This just started happening last week. When I put the truck into reverse, the engine lugs down and dies. It' as if the AT is fully engaging reverse gear with no clutching action. If give the truck a bit of pedal, I can put her in reverse and back up without issue. Going forward into Drive has no issues. Thoughts?

 

Speed sensor in rear diff? I had an v-10 excursion that would do this intermittently in reverse. Replaced that and never did it again. Not sure it will be the issue but it's cheap enough to try.

 

Might check your fluid level also.

 

No. Not possible. The speed sensor isn't used in reverse.

The problem is low pressure. Low pressure can be caused by low trans fluid, internal leaks, or a worn pump.

 

That's crazy then, that was the code and it repaired ours. Must of been coincidence. But if anyone would know I would believe it would be you sir.

 

Yup, fluid is low. Didn't even think low fluid would cause symptoms like this. Let me fill 'er up and come back with results after a few days of driving.

 

Does/can being low on tranny fluid harm the tranny?

 

Depending on how low, yes, it can damage the transmission.

If it is low enough that the filter sucks air the trans will lose line pressure. This will allow the clutches to release, and when it gets fluid again, slam back on. It is also not good for the pump to run dry, as the ATF lubes the pump.

 

To follow up on this thread, adding fluid and no more issues. Thanks to Mark to chiming and easing my fears.