here's a link for a video, from Raybestos. It explains a little about the "Z-Pack" 3-4 clutches.
http://www.raybestospowertrain.com/p..._zpak_mov.html
Here's what happens to a factory "single cage" 4L60E sprag when you start putting too much HP through it.
Here's what a good "double cage" sprag looks like
Here's the comparison of the bands. The one on the left is stock width, the one on the left is an Alto "wide band".
These are pictures that show what happens if you use a converter with no lock-up damper in it. Yes, this drum had been previously modified with a steel sleeve, and modified over-run piston. As you can see, it didn't fail at the spline part of the drum, it ripped the whole center out.
Frank
http://www.raybestospowertrain.com/p..._zpak_mov.html
Here's what happens to a factory "single cage" 4L60E sprag when you start putting too much HP through it.
Here's what a good "double cage" sprag looks like
Here's the comparison of the bands. The one on the left is stock width, the one on the left is an Alto "wide band".
These are pictures that show what happens if you use a converter with no lock-up damper in it. Yes, this drum had been previously modified with a steel sleeve, and modified over-run piston. As you can see, it didn't fail at the spline part of the drum, it ripped the whole center out.
Frank
Last edited by 12SCNDZ; 01-08-2006 at 09:00 AM.
01-08-2006, 11:44 AM
#10
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Join Date: Jul 2001
Location: Kingsport, TN
Posts: 1,889
Re: What broke in your 4L60E?
3-4 clutches 1st time (stock tranny), input drum second time but everything was pretty much wiped out (due to coolant leaking into stock tranny cooler), and I had a buddy's forward piston crack on his stock tranny.
Regarding the Frank vs Dana debate, these are two classy individuals. They each have two completely different ways of building trannies which both last. Even being competitors they still don't argue with one another on the board. You can't go wrong with either of these guys, but I personally went with Dana at Pro-Built as have all my friends and we have had zero problems. Excellent customer service.
Regarding the Frank vs Dana debate, these are two classy individuals. They each have two completely different ways of building trannies which both last. Even being competitors they still don't argue with one another on the board. You can't go wrong with either of these guys, but I personally went with Dana at Pro-Built as have all my friends and we have had zero problems. Excellent customer service.
01-08-2006, 02:29 PM
#11
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Join Date: Mar 2002
Location: Bay Area, CA
Posts: 1,736
Re: What broke in your 4L60E?
on both my 700R4 and 4l60E, it was the 1-2 clutches. Actually, the 2-3 on the 4l60E went too....
Frank V. Dana- We are really lucky to have 2 guys who know what the heck is going on, and help out any way they can. Kinda like madz28 v pcm4less tuning.
FWIW- I used Dana and Madz28 and was very happy with both!
Frank V. Dana- We are really lucky to have 2 guys who know what the heck is going on, and help out any way they can. Kinda like madz28 v pcm4less tuning.
FWIW- I used Dana and Madz28 and was very happy with both!
01-11-2006, 10:46 AM
#13
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Join Date: Nov 2003
Location: West Linn, OR
Posts: 1,752
Re: What broke in your 4L60E?
Originally Posted by Birdman7389
Frank V. Dana- We are really lucky to have 2 guys who know what the heck is going on, and help out any way they can. Kinda like madz28 v pcm4less tuning.
FWIW- I used Dana and Madz28 and was very happy with both!
FWIW- I used Dana and Madz28 and was very happy with both!
But I chose CPT and PCMforless.
For my Tranny I had slippage issues and nothing really broke, I believe the 3/4 clutches were going, and for some reason the front seal was leaking too.
Took it to Frank and got it built to what his top of the line was back then, ~ 2 yrs, and it is still holding up great...
Funny how he can improve on a great tranny, but he has.
01-15-2006, 07:00 AM
#15
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Join Date: Mar 2001
Location: Huntington, W.V. 25701
Posts: 564
Re: What broke in your 4L60E?
I have had some pretty decent luck with a local builder. But they dont like to stray from stock rebuilds to much and I'm gettin to the level where I need to start doing some hard parts. Trannies seem to be left more to the pro then engine rebuilds do. I would like to start doing my own rebuilds is th GM 4l60e service manual a good buy. (will i be getting over my head) Also there is no transbrake option for 4l60e is it the electronics?