Hey guys,

2 months ago my transmission "lost prime" (dealers diagnosis) and had to be towed to the shop. Thread below....

http://www.dieselplace.com/forum/showthread.php?t=304470

While I haven't had the exact problem again I have been getting alot of "shift range inhibited" messages lately. Say one every other day. Sometimes simply shifting to neutral then back to drive helps, and other times I have to completely shut the truck off and restart.

I know this was a sign of a bad NSBU switch in the 5spd. allisons but from what Ive read the IMS switch that the 6spds. have inside the pan seems to be more reliable.

Has anyone else with a 6spd. had to replace their IMS switch? Any tips on how to do it if so? Or should I be looking elsewhere for the problem?


Thanks in advance guys,
Jeff

Dealer replaced mine, IMS and VB valve body so I can't help you out on that. Lost my Transgo jr. and my deep pan, filter lock. The tech. said all that was wrong was my internal filter was sucking air.

Hey guys,

2 months ago my transmission "lost prime" (dealers diagnosis) and had to be towed to the shop. Thread below....

http://www.dieselplace.com/forum/showthread.php?t=304470

While I haven't had the exact problem again I have been getting alot of "shift range inhibited" messages lately. Say one every other day. Sometimes simply shifting to neutral then back to drive helps, and other times I have to completely shut the truck off and restart.

I know this was a sign of a bad NSBU switch in the 5spd. allisons but from what Ive read the IMS switch that the 6spds. have inside the pan seems to be more reliable.

Has anyone else with a 6spd. had to replace their IMS switch? Any tips on how to do it if so? Or should I be looking elsewhere for the problem?


Thanks in advance guys,
Jeff

I doubt you need a new IMS. Sounds to me like you are still having the same problem. A couple things to check:

1) How is your fluid level when warm? Is it in the middle of the hot band?

2) How long does it sit before this happens?

3) If you start the truck and let it run for a minute or two before you put it into gear what happens?


How many miles are on this truck? How many miles did you have before you first saw this problem? Has the trans ever been worked on? There are several things that can lead to a loss of prime.

My 07 Classic Did It To Me Today Shift Range Inhibted, I Went To Get The Boat Out Of The Water, Started The Truck And Put In Drive And Nothing, But The Message On The Screen.