Tough one to diagnose. But here goes, I've Been plowing snow in Albany area for two days, now the truck is vibrating/shaking pretty bad under load AFTER 25 MPH, both in and out of 4wd and smokes blue haze. Still Plows like an Oshkosh. Shifts good through all gears, no slippage, and will shift into OD if I can get it going fast enough on flat roads. It Will barely go 40 MPH. Am I on the verge if gelling or is it just the packed snow jammed in up in budd wheels and every thing else under there. Any suggestions, Please dont tell me torque converter ????? Thanks guys

 

I'd start by changing the fuel filter, fill the filter with some Diesel 911 or some emergency antigetl stuff and fire it up.

Is it the engine or drivetrain shaking? Is it load or RPM related?

People (this goes to everyone here), when you need help, a sentence or two doesnt always do it. We need details, details, details. No ofense intended, but I see people type 4 sentences, then apologize for such a long post. Dont apologize if it is pertinent info. It may save you in teh long run.

I am not going to apologize

Daniel

 

Also if you can post a picture, well not in this case but there have been some excellent pix on this thread that helped a lot, ...

 

No need to apologize and no offense taken, however I think the symtoms in my post are pretty good other than my signature is'nt showing up. Its a 93 W350. As stated in my post it seems to be load rated.

 

Plowing snow is hard on trucks! if it is speed related I would look at drivelines and u joints especially the front. You say it still does it in 2wd but did you unlock your hubs and try it? I lost a front ujoint in the axel and it would shake @25 something fierce.

 

Yes, my hubs are unlocked, and drive shaftsand u-joints are all good. I'm hoping its fuel related. My fuel filter was replaced 3 mos ago but I will put on a new one anyway. Please keep sending the idea's !!!

 

I second the fuel filter. Lack of fuel makes these engines shake and rattle and cough and everything else. Change that first. If that doesn't cure it then check the pressure of the lift pump. That could be the culprit as well.
Dan

 

What's the temperature where you're at? Does it run rough/lose power when you're over a certain throttle input (like after 1/3 throttle)?

Change the fuel filter and see if that helps. I usually fill it 1/2 with fuel supplement, then prime it full with #2.

 

You guys were correct, I was gelling up on a new tank of ULS as well as a few friends of mine. The cure was 1 Qt Power service 911. I also had the problem the next day, again 1 Qt of power service and 1/4 mile later all OK. I also changed the filter after the second bottle for good measure. Thanks