Mike Diaz

Solenoids have always been a problem on 4L60E transmisions. I don't know much about 6L80E's.

I think they may have, but I only dealt with transmissions that were 2003 and older since most newer trucks were under factory warranty when I worked there.

I never dealt with that problem. a lot of times, the dealer can reflash the pcm to help manage hard shifts. I'm gonna have some problems replying over the next few days, i hurt my elbow and it's really hard for me to type with one hand. Nice to find another Diaz on the board, where's your family from? Puerto Rico here.

I don't remember how much the Beast sun shell was, like $80? Probably well worth it. How's it been since the new shell and 3-4 clutch pack?

That's not too bad, I haul 5500 pounds about 120 miles every saturday night for stock car racing.

Sorry for not getting to this question earlier. I would have to connect the scanner to your truck and find out if the torque converter clutch solenoid is activating in 3rd gear. You might be able to watch to see if there's an RPM drop at partial throttle, but that might be hard to detect. I tried to look it up on alldatapro and I'm not finding any good info.

Yes, you are wrong, so I will correct you. The 4.8 and 5.3's come with the 4L60E and are not available with the 4L70E. The 4L70E only comes with the L76 6.0 in the 1/2 tons. The 6.0's in the HD's come with the 6L80E/6L90E. Oh, and you skipped my post about the 4L70E's???? Thanks for the correction, Alldata isn't always right. I never had a 4L70E transmission in the shop, I don't know of any problems with it.

I would go ahead and replace the filter and pan gasket, then have it flushed through the cooler lines. It's time to do it.

I always recommended dropping the pan first, replacing the filter and pan gasket, then flushing the transmission through the cooler lines at the radiator. We performed at least one of these services per day and never had one problem. That's a good one. I would tow in 3 in the city. Most likely, you won't be hitting speeds over 45-50 mph, so there's no need to have 4th gear engage. If you're on the highway, I would just take it slowly and get the speed up enough for the torque converter to lock up. Regardless, you should have an external cooler on that as well. How much weight are you towing?

I was referring to trucks with the cooler that runs through the radiator. An external cooler should be installed on any truck that does any kind of light or heavy towing or stop and go city driving. Thanks! I can be the beer and Jack Daniels guy

Wow, lots of replies, let me go through this post by post. No, the reaction sun gear is only used in 2nd, 4th, and reverse, so the only time you'll be doing damage is during a 1-2 shift, a 3-4 shift, a 3-2 upshift, or shifting into reverse. I must add that the replacement sun gear is much stronger than the factory one, because it's a one piece design, not a welded on piece like they did from the factory. If you didn't break it right away, you should be ok. If you removed it, and brought the transmission in we typically charged around $1000 for a complete rebuild, and $400-500 for sun gear replacement.. If the fluid smells and looks good, it's a good idea to get it changed about every 15,000-20,000 miles,depending on how hard you drive the truck, towing, etc. If your fluid smells burnt, or is getting discolored, most likely you already have a problem and some sort of failure down the road is imminent. Correct me if I'm wrong, but I think this is how it breaks down: The 4.8L and 5.3L can come with either a 4L60E, or 4L70E (4L60-E (RPO M30, M32, M33) / 4L70-E (RPO M70) The 6.0L comes with either a 6L80E or 6L90E (not sure what the difference is) The diesel comes with the Allison 1000. I have had zero problems ever with Mobil synthetic oils, although I never used them in transmissions. We got our transmission fluid from a local company and never had a problem. I'm sure it was just generic Dino oil though. Occasionally we used a product called Lube Gard that increased the silicone content of the fluid. Lube Gard would also get rid of the occasional torque converter shudder as well. Basically, as long as you're changing the fluid and filter on a regular basis, I wouldn't worry about switching over. It's more of a personal preference. We originally started using the tube and fin design, but started to switch over to the stacked plate design "if" the customer would fork over the extra money for it. That shouldn't do anything at all to hurt the transmission.

I've been in the repair business for the past 7 years, including almost 3 years as manager at a specialty transmission repair facility. I thought I would share a few of my experiences with the GM drivetrains. The 4L60E transmission was one of our most repaired transmissions when I ran the transmission shop. The biggest problem I dealt with was the loss of 2nd, 4th, and reverse. Most people thought they needed a complete rebuild when they brought their truck in, and 9 times out of 10, it would only be the "reaction sun shell" which is a $30-40 part from Transtar (www.transtarindustries.com). One of the biggest causes of the sun shell gear breaking is somebody shifting into reverse while rolling forward or trying to rock out of a situation where they were stuck in snow or mud. It puts a lot of stress on a small gear, and it can either strip out or break. You should always stop completely before shifting from drive to reverse (and vice versa). A reaction sun gear replacement should cost under $1000 including labor. The transmission must be removed to replace it. One of the other problems that I found on the 4L60E transmission was overheating from towing. If you tow, you should definitely consider getting a Hayden(or comparable) transmission cooler. Your torque converter takes a huge amount of abuse when you're towing and also put out a large amount of heat. If you drive hard, this should be one of your first modifications to the truck. If you overheat a transmission bad enough, you most definitely will be rebuilding that transmission and torque converter. Expect a $1500 to 2000 bill. Possibly more if you drive it until it stops. Another common problem I found on the 4L60E transmission was the solenoids going bad. There's no rhyme or reason as to why they go bad, but they do. The Electronic pressure solenoid (EPC) was the most common, and can cause slipping, overheating, and a check engine light. The cost to repair the solenoids was usually under $500. Always replace all the solenoids, never just one. Typically, during any type of service where the transmission pan needs to be removed, the filter should be changed. The last common problem I found on the 4L60E transmissions was a boost valve leaking internally in the valve body. The boost valve would bleed off pressure that is needed to properly engage the clutches and the torque converter. The fix is a "boost valve boring kit" that reams out the valve bore, then you install a larger valve. This is another major cause of overheating within the transmission. Most of the time, a transmission cooler will not help this problem. Typically this is a $300-400 repair. That's all I have off the top of my head, if anybody has any questions, feel free to ask, I still have my rebuilder's phone number if I get a questions I can't answer.