2001 Allison Transmission

[Gonnagetem]

2001 GMC "farm truck" (reg cab, 8ft.) 8.1

 

While driving, the " D " becomes not highlighted, and starts to shift funny, eventually not leaving 3rd gear. Stop and put it into park. The window is now flashing over the " 3 " , as if its in 3rd gear, but its flashing, and its in park.

 

Is this some type of code? Once, my check engine light did come on, but has gone off.

 

Any suggestions?

 

Sorry for my slang terms, hope you know what I mean.

[Gonnagetem]

anyone?

[spackelman]

Most times, it is the park nuetral switch on the driver side of the trans. Water gets in the switch and causes problems.

 

Easy to replace. Can't be 100% sure this is your issue.

[Gonnagetem]

Thanks for that. It makes sense, since when it started doing that, we just had got 8.5 inches of rain!

 

I'll put the grease to it!

[driscoja]

Thanks for that. It makes sense, since when it started doing that, we just had got 8.5 inches of rain!

 

I'll put the grease to it!

 

 

Did that fix your problem? I've got the same thing on my 2001 HD2500 after driving through deep snow and haven't had a chance to get it on the ramps to check it out. Thanks