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3500hd tranny problem

Discussion in 'Chevy Trucks' started by jrodgers, Mar 2, 2005.

  1. jrodgers

    jrodgers Senior Member
    Messages: 156

    Has anyone had this happen. Sometimes (more oftan than none) when Im driving my truck, it will shift into the passing gear (2nd or 3rd) and wont shift into the next gear. If I stop and sit for a couple minutes it will shift ok again. It only happens after a certain time driving, maybe 5 or 10 minutes. I dont think it is the tranny rather some sensor somewhere. Anybody?.....JR
     
  2. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    allison??? 4l80e???? powerglide???? what is it????
     
  3. jrodgers

    jrodgers Senior Member
    Messages: 156

    Uh?!? Well I know it isnt an Allison. It is a 2000 with a 6.5 diesel and an automatic tranny. I think it is a 4 speed. How can you tell?
     
  4. NJBuickRacer

    NJBuickRacer Member
    Messages: 59

    Check your throttle position sensor, if it is faulty the PCM may think you're at WOT and keep it in gear thinking you're accelerating.
     
  5. CHPL

    CHPL Member
    Messages: 80

    You have a 4l80e trans in your truck. There are 2 speed sensors in the trans one for input speed and one for output speed. What is happening is one sensor is dropping out or reading incorrectly and it make the trans default into 2nd gear. You can change the snesors your self. Buy both and replace them I am confident that it will solve your problem.
     
  6. jrodgers

    jrodgers Senior Member
    Messages: 156

    Thanks Im going to check those things and Ill let you know. I was going to bring it to Chevy but I would hate to bring it there for something I could easily do myself. Hey CHPL where do you live in NJ?
     
  7. CHPL

    CHPL Member
    Messages: 80

    I'm in cape may county, i work for a chevy dealer and also operate my own lawncare/ snowplowing compay.
     
  8. jrodgers

    jrodgers Senior Member
    Messages: 156

    Thats cool Im in Winslow, more north. Could you give a quick description of where these sensors are? I was under there but couldnt tell where they were. I could see where the shift cable is and I can see where there is a wire harness under there but there is alot of "stuff" under there. Certainly appreciate the help. JR
     
  9. CHPL

    CHPL Member
    Messages: 80

    Gonna Try To Attach Image
    Your Speed Sensors Are 22a And 22b In Picture
    They Are About Halfway Up And The Left Side Of Trans
    I Cant Get Image Size Correctly On Shop Computer Ill Try Later
     
  10. jrodgers

    jrodgers Senior Member
    Messages: 156

    Thanks.......
     
  11. CHPL

    CHPL Member
    Messages: 80

    I havent been able to resize the image i have on the shop pc. I' ll have to snap a picture and send it from home. Both sensors look the same they are on the left side and have connectors with 2 wires on them.
     
  12. CHPL

    CHPL Member
    Messages: 80

    try this here is a picture of your tranny

    Your-trans.JPG
     
  13. jrodgers

    jrodgers Senior Member
    Messages: 156

    That makes things very clear thanks a mil. you probably save me a good chunck of $$$, because I probably would have taken it to the dealer. How much do you think a job like this would be at the dealer? Can I get these sensors at an auto parts store or should I go right to Chevy? Thanks again , if you ever need anything just pm me. JR
    ps Love your Cape May Rips!!!!
     
  14. CHPL

    CHPL Member
    Messages: 80

    I would probably buy gm
    I can get them delivered to you if you want.
     
  15. jrodgers

    jrodgers Senior Member
    Messages: 156

    I have a Chevy Dealer(Turnersville) very close to me so I'll swing up there but thanks anyway I apprciate all your help and I will let you know how things go. Cant do it now we have like a mini blizzard going on. JR
     
  16. CHPL

    CHPL Member
    Messages: 80

    So have you had a chance to work on your truck?
     
  17. jrodgers

    jrodgers Senior Member
    Messages: 156

    Sorry I havent checked here lately. I have not had a chance to work on it but I did figure out exactly where they are so I am going to tackle it within the next couple days. I have another question. Today I was out running around with my truck like normal and I started to have a problem. Oh this is my 01 Silverado Duramax. So anyway I went and got diesel and after a little while it started to run strange like it was starving for fuel( I would give it the petal and it would hesitate and then go) it only lasted a few miles until the service engine light came on and it really started to act up. I made it home and tried to change the fuel filter and did it exactly like they said in my manual. Well I put it all back together it started running for a second and then shut off. I took the filter back off and filled it with deisel and primed it again and it did not do anything. Now it wont start at all. First do you think it was originally the filter or could the fuel pump or something have gone. I am ready to take it to the dealer but I figured let me check and see if you were around . At this point I will probably wait until tomorrow so if you see this write back as soon as you can. I have had nothing but probloms with this truck over the 4 yrs I have had it. Have you ever seen or heard about these trucks having alot of problems. Mine was bought in Feb of 01 so I would imagine it was one of the early early models. Are the new ones like this because I love the truck......When it is running.......Thanks in advance JR
     
  18. CHPL

    CHPL Member
    Messages: 80

    Well with out knowing what codes are in it I will say this as far as common things i have seen.
    Fuel filters blocked, when you change it you need to pump the primer on the top alot.
    Air filters blocked or the incorrect one installed.
    GAS put in tank by mistake(we probably pump out and clean a tank on a diesel once a month)
    Loose air ducts to intercooler or air intake
    Now the bigger problems fuel in crank case from leaking injectors
    Some injector failures.
    I know that if you read on the net about wide spread problems and I'm not sure if there are as many as the net makes it seem.

    In our shop we have probably replaced injectors on 6-8 trucks all together
    We have changed park neutral switches on allison transmission with a new part number probably about 10-12 times.
    We have only had 1 allison internal problem to my knowledge.
    On one 05 DMax I had a shorted wire to a fuel injector.
    They are a good engine trans combo.
     
  19. jrodgers

    jrodgers Senior Member
    Messages: 156

    I have a funny feeling that there is still air in the lines because after I changed the filter it started for a second and then seemed to run out of fuel. Now when I pump the primer the bleeder valve on top of the assembly should be open and fuel should come out. There is fuel coming out when I push it in but when I let it out it seems to suck air from the same hole. Is this normal? I tried pushing it in then closing the bleeder valve, then letting it out so that it wouldnt suck air on the up motion of the pump. Im am going to mess with it today if not Ill have to bring it in. Luckily it is raining. Thanks alot. Like I said before if you need my help in anyway (landscape ,lawn, plowing whatever) let me know. Oh this truck has had some of them problem that you mentioned. Park neural switch, transmission at 18,000 ,trans shift cable, busted out back light( oh wait I did that), and some other little things that have messed me up. I like the truck because it is comfortable ,has plenty of power, handles well(much better than my wifes 02 Suburban), and is just fun to drive. I will probably get another on no matter what. Anyway have a good day and thanks.........JR