Hard shifting 21 cummins

[Deadbuck]

My 21 cummins just started shifting hard from 1st to second. Any ideas? 39k miles. No lights on. Just wierd just started.

 

[AH64ID]

Which transmission?

 

[Deadbuck]

Which transmission?

2500 68rfe

 

[flan]

How has your driving style been? Same as always? The transmission does learn, and for instance if the truck is typically hooked to a trailer or heavy static load in the bed, then things change the trans may need to adapt to your new driving style.

 

[Deadbuck]

How has your driving style been? Same as always? The transmission does learn, and for instance if the truck is typically hooked to a trailer or heavy static load in the bed, then things change the trans may need to adapt to your new driving style.

To be honest.... I've been putting way more highway miles on it the last 4 weeks. Running up north after work every other day. Round trip 200 miles

 

[flan]

I don’t believe that would cause any issues you are seeing. You may have a issue coming up but not enough of one to trigger a CEL. I assume you have checked your fluid for proper level and discoloration/burnt odor?

 

[Deadbuck]

I don’t believe that would cause any issues you are seeing. You may have a issue coming up but not enough of one to trigger a CEL. I assume you have checked your fluid for proper level and discoloration/burnt odor?

Yes sir. Was doing it before then it quit for month or so. Guess that's what warranty is for.

 

[Deadbuck]

I don’t believe that would cause any issues you are seeing. You may have a issue coming up but not enough of one to trigger a CEL. I assume you have checked your fluid for proper level and discoloration/burnt odor?

And it don't seem to do it all the time

 

[flan]

Well if it ends up being something follow up with us, should be interesting to hear what the dealer says. good luck man.

 

[Deadbuck]

Well if it ends up being something follow up with us, should be interesting to hear what the dealer says. good luck man.

Thanks sir

 

[H3LZSN1P3R]

To be honest with no CEL it could just need a relearn it does happen with these transmissions from time to time

 

[Deadbuck]

To be honest with no CEL it could just need a relearn it does happen with these transmissions from time to time

What do you have to do to have it relearn?

 

[H3LZSN1P3R]

What do you have to do to have it relearn?

If you have AlfaOBD you can do it yourself if not then you need a scanner that can do it.