Allison Transmision not shifting

I have a 2003 2500HD diesel with the Allison trans. I changed the filters and fluid at 30000 miles. I tow occasionly and plow snow. I now have 67000
miles and the trans stopped shifting. I only have 3 speeds out of 5, engine light is on, Shift indicator shows 3 when in drive. Anyone have any ideas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
tre trans is runing if fail safe mode its still under warant take it to gm dealer more than likely it is the range switch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the info I am taking it to the dealer today. Yesterday when I was backing out of a parking space at Home Depot the shift from reverse to drive was so hard and loud I thought I hit something. I had to get out of the truck to check. I'll let you know what what the dealer says. I bought an extended warranty, I hope it helps. This might get expensive

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Any progress?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The truck is still at the dealer. They got it fixed late today they said it was a bad "park-neutral safety switch". I'll pick it up in the morning. Of course we has snow while the truck was down so I lost out on my snow plow work. I'll know more about the repair tomorrow and will tell all.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I got the truck back but I feel ripped off. I was charged $275.37 to replace a bad nuetral safety switch and fuse. The breakdown was Fuse $2.00, Switch $142.18, Waste Disposal (throw the switch away) $5.60 Labor $ 112.00 and Tax $15.59. They tell me the Premier extended warranty does not cover this work. This is on top of another refused warranty item from 2 months ago. Then I had fuel spraying all over the engine. A fitting on the Common Rail was leaking. They said it was a faulty injector supply line that had a bur that suddenly failed at 62715 miles. They debured the line and reinstalled it. I was denied warranty coverage( 100 deductable) because they were able to repair the part and did not replace it. The charge for that service was $249.32. I will NEVER buy another vehicle from that dealer again.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
It's going to be interesting to see what comes of another 2500HD I know of w/ the Allison in it that just exhibited a similar issue. The shift indicator would indicate a different gear than the truck was really in AND when it did go into gear, it would slam into the gear. It suddenly cleared up later that day and has been fine for three days, but it is going into the shop tomorrow. It is under the extended warranty as well. Sure sounds like everything I've seen about the NBSU switch everywhere on the web. It's yet another known issue . . .
Oh yeah, I've seen it reported that the NEW version of the switch, a black plastic, runs around $50 from an Allison shop and can be replaced easy enough by the DIYer. I understand the BAD version of the switch is tan in color. Wonder what version they replaced yours with??? Seems to me, it would definitely be worth crawling under it to look.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Louis Cyktor wrote:

    Aftermarket extended warrantees are worded very carefully as to what they will and will not cover. Mostly so they can not cover items. The GM Extended warentees are better, as they are very clear about items not covered.
    Call the warantee company and ask to speak to a customer services rep. Charles
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.