4l60e stator bushings and p1870 slip code

Discussion in 'Transmission Forum' started by Steinkebunch, Aug 30, 2015.

  1. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    MAKE: Chevy
    MODEL: S-10 Blazer
    YEAR: 1999
    MILES: 140k
    ENGINE
    : 4.3

    I have a p1870 transmission torque converter slip code. Poor mpg. Bluetooth scanner with Torque app shows 150+ TCC slip on level ground and steady mph. Also a slight amount of fluid leaks from small tranny vent tube while driving. Fluid temp at 205 degrees after 30 minutes of driving. Tranny Fluid pressures 80 psi at idle, and about 120 psi on highway.

    Dropped tranny pan. Fluid red. No debris. Discovered previous owner had already tried Transgo shift kit with TCC regulator/isolator fix. I thought it might be severe bore wear, so I installed a new valve body with reamed bore and Sonnax regulator/isolator sleeve and valves. Cleared code, but still no joy, P1870 and slip continues.

    To avoid tranny drop I tried one last ditch effort. Checked TCC apply valve for 1/2" of travel. Checked fine. I removed TCC apply solenoid, removed its screen, and put a check ball in its snout. Should have made engine stall in drive while stationary (brakes applied) as converter would be locked. No stall or stumble.

    So I dropped tranny. Converter looks brand new. No burn marks, perfect paint. Clutch packs not burnt. Drum where band rides still has scotch brite marks where someone removed any glazing. This tranny appears to have been recently rebuilt. I purchased the blazer a few months ago.

    The only potential problems I see are rear stator bushing wear and input/turbine shaft wear. See photos. The rear stator bushing is worn to the point where one of the oil grooves is completely gone. 180 degrees from that wear, the bushing has not even touched the shaft journal. Photos show bushing at worn spot and unworn spot. The turbine shaft where it inserts into the torque converter is dished and wore a fair bit. O-ring was ok or at least not flat. I removed the o-ring for the photo.

    My question is if this kind of wear can cause TCC slip? Is this my smoking gun? I plan to replace turbine shaft and stator bushing.

    image.jpg
    image.jpg
    image.jpg
     
  2. JackC

    JackC wrench

    Joined:
    Nov 14, 2006
    Messages:
    1,341
    Likes Received:
    14
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Nothern California
    We have only one really good trans specialist here.

    So, hang in there for bp042665 to find you and answer.
     
  3. bp042665

    bp042665 hunting nut

    Joined:
    Nov 26, 2012
    Messages:
    532
    Likes Received:
    8
    Gender:
    Male
    Location:
    Iva South Carolina
    check for the check ball in the input drum also check the seal on the input shaft. Where did you get the valve body from was it a good company
     
  4. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    Thanks for the input. The valve body was from an ebay seller. But it was definitely reamed and has a Sonnax valve installed in the reamed regulator bore. New solenoids. I suppose the AFL bore could be wore but surely not on both the old and new body both.

    Do u mean the check ball in the end of the input shaft? It's present, suppose I should make sure it seals. But I'm gonna replace the entire drum and input/turbine shaft anyway.

    As for my original question, could the rear stator bushing and input shaft pilot journal wear alone cause the slip?
     
    Last edited: Sep 3, 2015
  5. billr

    billr wrench Staff Member

    Joined:
    Mar 12, 2007
    Messages:
    5,646
    Likes Received:
    55
    Did the VB get all the Sonnax repairs/upgrades, or at least the full Sonnax "Sure Cure" kit?
     
  6. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    No, only the TCC Isolator & Regulator Valve Kit, as well as accumulator pistons.

    I had just figured since someone before me tried the whole Transgo kit, then I tried a different valve body with Sonnax regulator/bore, it was unlikely to be VB.
     
  7. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    I'm getting the sense that you don't think the rear stator bushing wear is bad enough to cause the problem...and that it may still be the valve body...
     
  8. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    Could the line pressure results posted in my OP give us a clue about the problem being in the pump vs the valve body? 80 psi idle/120 psi cruising at 2000 rpm.
     
  9. billr

    billr wrench Staff Member

    Joined:
    Mar 12, 2007
    Messages:
    5,646
    Likes Received:
    55
    I'm not savvy enough on that (or any other) auto transmissions to even have an opinion on that bushing wear. As to the pressure, there is probably a "quickie" test for that, but I don't know the particulars. On a Saturn S-series TAAT you should have about 60 psi idling in P, then when you pull the line-pressure fuse the line-pressure should rise quickly to the max (about 260 psi), indicating that the pump can provide proper pressure. that test kind of eliminates the pump as a problem, hopefully the 4L60E has a similar kind of pressure test and somebody else can provide the particulars. Note that you will still have no real handle on the PWM control of LP, for that you will need a factory-type test setup.
     
  10. bp042665

    bp042665 hunting nut

    Joined:
    Nov 26, 2012
    Messages:
    532
    Likes Received:
    8
    Gender:
    Male
    Location:
    Iva South Carolina
    ok the bushing is a issue but not for the lock up problem that is a valve problem i use central valve body for my reman valve bodys they do all sonax upgrade not just 1
     
  11. EricC

    EricC Hero Member

    Joined:
    Nov 14, 2006
    Messages:
    401
    Likes Received:
    3
    Gender:
    Male
    Occupation:
    Shop Foreman, County Garage
    Location:
    Tulsa, OK
    Home Page:
    I'm going to add this because before bp came onto the scene, we had another transmission guru here that had some insight into this. Search this site for P1870 back in the 2007ish era for more info.

    Having said that, I'll leave you with this, and the fact that with your current mileage, a complete overhaul might not be out of the question.

     
  12. bp042665

    bp042665 hunting nut

    Joined:
    Nov 26, 2012
    Messages:
    532
    Likes Received:
    8
    Gender:
    Male
    Location:
    Iva South Carolina
    i stand corrected on this bushing problem i just have never expeinced it myself see even i can still learn something new lol
     
  13. Steinkebunch

    Steinkebunch Newbie

    Joined:
    Aug 30, 2015
    Messages:
    6
    Likes Received:
    0
    Gender:
    Male
    SOLVED!
    I installed a new bushing and new turbine shaft/input drum. The P1870 code is gone and TCC slip is back to acceptable levels at lockup. Appears that the bushings are vital to allowing the teflon rings to seal on the turbine shaft.

    It was a long journey and I learned a lot. It would have been simpler to just pop a new tranny in and drive on. But I'm glad I stuck with it and learned.

    Thanks for all the input. Hope this helps someone else down the road.

    Remember that if the Transgo or Sonnax band aids don't fix your P1870 code, the problem is deeper. In fact, if you have the code, you probably are on borrowed time , even if the bandaid valves make your code disappear. Transman seems to know what he's talking about.
     
  14. billr

    billr wrench Staff Member

    Joined:
    Mar 12, 2007
    Messages:
    5,646
    Likes Received:
    55
    Here is my long-running P1870 tale, for comparison or reference. The vehicle now has 145K miles on it, 8 yrs. later, and the trans is still operating acceptably. It still routinely will set the code (clears automatically at key-on) and still leaks, but I ain't digging into it until it gets worse. Now we are using it for occasional towing...

    http://www.batauto.com/threads/97-chev-van-code-p1870.4013/
     
  15. urb0123

    urb0123 Newbie

    Joined:
    Dec 13, 2016
    Messages:
    2
    Likes Received:
    0
    I did like billr did and just ignored it. Read on to find out what can go wrong with ignoring a P1870

    97 K1500 suburban I did a rebuild six years ago. The 3-4 clutch packs burned out and we ignored it for about 2 years, just drove in 1st and 2nd.

    I put in a Transgo HD2, beast sunshell, 5 gear planetaries, new reverse drum and replaced all the standard stuff(seals, bands and frictions).
    I got it all back together and it worked great. Only problem was it still had a P1870 code. I was annoyed but didn't have time to deal with it.

    Fast forward 6 years and the pump rotors died. They were in multiple pieces and looked like they exploded. (I got a sinking feeling when I found pump vanes in the neck of the trans filter)

    My best guess at this point is that given the wear on the tangs, the torque converter wasn't seated completely(2/3 of the way). Add the high line pressure because of the P1870 code and I can see why the rotors gave out.

    So I have to figure out what is causing the P1870 code. I remember having trouble getting one of the pump bushings out and may have just left it in. I'll check that tonight. I know the front bushing is thrashed.
     

Share This Page