Ok, this is going to be hard to describe but I will give a try....

Yesterday I was towing my 40 foot 5er (15K lbs) to my RV repair guy's shop. As I was skirting around the northwest side of Austin, there are a number of fairly steep hills. On one of them I had to come to a complete stop going up hill. When the light turned and I applied the throttle, I could feel something slipping while it was transitioning from full stop to forward motion - there was no wheel spin. There really wasn't a sound but it I felt it. It only lasted about 2 or 3 seconds then it went away. Once I felt that I then started to try to make it happen again. On a fairly level highway at a stop light, I purposefully got on it hard from a dead stop and could fill it again (not as pronounced) but I could feel it.

Here is a little more information and background...
When I got to my RV guy's shop, I had to back up a very slight incline a bit and my truck was really straining but I wasn't getting much movement. I was surprised at how much my engine was straining with no wheel spin or movement. Also back in the summer, when I was in Colorado at an RV Park with heavy thick gravel I came to stop before making a turn into to our spot. When I started forward again I had a very loud straining engine with no forward movement or spinning tires. I then put it in 4WD and it did it again - straining engine - no spinning tires. I finally really punched the throttle and the wheels then broke free and started spinning and I moved.

I am wondering if this is a torque converter issue or transmission issue. While I am far from a expert in this area, it sounds to me like torque converter. Any thoughts or advice. After my experience back in the summer, I had my dealer check out the transition and they found nothing.

Thoughts?

Thanks,
Chris

 

Subscribed to this thread. Something's going on with mine too.
https://www.ford-trucks.com/forums/1...n-stopped.html

 

Might be a long shot, but make sure your brakes aren't locking up on the trailer.

 

Nope - definitely not a brake issue. Thanks for asking.

 

My issue doesn't sound like yours at all. I am definitely 1st gear or reverse when this is going on. Only happens under a load condition.

Thanks.

 

I know you said not trailer brake issue. But sounds like a trailer brake is not releasing when in reverse and getting stuck at a stop until they break loose. When trailering any trailer, do you ever pull to a stop, jump out truck and feel each trailer wheel and hub for heat? Make this a habit and it can help out with bearings and brakes in the future if not this time.

 

Don't discount a brake issue. These new trucks have nannies like traction and stability control systems that can malfunction. All operate with the abs module which can easily lock the wheels up.

 

Have you checked the transmission fluid level? Low fluid can cause a torque converter to slip. Also check for contaminants...

 

If you still hooked up to the trailer unplug it and try to move it and back up in the same area. Take it for a ride and when it does it unplug and try to see if it went away.

 

I appreciate the input. I do not believe this is tied to trailer brakes. I will experiment but since it happens in forward and reverse and only when I am on a hill, I just can't see that being the source. I will check trans fluid, etc. and work on duplicating.

Thanks.

 

I know some of the times it happened was not on a hill but maybe hill start assist working as it is supposed to or not???

 

If I had to guess I would say something is up with the "hill start assist" since it only seems to happen when your on a hill / incline. Try turning the hill start assist off and see if it eliminates the problem.
Good luck