2003-2007 HUMMER H2 – 2006-2007 HUMMER H3 – 2005-2007 Saab 9-7X Problem – Drivers may experience the loss of 3rd and 4th gear, erratic shifting, slipping, freewheeling above 30 mph and a P0757 DTC. Solution – In order to repair this transmission problem, the 2-3 shift valve, 2-3 shuttle valve, and the valve bore will need to be cleaned ... 2007 Hummer H3 4dr SUV. 242-horsepower 3.7L I5 5-speed manual AWD w/low range. 66000 mi. US $180. Rear U joint failed ten days out of five year warranty, had my local shop change both U joints on shaft, one that failed is greasable, non failed is non greasable, same job would have cost $580.00 at local dealer with truck just 10 days oow. Recall List for the 2007 Hummer H3. Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the ...I went to the local dealer and after computer inspection they saw the code po717 input speed sensor with low voltage. they reset the code and asked me to come later. now my hummer is not shifting the gear from 2nd to 3rd and when i shift on D from idle position it drags to speed up even. is it due to some switch or the transmission has gone bonkers?Aug 18, 2008 - It is in the engine bay on the driver front side of the motor. Look at the battery and just below it is the ECM/TCM on a bracket right beside ... [SOLVED] - Transmission Shifting Issues. Mar 26, 2011. Additional "TCM" Transmission Control Module. Dec 23, 2014. A "how to" for removing the ECM/ TCM. Apr 9, 2006.Feb 16, 2016 · hey buddies ! my H3 2007, I have the following problem 5 months ago: in morning or after a long time stopping (more than 7 to 8 hours), it so, when I start the engine, it is stopped with the message on dash: service stab system, tracation failed, reduced power. so, I try starting engine after less than a minute, with pressing on the race roughly. stopping again, and trying again, all this for ... 3 model years affected. 2006, 2007, 2008. Average mileage: 93,430. (33,456–224,450) Check Engine Light Diagnosis & Testing : $88 -$111. The average cost for a Hummer H3 Check Engine Light Diagnosis & Testing is between $88 -$111. 2007 Hummer H3 Transmission Problems Find something helpful? Spread the word. Click on a problem below to read more. Transmission Failure 5 Transmission Cooler Busted In Radiator 1 NHTSA:... Hummer H3 Stalling Problem Causes. Here are some of the issues that cause the H3 to stall out. Remember, a vehicle needs air, fuel, and spark to run. It needs them in the right quantities and intervals, or it won’t run right. Fuel. Fuel issues are one of the most common reasons that a vehicle would stall out, that includes your Hummer H3.2007 Hummer H3 4dr SUV. 242-horsepower 3.7L I5 5-speed manual AWD w/low range. Hummer H3 in Virginia, United States. Jun 2014 - Nov 2014. Sep 2014. 50000 mi. US $850. Due to a poorly designed sunroof draining sust leaks caused sensors to get wet and tripped the warning lights to ping ABS and stability system errors.Aug 18, 2008 - It is in the engine bay on the driver front side of the motor. Look at the battery and just below it is the ECM/TCM on a bracket right beside ... [SOLVED] - Transmission Shifting Issues. Mar 26, 2011. Additional "TCM" Transmission Control Module. Dec 23, 2014. A "how to" for removing the ECM/ TCM. Apr 9, 2006.Transmission in NEUTRAL/Air Conditioner is OFF ECT Sensor Engine Data 1, Engine Data 2, Engine Data 3 °C/°F Varies IMPORTANT: Review the system operation in order to familiarize yourself with the system functions. Refer to Cooling System Description and Operation . 2007 Hummer H3 2007 ENGINE Engine Cooling - H3 MY Oct 21, 2011 · I went to the local dealer and after computer inspection they saw the code po717 input speed sensor with low voltage. they reset the code and asked me to come later. now my hummer is not shifting the gear from 2nd to 3rd and when i shift on D from idle position it drags to speed up even. is it due to some switch or the transmission has gone bonkers? Problem with your 2007 Hummer H3? Our list of 8 known complaints reported by owners can help you fix your 2007 Hummer H3. 2007 H3 WONT GO IN REVERSE. Asked by HAASTYLE Jul 29, 2016 at 01:34 PM about the 2007 Hummer H3. Question type: Maintenance & Repair. PUT THE H3 IN REVERSE. PRESS THE GAS MOVES ABOUT 6-8' THEN ITS. LIKE IT IS NEUTRAL NO MOVEMENT.Transmission problems have been reported by some owners of the 2007 Hummer H3. Image source: Wikimedia. Several owners have complained that their Hummer lost power and exhibited shifting problems while they were on the road. Others reported that their transmission was shaky for a few days. Most of them also had trouble shifting into gears.Worst 2006 Hummer H3 Problems #1: Leaking Valves 2006 H3 Average Cost to Fix: $2,500 Average Mileage: 87,000 mi. Learn More #2: Engine Runs Roughly 2006 H3 Average Cost to Fix: $3,000 Average ...2007 Hummer h3 transmission failure. While going uphill hummer front end shakes and lost all gears. after 20 min it was fine but then a week later happened agian and lost all gears and grinds going into park. hummer is broke down and undrivable. just had oil and fluids checked a week ago. all was fine. Has 69000 miles.Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the recommended solutions. Recalls don't ... 2007 Hummer H3 problems (8) View all. 2008 Hummer H3 problems (8) View all. 2009 Hummer H3 problems (7) View all. 2010 Hummer H3 problems (5) View all. Get back on ...Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the recommended solutions. Recalls don't ... Aug 15, 2023 · The Hummer H2 has decent reliability, With J.D. Power giving the 2009 model a score of 3 out of 5. The Hummer H2 has been known to develop problems like mode door actuator failure, gas cap issues, low oil pressure, and engine stalling, among other things. Recall List for the 2007 Hummer H3. Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the ...124 Location Spain May 25, 2015 #1 Well, I have a 2006 Hummer H3 Luxury Automatic with 70000 miles on it. I started to notice that the shifting in 1-2 and 2-3 is a bit slow..like there is first a disengage of the previous gear and then the upshift occurs, the 1-2 is harsh and the 2-3 is not harsh.2007 Hummer H3 Flush brake fluid every 60,000 miles. Brake fluid can become dirty and may cause problems in the brake system ; it should be flushed every 60,000 miles. 2007 Hummer H3 Flush cooling system every 60,000 miles. GM recommends replacing the engine coolant at 100,000 miles; however, our technicians tell us that the coolant may become ... P0700 is a common code if it’s an electrical issue related to the transmission. If something has gone wrong in the transmission, your H3 may not be able to accelerate anymore, or it’ll. If it can no longer shift, it could be caused by a solenoid/valve body that has gone bad, clutch packs, debris, and much more.2010 Hummer H3 V8-5.3L: Service type Gears slipping when accelerating Inspection: Estimate $94.99: Shop/Dealer Price $104.99 - $112.48: 2007 Hummer H3 L5-3.7L: Service type Gears slipping when accelerating Inspection: Estimate $94.99: Shop/Dealer Price $105.02 - $112.55: 2006 Hummer H3 L5-3.5L: Service type Gears slipping when accelerating ... 3 model years affected. 2006, 2007, 2008. Average mileage: 93,430. (33,456–224,450) Check Engine Light Diagnosis & Testing : $88 -$111. The average cost for a Hummer H3 Check Engine Light Diagnosis & Testing is between $88 -$111. Dec 11, 2020 · Usually the starter is mounted on the engine side of where the engine and transmission mount. If this is the case then you do not need to remove it. It will stay on the engine. Here is a video that shows how to remove a transmission in case you need this: Also, I attached the entire process from the manual for this vehicle in case you need that ... Jul 31, 2017 · Oil sign on at idle, stop, parked. Hummer H3X oil signal comes on at just about form of the car not moving forward. I notice that this happens only in the summer time, and the car has been driven for at least 45 minutes. If it's cold there is no oil signal. I changed the thermostat,oil sensor switch, and I have done a full oil and filter change ... 2007 Hummer h3 transmission failure. While going uphill hummer front end shakes and lost all gears. after 20 min it was fine but then a week later happened agian and lost all gears and grinds going into park. hummer is broke down and undrivable. just had oil and fluids checked a week ago. all was fine. Has 69000 miles.723. Location. Louisiana. Jan 23, 2015. #10. If there is a broken front drive line component and with the vehicle in 4hi normal, and the trans in a forward speed, the output shaft of the transmission will turn sending motion to the corner with the broken component but no vehicle motion.Feb 7, 2022 · Hummer H3: I am working on a 2007 Hummer H3, 5 spd trans, I am working on a 2007 Hummer H3, 5 spd trans, 3.7 L engine. I just replaced the engine and put in a new clutch while the engine was removed. The P0700 code in your Hummer H3 is a generic OBD-II code that indicates a malfunction within the transmission control system. This code is not specific to any particular issue but rather points to a general fault in the system. Additionally, the P0700 code usually appears in conjunction with other transmission-related codes or shift solenoid ...Common symptoms of overheating include smoke coming from under the hood, a pegged temperature gauge, and (eventually) a blown head gasket. If your H3 is overheating, stop driving it immediately to avoid damaging the engine. Ignoring an overheating engine can lead to serious engine problems. A blown head gasket, engine block, or cracked head are ...2007 Hummer H3 Transmission Problems Find something helpful? Spread the word. Click on a problem below to read more. Transmission Failure 5 Transmission Cooler Busted In Radiator 1 NHTSA:... Usually the starter is mounted on the engine side of where the engine and transmission mount. If this is the case then you do not need to remove it. It will stay on the engine. Here is a video that shows how to remove a transmission in case you need this: Also, I attached the entire process from the manual for this vehicle in case you need that ...5 complaints Most Common Solutions: transmission rebuilt (2 reports) changed radiator and transmission cooling system (1 reports) not sure (1 reports) replaced valve body (1 reports)...2) (regular easy, 30 minutes to complete) Scoot under the your H3 with a 10mm socket and wrench to remove the 4 bolts holding the encoder motor on. While it is still plugged in with the parking brake on and the vehicle in neutral, press the buttons on your dash to see if it is moving to each distinct position.Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the recommended solutions. Recalls don't ... 2007 Hummer H3 4dr SUV. 242-horsepower 3.7L I5 5-speed manual AWD w/low range. 66000 mi. US $180. Rear U joint failed ten days out of five year warranty, had my local shop change both U joints on shaft, one that failed is greasable, non failed is non greasable, same job would have cost $580.00 at local dealer with truck just 10 days oow. Oct 4, 2019 · This humming sound will change with the engine’s RPM. Unplugging the alternator from the wiring harness should stop the noise. 2. Power Steering Pump. A failing power steering pump. The power steering pump is a common reason your Hummer H3 might whine when accelerating. If it gets too low on fluid, it’ll whine a lot. Dec 4, 2019 · Bad Torque Converter Symptoms: Hummer H3. Here are some of the most common bad torque converter symptoms that could happen to your H3. 1. Slipping Transmission (Low Speed) The torque converter “stall speed” is the speed that the engine needs to be turning before the torque converter will begin engaging the transmission. hey buddies ! my H3 2007, I have the following problem 5 months ago: in morning or after a long time stopping (more than 7 to 8 hours), it so, when I start the engine, it is stopped with the message on dash: service stab system, tracation failed, reduced power. so, I try starting engine after less than a minute, with pressing on the race roughly. stopping again, and trying again, all this for .... Feb 7, 2022 · Hummer H3: I am working on a 2007 Hummer H3, 5 spd trans, I am working on a 2007 Hummer H3, 5 spd trans, 3.7 L engine. I just replaced the engine and put in a new clutch while the engine was removed. Common symptoms of overheating include smoke coming from under the hood, a pegged temperature gauge, and (eventually) a blown head gasket. If your H3 is overheating, stop driving it immediately to avoid damaging the engine. Ignoring an overheating engine can lead to serious engine problems. A blown head gasket, engine block, or cracked head are ...2007 Hummer H3 Flush brake fluid every 60,000 miles. Brake fluid can become dirty and may cause problems in the brake system ; it should be flushed every 60,000 miles. 2007 Hummer H3 Flush cooling system every 60,000 miles. GM recommends replacing the engine coolant at 100,000 miles; however, our technicians tell us that the coolant may become ... Aug 18, 2008 - It is in the engine bay on the driver front side of the motor. Look at the battery and just below it is the ECM/TCM on a bracket right beside ... [SOLVED] - Transmission Shifting Issues. Mar 26, 2011. Additional "TCM" Transmission Control Module. Dec 23, 2014. A "how to" for removing the ECM/ TCM. Apr 9, 2006.If your 2007 Hummer H3 ’s transmission is slipping and there are no leaks, the solenoid is the next item that you should check. Clutch Problems The clutch is located within the torque converter and can occasionally become jammed.When there is a large leak in the Hummer H3’s EVAP system, it will throw the P0455 OBDII Code. P0455 indicates a large leak in the evaporative emission control system. (EVAP). There are different leak size codes. For example, P0456 means your H3 has a small EVAP leak. While the trouble code may state that there is a “large leak” in the ...The 2007 Hummer H3 has 7 problems reported for leaking radiator. Average repair cost is $580 at 80,200 miles. ... H3. Automatic transmission; 92,000 miles; A D V E R T I S E M E N T S.Problem with your 2007 Hummer H3? Our list of 8 known complaints reported by owners can help you fix your 2007 Hummer H3.Nov 25, 2019 · 1. Blue Smoke. The most obvious and a telltale sign that your H3 is burning oil is blue smoke. Blue smoke indicates that oil has made its way to the combustion chamber. It is then burned with the gasoline and tints the exhaust blue. Your exhaust will look more like a two stroke engine if it’s bad enough. Here’s more on blue exhaust smoke. 2007 Hummer H3 Flush brake fluid every 60,000 miles. Brake fluid can become dirty and may cause problems in the brake system ; it should be flushed every 60,000 miles. 2007 Hummer H3 Flush cooling system every 60,000 miles. GM recommends replacing the engine coolant at 100,000 miles; however, our technicians tell us that the coolant may become ...The transmission in your 2006 Hummer H3 is the part of the 2006 Hummer H3 that directs the power from your engine to the driveshaft which in turn helps to turn the wheels on your 2006 Hummer H3 . Following good preventive maintenance procedures for your transmission will always help your transmission perform better, last longer and require ... Jul 12, 2022 · The most common gear issue for a 4L60E transmission is a loss of third gear. This problem typically occurs out of the blue. You can put the vehicle into drive and shift it into second gear without issue, and just as you try to go into third, nothing happens. It’s as if your vehicle is stuck in neutral and can’t proceed. May 29, 2020 · A bad fuel pump, ignition problems, clogged fuel filter, bad mass airflow sensor, and bad crank/camshaft sensors are just a few of the problems that can cause an engine to not start. 5. Poor Shifts. The transmission may have a hard time shifting, or not even be able to shift at all. Conclusion: Hummer H3 Bad PCM Symptoms The 2007 Hummer H3 has 1 problems reported for transmission cooler busted in radiator. Average repair cost is $2,000 at 92,000 miles.Jul 1, 2012 · The 2007 Hummer H3 has 7 problems reported for leaking radiator. Average repair cost is $580 at 80,200 miles. ... H3. Automatic transmission; 92,000 miles; A D V E R T I S E M E N T S. Feb 16, 2016 · hey buddies ! my H3 2007, I have the following problem 5 months ago: in morning or after a long time stopping (more than 7 to 8 hours), it so, when I start the engine, it is stopped with the message on dash: service stab system, tracation failed, reduced power. so, I try starting engine after less than a minute, with pressing on the race roughly. stopping again, and trying again, all this for ... 2007 Hummer H3 4dr SUV. 242-horsepower 3.7L I5 5-speed manual AWD w/low range. Hummer H3 in Virginia, United States. Jun 2014 - Nov 2014. Sep 2014. 50000 mi. US $850. Due to a poorly designed sunroof draining sust leaks caused sensors to get wet and tripped the warning lights to ping ABS and stability system errors.Dec 2, 2021 · The most common issue is with the transmission that may be because of mechanical issues, general wear, and tear, due to fault in the system, or by any accident. Let us discuss the hummer h3 transmission issues. Hummer H3 Shifting Problems source: https://www.aamcoleessummit.com/ Hummer H3 is a standard model of the hummer series. The P0700 code in your Hummer H3 is a generic OBD-II code that indicates a malfunction within the transmission control system. This code is not specific to any particular issue but rather points to a general fault in the system. Additionally, the P0700 code usually appears in conjunction with other transmission-related codes or shift solenoid ...Hummer H3 2006 to 2010 common problems, issues, recalls, defects and complaints.About Us : http://www.howstuffinmycarworks.com http://ww...Dec 4, 2019 · Bad Torque Converter Symptoms: Hummer H3. Here are some of the most common bad torque converter symptoms that could happen to your H3. 1. Slipping Transmission (Low Speed) The torque converter “stall speed” is the speed that the engine needs to be turning before the torque converter will begin engaging the transmission. Aug 18, 2008 - It is in the engine bay on the driver front side of the motor. Look at the battery and just below it is the ECM/TCM on a bracket right beside ... [SOLVED] - Transmission Shifting Issues. Mar 26, 2011. Additional "TCM" Transmission Control Module. Dec 23, 2014. A "how to" for removing the ECM/ TCM. Apr 9, 2006.Mar 6, 2018 · 2007 Hummer h3 transmission failure. While going uphill hummer front end shakes and lost all gears. after 20 min it was fine but then a week later happened agian and lost all gears and grinds going into park. hummer is broke down and undrivable. just had oil and fluids checked a week ago. all was fine. Has 69000 miles. If your 2007 Hummer H3 ’s transmission is slipping and there are no leaks, the solenoid is the next item that you should check. Clutch Problems The clutch is located within the torque converter and can occasionally become jammed. 2007 Hummer H3 problems (8) View all. 2008 Hummer H3 problems (8) View all. 2009 Hummer H3 problems (7) View all. 2010 Hummer H3 problems (5) View all. Get back on ... Mar 31, 2018 · PLEASE SUBSCRIBE! Free and easy for H3, Chevy Colorado, GMC Canyon owners with this common no-start issue, check this out! A possible work-around to this d... The transmission in your 2006 Hummer H3 is the part of the 2006 Hummer H3 that directs the power from your engine to the driveshaft which in turn helps to turn the wheels on your 2006 Hummer H3 . Following good preventive maintenance procedures for your transmission will always help your transmission perform better, last longer and require ... Mileage: 185,975 miles MPG: 14 city / 18 hwy Color: Black Body Style: SUV Engine: 5 Cyl 3.7 L Transmission: Automatic. Description: Used 2007 Hummer H3 with 4WD, Bucket Seats, Skid Plate, Suspension Package, Luggage Rack, 1SC Package, Keyless Entry, 1SD Package, Fog Lights, 16 Inch Wheels, and Full Size Spare Tire.Usually the starter is mounted on the engine side of where the engine and transmission mount. If this is the case then you do not need to remove it. It will stay on the engine. Here is a video that shows how to remove a transmission in case you need this: Also, I attached the entire process from the manual for this vehicle in case you need that ...Oct 4, 2019 · This humming sound will change with the engine’s RPM. Unplugging the alternator from the wiring harness should stop the noise. 2. Power Steering Pump. A failing power steering pump. The power steering pump is a common reason your Hummer H3 might whine when accelerating. If it gets too low on fluid, it’ll whine a lot. Feb 26, 2015 · Chock the wheels. Make sure the ignition is on, but not running. Find the shift cable under the vehicle and disconnect it. Try to shift it from the inside. If you are able to move the shift lever, then there may be a transmission issue. If you cannot move the leaver. Official recalls have been issued for the 2007 Hummer H3 by the NHTSA. The complete details of all recalls are listed below, along with what they cover and the recommended solutions. Recalls don't ... P0700 is a common code if it’s an electrical issue related to the transmission. If something has gone wrong in the transmission, your H3 may not be able to accelerate anymore, or it’ll. If it can no longer shift, it could be caused by a solenoid/valve body that has gone bad, clutch packs, debris, and much more.The 2007 Hummer H3 has 3 problems reported for check engine light on. Average failure mileage is 108,000 miles. ... H3 3.2L. Automatic transmission; 55,000 miles; H3 Hummer 2007 check engine light ...Jul 1, 2012 · The 2007 Hummer H3 has 7 problems reported for leaking radiator. Average repair cost is $580 at 80,200 miles. ... H3. Automatic transmission; 92,000 miles; A D V E R T I S E M E N T S. 2007 Hummer H3 4dr SUV. 242-horsepower 3.7L I5 5-speed manual AWD w/low range. 66000 mi. US $180. Rear U joint failed ten days out of five year warranty, had my local shop change both U joints on shaft, one that failed is greasable, non failed is non greasable, same job would have cost $580.00 at local dealer with truck just 10 days oow. Transmission in NEUTRAL/Air Conditioner is OFF ECT Sensor Engine Data 1, Engine Data 2, Engine Data 3 °C/°F Varies IMPORTANT: Review the system operation in order to familiarize yourself with the system functions. Refer to Cooling System Description and Operation . 2007 Hummer H3 2007 ENGINE Engine Cooling - H3 MY Model Lineup. The 2007 Hummer H3 is offered in two trim levels: base ($29,405) and H3X ($37,545). Both are powered by a 242-hp five-cylinder engine. A five-speed manual transmission is standard; a four-speed automatic is optional ($1,695).2007-07-16.2003-2007 HUMMER H2 – 2006-2007 HUMMER H3 – 2005-2007 Saab 9-7X Problem – Drivers may experience the loss of 3rd and 4th gear, erratic shifting, slipping, freewheeling above 30 mph and a P0757 DTC. Solution – In order to repair this transmission problem, the 2-3 shift valve, 2-3 shuttle valve, and the valve bore will need to be cleaned ...Jul 29, 2016 · 2007 H3 WONT GO IN REVERSE. Asked by HAASTYLE Jul 29, 2016 at 01:34 PM about the 2007 Hummer H3. Question type: Maintenance & Repair. PUT THE H3 IN REVERSE. PRESS THE GAS MOVES ABOUT 6-8' THEN ITS. LIKE IT IS NEUTRAL NO MOVEMENT. The 2006 Hummer H3 has 529 problems & defects reported by H3 owners. The worst complaints are engine, electrical, and body / paint problems. ... 2007; 2006; Print report. ... transmission problems ... Remove the cap and place a funnel into the opening. Refill the container with the recommended amount of transmission fluid. Return the transmission fluid container’s cap. Turn on the Hummer’s engine and allow it to idle. Attempt to change the Hummer’s gear by shifting the shifter lever to check if the problem persists.To check the fluid level, follow these steps: Park your H3 on a level surface and apply the parking brake. Start the engine and allow it to reach operating temperature. Shift the transmission through all the gears, then back to Park or Neutral. Locate the transmission dipstick – it might be hiding near the firewall.David answered about a year ago. There is a pipe running off the oil pump (oil pickup tube/pipe) that has a screen/ mesh in its end , this can become clogged with debris, especially from small bits of timing chain guides being warn from timing chain , this will cause low flow of oil causing oil light to come on. Mark helpful. Sep 10, 2019 · Hummer H3 Stalling Problem Causes. Here are some of the issues that cause the H3 to stall out. Remember, a vehicle needs air, fuel, and spark to run. It needs them in the right quantities and intervals, or it won’t run right. Fuel. Fuel issues are one of the most common reasons that a vehicle would stall out, that includes your Hummer H3. P0700 is a common code if it’s an electrical issue related to the transmission. If something has gone wrong in the transmission, your H3 may not be able to accelerate anymore, or it’ll. If it can no longer shift, it could be caused by a solenoid/valve body that has gone bad, clutch packs, debris, and much more.Sep 29, 2019 · P0700 is a common code if it’s an electrical issue related to the transmission. If something has gone wrong in the transmission, your H3 may not be able to accelerate anymore, or it’ll. If it can no longer shift, it could be caused by a solenoid/valve body that has gone bad, clutch packs, debris, and much more. Feb 13, 2012 · SOURCE: 2006 H3 Hummer fan problem Hi if your internal fan not work in any position well i fixed up myself easy and save your money. locate the fan motor air just outside right courtesy drawn document in front of passenger. go from down and look up you will see a motor with a big connector white with 2 screw secure inside the motor block. loose the two screws and pull out gently the connector ... Jul 11, 2023 · Remove the cap and place a funnel into the opening. Refill the container with the recommended amount of transmission fluid. Return the transmission fluid container’s cap. Turn on the Hummer’s engine and allow it to idle. Attempt to change the Hummer’s gear by shifting the shifter lever to check if the problem persists. Model Lineup. The 2007 Hummer H3 is offered in two trim levels: base ($29,405) and H3X ($37,545). Both are powered by a 242-hp five-cylinder engine. A five-speed manual transmission is standard; a four-speed automatic is optional ($1,695).2007-07-16.