backward driving

[SilentSpeedy]

I noticed lately that when I back up it feels like the brake is tightening up. First I blamed it on the parking brake not releasing after use, but now I am no longer using the parking brake for that reason, and it still is binding up. I checked underneath and the parking brake was not engaged. It only does that when I back up, anyone know what that can be, and am I at risk of breaking something?

 

[gimpyrobb]

Are your valves on the trans sending air to the sprague to tell it which direction you are going?

 

[sethnagy]

I have the same exact symptom with my truck. I suspect the sprague? or sprag? is the issue, however I'm not sure. The reason I think it is in the transfer case is the front wheels are not engaging in reverse.

My plan is to talk with one of the local national guard mechanics, Kenny. He'll help me. Below are a few pics of when we changed some seals and fixed a leaky front axle. (I always like looking at pics on other posts). If I find something out I'll let you know.

 

[dmetalmiki]

sprags

yep that's the sprags. Check underneath when a buddy shifts from 1st to reverse and back again ..you should hear the piston operating the sprag. if not check the filter ,piping and operating cylinder. (seals)

 

[98hd]

Better yet take a pair of needlenose vice grips and clamp off the supply line to the air valve on the top pass side of the trans. This will kill air to the valves and put the sprag in neutral. If your problem goes away you know it's the vavles. If not it could be the sprag unit itself.

If the vicegrip trick doesn't work, you can pull the front driveshaft to narrow it down to the transfer case assy.

 

[OLDCHEV4X4]

Ground rod drivers?

 

[sethnagy]

Thanks for the help! I should be able to track down the problem now.

Oldchev4x4 the pics of the rods are actually two slide hammer pullers. They are used to pull the seal when replacing the front axle seal. They are made from ground rods and they work great!