Transmission Problems On 4l60e Equipped GMC Truck

[bowserb]

So does anyone know if this sun gear has been upgraded in the new models GMT-900?

Just curious if it is across the board, I know GM made some changes to the trannys and was wondering if a better one was actually installed?

[2018GMC]

GREAT info in this topic. I remember back in high school, my auto shop teacher preaching about coming to a COMPLETE stop before shifting gears. Most of us thought it wouldnt do much (if any) damage. Sounds like he was right!

 

Have you had any 6 speed GM trannys (6LE 70/80) or something like that in for repair? I'm sure there aren't as many out there as the 4 speeds since the 6 was only in Denalis and SUV's. 2009 year available in the 1500's.

I could have sworn I remeber someone saying the 6 speeds were mostly selnoids.

 

What do you think about their build quality comared to the 4 speeds?

 

Thanks!

Edited August 31, 2008 by 2009 GMC

[Tucson_02Silverado]

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?

 

I was charged $60 for the Beast Sun Shell. They're around via the net from a few between $45 and $85. I have just about 13K on the 2nd rebuild that has the Beast and the Alto 3-4 clutch pack. It's holding up well. I do notice that with the Alto the top end shift are firm and quicker than before, and in general the temps have stayed around 170F (via Denali cluster guage) even during the 100+ heat

[Schmids5.3l]

If and when mine goes its TH350, TH400, or 4l80 time, I'm not going to gamble/waste thousands buying a built 4l60 and putting it in a truck just to have it fail later down the road again. IMO It should have never made it's way into trucks.

[LAGA]

Mike, I have a 07 Vmax with a Blackbear tune. Should I invest in a shift kit or Vette servos ? I do not beat on the truck, but it does get some spirited driving with no towing?

[satori]

I'm getting the impression these transmissions are rather fragile. Is that really the case? It's making me reconsider purchasing a TT or doing any tuning. I would like more power, but this makes think it'll just strip this gear quicker.

[wlvrn1215]

Jeff can be the rear end guy

 

Thanks for asking, but I think I'll decline. Maybe you should ask daddy? Or maybe try the one of my gay internet sites? Good luck in your search cutie.

 

 

 

Hey daddy Jeff wanted me to ask if your gay or something like that...Take his man card quick...

 

 

PS fixed it for ya Jeff!!

Edited August 31, 2008 by Z71chev

[Mikeee]

If and when mine goes its TH350, TH400, or 4l80 time, I'm not going to gamble/waste thousands buying a built 4l60 and putting it in a truck just to have it fail later down the road again. IMO It should have never made it's way into trucks.

If you are referring to your 2003, I believe that you will have to go with the E for ELECTRONIC control. I don't think you can go backwards in technology.

[bowserb]

just curious I asked before but didnt get an answer, has the sun gear been upgraded in the GMT-900s? has the transmission been improved at all just curious?

[88m53453]

here's a question that no one has answered in another forum on this site. 2005 Sierra 76,000 miles 4.8ltr 2wd. Was driving in a heavy rain storm and the transmission began acting beyond strange. On light throttle the trans would downshift and upon heavy throttle the trans would upshift, Exactly the opposite of what it should do. Stopped, paid a toll and from that point on, it was fine. Went into have dinner for an hour, came back out and all"seemed" fine. Drove about 20 minutes and the trans began slipping badly. Pulled over , checked fluid, fluid was perfect in color and level. There was no burned smell as well. Stopped at a friend's house for a few minutes and drove the last 30 minutes home with no problem. That was 2 months ago, with no problem since. Any ideas of what to do to prevent a reoccurence, I am reasonably sure it is a water problem getting into a wiring harness somewhere, but any help on how to proceed would be great

thanks

[Mike Diaz]

Mike ,what about the NBS 4L60E 2-1 downshifiting bump ,when stopping at the light?

I had that problem in my 2007 ,but my 2008 is perfect...

 

BTW my name's Luiz Diaz...

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.

[Mikeee]

I talked to my trans guy, who has 35+ years experience, and got some expanded info. No right or wrong about the OP ... just more information.

 

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.

 

This problem is done here all the time -$600/2wd: $700/4wd.

The actual problem is not from "rocking the vehicle" or from no complete stop from reverse to drive, but rather a problem with a vendor that did not radius the edge of the spline, but then another problem showed up with splines stripping, so at that point they were heat treated.

 

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.

 

ALL transmissions will benefit from a cooler! Is it necessary? In some cases yes.

 

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.

 

Solenoids are not anymore of a problem on this transmission than any other, unless aftermarket [China] ones are used.

 

Typically, during any type of service where the transmission pan needs to be removed, the filter should be changed.

 

True.

 

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.

 

This is not a boost valve as it is located in the pump. The valve in question is the TCC regulator valve, and this is normally done in this shop for $395.

[neto1978]

Mike ,what about the NBS 4L60E 2-1 downshifiting bump ,when stopping at the light?

I had that problem in my 2007 ,but my 2008 is perfect...

 

BTW my name's Luiz Diaz...

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.

 

 

Actually from MALAGA-SPAIN ,but I live in Brazil...

tks

[Schmids5.3l]

If and when mine goes its TH350, TH400, or 4l80 time, I'm not going to gamble/waste thousands buying a built 4l60 and putting it in a truck just to have it fail later down the road again. IMO It should have never made it's way into trucks.

If you are referring to your 2003, I believe that you will have to go with the E for ELECTRONIC control. I don't think you can go backwards in technology.

 

 

It's very possible, there are a few guys on PT.net who have done it with write ups. I'll get a link later today.

 

Edit: link: http://www.ls1tech.com/forums/showthread.php?t=815618

Edited September 1, 2008 by Schmids5.3

[smitty67]

I've got an 07 vmax with a ghost in my trans. occasionally when I launch hard the 1/2 shift hangs up, the speedo bails out, then I've got neutral until I come to a complete stop after that everything is back to normal .I've been trying to narrow down what triggers this 3rd or OD same result. If I leave it in 3rd when it bails and throttle up it will move at 5000rpm but still no speedo and lots of slippage no noticable change in trans temp.between 140-186. It happens anytime now and getting worse . Dealer says no codes "bring it back in a box" any suggestions?