got-a-ls1

iTrader: (12)

Ok so me and a buddy spent the day today trying to fix a trans that has no 2nd gear. started out changing the accumulator and the servo. that didnt change anything so we changed every solenoid in the trans and that didnt change anything. we then swapped valve bodies and that didnt change anything. the first thing we did was check the pressure and it was rock steady around 60psi in each gear on the lift with no pressure loss.

we came to the conclusion that the band must be junk, but i can lock it in 4th gear, lock the converter and have no slip in 4th WOT. has anyone ever encountered this bs before? i mean we literally changed everything in the valve body... servo.. everything. ideas?? the pan wasnt even really full with much junk... but looking up by the valve body you can see the drum is kinda scored where the rivets on the band are. so we are assuming thats why its junk, but why would 4th gear not slip at all ??

thanks...

mrvedit

Sounds like you already know the 4l60e very well. You there probably already know/tried all this, but here are my thoughts:

In 4th gear, both the 4th gear servo AND the 2nd gear servo have pressure to engage the band. Sounds like the 2nd gear servo cannot do it by itself. It could be that the band has worn down a lot and there is now excessive clearance on the servo pin.
Put a crowbar on the servo cover and measure/estimate how much you can move the cover in. It should be only 1/16" to 1/8". Much more indicates excessive clearance. If true, you could get a longer pin, or even weld a blob on the end of the existing pin. There are pin extenders, but they are known to fail. Regardless of how you get a longer pin, you will need to grind it down to the correct length and shape.
The Sonnax instructions might help:
http://www.sonnax.com/system/instruc...911-03K-IN.pdf

Also, this Sonnax 2nd gear servo kit includes a longer pin.

Finally, you might try the Sonnax 77701-04SK Corvette servo seal kit - it replaces the stock seals with O-rings which might seal better in a worn servo bore.

Good luck.

got-a-ls1

iTrader: (12)

thanks man.. you know what now that i think about looking up at the band it did seem pretty damn loose around the drum with the servo installed.. which probably means its worn out also haha.. but maybe i will try welding on a blob on the end of the pin and see if it changes anything. this is a stock car i picked up just to cruise in, dont really want to pull the trans right now as im in the middle of having a 4l80e done for the turbo t/a right now. damn trannies

does the 4th gear gear circuit on the servo have more travel then 2nd? i guess it could also be the bore in the case as well i didnt really look in there since its almost impossible while in the car. need a bore scope i guess haha

SKOKED67

put a band in:

mrvedit

I don't know whether the 4th gear or 2nd gear servo piston has more travel. Perhaps one of the pro builder does. If you really need to know, I could contact one.

If you are comfortable welding a blob on and grinding it down a bit, that might give you a working car until you are ready to rebuild the trans and replace the band.

got-a-ls1

iTrader: (12)

yep thanks a lot man.. we put .100 in the end of the servo pin, 2nd gear works, doesnt shift real great but holds fine in gear. i guess the band can wear out enough to work fine in overdrive but not for 2nd.. i guess that means the servo either has more pressure in 4th gear or more travel. either way it works for now haha

mrvedit

Cool. Glad it worked. Now you can tell people you fixed your transmission with a welder!

got-a-ls1

iTrader: (12)

haha yep thatll make em wonder!

pvfjr

I know it's a bit late, but for future searchers, I thought I'd throw my 2 cents in. My silverado is doing the exact same thing. Perfect 4th, and no second. I tried the accumulators and servo swaps, no change. Solenoids tested fine, etc. Now I knew something was toast judging by the friction material in the pan, so I am in the middle of a full rebuild. I didn't want to start the rebuild until I knew there wasn't a control issue (who wants to smoke brand new clutches and bands?).

I had a chat with a guy at Transgo. He said that the 4th gear servo piston does have a bit more travel than 2nd. He was certain that my band was well worn and developed too much clearance. Dana from probuilt auto didn't seem to be able to verify this, but that's what the tech at Transgo told me--for whatever that's worth.

I kinda wish I'd run across your thread so I could band-aid this truck until I graduate college and move into a place with a garage, but oh well. Here's hoping my rebuild works. Sure would have been nice to fix it with a welder without removing the trans or the pan though...

mrvedit

As long as you replaced the band, you should be fine. After this thread I suggested welding to lengthen the servo pin and it has worked well for several others too; but it is a bandaid to get a bit more life out of the trans.

Sometimes 2nd slips first, sometimes 4th.

tnmotown

iTrader: (107)

Interested, mine is having the same symptoms. 4th gear works fine but 2nd slips like a ****.

Does anyone have a picture to help describe on how to lengthen the servo pin? I know this is just a bandaid fix…

wedo

If you can see score marks on the drum it will need to be replaced when you do o/h . There is a company called fitz-all that has pin extenders . http://www.teckpak-fitzall.com/spgm.cfm?id=77605G

Michael Bergey

I have a 4l60e transmission with no 2nd gear and no codes being shown, what wrong

MaroonMonsterLS1

start a new thread. I'm not saying that to be rude or mean...I'm saying that because that's how you'll get the best help.
start a new thread and list your vehicle, mileage, issues, and any diagnostic steps youve tried as well as any helpful information you can provide.

RevGTO

iTrader: (12)

Michael, did you read the posts above? Is 4th gear holding? If so, the answers are all above.

I'll give you a chance to respond with any comments or questions. Otherwise start a new thread if needed and this one can be closed down.