My truck won't accelerate....any insight?

Well unfortunately this is my first post on this forum, I have been trolling the forum for a few weeks and never had a chance to sign up till now to introduce myself and become more active but hopefully will be from now on.

I'm having a huge issue now with my truck.

It is a 2007 Western Star 4900 series with the Detroit diesel 14L mated to a 10spd eaton fuller and just now am sitting at 12800 miles, yes 12 thousand not 128 thousand miles. It was converted new into a 3301DS Haulmark Motorcoach and pull a 36ft tag hitch stacker

Well down to my problem

I left Tampa Florida to come up to a race event at VIR( Virginia international raceway) which is about 700 miles each way. About 4 hours into the trip along the border of Florida and Georgia all of a sudden I lose power under acceleration in my 8th, 9th, and 10th gears. I can not get the truck to do over 60mph and any type of incline the truck really struggles

I've already checked all the gauges and they are all reading normal, oil temp, oil pressure, boost seems to be low but I'm guessing that's only showing since I am not getting ful power, front rear and rear rear axle temps are normally( maybe about 20degrees higher then normal, but I was thinking that is due to my outside air temp showing triple digits on the road), air cleaner restriction is fine, etc and in my catalog computer shows that everything is fine but shows that although I am not feeling the power the computer says I am at 100% engine load and getting my full 1680 ft/lbs of torque

I just had the oil changed before this trip, and i was present when they did it so I know it was done with new filters and oil and nothing else was touched.

So I have no clue what it could possibly be

I did notice a bit of white smoke coming from the exhaust when I was under heavy load trying to get up to speed but other then that everything else seems normal.

Any help would be great, unfortunately if I am not able to DIY fix it by tomorrow I will be forced to drive the distance back to Tampa and take it in for repairs then

Again thanks for any info, hopefully on the return trip it won't leave us stranded in the middle of no where

- Jim

 

Thanks, that was kind of what 2 other truckers at a rest stop said to me as well but I'm in the middle of freaking no where and won't be able to get my hands on new fuel filters till I get back home

Also here is an image of the truck



So if any of you see my on the road back to Florida from Virginia driving slow as balls don't get mad, it ain't my fault lol

 

No the rpms keep dropping in those upper gears, like for instance i'll be on close to level ground and I'll floor the pedal and the rpms stay right around the 15 mark and won't go higher so I shift into the next gear, drops down to like 11 and continues to climb up to 15 and just stays there in 10th gear

So I was thinking it's either the clutch is slipping bad or fuel filters

 

Any way I can find out with motor I have? Like something on the serial or something that would help identify it? Dealer I bought it at won't be open till Wednesday due to the holiday so I'll already be back in the sunshine state by then so that really doesn't help

Thanks again
- Jim