H3 Huge powerloss issue. Help please.

[groomsxxx]

Hello everyone. I am new here. I was referred here by someone on the hummer forums. I am having an issue and would like to see if anyone has any clue what is going on or has encountered this issue.

2007 hummer h3x with about 53000 miles

I know I should go to a shop, but I am trying to see if anyone here might have a better idea of what is going on. I had been getting the catalyst system efficiency below threshold code. Ignored it for a little bit..Got some random misfire code, then a month ago as I was driving home on the interstate, I lost power and I drove to the side of the road. Cut it off and couldnt get it to really go over 35 mph. Basically was going 35mph at 5 rpm. for about 7 miles to be able to make it home.

I bought a magnaflow exhaust manifold, walker secondary cat pipe, 2 new o2 sensors, properly gapped the NGK Iridium IX Spark Plugs (New OEM spark plugs will be here today. Have heard diff reviews on the ngk iridiums and just going to go back to Oem) and also installed brand new coil packs as well. Just got it all installed and went for a test drive.. as soon as I got down the road and got closer to 35/40 mph it started to lose its power again and just rev.(it wouldnt go any faster and was just revving)

Does anyone here have any ideas on what this issue could be? Any help is def appreciated.

 

[USMC_TOP]

If your engine rpm is going up and you can't gain anymore speed I would look toward transmission


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[groomsxxx]

Thanks. could it be just a switch/motor? could it be possible transfer case issues?

 

[4speedfunk]

Codes?

 

[groomsxxx]

yeah. just code po300 random misfires

 

[groomsxxx]

I also added an external trans oil cooler months ago too.

 

[USMC_TOP]

Still leaning trans IMO


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[groomsxxx]

I appreciate your input. I have to take it to a shop soon. I just was wanting some feedback. And I certainly dont want to be taken as a fool.

 

[woodwardsh3]

let us know what they say.

 

[groomsxxx]

thanks. I will. just wanted to see if anyone had experienced this before and had a clue. ty

 

[CaseyS]

Sounds like transmission. Did you check your trans fluid level after adding the cooler? If you ran it low enough to the point that it slipped for that long to get home its toast. Check your fluid level with the engine warm and running and see whats on the dipstick. See if you can isolate the slipping to a particular gear by manually shifting. If both 3 and 4 are slipping I'd bet its the 3/4 clutch pack in the trans.

 

[groomsxxx]

sorry, this is probably going to sound stupid but I would I manually shift to 4th? Also this is an automatic.
Some other info is that the day I couldnt go over 35 mph and it was at about 5 rpm to do that , when I got home and parked. I put it in reverse and it wouldnt go in reverse. However after moving through the gears and recranking, It did go in reverse. I had driven the vehicle 60 miles a day , mon through fri for months after the transmission cooler install. I did check the Transmission oil after this incident and it was low and I had to add almost 4 quarts.

 

[USMC_TOP]

Ouch sorry my friend but I think you toasted your transmission. Get multiple quotes, look for shops that just do transmissions dealership will cost big bucks. If you were in the central Michigan area I could point you in the right direction


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[groomsxxx]

I've started trying to get some quotes. I see http://www.streetsmarttransmission.com/ said $1470 for reman trans shipped to shop.
3 year unlimited mile warranty

Remanufactured 4L60E Transmission Upgrades:

-Remanufactured pump, with new line bore bushings to eliminate leaks and provide superior flow and durability.
-Remanufactured valve body, with complete system correction and recalibration kit, improves pressure control and shift quality.
-Remanufactured and improved torque converter tested for leaks, concentricity, and balance. Upgrades exceed OE requirements and eliminate the possibilities of front seal leaks, premature bushing wear, and vibration.
-All new, bushings installed in key locations to improve internal fluid flow control and fluid pressures.
-Complete system correction and recalibration kit installed to address several OE flaws. Modifications include updates to servos, the PR system, and valve body accumulators.
-Heavy-duty recalibration kit installed to reduce slippage and increase durability.
-Complete road simulation using a dynamometer testing program called C.A.R.S. (Computer Aided Road Simulation). Every transmission is cold and hot tested before shipment.

 

[groomsxxx]

Then there is this one http://www.ebay.com/itm/262813970094?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
with a 2 year no hassle warranty

THESE UNITS WILL HANDLE UP 750HP AND OVER 700 POUNDS OF TORUQE ..TURBO OR SUPER CHARGED ENGINES NEED ANTI BALLOON CONVERTORSRAYBESTOS Z PACK CLUTCHES AND NEW KOLENE STEELSWIDE ALTO ENERGY BAND BEAST HARDENED SHELLSUPER SERVO SETUPDATED SPRAGS ALL THROUGHOUTHEAT TREATED SHAFTS500 BOOST VALVE KIT13 VANE PUMP KIT WITH HD ROTORNEW SEALS, GASKETS, O-RINGS, BUSHINGS AND WASHERSNEW FILTERNEW HD CONVERTOR (2000 STALL IF NEEDED)B&M MATCHED WITH TRANSGO SHIFT KIT HD2AMERICAN MADE 5 GEAR PLANET SETSTHIS TRANNY WILL SHIFT NICE AND XTRA FIRM WITH GREAT POWER AND PERFORMANCE FOR YEARS
​

$150 refundable core charge
​

 

[VIPNiSS]

welcome man.. i see you posted in here.. this forum is more active in my opinion.

 

[groomsxxx]

Thank YOU for your referral.

 

[CaseyS]

About half the cost of transmission service is in the labor to get it out and back in, especially a 4wd. Any local reputable transmission service should be able to add any of the upgrades listed in those online listings. You would probably be shocked to know that a rebuild kit can be had for under $300 provided you haven't broken any hard parts.

Buyer beware if you get a transmission online, the hummer 4l60e has some unique parts like the pan, filter, belhousing, valve body, and 1-2 accumulator. A standard build 4l60 won't bolt right up. That's why you will likely be better off rebuilding what you have.

You symptoms sound like the forward clutches are probably friction welded together and smoked.

 

[groomsxxx]

out of the two reman trans i posted here.. anyone here tell me which one is better though?

 

[Kyle]

are both shops aware of the "special" trans requirements?

 

[groomsxxx]

I am not sure yet. What should I be talking to them about exactly?

 

[groomsxxx]

one guy said "
As I'm not a mechanic, I do know that it has a different size output shaft than the normal 4L60E. It may also have a different pin connector for the electrical harness.


Most of our competitors will try to discredit us, as our pricing is not in line with theirs. We build our own units, with our own employees. And we take great pride in our work. However, we do not try to make too much on each unit we sell."
"Yes, like the Corvette and most other vehicles that use this type of unit, it will not interchange with other 4L60E's."

 

[Kyle]

hmmm sounds interesting to me, I would stay away from online places and try to find a good shop near you that could just rebuild the current trans so you know it will fit perfectly. that would be ideal

 

[groomsxxx]

I've read that remanufactured are better than rebuilt.

 

[USMC_TOP]

I would use a good shop in your area for one reason. You buy a rebuilt online, you have it put in, a week later it fails, you pay a the guy again to remove it and send it back and so on with the story.


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