I have a transfer case that has the lever on the floor of the truck. With the front hubs locked in should I be able to switch into 4WD (High) on the fly, or do I have to stop first? I thought I remember being able to switch on the fly last winter. It will shift just fine if I stop first, but I just thought that I was able to shift on the fly at 50 MPH last year. I changed the fluid a month or two ago, and I tried to shift on the fly after that and I got a grinding noise and it wouldn't go into 4 high. The oil that I drained out of the T-Case was brown and didn't flow like ATF. Everywhere I read says that I am suppose to fill it with ATF? I just want to make sure that everything is working correctly. Any help/info would be great. Sorry for the really long post. Thanks in advance.

 

Yes, you can shift on the fly, but you'll get grinding if your front hubs are not locked.

Mercon ATF is the correct fluid for the case, per your owner's manual.

 

Ok, thanks. I will have to make sure it works before the snow flies tomorrow. Maybe the problem was that I didn't have my hubs locked in. Thank you.

 

You should be able to shift on the fly to 4hi. To go to 4Lo though you need to be in nuetral, and have your foot on the brake.

 

Ok, thanks. I think I didn't have the hubs locked in since it was dry outside and I was just warming the fluid up and just mixing the new fluid. Operator error. Doh!