2001 Tahoe 5.3 4L60E slipping - any help?

[TheSavage4.7]

Hi everyone,

I picked up a 2001 tahoe a few days ago. Absolutely love the truck and it’s pretty much fully loaded aside from missing heated seats.

Once it gets warm (atleast i haven’t noticed it as much when it’s cold) the trans shift flares a bit from 2-3 and when passing someone up it’ll slip a bit. No codes or anything, drives smooth aside from engine/trans mounts being bad. I should add the trans fluid is nice and red, maybe a little worn but nothing too bad. I have to change it soon and i was wondering if there is anything else i should change to maybe help fix this while im down there. Also, 2-3 only flares while under heavy throttle.

Should add, it has almost 242K on it. Engine is as smooth as butter.

 

[supton]

242k? city or highway? Regardless, I would be looking for a rebuilder. You could drop the pan and see what is in there, but this sounds like how these trans like to go.

 

[Lubener]

At 242k miles, it likely is just worn out and there's not much you can do for the long term.. You can't add back clutch material and various metals back onto parts when they have worn off.

 

[skyactiv]

Where do you live? There is a member in Fort Worth, TX that has a shop and is renowned for his transmission work on those vehicle's.
His member name is Clinebarger.

 

[TheSavage4.7]

242k? city or highway? Regardless, I would be looking for a rebuilder. You could drop the pan and see what is in there, but this sounds like how these trans like to go.

It was highway driving i’m pretty sure, the engine runs better than my friends Chrysler 5.7 that has just shy of 15k on it. If the trans goes, i’ll definitely drop a new trans in her.

 

[TheSavage4.7]

At 242k miles, it likely is just worn out and there's not much you can do for the long term.. You can't add back clutch material and various metals back onto parts when they have worn off.

Good point!

 

[TheSavage4.7]

Where do you live? There is a member in Fort Worth, TX that has a shop and is renowned for his transmission work on those vehicle's.
His member name is Clinebarger.

I’m in the cali bay area, planning on moving to texas in a few months. I will definitely be checking him out!

 

[LongTime_Lurker]

Double check your fluid level before doing anything else. If you are a little low, your transmission’s pump can draw in air while turning or accelerating.

Service the transmission and inspect the pan for debris. Change the fluid and filter. Take your truck on a test drive and note the shifting behavior.

If there is no improvement, you can try adding one of those fixes in a bottle to help with marginal seals. At the end of the day, you are only postponing the inevitable. The 4L60-E has a weak 3-4 clutch pack.

 

[wlk]

I'd try a fluid change with Lubegard Red, Maxlife and maybe a tube of 2 of Shudder Fix. Other than rebuild, probably only thing that may buy you some time

 

[TheSavage4.7]

Double check your fluid level before doing anything else. If you are a little low, your transmission’s pump can draw in air while turning or accelerating.

Service the transmission and inspect the pan for debris. Change the fluid and filter. Take your truck on a test drive and note the shifting behavior.

If there is no improvement, you can try adding one of those fixes in a bottle to help with marginal seals. At the end of the day, you are only postponing the inevitable. The 4L60-E has a weak 3-4 clutch pack.

I do think it’s a bit low fluid wise. The trans shifts great as long as i don’t beat on it much, so i will definitely be saving up for a performance built 4L60E.

Considering doing a build series on youtube too about it, would be pretty cool i think.

 

[BrendanC]

for old 4l60/80’s, the lucas transmission fix has limped them along for quite a while longer for me. drop the pan, change the filter, dump half a gallon jug of dex VI in it, pour the lucas into the half empty jug of fluid, shake it up and then fill until at full line on dipstick. i cant remember what the fill spec on a 60e after a pan drop.

another good thing to do is replace cooler lines. the old rubber lines can swell internally and block fluid flow. a restriction in the cooler circuit can make these units act up. the radiator coolers are also known to plug up on higher mileage units so i would look into bypassing it and adding a new transmission cooler. the you can slip hose over the quick connect “barbs” and hose clamp behind them. ran this way for over 100k miles before just making AN lines.

 

[Chris142]

About 30 years ago I had a slipping 727 in a dodge ramcharger. I added a qt of trans-x and it lasted several years after.

 

[michaelluscher]

@clinebarger is one of our resident transmission experts

MAF clean/reading correctly?
Check and adjust fluid level as a matter of course
Maybe throw in a bottle of LubeGard Red?

But at that mileage, it doesn't owe you anything, I'd start saving for a rebuild

Obligatory 4L-Slippy comment
/s

 

[TheSavage4.7]

@clinebarger is one of our resident transmission experts

MAF clean/reading correctly?
Check and adjust fluid level as a matter of course
Maybe throw in a bottle of LubeGard Red?

But at that mileage, it doesn't owe you anything, I'd start saving for a rebuild

Obligatory 4L-Slippy comment
/s

I found the issue.

Trans was a good 2 quarts low, still under the 2 hot dots when it’s fully warmed up, but it’s driving much better.

No more slipping at all.

 

[The_Eric]

For the OP and any others searching this thread, I've had a bad MAF cause shift issues in this platform. In fact some transmission rebuilders specify clean or replace the MAF

 

[TheSavage4.7]

For the OP and any others searching this thread, I've had a bad MAF cause shift issues in this platform. In fact some transmission rebuilders specify clean or replace the MAF

Good to know. I am probably going to go ahead and replace that.

 

[TheSavage4.7]

After a few days of driving it, the adaptives seem to have helped it out a bunch with shifting. Feels very solid now, I am probably going to go and install a corvette servo and some other mods to the trans to help it along.

 

[TheSavage4.7]

Don't think I added this, but the plugs appear to be original, or close to it. They are ancient and the gap is all forms of out of spec, lol.

 

[clinebarger]

After a few days of driving it, the adaptives seem to have helped it out a bunch with shifting. Feels very solid now, I am probably going to go and install a corvette servo and some other mods to the trans to help it along.

No shift adapt on pre '07 4L60E's, Without a ISS (Input Speed Sensor)....The PCM cannot accurately measure "Shift Time"

Installing a Vette 2nd Servo requires a larger 3rd Clutch feed orifice in the spacer plate to operate 100% effectively.

 

[350Rocket]

No shift adapt on pre '07 4L60E's, Without a ISS (Input Speed Sensor)....The PCM cannot accurately measure "Shift Time"

Installing a Vette 2nd Servo requires a larger 3rd Clutch feed orifice in the spacer plate to operate 100% effectively.

Is this why torque pro displays an obviously incorrect amount of shift timing?