Transmission issues

[GeoGoGo]

Hi Guys!

I am currently searching for my ideal TB and I have noticed something. It appears to me that there is an inordinate number of TB with bad transmissions. Are these transmissions exceptionally weak? What can be done to prevent problems above and beyond fluid and filter changes? What is it that fails in the transmissions? Is it any one thing?

Thanks everyone!

 

[webdawg]

What is the mileage on your transmission? The general consensus is that no one maintains the tranny and they only get 'fixed' when they start having issues and it is too late.

Some people just do a pan drop and filter exchange. It has also been recommended to do this: http://forums.trailvoy.com/articles.php?do=viewarticle&artid=88

Others will talk about upgrading parts and such, which I think is fine but you better have the dam transmission manual and do it right. People talk about switching out the 1-2 accumulator piston like it is just an open and swap but they forget to mention about the paper gasket that is under the accumulator housing. How are you going to swap when you rip the gasket taking the housing off.

The key to it all is examining the fluid and determining the state of the transmission.

Here is a post about that too: http://gmtnation.com/forums/threads/the-dreaded-transmission-flush.8288/

 

[Robbabob]

Seems you must be kind of new here; Welcome to the Nation!

Transmissions are rock solid when the fluid and filters are changed on schedule. Trans case and differentials, too. You must be shopping where current owners have been neglectin their vehicles.

Do not buy from anyone that cannot quote you proper intervals.

 

[steveO]

A reputable trans guy told me that the 4L60e properly maintained should last 150-200K..
By design they just wear at some point and need to be rebuilt.
Lack of maintenance and excessive operating temp are the enemy.

Considering the age and mileage of many of these vehicle, it is no surprise you are finding a number of them with trans issues.

The good new is if the engine was maintained it could last you to 300K so an investment in repairing the trans might be a good one... that is if the rest of the key components, transfer case, front and rear diff are in good shape.

 

[GeoGoGo]

Just saw a bunch more. What does it cost to replace a TB tranny? A lot of these are sub $1000, is it work replacing a tranny in something like that?

 

[Jrgunn5150]

Just saw a bunch more. What does it cost to replace a TB tranny? A lot of these are sub $1000, is it work replacing a tranny in something like that?

Absoultely, you can get a new trans from GM for like 1400, or a variety of other sources.

I've recently found out that the 4.2's have a higher stall converter than the V8's. I've been wondering for awhile myself, since the roads are littered with 250k + pickups and fullsized SUV's, and I know Bubba isn't filter/fluiding the ole straightpyped Z71 on schedule. I'm starting to suspect the higher stall speed builds heat in them that kills them.

 

[Bow_Tied]

The trans in my Denali blew @73,900miles. It had a quality aftermarket cooler added followed by a dealer service of fluid and filter @ just over 60k miles. Blew the forward sprag while my wife just commuting to work. Shit happens, maybe there was a bad batch of parts, maybe the PO of our rig abused it, who knows. The 4L60Es in the 2 Jimmys I have had were rock solid. Maybe every so often someone rolls snake eyes. One thing though - for every trans failure you read about on a forum there a thousands working fine that aren't mentioned. Forums can blow issues out of proportion vs. production numbers... though they can indicate relative trends.

 

[6716]

My '05 is currently parked due to transmission problems ... at 235,000 miles.

In reading up on the transmission, some of the hardcore/heavy duty forums for full size stuff out there and kind of down on the 4l60E and prefer the 4L80 as heavier. The 4l60E is the same transmission as goes in the Corvette and other lighter platforms.

Some of the stuff that goes wrong with these transmissions isn't too difficult or expensive to fix. I did a shift kit with new separator plate and accumulator pistons and the torque converter clutch valve bypass for $200 and a day under the truck.

A known weak spot seems to be the sun shell, there are aftermarket sun shells in the rebuild market that specifically advertise upgraded strength.

Every so often I read a thread on here where somebody is driving along and something goes bang and it starts to grind and it turns out it was the sun shell. They had good maintenance, too, and the sun shell just went.

The good news I guess is that the transmission is pretty common and there are rebuilds everywhere and shops know them pretty well.

 

[kazootom]

I just purchased an 2008 Chevy Tahoe with 100,000 miles. Drove fine worked perfect. Only problem small transmission leak coming from bell housing. Problem was front sealing. Removed transmission disassembled and replaced to clutch material and did all up dates. Torque converter was just fine. Total bill with labor $1,400.00.
Trans shop said inside looked good only reason for rebuilt labor was already paid labor just need rebuild kit.
So any number of things can lead to high repair bills. Wish it would not have leaked.

 

[Kurb]

A coworker lost the tranny in his TB. The shop actually kept one on hand since they were replacing them so frequently. The shop said they normally fail around 100,000 miles. This had me nervous, but mine is still going strong at over 160,000 miles. I shouldn't have said anything. One problem is the cooler lines. One of them will leak, which could kill the tranny if you don't regularly check the fluid.

 

[Sparky]

Some people hate on the 4L60E. Yes, it has a few potential shortcomings but they aren't bad transmissions. "Normally fail at 100k" is a load of nonsense. Yes, some do, but that is definitely not the norm.

I always address a few points of possible failure early on when I get a vehicle with one with a fairly simple shift kit I've mentioned on here before, but other than that I just drive the thing. 170-something K on the 1998 one (and counting), closing in on 215k on the one in my 02 Trailblazer (and counting), only 138k on the 07 Silverado (still a baby lol).