4L60E help needed - 3rd & 4th vanished&returned&vanished...


CrazyHorseUK
05-05-2006, 02:49 PM
Hi Guys,

I'm having a real nightmare with a 4L60E in my 94 Jimmy (4.3L vortec, 2WD). Basically its a recon trans & TC 30,000 miles ago & has always been smooth. Smooth changes, no noise, just right. New filter & fluid a couple of weeks ago, recently been on a few long journeys without a problem, and now its just lost 3rd & 4th. I know people have posted on here with this problem before (http://www.automotiveforums.com/vbulletin/showthread.php?t=443626) but the replies seemed to suggest burned out 3/4 clutches, which I don't think is the case this time.

Basically, it will start off in the morning working fine (all four gears, no problem, really smooth as always). At some point within 10-20 miles or so it will go to change up into 3rd and it just wont be there (engine revs freely just like being in neutral). If I manually shift into D (3rd) it is the same (like being in neutral), but 1st & 2nd both still work. After a while it will just all start working again - all four gears, back to normal, smooth as always. Later on it will loose 3rd & 4th again, seemingly for no reason, and eventually it will all come back, also seemingly for no reason.

I've checked around the outside, and everything is as it should be (plugs correctly fitted, wiring secured out of the way, nothing loose, leaking or out of place. The fluid is clean, a little too full (1/2" over the mark when hot) but otherwise OK.

I can't believe its the clutches, as it always comes back - I'm guessing its the electrics not selecting correctly, but I don't know enough about it. I really need some help, so I'm hoping someone out there has the answer.

All the best,

Mike.

maxwedge
05-05-2006, 03:39 PM
Needs to be scanned on a trans function scanner, shifts can be commanded and confirmed and slippage errors noted, this will determine if the problem is deep in the unit. Make sure the engine is coming to full temp also.

CrazyHorseUK
05-06-2006, 03:25 PM
Hi,
I've checked the PCM trouble codes with a jumper wire in the ALDL socket, and there are no codes stored (just flashes 12 over and over).
There are no dealers around here who have a trans function scanner (to my knowledge), so I'll have to buy one - can you recommend a brand name for me to look for, or even a place where I can buy one (I'm in the UK, so need a shop who will send internationally).
I'm still no closer to fixing it so far...the transmission shops I've asked on the phone just want to sell me a new one, but nobody has any constructive ideas about how to find the problem. I really do appreciate any help you can offer, as otherwise I'm on my own.
All the best,
Mike.

maxwedge
05-06-2006, 03:49 PM
A bi directional trans function scanner is very expensive as there really no stand alone unit like this, a Snap on scanner with the full trans cartidge is one, but very pricey. What you describe sounds like it will probably be internal, check the large connector on the trans, disconnect clean up and reconnect, I assume this actually is a 4l60e, no tv cable right?

blazes9395
05-11-2006, 05:29 PM
i don't think clutches are the problem. It sounds to me like you either have a valve body problem, or a solonoid problem, i would bet valve body. it could be a sticking valve causing all these problems. this further is convincing me because you state you recently did a trans oil change, and thats usually where things can go wrong, as new oil begins to clean deposits in the transmission, and these deposits travel in the oil and can cause sticking valve, solonoids etc. The cheapest, best scanner on the market in my mind, for the average do it yourselfer, is the AutoXray scanners. Go to their site www.autoxray.com (http://www.autoxray.com) and take a look. Either way

Treurentner
05-21-2006, 01:10 PM
Hi,
did you read this?

Bulletin No.: 01-07-30-038B
Date: January 26, 2004

DTC P0757 Set, SES Lamp Illuminated, Poor Performance of Transmission, Transmission Slipping (Clean Transmission Valve Body and Case Oil Passages of Debris)
Models:
1999-2004 Passenger Cars and Light Duty Trucks
2003-2004 HUMMER H2
with 4L60-E/4L65-E Automatic Transmission (RPOs M30/M32)

Supercede:
This bulletin is being revised to add model years and change Cause and Correction information. Please discard Corporate Bulletin Number 01-07-30-038A (Section 07 - Transmission/Transaxle).
Condition
Some customers may comment on any of the following conditions:

^
The SES lamp is illuminated.
^
No 3rd and 4th gear.
^
The transmission does not shift correctly.
^
The transmission feels like it shifts to Neutral or a loss of drive occurs.


The vehicle free wheels above 48 km/h (30 mph). High RPM needed to overcome the free wheeling.

Cause
The most likely cause is chips or debris plugging the bleed orifice of the 2-3 shift solenoid (http://www.alldatapro.com/alldata/PRO~V7985125~C33962~R0~OD~N/0/77993956/78154671/78154933/78154935/34853741/34857029/56218937/56514627) (367). This will cause the transmission to stay in 2nd gear when 3rd gear is commanded and return to 1st gear when 4th gear is commanded.
DTC P0757 may also be set if the 2-3 shift valve (368) or 2-3 shuttle valve (369) were stuck, restricted and/or hung-up in its bore.
Correction
^
Inspect / Clean the 2-3 shift valve (368), the 2-3 shuttle valve (369) and the valve bore of debris / metal chips.
^
Inspect / Clean the 2-3 shift solenoid (http://www.alldatapro.com/alldata/PRO~V7985125~C33962~R0~OD~N/0/77993956/78154671/78154933/78154935/34853741/34857029/56218937/56514627) (367) opening of debris / metal chips. While inspecting the 2-3 shift solenoid (367), look for a screen over the solenoid opening. If the solenoid DOES NOT have a screen, replace the solenoid with P/N 10478131 that does have a screen over the solenoid opening.
Refer to the appropriate Service Manual for additional diagnostic information and service procedures.









Parts Information
Parts are currently available from GMSPO.
Warranty Information
For repairs performed under warranty, use the applicable published labor code and information.


regards

Marco

wafrederick
05-21-2006, 01:40 PM
Did you check the Fluid and did the fluid smell like a stinky smell?Check the fluid first.If the fluid stinks,it is inside the transmission and needs to be rebuilt.Replace the torque converter too and get one that is painted dark blue,do not get one painted green.The ones painted green are junk.It does not have a cable,starting 1993 and up are electric doing away with the cable.The new Snap On scanners are junk,all I hear are problems with them and have to be sent in for repairs.I know the Vetronix scan tool will read the transmission codes.The GM Tech 2,GM's factory scan tool will read the codes also

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