derek_silvy

Alright, I got back from my trip today and my dad told me my transmission wasn't shifting into 3rd gear. I had just gotten my tune in the day before I left, with a lil firmer shifts and raised shiftpoints (to 5900). He drove it a little bit and got on it just a lil from what he said, nothing too crazy.

My dad said initially it was giving him problems on the way into town with the tach kinda jumping and it not feeling right and then on the way home it it went to second and just flew out as it would go into third, but could be brought back down to a lower speed and second would work. Now once it tries to shift into third and flies out of gear it will not even engage second. I have to stop it and let it go to first and shift to second but I have to keep below about 30.

FWIW I tried getting to third in Tow/Haul mode, which the tuner did not touch, but it does the same thing -- flies out at what would be the shift to third.

What are my options here guys? What will a rebuild cost me if I want it to last while handling power and maybe seeing the drag strip once every month or two? Could it not actually need a rebuild, but maybe something minor?

This is a 99 4L60e with 80K, a vette servo and slight tranny tuning.

Thanks!

James B.

iTrader: (1)

Sure sounds like a smoked 3-4 clutch pack to me....

derek_silvy

So, the "smoked 3-4 clutch pack" will keep it from shifting to third?

They have to take everything apart for this, right?

How much are we looking @ here if I wanted this to hold up, maybe with a higher stall and a 75 shot run past it?

James B.

iTrader: (1)

In a 4L60-E the 1-2 shift is done by engaging the band. In the 2-3 shift the band disengages as the 3-4 clutch pack engages, at the same time. For the 3-4 shift the band engages again.

If the 3-4 clutch pack has failed you will end up with a 2-1 downshift for the 2-3 shift. The vehicle will not lunge forward because a sprag, which works like a mecahnical diode, allows the output shaft to overrun the input shaft. This is why it feels like neutral - the engine cannot turn fast enough to match or exceed the vehicle's speed in that gear. It's really not neutral, it's first gear, but with overrun.

Unfortunately you need a rebuild. There are much better-than-stock clutches available for the 3-4 pack.

derek_silvy

Thansk for the help. Any idea on price for a build that will hold power next time?

James B.

iTrader: (1)

There are a lot of things you can upgrade. It depends on not what you can do but how much power you want it to hold up to and how much you are willing to spend.

For the hard parts, a heavy-duty Reaction Shell is a good upgrade, the hub is notorious for cracking. Also available is a hardened input shaft with a stronger drum and an improved reaction carrier shaft. There's a 34-element double-caged sprag available. From the 4L65-E both 5-pinion planetaries can replace the 4-pinion ones in your 60.

As far as consumables there are a few performance rebuild packages available from different suppliers. Look for one that includes or has an option for the Raybestos Z-Pak clutches for the 3-4. Those are single sides and better resist warping (coning) than conventional clutches. Most performance kits will include a Kevlar band.

A shift kit will help too, but keep in mind that shifts too firm will stress the hard parts and shifts too soft will shorten servicability of the clutches and soft parts.

Read some of the related threads. The 4L60-E's limitations have been discussed countless times on this forum and a lot of great information is available in the archive.

Automatics

Go to http://www.700r4l60e.com/store/customer/home.php?cat=22 this should give you everything you need, just specify year & model (LS1, etc.). If you have any questions on this, let me know?

derek_silvy

Alright.. when you say everything I need.... I mean... what else... anything?

Could I just bring the tranny shop my broken tranny, and give them this kit and say "just use that and charge me for nothing but labor."

I noticed on one of this kits that it says that it comes with an OEM sprag. Don't those fail quite often?

That which I jsut quoted worries me about that. I'm revving to 5900-6000 so my LS6 cam can work.... can I only safely rev to 5500?

Thanks for the help!

marc_w

This sounds just like one of my older 4L60's when I had a sticking 2-3 shift solenoid. It was throwing codes on it... do you have the light on?

Mine would only act up on hot days in the summer. The truck would go from first to second, okay, second to third was like hiting neutral for a few seconds - if you stayed on the gas, the tranny would **SLAM** into gear, fall out again, and SLAM back in. It was nasty. Something could have broke pretty easily.

I'd drive around in second until I could pull over and clear the code. I'd clear it, and I could drive around fine until the code was thrown again. Minutes, or days later.