HMMWV Transfer case

[trooper632]

Can someone tell me what the "HL" is on the transfer case shifter. Is it a High Lock maybe for locking front and rear Diff's.

 

[jeremymx26]

The transfer case has an internal differential that allows slip front to rear for road driving in H.

HL locks this differential to send torque to the front and rear equally.

Use only HL when surface is slippery or transfer case damage will result.

 

[2w091]

Per the -10 manual HL should be used for deep snow, sand, or mud only. If you drive in HL on pavement or another non-slip surface too long you can throw a short shaft or cause other damage.

 

[trooper632]

Thaks

 

[NDT]

To lock the axle differentials you are supposed to perform "brake throttle modulation".

 

[2w091]

We had a neighboring agency drive theirs around in HL and throw a short shaft. I put a caution in our pre-use checklist and labeled the actual shifter.