Danny

iTrader: (16)

Hey guys,

I have a 2002 Avalanche 1500 2wd with a 4L60e tranny 150k miles. Earlier this year I was having issues with the trans taking too long to shift into 2nd from 1st. It would happen after a complete stop. It's almost like I had it in "hauling mode". It would shift at around 2500 or so. It would do this every once in a while, then it stopped. I've never had any other issues with the trans.

Fast forward to this Monday. I'm taking off from a stop and when the trans shifts from 1st to 2nd it felt like it slipped or "let go". Then it grabbed 2nd and continued to drive normal. It did this a few times this week.

I'm thinking it's the solenoid. What do you guys think?

mrvedit

I suspect your band is worn and you will soon loose 2nd completely.
Here is a similar thread - start at post #2 where I explain how to measure the end play of the servo and some options to get a bit more life out of the trans.

https://ls1tech.com/forums/automatic...t-trouble.html

Once you report the servo end play, we can go from there.

HomeSchool

If you think its the solenoid swap in a new one into the valve body harness (its pretty easy) and take her for a spin. It it's still acting up, might be time for a rebuild. 150k on a stock 4l60e is plenty of time for it to go bad.

Danny

iTrader: (16)

I'm going to replace the solenoids and harness this wknd. Worse case scenario if it doesn't fix the issue at least I've already purchased some parts towards a rebuild.

Btw, it's been behaving right these past few days.

216StealthSS

4L60 in a 04 tahoe, has the 1-2 soft slip shift, sometimes once in a while it will not shift down at a stop and when i accelerate its starts shifting back into first,( once in a while). 52k later still have the same trans. simple shift kit may help. 206k on i think "original" transmission. i am the 2nd owner so not 100% sure. i am doing well so far. (fingers crossed)

Danny

iTrader: (16)

Now that you mentioned it, my Avy used to do that as well. I would come to a stop and when I would take off it would still be in 2nd. After a few seconds it shifts into 1st and all is well. It did this a few times last year or the year before. But hasn't done it in a while.

Danny

iTrader: (16)

Well guys I never got around to swapping in new solenoids. On the way home from work last night the trans said it loud and clear that it needs a rebuild. I took off from a stop like normal. The trans shifted into 2nd and just before it shifted into third I gave it about 1/2 throttle and the rpms shot up to like 3k and the truck was not accelerating. So I backed off and allowed it to shift into 3rd. At around 40mph I again accelerated and the same thing happened. I had to baby it the whole way home. Anything more than 1/4 throttle and it would slip. When I pulled into the driveway I foot braked it and with about 1/2 throttle she started slipping. The smell of burnt clutches/fluid was very noticeable.

So needless to say I need a rebuild. But I'm still happy. This trans gave me 150,025 hard miles.

This morning I stopped by my tranny shop and picked up a rebuild kit. Do you guys think I should replace the 4 pinion sungear with a 5 pinion version? I don't do any racing with my truck and almost never tow. But I do have a pretty heavy foot when gas prices are down. Lol.

mrvedit

Sorry to hear about your trans, but I can't say I am surprised.
I would not bother with the 5 pinion upgrade; for one thing due to recent GM changes to the pinion, quite a few other parts need to be upgraded too.
I would recommend getting the 4L65E rebuild kit as this will have a better 7-friction 3/4 clutch setup; and that is the only difference. That only adds about $10.
I would also suggest the Sonnax Smart Shell; besides being a stronger shell, it also puts lets strain/heat on the rear pinion bearing. That adds about $90.
If your budget allows, get a new reverse drum; the recommended ACDelco one is about $90. With a new reverse drum, you can optionally install a wide band.
Last, get the Sonnax 4L60E-LB1 boost valve; that will tighten all your shifts and increase line pressure (including max line pressure) to reduce wear and friction.

HomeSchool

Don't Forget a shift kit!

Danny

iTrader: (16)

A shift kit on a daily driven truck? It's basically the family vehicle.

mrvedit

Yeah, I know HomeSchool loves his shift kit, but seems like overkill in this case. The Sonnax boost valve I suggested (above) will firm things up without the complexity of a full shift kit. The boost valve is also trivial to install; a full shift kit is not.

Danny

iTrader: (16)

Ok I'm gonna head back to my trans shop tomorrow morning and pickup the following parts that didn't come in the master kit:
Separator plate
Sunshell (the beast)
Both shift solenoids
Downshift solenoid
TCC solenoid
Pressure sensor
Wire harness
And a rebuilt converter.

Does anyone have any other ideas on what else to get. Remember...it's a stock rebuild. Just replacing the weak **** that commonly goes bad.

HomeSchool

Not all shift kits are for performance, transgo makes a shift kit which makes shifts smooth, and helps correct from the factory issues as to why the tranny might blow in the first place. A great choice for not alot of cash to help that rebuilt tranny last, check it out -> http://www.transgo.com/products.php?...dcountview=Yes