Thread: Rear/front diff
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  #26  
Old 04-27-2006, 11:54 AM
rkcrawl rkcrawl is offline
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Join Date: Apr 2006
Location: Knoxville, TN
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A couple of things to think about:

Were the rigs experiencing these issues Auto or Manual? You have to consider the torque convertor on auto when figuring the over all gear ratio... While the by the numbers ratio for a H3 with Auto, 4.0:1 TC gears and 4.56 gears in the axles the crawl ratio is about 56:1, when you factor in the Torque Convertor, you end up with approximaitely 100:1 ratios.

The next thing to consider: The front diff looks like its aluminum, which if stressed hard enough may allow for some case deflection. Possibly enough in high traction environments that you may start stripping off ring gear teeth.

I did this a couples time on a 9" Ford axle that was in the front my competition buggy using stock Ford 9" carrier. I stripped teeth much in the same way as shown in Bebe's picture. (Note, I also broke bearing caps which contributed to the teeth breakage). I did this 3 times before I installed a stonger case (Ford 9' axles use a drop out third member like Toyota axles).

The last thing to consider is that GM used a standard cut gear in the front which is well known to be weaker when used in a front axle application (vs a revese cut gear, think Hi-Pinion diff in the front). This is because the gears are running on the "coast" side of the ring gear teeth.

Add that to a fairly small ring gear..

I hope that this is isolated, but larger tires, lots of torque, good traction, heavy rig.... you might just be pushing the front diff past its design limits.

I hope not, because while my H3 is my DD, it will server some double duty as a toy and see Tellico, Windrock and who knows where else.

Jim O
www.etoracing.com
06 H3 Lux/Adv
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Jim O'Brien
'06 H3 Slate Blue Lux/Adv
www.etoracing.com
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