Did My First 5th Wheel Slide Today

In my training, 5th wheel adjustment was never covered at all. Today I picked up a heavy load and went from the shipper to a CAT scale. All the weights were close to the limits but my steer axel was at 12,920. So I had to slide my 5th wheel back all the way. Here’s the funny part: I called after hour company services for instruction and nobody there knew how to slide a fifth wheel. So they texted me a link to a Junior Honduras YouTube video showing how to do it. The procedure is not very hard. I got my 5th wheel repositioned in about 30 minutes. I’m happy that I now know how to do it. If you are in school, ask your instructor how to do it so you will know before the need arises. Or, just watch the Junior Honduras video. Lol.

After the adjustment, I re-weighed and was at 11,300 on the steer axel and all the other axel weights were still good.

So how did you do it lol? I have never had a truck with a sliding 5th wheel but I did cover it in school and there's a couple threads on here with some tips.

Hmmm my new truck had it set with king pin jaw dead nuts centered between the drives. Never had a need to adjust it,seems all the way back might'a been extreme, but I know nothing lol How'd it steer going down the road Bruce?

Something doesn’t sound right here. Is your trailer air-ride?

To clarify further...

In almost 10 years of driving, I’ve only slid the fifth wheel one time for each tractor I’ve ever driven. Set it and forget it. As Steve Reno indicated, a centered fifth-wheel between the two drive axles is usually satisfactory.

Moving it to the very last setting towards the rear of the frame, is going to cause very poor handling characteristics when loaded. You’ll bounce and roll.

So the air-ride question; many air-ride trailer suspension systems empty the airbags when the trailer parking/emergency brake is pulled (red knob). If this is done sitting on the scale, it will shift more weight to the steer axle to the point of lifting up on the fifth wheel. Where does the weight go? To the steer axle.

When I drive onto a scale I gradually stop, allow the truck to settle for a few seconds then slowly release the service brakes long enough to get an accurate weight. Scales are level so there is minimal risk of the truck drifting. Once I get the weight I then pull the parking brakes.

Otherwise...if this was not the case, meaning a leaf spring suspension trailer, rather unusual. So if you don’t mind describe in more detail what occurred.

My trailer is not air ride equipped. Also, I had just filled up the diesel and def, which added weight. After sliding the 5th wheel, I noticed no difference in handling at all. But after the last weigh showed I only have 11,300 on the steer, I’m going to slide it forward a couple of notches this morning after my 10. Like I said, this was the first time I’ve had to do the slide. I was surprised there was an issue.

I think G Town figured it out. Thinking back to the first weigh, I did set my brakes because I had to open the door to step out and push the call button. Then when I got back in the seat, I forgot to release the brakes before they weighed me. So I probably got the over weight reading because of what G Town suspected.

However, I did learn how to do the “slide”, so it’s another thing learned from experience.

I have never moved any after the first time I was issued any specific tractor, either.

HI Bruce.

Learning is always a process and usually a good thing. The sliding 5th seems a useful feature if ever needed. However, both of my trainers cautioned me about using this feature. Both of them advised me to never touch mine. "Never" being the operative word with added emphasis on their part. LOL. I'll be leaving mine alone for now. I've got enough other things I'm trying to make sure I get right for now.

I'm glad to hear it worked out for you when you used it.

Set it once and forget it. Centered between the drive axles is usually optimal.

I’m still perplexed on what happened here...

HI Bruce.

Learning is always a process and usually a good thing. The sliding 5th seems a useful feature if ever needed. However, both of my trainers cautioned me about using this feature. Both of them advised me to never touch mine. "Never" being the operative word with added emphasis on their part. LOL. I'll be leaving mine alone for now. I've got enough other things I'm trying to make sure I get right for now.

I'm glad to hear it worked out for you when you used it.

I've only had to do it once and it was because the fairings were too close to the trailer.

I don't recommend doing it and I don't like doing it because they may look like they locked back in place, but there's always a chance it didn't. If it didn't, that trailer is going to rear end the tractor the moment you hit the brakes. It's best to leave it alone.