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  1. A

    H3 2006 hummer h3 shift solenoid p0787

    Hi guys, I recently made an transmission oil change and replaced the shift solenoids, for some reason the truck drives but don't shift. Reverse 1,2,3 works. I was getting the code p0787 before and is still there even after replacing them. I went to autoparts to buy the solenoids, They told me...
  2. C

    2006 H3 Driveline Noises

    Hi, looking for insight on driveline noises. Yesterday, suddenly have scraping, grating, grinding noise in 1st or Reverse under acceleration and any gear under deceleration. No noise when after shift to 2nd, 3rd, 4th. No noise in N either rolling or parked. no noise in P. No noise when...
  3. Grimmjow

    H3 Whole Laundry List of Problems from Driving Across the US - HELP?!

    My H3 has been a nightmare recently. I just moved across the US from Wilmington, NC to Phoenix, AZ. Left my car in Charlotte, NC with a sib and just drove it here this past weekend after it had been sitting for a month. My problems started with the usual sunroof leak. Fixed the hoses before...
  4. Z

    when the Tranny goes on my Alpha

    I've been taking care of keeping the fluids changed with full synthetic penzoil but Im concerned. My 100K mile 2009 alpha is almost 10yrs old, is my daily driver and I have been doing a lot of towing lately. I have made 3 summer time round trips of 3400 miles pulling anywhere from 8K to 3500lbs...
  5. humvee

    H3 Tranny dead

    Part of my V8 swap included adapting the i5 tranny to the V8 setup/ torque converter. Replaced the stator shaft with (A74529E), band and servo. Torque converter from an alpha and bell housing from a Yukon. The truck ran perfectly, but I had (EDIT:slight) leaking issues. Changed the seal twice...
  6. Shrubf4

    Odd shifting

    Had this weird thing happen recently where in the 20mph range, my transmission(I'm assuming) will miss grabbing the next gear, my rpm's will shoot up to around 3k and I'll coast for a second until they drop and it clunks into the correct gear. This is intermittently happening, but today, it did...
  7. pbarnes

    H3 5-Speed Clutch or Transmission?

    Morning Folks, I'm hoping someone out there can help a fella out. I’ve noticed the Clutch in the H3 is having to travel farther and farther out (off the pedal) before catching 1st Gear, over the last several months. I've taken her in to Cottman Transmission and low and behold, the...
  8. N

    H3 H3 3.7 I5 Rattling from transmission ??????Any ideas .

    hey guys , So earlier today i went to start my h3 up to take her out and run some errands. Well i didnt notice this till i got to the gas station but there was a rattle coming from under the truck it sounds like some bolts in a can being rattled around .my first thought was maybe the heat...
  9. Jeremy

    Transmission OUT! Advice?

    Okay, so heres the rundown. My '07 Hummer is in the shop and my transmission is being gutted and needing to be rebuilt. Since I don't know hardly anything about transmissions I can't provide exactly everything that mechanic told me is wrong with it but he basically said that everything was...
  10. alrock

    H3 Transmission Cooler Thread Number 3 - install with pictures

    Better late than never in joining the party, right? Reloader and I installed a transmission cooler in my H3 today, about a week after he did one in his. One of his primary concerns was that maybe he bought a two small of a cooler and after a bit of research, it appears that the 14,400 BTU ones...
  11. F

    How To: I bypassed my Transmission cooler with an external

    I was concerned about the dreaded transmission cooler problem so I installed a B&M Supercooler, bypassing the transmission cooler in the radiator. The convention I use is looking into the engine compartment from the front of your Hummer. So right side = Drivers side, also this is for USA. You...
  12. autumn walker

    Upgraded Driveline / Transmission UCP?

    So I have managed to destroy my factory driveline UCP. Pulled it off, welded in some 1/4" checker plate, put it back on, bent it again. What are you guys doing with your driveline to protect it? I'm getting tired of pulling my stock UCP off and reshaping it so it doesn't vibrate off my exhaust!
  13. alrock

    H3 - ATF fluid change procedure

    I did a fluid drain and fill today. I chose not to do a full flush in part as I just wanted to try this out and see the contents of the pan and the state of the old fluid myself. A drain and refill replaces about 5 quarts of fluid and I believe the transmission holds as many as 11 quarts. (Total...
  14. L

    Confused about ATF levels

    Hi guys, Yesterday I decided to do a routine check of my ATF levels after having been driving around town for about 30 - 45 minutes. The engine was definitely up to normal operating temperature, and I assumed the transmission was, too. I stopped, set the parking brake and put the truck...