Question: Keep getting stuck in third gear

[TCfishman]

I have a 2005 kodiak 4500 lly, 5 speed Allison. The light that comes on is a wrench and gear. Weve had this problem several times. Seems to be the speed sensor. Why does this happen do often? Do my mechanics not actually fix the whole problem by just replacing the sensor? The cluster also has issues, oil pressure gauge and speedo don't always work. The truck also has a PTO for a fan that creates suction. If that matters or not.

 

[JustinD]

Stuck in third usually means it limped.......

 

[TCfishman]

Well sometimes it works for some reason. what's "limped"? I'm a new LLY owner so any info is learning for me. Thank you.

 

[JustinD]

Usually if it slips or gives the TCM/ECM any indication of slip it will put it in "limp mode" stays in third gear.

 

[TCfishman]

I see, would that cause the cluster to malfunction or could the cluster cause the VSS to malfunction?

 

[JustinD]

Not sure about the cluster??

 

[MACKIN]

You need to scan it for stored codes in order to trouble shoot why it's possibly going into limp mode. Do you lose reverse?

The cluster issue is separate problem. Could be just bad

 

[TCfishman]

Never lose reverse. We had it scanned, he said a couple sensors, never got the codes, I'll see If they will give them to me. Like I mentioned, we've replaced these same sensors at least 5 times in 2.5 years, very frustrating.