This guy walks into the shop today... :(

[Demons_Ram]

Vehicle operator driving an AM General M-925 5 ton truck, with the Cummins 8. 3 liter, comes in the shop today and says, "I think there's something wrong with my fan belt... " Well of course, we go out to take a look and, what do we find? :--)



What's wrong in these pictures?

 

[MoparBob]

Did he actually have no idea how that happened? From the pics I couldn't see any obvious pulley alignment problems... am I missing something? I've never seen a belt off like that without there being a reason.

 

[MoparBob]

now that I look... . wow is that thing messed up. What's the full story... missing a pulley? Routed wrong? I see it running on an idler like it was a pulley...

 

[The patriot]

ahhhh the ol shrinkage

Must have runned through a puddle of cold water. :-laf

 

[Pmaloney]

Nice balancer!!! :--) :--)

 

[jwilliams3]

Nice balancer!!!

Ding! Ding!

 

[Demons_Ram]

Pmaloney,

Good eyes... Here's the missing clue that was laying under the fan shroud on the cross member. This paticular truck spent over a year in Iraq and is about 20 years old. So, between the two the rubber in the balancer just couldn't handle the stress of driving the accessories.

 

[MoparBob]

DUH!!! That's what was throwing me off... seeing what appeared to be a idler where the Harmonic Balancer was supposed to be. I should've caught that too , having replaced one for the same reason when I was stationed in Kuwait years ago.

 

[Demons_Ram]

Bob?

Bob,

Know any tricks for getting more power of of these things? Some of these things are so detuned they couldn't pull a sick wh**e off a toilet. Especially the wreckers. When I was in South Korea we called ours DRAGONFLY. It would drag it's a*s up a mountain and fly on the way down. Had to be careful not to smoke those brakes.



Tom

 

[Pmaloney]

At least it came off clean, and doesn't appear to have done any damage.....

 

[WDixon27]

the old 4 cylinder volvo gas motors do that, sometimes making quite a mess on the way out

 

[MoparBob]

The only thing that I have heard of was a few of the guys in the motorpool had turned the governor's up a bit for a few more revs. I know somebody out there should know a trick or two to crank them up. There has to be a way to work with the injector pump to crank it up some and those things are notorious for having fuel starvation problems from clogged fuel filters and weak pumps. I'll ask around and see if I can get in touch with someone who might have an idea on that. By the way... what year is it?

 

[Demons_Ram]

1987 but, we have these in the fleet up to 1991. The 5-ton trucks have the Cummins NHC-250 or 6CTA 8. 3L diesel engine with Allison 5 speed MT654CR transmissions. Photo of injection system included.



These things are finally getting replaced (slowly) by the FMTV's that Stewart & Stevenson makes with th Caterpillar engine (HUEI injected), Allision Transmission with TECIII computer control, Computer controlled CTIS (Compterized Tire Inflation System), and Computerized ABS. Three different computers controlling each function. We have to have a special diagnostic computer (MSD-ICE) just to figure out what's wrong with them. Gone are the old and simple days of repair.

 

[MoparBob]

Sounds like you're in the military or working for a contractor maintaining military equipment. The new LMTV's and FMTV's where I'm at seem to be a nice step up from the old 5 tons. Now, if we could just get a programmer for those cats... :-laf . I'll poke around and see what I can come up with on those cummins.

 

[MoparBob]

No luck with finding anyone that knows a trick or two to give those long in the tooth 5 tons a little bump in power. I did fiind someone who knows a "wrench" who knows how to coax a little more out of the PLS's and family... I'm trying to track him down. Maybe he'll know a trick or two for the 5 tons as well.

 

[DogDiesel]

There is an Military Work Order on the M936A2 5 ton wreckers with that 8. 3 engine which gives more power and more few more RPMs. Follow the receipe for the MWO and you get the bump in power you are talking about.

Wayne

 

[MoparBob]

Only thing that I have been a able to come up with so far...



There is a military power upgrade for the 5 tons & family designed for the wrecker version. I forget what they call those type of documents or forms or workorders. If you can find that... you can bump the power up to wrecker specs. How much of an increase it provides I have as yet been unable to ascertain. I'll find out eventually though if someone doesn't help me out here though... .