4L60E Reliability stock vs. modified??

[MartyMcFLy]

I've heard mixed reviews about the 4L60E and that it isn't the most reliable. How would it do with a few engine modifications such as a cold air intake with a catback exhaust and/or cams? Would the extra HP/TQ affect its longevity or would it even hold up?

I know the Denali has a slightly more robust tranny able to handle 380 ft./lbs.

Would the tranny be questionable pushing past stock numbers?

 

[08HoeCD]

A CAI and catback exhaust won't affect anything than the sounds your vehicle makes and the size of your bank account. You might gain 2hp at most. A cam might reap a little more power, but not nearly enough to affect the longevity of your trans.

A custom tune is what most find to be the best bang for the buck in terms of power gains before you start spending $$$$ on a blower, etc. Still, a tune won't hurt your trans.

 

[Tonyrodz]

I've heard mixed reviews about the 4L60E and that it isn't the most reliable. How would it do with a few engine modifications such as a cold air intake with a catback exhaust and/or cams? Would the extra HP/TQ affect its longevity or would it even hold up?

I know the Denali has a slightly more robust tranny able to handle 380 ft./lbs.

Would the tranny be questionable pushing past stock numbers?

Bought my Hoe used in 2012. I didn't get any service records with it, but it was owned by a real estate company, so it needed to be maintained. Ran great, and only issue before my mods were the knock sensors. Bought it with 212,000 and I THINK the trans was done. Once I started doing mods--swapped the 4.8 to a 6.0 with cam, headers, tune, 3000 stall convertor, etc, etc, it all finally caught up to the stock trans. So depending on your trans--mileage, maintenance etc, and depending on your mods, you take a chance of blowing your trans. So, beef it up and you'll get some longevity out of it--depending how you drive and how radical your mods are.

 

[MartyMcFLy]

Bought my Hoe used in 2012. I didn't get any service records with it, but it was owned by a real estate company, so it needed to be maintained. Ran great, and only issue before my mods were the knock sensors. Bought it with 212,000 and I THINK the trans was done. Once I started doing mods--swapped the 4.8 to a 6.0 with cam, headers, tune, 3000 stall convertor, etc, etc, it all finally caught up to the stock trans. So depending on your trans--mileage, maintenance etc, and depending on your mods, you take a chance of blowing your trans. So, beef it up and you'll get some longevity out of it--depending how you drive and how radical your mods are.

What did you end up doing for the trans?

 

[MartyMcFLy]

A CAI and catback exhaust won't affect anything than the sounds your vehicle makes and the size of your bank account. You might gain 2hp at most. A cam might reap a little more power, but not nearly enough to affect the longevity of your trans.

A custom tune is what most find to be the best bang for the buck in terms of power gains before you start spending $$$$ on a blower, etc. Still, a tune won't hurt your trans.

People on this forum have been claiming 20-30+ hp from a CAI and cat back. I don't know the torque numbers, but that seems substantial.

 

[Tonyrodz]

What did you end up doing for the trans?

Had to get it rebuilt. Used better internal parts, vette servo and shift kit. Shifts nice and firm.

 

[08HoeCD]

A tune, yes, but no chance an intake and cat back alone will yield that kind of gain on these trucks.

 

[MartyMcFLy]

Bought my Hoe used in 2012. I didn't get any service records with it, but it was owned by a real estate company, so it needed to be maintained. Ran great, and only issue before my mods were the knock sensors. Bought it with 212,000 and I THINK the trans was done. Once I started doing mods--swapped the 4.8 to a 6.0 with cam, headers, tune, 3000 stall convertor, etc, etc, it all finally caught up to the stock trans. So depending on your trans--mileage, maintenance etc, and depending on your mods, you take a chance of blowing your trans. So, beef it up and you'll get some longevity out of it--depending how you drive and how radical your mods are.

What year is your whip and how much did you pay for it? How much money did you end up putting into it with all the modifications?

 

[Tonyrodz]

It's an 03. Back in 2012, with 212,000 we paid $5500. It was in excellent shape. All told we put in maybe $10,000 or so. That wasn't planned, just happened. I'd never spend that much intentionally. Check out my build thread for everything that I've done.

EDIT: If you're on a cell, just turn it sideways. You'll see the link to my build thread.

 

[MartyMcFLy]

It's an 03. Back in 2012, with 212,000 we paid $5500. It was in excellent shape. All told we put in maybe $10,000 or so. That wasn't planned, just happened. I'd never spend that much intentionally. Check out my build thread for everything that I've done. View attachment 212293

EDIT: If you're on a cell, just turn it sideways. You'll see the link to my build thread.

Wow, you put a lot of $$ into it! That's brave!

I paid $5000 for my '05 w/ 106,000 miles. I wasn't sure if I overpaid, but it there are no issues and no rust.

 

[MartyMcFLy]

A tune, yes, but no chance an intake and cat back alone will yield that kind of gain on these trucks.

what kind of tuner would you recommend? Are there any on the market that would do a good job?

 

[08HoeCD]

Go straight to Black Bear Performance

 

[Tonyrodz]

Wow, you put a lot of $$ into it! That's brave!

I paid $5000 for my '05 w/ 106,000 miles. I wasn't sure if I overpaid, but it there are no issues and no rust.

Brave or stupid! The $$ slowly crept up. Never would've spent that much intentionally. I thought I paid too much for the mileage, until I started comparing prices to other tahoes and yukons. I paid about average for the time. Other then the mileage, it was in fantastic shape--inside and out. By the looks I would've guessed it had less then 100,000 on it.
Transmission reliability

 

[fozzi58]

A CAI and catback exhaust won't affect anything than the sounds your vehicle makes and the size of your bank account. You might gain 2hp at most. A cam might reap a little more power, but not nearly enough to affect the longevity of your trans.

A custom tune is what most find to be the best bang for the buck in terms of power gains before you start spending $$$$ on a blower, etc. Still, a tune won't hurt your trans.

People on this forum have been claiming 20-30+ hp from a CAI and cat back. I don't know the torque numbers, but that seems substantial.

I just added the AFE CAI and a Blackbear tune. I still need to re-record a driving scan so BB can fine tune the program. But from a "seat of my pants" feel, I can honestly say I picked up solid 30 HPs & TQ. It could be more. Putting the sound aside (much more aggressive and a lot louder at >1/2 throttle), the response from the go pedal is much better, and the shifts are firmer. My only disappointment is I couldn't chirp the tires shifting from 1st to 2nd at full throttle (hehe). Def going for headers and Corsa touring exhaust in the spring...and an updated tune from BB.

Apologies on hijacking thread. Now back to our regularly scheduled program....

 

[Martinjmpr]

I feel like the 4l60 is almost a "maintenance item" on these trucks. Kind of like a timing belt on a car that has a t-belt. The good news is that from what I can see, once the 4l60 is rebuilt it's better than new. I have about 30,000 miles and almost 2 1/2 years on my rebuilt 4L60 and most of that mileage was pulling a travel trailer through the Rocky Mountains over 10,000'+ passes.

The other "good" (as in "less bad") news is that since rebuiling 4L60's is such a common occurrence, most transmission shops have a pretty set "rebuild kit" at a reasonable price. I know when I was asking about repair costs on my old Toyota they said that transmission rebuilds were $4000+ on those. By contrast, the rebuild on my 4L60 was $2000.

Now that sounds like a lot, but when I consider that my Suburban is paid for and always has been, the way I look at it is that $2000 represents 4 $500 car payments that I didn't have to make. Given that it's lasted 2 1/2 years and 30,000 miles, I'm pretty happy with that.

 

[inmypassatlife]

intake, high flow cats, cam, and tune would yield a good 50-70HP depending what specs you go with.

 

[inmypassatlife]

I bought mine from a good friend, 116k original miles, already had a GM remanufactured installed at 77K, i did fluid and filter as soon as bought it home. Was good for awhile....I owned it about 15 months when it took a shit coming back from a trip in New Mexico at about 132K, slipping 3-4. I swapped fluids and filter again but band material was heavy and I limped it around for another 60 days.

This truck "sat" for nearly 4 years, my buddy gifted it to his mom dropped on 24s already, but she drove it maybe 500-600 miles in that span of time, I went around replacing all kinds of worn bushings etc. I have a really good hookup for trans work locally. I got a decent HD build for $850