Shop said that my input shaft broke off inside the transmission (Anybody had this problem or heard of this?). and I would have to of had to beat the s***t at of it for that to happen. Which I didn't do any off roading. One time I went up and down a steep mountain in four wheel low this year about a month before the tranny went. He said he never saw this before. He said he has to see about getting the input shaft out of the transmission and would call me. Said if I need a new one it would be under a hundred bucks. Anybody know if its possible to vandalize my vehicle in a way to make this occur by getting under my vehicle? I got a fabtech lift. I wonder if the previous owner beat it and thats why. Bought it in 2019 with 90k and had to get a new Transfer case at 93k. It's at 109K now. Any input on this is greatly apprieciated.

 

Input shaft failures most often begin with a crack in the root of the splines and propagate at a 45-degree angle. The crack initiates and grows through the hardened outer layer of shaft material when high torque impacts occur. These cracks are generated with a high torque spike above 4500 lb-ft.

 

Its a known issue with the 4L60/65 specially on vehicles with oversized tires, performance upgrades, etc. Sonnax sells a billet input shaft and drum that is super strong and resolves the problem once and for all but its not cheap.

 

Do you know the part number for this? I called Sonnax and at first they stated that they don't have one specific to the H2 application? Then he said he would check on it and call me back.

 

The kit part number is;77733-11KA

Check out this link:
https://www.sonnax.com/parts/5191-sm...ty-input-shaft

 

Thanks H2 SUT. The rep from Sonnax emailed me this. 06 H2 with my VIN, the part number should be part # 77733-12KA. Summits EST shipment 11/29. Wish I would of got a H2 08-09. You notice a big difference from your 05-06?
So by VIN, your vehicle should have the late input shaft with provision for an ISS, which would use our part # 77733-12KA https://www.sonnax.com/parts/5188-sm...ty-input-shaft if you want the version with our Smart Tech drum.



If its apart and the shop wants to verify this, have them look for a reluctor on the shaft, shown below with the red arrow:







Tory J. Royce

Sonnax Transmission Company, Inc.

(802) 463-0388

 

The 05 and 06 were identical except the 06 was an adventure and had air suspension. Both these were equipped with 410 ratio differentials. The 08 has a 373 and with the 6 speed transmission it does do a little better with acceleration and fuel economy.
I think if GM would have kept the 410 with the 6.2L and 6L80 trans there would have been a major acceleration difference between the 08 and the prior years. My guess is GM was doing everything they could to get the H2 fuel economy better.