2018 3500 DRW struggles uphill with 5th wheel

[Tom Robinson]

I tow a 40' 5th wheel with a max weight of 21,000 lbs. I haven't weighed it recently, but I'm pretty sure I'm not exceeding that, at least not by much. We recently made a short trip in the Texas hill country and the truck struggled up the moderate hills, slowing to 30 mph or so. We had a mega cab when we first purchased this trailer and it didn't seem to bog down like this truck is. Same tranny and HO output setup on both. Unloaded performance is good. I haven't had it in the shop yet to see if there's anything particularly wrong, so I'm looking for ideas. Kinda sucks with a towing capacity of 31k.

 

[MADDOG]

Are you in Full Auto or Tow/Haul mode?

I assume you have calculated your Gross Combined Vehicle Weight Rating and you aren't over the max.

 

[JNelson]

Check your fuel filters and your boost.
Plugged filter(s) and or boost loss will cut Your power down considerably.
Also the air filter.

 

[mtofell]

I'm pretty sure I'm not exceeding that, at least not by much.

Hard to help until you answer this

 

[Choupique]

As stated earlier, make sure you have clean OEM fuel and air filters. Make sure you are in tow/haul mode. That rig in good operating condition is ridiculously powerful but even so, a big toy hauler going up a steep grade and bucking a 40mph headwind is a ridiculous load. Slowing down to 30mph does not sound right though.

 

[BossHogg]

I tow a 40' 5th wheel with a max weight of 21,000 lbs. I haven't weighed it recently, but I'm pretty sure I'm not exceeding that, at least not by much. We recently made a short trip in the Texas hill country and the truck struggled up the moderate hills, slowing to 30 mph or so. We had a mega cab when we first purchased this trailer and it didn't seem to bog down like this truck is. Same tranny and HO output setup on both. Unloaded performance is good. I haven't had it in the shop yet to see if there's anything particularly wrong, so I'm looking for ideas. Kinda sucks with a towing capacity of 31k.

More information is needed. Going up the hill when it is struggling, what are the engine RPMs and the transmission gear? Are any DTCs set, how about historic DTCs if you have a code reader? What is the boost pressure? What is your axel ratio?

 

[Tom Robinson]

As I recall no DTC's were set, however I am intermittently getting the "charge air temp" fault. Happens when outside temps are in the 60's. Tow/haul mode is on as well as auto exhaust brake. I didn't note the RPM's exactly but definitely above 2000 and in drive it doesn't show the gear. Fuel filters were recently changed. Air filter is somewhat dirty, but not bad. I'll change that anyway.

 

[Tom Robinson]

More information is needed. Going up the hill when it is struggling, what are the engine RPMs and the transmission gear? Are any DTCs set, how about historic DTCs if you have a code reader? What is the boost pressure? What is your axel ratio?

Axle ratio is 4.1, per the window sticker online. I recall boost pressure being close to 30 on the gauge.

 

[Choupique]

If you are getting charge air temp faults than you have an airflow issue.

 

[62Blazer]

You made a comment that a previous truck "didn't seem to bog down as much".......assuming you ran the exact same hills under the same conditions with that truck? I guess the point is just making sure there is a problem and that you are not expecting too much out of the truck. What was the grade % of the hill?