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  1. 2006 LBZ motor and trans overheating into limp mode instantly

    06-07 LBZ & LLY Duramax Powertrain
    Long time forum searcher and can usually find what i'm searching for but ran across a problem this summer i cannot seem to fix yet and would appreciate any ideas. -Problem- Truck Allison and LBZ are getting hot instantly while pulling hills and warnings go off. (ECT 250, EGT 1400+, Trans Fluid...
  2. Is my Transmission going bad?

    I have a 2007.5 GMC Serria 2500HD LMM with the 6-speed Allison Transmission 4 wheel drive, the other day I went and picked up a mini excavator and was towing it home when I noticed something iv never noticed before. I stopped at a red light in town and when the light turned green I let off the...
  3. 2009 Duramax shifting issue

    911 Problems Forum
    Tried posting in Transmission Shop... Hi all, First time I have had an issue with this truck. 2009 chevy silverado 2500hd duramax with allison 199k miles at Diesel mechanic every 6k for maintenance. The facts: Driving normal at slow speeds (City road) when check engine came on. Gear...
  4. 09 Duramax 2nd gear only (unique fourm, I read tons of others before posting)

    Transmission Shop
    Hi all, First time I have had an issue with this truck. 2009 chevy silverado 2500hd duramax with allison 199k miles at Diesel mechanic every 6k for maintenance. The facts: Driving normal at slow speeds (City road) when check engine came on. Gear selection P,R,N,D disappeared. (Don't...
  5. To Flush or Not To Flush

    01-04.5 LB7 Duramax Powertrain
    2014 chevy silverado 3500 HD 6.6L Duramax / 6 speed Allison... While getting some brake work done, I was thinking of having the transmission flushed. But the mechanic told me that if it's never been done before, I could have a blown transmission within a week. I guess a flush would clean all...
  6. Ready To Set This Truck On Fire And Call It A Day!! (Infamous P0872 Code)

    Transmission Shop
    I'll try to keep this short and still include all the details. First things first: 2005 2500HD Duramax LLY 2wd Base Model Allison 1000PK Trans 317,000 miles So this is a shop truck / equipment delivery truck for our shop. (Equipment rental business). Its had years of hauling equipment and...
  7. LBZ Transmission Noise

    Transmission Shop
    I recently pulled my transmission after the torque converter went bad. While I had it out, I decided to pull it apart and inspect the internals. Mind you, I have built one of these transmissions in the past with good success on my LB7. I found the C3 clutches had a little more wear than I liked...
  8. Is the manual the same?

    Transmission Shop
    Is the ATSG manual the same for all years of allison 1000's in our trucks or is there a specific manual for 6 spds? Thanks!
  9. Allison and a 454??

    Transmission Shop
    drive 1997 K2500 chevy suburban with the 7.4L(454) big block and the stock 4L80E tranny is starting to go i think and i was curious if anyone knows if i would be able to put an allison into it with out a lot of modification, and if i can what model would be best or easiest, any info would be...
  10. Can tranny take more?

    01-04.5 LB7 Duramax Powertrain
    i have a LB7 with the stock tranny. i have a ppe boost valve k and n cold air with AFE filter. 4 inch turbo back exhuast, and edge juice with attitude on level 6. im not sure what the hp and torque is. maybe 485 hp 850 lbs? at crank. question is how much more can a stock allison take before...
  11. 6-speed in my '03?

    01-04.5 LB7 Duramax Powertrain
    Ok, 2003 GMC D/A...on the dash it shows D 3 2 1, but I have counted the shifts many times now and it shifts 5 times. The last shift is at about 55mph and 2k rpms. Also 2nd and 3rd are really close. Is it possible someone has swapped it? How can I tell? Thanks in advance
  12. cummins conversion exhaust help

    Hey, My family business put a 5.9 cummins in a 1936 white yellowstone park tour bus. We have a fully built allison behind it, and a custom firewall. What i need help with is a source for custom intercool built, exhaust manifold, custom 4 inch turbo back exhaust and a jake brake, all steel...
  13. Allison trans falls out of gear at a stop

    Transmission Shop
    I need help. My 2001 2500 HD has this weird problem and is getting worse. When I stop at a light and 15 seconds later it feels like someone drove into my back bumper,a really strong loud clunk. Also when I roll through a turn and I step on the gas its like in neutral and when the revs come down...
  14. P0851 NSBU Problem?

    06-07 LBZ & LLY Duramax Powertrain
    Hey guys, So I just bought a new/used 06 Duramax w/ 45K miles. Before I bought it, I ran my PPE to see if any codes came across, and it was clean. I drove it up from Seattle to Anchorage (total of about 2400 miles), and when I hit Whitehorse (about 700 miles from Anchorage) the truck chimed at...
  15. Need help allison tranny

    Transmission Shop
    just replaced my allison tranny in my 2004 chevy..... all went well until I plug the pnp up.. mine hads a 2plug pnp... the new allison has a 1plug.. i looked more into this.. my truck is a lb7 2004 the new tranny is a lly 2004.5.. i got a new pnp for a 2004 Lb7 this does not fit the new tranny...
  16. allison not working

    Transmission Shop
    The allison in my fathers 03 duramax is not shifting and as a result it tops out at 20, 40 or 60 mph when it wants to. The truck is completly stock any help would be appreciated.
  17. 03' Silverado K3500 shifting problem

    Transmission Shop
    I'm out of ideas of what the problem is with the truck. When you go from park into reverse it slams into gear, when you go into drive it pulls/lurches foward with moderate pressure on the brake, when its in neutral it says its in 3rd gear and none of the other gears on the PRNDL light up when...
  18. Allison transmission cooling help!!

    06-07 LBZ & LLY Duramax Powertrain
    Hey guys I am having some trouble with my transmission getting too hot. I have a 2006 GMC Sierra 3500 with 140,000 miles on it. 6.6/Allsion. First I was driving home in traffic on a very cold day. I had remote started my truck and it setting idling for a while and I believe at the time I had...
  19. Tranny fluid help

    04.5-05 LLY Duramax Powertrain
    looking to change tranny fluid from the original dexron III to a SYNTRANS from john deere.... it was my buddy's idea who works for john deere.... it is approved for allison use.... just wanted to get some input before i possibly make a mistake...
  20. Allison Problems - Limp Mode when warmed up

    Transmission Shop
    Need some assistance here from the Allison experts here. I'll start with what the truck is doing/codes thrown and provide some back-story on things I’ve changed before this started to happen. Truck - '02 Silverado 3500, 4x4. Everything is stock. I do have aftermarket MBRP exhaust, Banks...