ddes

Hi guys,

I'll start with a disclaimer: yes I have searched this site thoroughly as well as Google, and have found answers that loosely pertain to my question, but nothing specific.

Recently I seem to have lost 3rd and 4th gear. I'm not sure the difference between 'no 3rd/4th' or 'slipping 3rd/4th,' but I can say that when in OD or D, which ever makes you happy, the transmission will start in 1st and shift normally into 2nd. However, when it comes time for 3rd, say around 25-35mph depending on throttle, the engine will rev as though it is in 'neutral' until it catches in the very upper RPM range, 1k or so before red line. I presume that this must be 1st gear.

Is this symptomatic or burned up 3-4 clutches? I'm not an expert, but logic tells me that bad 3-4 clutches wouldn't cause the transmission to downshift into 1st. Instead, I presume the trans would either stay in 2nd, or attempt a **** to 3rd and then shift back to 2nd. Then again transmissions do seemingly illogical things to those untrained.

Basically for the sake of money, I would like to decide if I just need to replace a solenoid or the VB before I pull the trigger on a $2,000 rebuild for a 14 year old truck.

I have changed the fluid too. It was definitely dirty, and had a strong smell to it, as tranny fluid does anyhow, but I wouldn't describe it as being burned per se.


Thanks a bunch in advance.

coryforsenate

iTrader: (1)

Transmission slipping in 3rd/4th in a 4l60e is usually a burned up 3-4 clutch pack. The friction material from the burned up clutch pack would make the fluid dirty.

Most common cause of a burned up 3-4 clutch pack in a 4l60e is a bad 3-4 piston seal.

Hooking a pressure gauge up could give more info, as could a scanner to see if there's any codes.

ddes

Unfortunately I'm figuring the same thing. Everything seems to point to a burned up clutch pack; I'm just hoping that it may have been a cheaper fix. I'm hesitant to spend almost what the truck is worth on a rebuild.

Thanks for the reply. I'll have to start shopping around for builders.. the cheapest I've found so far is $2,000. Another shop wanted $2,500 and the third shop wouldn't touch it. He wanted me to buy a new transmission from GM.

Is it strange that the tranny is shifting 1-2-1? Is that normal when the 3-4 clutch pack goes?

coryforsenate

iTrader: (1)

Your quotes seem a little on the high end unless they're including some upgraded parts and/or a new torque converter.

If you're mechanically savvy you could buy a rebuilt 4l60e from a reputable builder and swap it yourself.

I've never read anything about shifting from 1-2-1. I'd guess it's not actually in 1st, it just feels like it from the slipping. I'm no expert, mrvedit or bbond105 would be good folks to answer that for you.

mrvedit

Your "the engine will rev as though it is in 'neutral'" is a typical symptom of a worn out 3/4 clutch. Yes, a worn out 3/4 clutch is the most common problem with the 4L60E.

Unfortunately the price of $2000 is typical for a rebuild with remove/install of the trans. As Cory mentioned, the $2500 may include a new converter, which is a good idea to ensure that any debris in the old converter doesn't damage the new trans.

What year is the truck and in what city are you?

bbond105

I would think the 1-2-1 shift, if that is really what is happening, is because of the decrease in vehicle speed form the trans slipping and the high RPMs causing the trans to down shift to 1st. I would advise that you find a reputable independent shop for your rebuild or a sponsor on here, but most definitely stay away from the large trans chains.

clinebarger

The 3-4 clutch is shot, A 1-2-1 is exactly what it is happening, Most people don't rev to the point they catch up to Lo Roller Clutch & it starts pulling again.

The only clutches "ON" in 3rd are the Forwards & 3-4's, If the 3-4 don't hold, Just the Forwards are holding putting it back in 1st gear.

ddes

Thanks for the replies guys.

OK well my worst fears are being realized haha.

It was two small local shops who gave me those quotes. It looks like I know what I have to do.