H1 Drivetrain trouble
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Junior Member
Joined: May 2016
Posts: 13
H1 Drivetrain trouble
This past weekend I noticed a low rumble when on the accelerator. It went away when I let off. It was probably every two feet or so that I would hear and feel the rumble. Is it a gear problem or shaft? And how do I troubleshoot or fix?
Thanks,
Thanks,
Senior Member
Joined: Dec 2015
Posts: 188
From: The Great state of Texas near Austin
I do road service and could come take a look at it if you like. Call me whenever is good. Im the closest / only hummer mechanic near you. I work on all the trucks I know of in San Antonio.
Member
Joined: May 2016
Posts: 60
If you have a rotational noise in a Hummer it's simple math......I'll explain:
When the drive shaft rotates 2.73 times (most Hummers have 2.73 gear ratios) your halshaft output has 1 rotation. You halfshaft has to spin twice (backwards) to equal one of the wheel rotation because of the 2:1 reduction gear in the hub. So....if you hear a noise at slow speed start to count. How many times per tire revolution do you hear the noise? One time per tire revolution is the tire, the wheel hitting something, or whatever. Twice per wheel revolution is the halfshaft (bad joints) or halfshaft bolts backing out (although if 2 bolts are hitting you'll actually hear more noises but you should ALWAYS look for halfshaft bolts backing out when you hear a rotational noise. 2 x 2.73 = let's call that 6 times (for simplicity) per wheel revolution is the input side of the differential (drive shaft, carrier bearing,and similar).
Hope this helps. This is how I help a customer diagnose an issue over the phone.
When the drive shaft rotates 2.73 times (most Hummers have 2.73 gear ratios) your halshaft output has 1 rotation. You halfshaft has to spin twice (backwards) to equal one of the wheel rotation because of the 2:1 reduction gear in the hub. So....if you hear a noise at slow speed start to count. How many times per tire revolution do you hear the noise? One time per tire revolution is the tire, the wheel hitting something, or whatever. Twice per wheel revolution is the halfshaft (bad joints) or halfshaft bolts backing out (although if 2 bolts are hitting you'll actually hear more noises but you should ALWAYS look for halfshaft bolts backing out when you hear a rotational noise. 2 x 2.73 = let's call that 6 times (for simplicity) per wheel revolution is the input side of the differential (drive shaft, carrier bearing,and similar).
Hope this helps. This is how I help a customer diagnose an issue over the phone.
Member
Joined: May 2016
Posts: 60
If you're in Segiun call my brother (Ian at Rollin Road Service). He is the most experienced Hummer mechanic in your area. He's in south Austin and cam come to you but we also have a house at Canyon Lake if that's more convenient for a project.
