Calling all Techs...Gas man to the gas pump?

I have been dabbling with swapping out a trans or two here and there but, I have no technical background and consider myself somewhat of a mechanical dolt. That being said I have no idea what is happening with what I just did.

Ok so I bought a 18 yr. old Tahoe with some super swamper tires.. knowing full well from sellers description it had been "slipping". I can here the groans now (yes I've checked out many other threads).

So for as to what it's doing. When I first got it, it would only change out of 1st gear somewhere around 4000rpms. However, if recollection serves me, it would bypass 2nd gear completely jump to 3rd. Both 1st and 3rd seemed fine but, to get it to third I had to rev up said rpms and let off the gas. I drove it home like this for almost 40 miles and it did not do anything else. 2nd gear did not work even manually shifting it.

Fast forward a few days and after having dropped the pan. The ATF was black and smelled burnt, as it was when I bought it. I went ahead even after I was fairly certain from reading other posts that the solenoid pack I bought would not fix anything. Regardless I swapped the 1-2 shift & 3-4 shift solenoids, along with the 3-2 downshift and the PWM solenoid (I did not change the.TCC lockup solenoid).
​​​​​I also changed the stock servo for a Corvette servo, as well as, pit a longer servo pin in it. Per mrvedit's suggestions on several threads I used a pry bar to push in the servo cover and would guestimate that it depressed around 3/8" possibly 7/16ths. I took out the servo pin that was in there (a two ringer? if that's the correct terminology) and replaced it with a no ringer. I did not have calipers to measure it but it appeared to be between 1/8th to 1/16th bigger than the pin that was in there. I replaced said pin without grinding anything. When I replaced the servo cover and depressed it again with the pry bar there was about 1/8th - 1/16 play. I filled with oil. Topped it off and drove it.

NOW, it's doing something way different. If in (D) Drive it will shift from 1 to 2 normally but when it gets to 3rd it slips completely. It might have caught 3rd one time briefly in my hours long drive but, it mainly just spun. I could however start it NOW, it's doing something way different. If in (D) Drive it will shift from 1 to 2 normally but when it gets to 3rd it slips completely. It might have caught 3rd one time briefly in my hours long drive but, it mainly just spun in 3rd. Except however, if I started off from a stop by manually shifting into first and then manually shifting to 2nd, skipping over manual 3 and putting it in Drive. That way it would catch 3rd gear about 80% of the time depending on rpms. If the rpms were not high enough it would spin 3rd. I have No 4th gear and have not ever been able to find 4th on this truck.
I guess my questions would be:

1. Why is 2nd working now but not 4th?
   
2. Should I try the extra long Sonnax Servo Pin since that ⅛" longer one seemed to work?
   
3. Why would 3rd gear work in Drive but not when manually shifting to it?
   
4. Could my power steering not working well except it seems at higher speeds have anything to do with it?
   

Any help would be much appreciated.
Sorry for the Money Dick post, just want to get all the info out first.

 

O man!
I was gonna tell you...
But you figured it out!

The damn Power-Steering not working well, makes the Transmission act all crazy!


Lol! I couldn't help myself...
The transmission is just tired.
You are describing characteristics that are very common for a 4L60E Family Transmission that is worn, and in need of a rebuild.

The 2-4 Band is worn... Adding some length to the apply-pin can give a little more life, for 2nd/ 4th gears to operate.
The 3-4 Clutch is worn, and struggling to apply/ hold 3rd/ 4th gears.

There is nothing strange going on... and no reason to get excited.
Just normal old and worn Automatic Transmission stuff.
The transmission is 18 years old with Black ATF, and slips.

Time to have that 4L60E rebuilt... which is something that probably happens almost every day somewhere in the world (there are a ton of this transmissions).
Good luck and have fun!


BTW...
The Power-Steering System and the Automatic Transmission in your vehicle, share nothing in common that could cause one to affect the other.
If anyone else tells you different; then send the out to purchase some Blinker-Fluid for there car!

 

I figured they weren't connected but this 2003 Tahoe is new to me. I hate any cars that have these sensors everywhere. I have never owned a car that had OBDII until this Tahoe lol.


I also just got a deal on an 05 suburban with 110,000 and it's the LT autoride. It boggles my mind all these things being put in these cars today. I read this while researching the power steering problem and read this about the VSS which I had read can sometime produce some similar circumstances in the 4L60E as to what I'm experiencing. So just was wondering. Yeah needs a rebuild for sure but, as I have read on here so many times... I just need another 10K out of it LoL!
​​​​​​The Variable Effort Steering (VES) system controls the amount of steering effort needed to steer the vehicle as vehicle speed and steering wheel position and turning speed changes. The Body Control Module (BCM) or Electronic Suspension Control (ESC) module, vehicles equipped with Real Time Damping (RTD), controls an electronic Variable Orifice (EVO) solenoid located in the power steering pump's output fluid orifice. The solenoid consists of a pintle valve which moves in and out of the orifice, regulating power steering fluid flow. The BCM/ESC module varies the amount of steering effort by commanding more or less current to the solenoid. At low speeds, no current is commanded and the pintle is fully retracted which provides maximum fluid flow and maximum steering assist for easy turning and parking maneuvers. At high speeds, more current is commanded to the solenoid and the pintle moves closer to the orifice, decreasing fluid flow, providing firmer steering (road feel) and directional stability. The VES system uses the Steering Wheel Position sensor input to calculate lateral acceleration during abrupt driving maneuvers. The system also uses the Vehicle Speed Sensor (VSS) signal from the Powertrain Control Module (PCM) via a class 2 serial data circuit. The control module is constantly monitoring these inputs to achieve the desired current to the EVO solenoid. The BCM/ESC module has the ability to detect malfunctions within the VES system. Any malfunctions detected will cause the EVO outputs to be disabled. Some VES system malfunctions may cause the SERVICE STABILITY SYSTEM warning message to be displayed on the Instrument Panel Cluster (IPC) message center.

Thanks for the reply.

​​​​​​Bob M.

 

Wow!
I did not expect a Thread titled: "4L60E has problems", to get into some of the Stabilitrak/ Electronic Suspension Control System.

I am glad that you got the gist of how the Variable Electronic Power Steering functions...
But much of the information that you regurgitated about Stabilitrak/ Electronic Suspension Control is incorrect.
Some of which comes from certain year Cadillac K-Trucks only.

Do me a favor, and do not try and work on anything in your vehicle related to the "Class Two Data" Line/ System...
You make cause entire systems in your vehicle to not operate.
I understand that you are not familiar with any vehicles with OBDII and newer.
Thank goodness you do not have a newer GM vehicle with GM High-Speed/ Low-Speed LAN (CAN BUS).

Anyway... So are ya looking for places to have your Transmission rebuilt?