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allison

  1. 01-04.5 LB7 Duramax Powertrain
    Hey guys, yesterday i was headin to work in my 02 duramax and my truck revved up and i think it came outta 5th gear and into 4th and the service engine light came on. I was going about 65 on cruise, and i hit the gas to accelerate to go around this car and thats when it happened. Any ideas? to...
  2. Transmission Shop
    A few months ago I posted on here about intermittent shifting issues I was having with my 2011 GMC LML. Someone said to try changing the brake switch and that solved my problems for the time being, but after a few weeks they started coming back again. I was pretty convinced that the problems...
  3. Exterior
    Hello, I’m new here. I have a 2007 LMM Crew Cab. For some reason it came stock with an annoyingly small 26 gal fuel tank. I’m curious if anyone has done an upgrade and what your experience was? Will a larger stock tank fit with no modification? Also, I’m wondering about the Allison Transmission...
  4. Transmission Shop
    Hey guys, looking for some advice on my truck. It is a 06 duramax lbz all stock with the allison automatic 186k miles. Yesterday driving my truck home from work I noticed my truck was shifting later than usual, and at some speeds(right around 32-45) didn't want to shift up into the higher gear...
  5. Transmission Shop
    I just joined the forum last night. I'm desperate for some guidance on the random shifting issues I am having with my 2011 GMC 3500 Sierra 4wd. It started a couple weeks ago. I pulled up to a job site and when I went to leave and put it in gear, I got the "shift inhibited" message and it would...
  6. Transmission Shop
    I need this truck every week for my compost route, satellite garbage truck on the back. 70,000 miles, well kept. Was working fine until Thursday the trans was slipping a little going up 2nd to 3rd then later in the day clunking down into 1st coming to a stop. No lights or codes no warning. What the?
  7. 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...
  8. Drivetrain
    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...
  9. 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...
  10. 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...
  11. 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...
  12. 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...
  13. 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...
  14. 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!
  15. 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...
  16. 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...
  17. 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
  18. Diesels
    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...
  19. 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...
  20. 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...
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