Transmission Troubles

[Z71Heat]

I am posting this in 2 sections on the forum.

I have a 2000 Tahoe (New body style) with the 4L60 Transmission. I have around 102,000 miles on it and the trans is pissing me off. I was on my way to an important meeting today and it started acting up. As I pulled to the side of the road to look at my map, it downshifted hard. As I began to pull away it revved but only moved a little, so i hit the gas a bit more and it CLUNKED and CLUNKED, it's done this before once in a while but not all the time. I pulled onto a side street and went slow ( it sounds like something gets disconnected, it's a real weird CHATTERING sound) So I shut the truck off, waited 5 minutes started it and everything was fine. I know it's getting hot out and trans are running hotter, but I dropped the pan at 80k and flushed it with Amsoil synthetic fluid. The trans runs around 195 degrees so I dont think the fluid broke down. Is is MAYBE a transfer case problem? I can't stand when it does this and I am getting tired of it. ANY IDEAS? It seems like it takes longer to shift now since I have the A/C going full blast, not sure if that has anything to do with it.

 

[Z71Heat]

The noise is in DRIVE going forward, BUT it does make a "disconnecting" sound when in reverse ALL the time, but the sound isnt noticible to the everyday driver. I notice it because I drive it everyday. Are the 00-06 transmissions shi*? I always thought the 00-06 were built pretty damn good.

 

[ugachs24]

The noise is in DRIVE going forward, BUT it does make a "disconnecting" sound when in reverse ALL the time, but the sound isnt noticible to the everyday driver. I notice it because I drive it everyday. Are the 00-06 transmissions shi*? I always thought the 00-06 were built pretty damn good.

They are built very well, but the transmissions are the weak areas of the GMT 800's. That's one of the main reasons I got rid of my 2003 Z71, it had 114k and the had tranny started slipping, harshly downshifting, and making noises that I knew couldn't be anything good. I didn't trust my wife driving it 500+ miles a week anymore. I think most people usually get between 125-150k out of them, but then some of them blow out at 20k and others last until 200k. I don't know if you tow or not, but towing significantly decreases the life of the transmissions in these things.

 

[Rollin Thunder]

TOWING KILLS TRANNYS, my 06 lost hers at 42k, but i frequently (like 3 times a week) towed my 5k boat 2 hours round trip.


plus when i was not towing the boat i was hauling crap away from properties to the dump, requiring 4wd and going threw mud (land fill also is a huge hill)

needless to say i can tell you the gmt 900s (07 and up) have a HUGE improvement and shifts more smoother and quieter as well as less bad noises, i have only towed the boat with it once, did very well, still had lots of power, but will probably only tow every once and a while, and get a pick up truck to tow the boat with.

 

[Z71Heat]

I DONT TOW AT ALL!!! I towed maybe one time in the 30,000 miles I have owned the truck. What is the outcome? If I need a new trans, what are the recomendations? I do drive harder than most people, so I want a TRANS that will last and deal with my lead foot. Is there a diffrent trans/more heavy duty I could put in it? What price range am I looking at?

 

[Rollin Thunder]

I DONT TOW AT ALL!!! I towed maybe one time in the 30,000 miles I have owned the truck. What is the outcome? If I need a new trans, what are the recomendations? I do drive harder than most people, so I want a TRANS that will last and deal with my lead foot. Is there a diffrent trans/more heavy duty I could put in it? What price range am I looking at?

you can put GM's heavy duty tranny in, the 4L80E, best tranny avail, next to the allsion 6 speed. :thumbsup:

 

[Z71Heat]

you can put GM's heavy duty tranny in, the 4L80E, best tranny avail, next to the allsion 6 speed. :thumbsup:

Isnt the 4L80E in the Suburbans?? If I put it in the tahoe, what affects would it have to the rest of the truck? When transmissions are replaced, are the transmission controllers replaced as well?

 

[Z71Heat]

Whats the deal if I want to convert/swap my 4L60-E Transmission to a 4L80E Transmission? Is that a MAJOR setback (cost wise) ??

 

[Yuke2K]

Whats the deal if I want to convert/swap my 4L60-E Transmission to a 4L80E Transmission? Is that a MAJOR setback (cost wise) ??

Yes, it's expensive. You're looking anywhere from $2000-$2500 just for the trans depending on who you know and where you go, then you have to pay for the installation and the adapters and whatnot. Probably at least a $4000 job when all is said and done.

I'd just rebuild the one you have or buy a fresh trans, and have someone install upgraded parts that are more wear resistant to your lead foot. Alot of the LS1 guys I used to hang with were always talking about replacing stuff in the 4L60E...namely the servos/bands, planetary gears, etc. Not sure if that applies in this case, but it's something to look into. At any rate, it would probably be much cheaper than getting the 4L80 conversion. The 4L80 is a great unit but unless you're running a blower or something and making TONS of power, I don't see the cost-to-benefit ration really panning out for you...unless you've got tons of money to blow on it lol.

 

[Z71Heat]

Yes, it's expensive. You're looking anywhere from $2000-$2500 just for the trans depending on who you know and where you go, then you have to pay for the installation and the adapters and whatnot. Probably at least a $4000 job when all is said and done.

I'd just rebuild the one you have or buy a fresh trans, and have someone install upgraded parts that are more wear resistant to your lead foot. Alot of the LS1 guys I used to hang with were always talking about replacing stuff in the 4L60E...namely the servos/bands, planetary gears, etc. Not sure if that applies in this case, but it's something to look into. At any rate, it would probably be much cheaper than getting the 4L80 conversion. The 4L80 is a great unit but unless you're running a blower or something and making TONS of power, I don't see the cost-to-benefit ration really panning out for you...unless you've got tons of money to blow on it lol.

Yuke2k, how is your truck? how many miles? any major complaints or repairs?

No I dont have tons of money to blow on it, I was figuring around 3k at the most. I guess my current trans can be rebuilt with better guts. I have the police edition tahoe, but I guess that didnt do any good....more heavy duty my as*!!! I hope that it will keep going until at least 130k-150k, then I will replace it and run the truck well over 200k. By then gas will be 15 bucks a gallon and people will be walking everywhere!

 

[Nappers]

I have 128,000 miles on the clock, no problems yet with the tranny and only had to replace a check valve on the 2nd air injection system (40 bucks). I drop the pan on the tranny every year and replace the 6-8 quarts it dumps with a new filter and shifts smooth as a babies rear.

 

[Yuke2K]

Yuke2k, how is your truck? how many miles? any major complaints or repairs?

No I dont have tons of money to blow on it, I was figuring around 3k at the most. I guess my current trans can be rebuilt with better guts. I have the police edition tahoe, but I guess that didnt do any good....more heavy duty my as*!!! I hope that it will keep going until at least 130k-150k, then I will replace it and run the truck well over 200k. By then gas will be 15 bucks a gallon and people will be walking everywhere!

Well I'm guessing that you picked it up as a used police vehicle then? If thats the case, just think about this: if it wasn't a heavy duty, that thing would have died long ago under that kind of abuse!

Our patrol vehicles are 06-07 Ford Explorers, and they are holding up ok, but the transmissions are starting to slip at less than 40K miles. Just the nature of the business I guess.

Anyway, my yuke is holding up remarkably well. I bought it about 18 months ago with 82XXX miles on it, and purchased a warranty for about $2500 extra. I had been regretting it becasue NOTHING had gone wrong with my truck, but recently I discovered a leak that appeared to be coming from the transfer case. I caught it early enough though, and they replaced the slip yoke and U-joint in the tailshaft, as well as the drivers side axle seal and vent tube on the front diff. All told it would have been about $550 to get it all fixed, but all I paid was the $100 deductible on the warranty, plus the cost of the vent tube + tax since it wasn't covered, which was only $37. Getting all that done for $137 is ok with me!

It's been a fantastic truck though, really really great vehicle. It's taken my wife and kids all across the country and back without a hiccup. I'm at 97K miles now, and it's still going strong. The only thing really "wrong" with it is that it has a little bit of piston slap when it's cold, but about two minutes after you start it and the pistons get a chance to warm up and expand, the slap goes away completely. On hot summer days, it doesnt make any noise at all.

 

[Gordo]

well I hope this doesnt bring me bad luck but Im over 90k and no problems at all. No slipping or knocking or weird noises. so I hope Im one of the lucky ones that make it to 200k --knock on wood--

 

[MyBlkBurban]

not to hijack - Does the Suburban have a 4l60E or a 4L80E ? and how does the Suburban hold up to it ?

 

[Rollin Thunder]

not to hijack - Does the Suburban have a 4l60E or a 4L80E ? and how does the Suburban hold up to it ?

The sub and yukon xl 1500 have the same tranny as a tahoe, you need to get the heavy duty 2500 (3/4 Ton) to get the 4L80E tranny in a suburban or yukon xl.

 

[Rollin Thunder]

well I hope this doesnt bring me bad luck but Im over 90k and no problems at all. No slipping or knocking or weird noises. so I hope Im one of the lucky ones that make it to 200k --knock on wood--

your tranny is different though, also better than the 4l60E, (gmt 800) denali's have a 4l65E, handles all the stuff better.

 

[MyBlkBurban]

The sub and yukon xl 1500 have the same tranny as a tahoe, you need to get the heavy duty 2500 (3/4 Ton) to get the 4L80E tranny in a suburban or yukon xl.

Thanks :thumbsup: I guess Suburban's have it a little rougher 'cause of the added weight too I used to have a Bronco and the Bronco had the same weakness -- a poor stock tranny that could not take too much heat/stress and cost a ton and a half more than most other trannys

 

[Z71Heat]

Well I'm guessing that you picked it up as a used police vehicle then? If thats the case, just think about this: if it wasn't a heavy duty, that thing would have died long ago under that kind of abuse!

Our patrol vehicles are 06-07 Ford Explorers, and they are holding up ok, but the transmissions are starting to slip at less than 40K miles. Just the nature of the business I guess.

Anyway, my yuke is holding up remarkably well. I bought it about 18 months ago with 82XXX miles on it, and purchased a warranty for about $2500 extra. I had been regretting it becasue NOTHING had gone wrong with my truck, but recently I discovered a leak that appeared to be coming from the transfer case. I caught it early enough though, and they replaced the slip yoke and U-joint in the tailshaft, as well as the drivers side axle seal and vent tube on the front diff. All told it would have been about $550 to get it all fixed, but all I paid was the $100 deductible on the warranty, plus the cost of the vent tube + tax since it wasn't covered, which was only $37. Getting all that done for $137 is ok with me!

It's been a fantastic truck though, really really great vehicle. It's taken my wife and kids all across the country and back without a hiccup. I'm at 97K miles now, and it's still going strong. The only thing really "wrong" with it is that it has a little bit of piston slap when it's cold, but about two minutes after you start it and the pistons get a chance to warm up and expand, the slap goes away completely. On hot summer days, it doesnt make any noise at all.

I bought the truck from another cop with about 78 k on it. I just got the trans rebuilt last week by a very good rebuilder in the area. He gave me a good price (wholesale for the most part) because I was friends with him. The total job cost me $2500.00. He told me that when he opened up the trans it looked like a cement mixer inside of it and the plaetary gears were all chewed up. The tahoes and suburbans with the 4L60E had "pressed" together gears, the new gears he put in were welded. Thats where my tranny failed.