Jump to content

4L60E won't shift into reverse correctly

thecraft

Recommended Posts

thecraft Senior Enthusiast

thecraft

Posted
Posted

Alright, I've got two problems with my '95 that I hope someone here can help me with.

 

The first problem is that my transmission (4L60E) has trouble shifting into reverse. It rarely shifts into to reverse properly, maybe 10% of the time at the most. Most of the time it will engage, but the truck rattles like crazy and moves very slowly. Sometimes if I rev the engine a bit while it's doing this, it will engage with a soft lurch. The rest of the time, the truck will just sit there. If I rev the engine, the transmission will engage with a violent jerk... I left a couple of tire marks in parking lots doing this. It's been doing this for a while now (since the previous owner had it) and seems to be getting slowly worse. The only temporary fix I found is to shift back and forth between Park & Reverse until it works. The transmission works perfect other than that...

 

The second problem isn't serious, but I like to get rid of that d**n SES light. I used the ol' paper clip trick to retrieve the service codes and turned up with "32 - EGR open command did not change MAP sensor signal. Normal EGR flow should cause slight decrease in manifold vacuum which would change MAP sensor signal." I know that service codes aren't always accurate, but I'm willing to bet that it's my EGR valve because it's never been taken off since the truck was built. However, I don't have any of the symptoms of EGR problems like rough idle (valve open) and engine knock (valve closed). Anyways, if I take off my EGR valve, how can I check if it is working correctly? Can I clean it with something like carburetor cleaner or do you think I would need to replace the valve?

 

Thanks for your help!

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Chuck FB
      Joke Thread

      By Chuck FB · Posted

    • txab
      Gas Prices

      By txab · Posted

      $3.59  
    • needafix
      2019+ Brake failure, it's complicated

      By needafix · Posted

      I'm not sure if this should be a new topic, let me know if it's out of place. This my first post. Thanks 85077522 - AC Delco GM Genuine Parts Brake Master Cylinders. Anyone else had to replace this brake master cylinder yet. I didn't do any brake work, it looks like new parts and I've had the truck for about 4k miles, 119k total miles.  When it started to throw codes I did the calibrations with a bidirectional scanner and got the codes to clear but they came back so I did the routine; base bleed, automated bleed and final base bleed. All that with Bosch ES16-32N fluid (please look it up). That seemed to fix it but 100ish miles later it failed again so I ran the same process but with a pressure bleeder this time and got the same results, fixed for 100ish miles. The original fluid looked bad and I thought I got most of it out, it could've been the wrong fluid. The codes; P25A2, C05B0-00, C2A1B. I can get them to clear but not for long. The C05B0 indicates a leak in the front circuit (which is bone dry) so I'm thinking of doing the bleed process on that front again today and I don't know if that's taboo to just do the front but at this point it seems like it's worth the try anyway. The new master cylinder/module unit is supposed to get here today. But now I'm pretty much convinced this install is over my head. I've called several shops and some mobile guys that I know but this thing is like radio active material, scary wise. I did get 2 local shops say they should be able to do it, one says he has the SPS2 programing capability. And with the battery disconnected is there supposed to be pedal resistance, mine is to the floor, then if I pump it I can get some resistance. I had a panic stop prior to this issue which may have contributed from what I read. And on the first attempt to bleed and hydraulic test the scanner listed things to look for and one was any gaps between the pad and rotors which I did notice on the RF corner and I removed the outer pad (where the gap was) cleaned it and the hardware and didn't see a gap after that but will re-check it. I read that if pushing the caliper pistons back then you're supposed to open the bleeder so as to not push fluid backwards into the abs module or it will damage it. If that's true then that's also a possibility from the previous owner having the brakes changed before I got it. I'm using an XTool ip500 scanner. Any suggestions, questions and comments welcome. 
    • Donstar
      Navigating senior years.

      By Donstar · Posted

      Next Friday will be my 6 week point from my right knee replacement.  The surgeon says it will be fine if I choose to drive after this checkup.  I know I could drive now but best to do as my surgeon (and my wife) tell me.  Richard compared being 62 to 72.  I remember when I was in my early 60's I was experiencing slow but regular decline in my mobility.  Thanks to good medical support,  i continued to fight the speed and spread of this decline. During my 60's I worked on non-surgical methods and just when I turned 70, my orthopedic surgeon recommended joint replacements.  In a little over a year, I had one shoulder and both knees replaced.  This hasn't been a terribly fun experience, but worth the discomfort as my future mobility health trajectory has reversed.  It is a treat to now be watching my mobility. balance and confidence steadily improve!
    • Another JR
      Trailer TPS Sensor Question Rim Size

      By Another JR · Posted

      Grommets with the right cement should be perfectly fine. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...