cracks in steel cab of a DM.

[Ardenmack]

Recently I bought a 1985 DM roll off truck with about 276k miles. The truck was sitting for over 5 years according to the owner, but looked in good shape. After doing much work to the fuel pump, injectors, hoses, etc I began to notice a lot of cracks in the cab some as long as 6" . Cracks where found by the fire wall, behind the air filter, by the wire harness and specially by the hinge post of the passenger door, where an additional plate was welded. I was alarmed when I finally was able take it for a drive, even thou the road was not the smoothest both the cab and truck felt and sounded like it was going to pieces. This is my first Mack, I own two other Autocars about the same vintage but they don't sound like this. I would appreciate help in this matter, perhaps from some experience Mack owners.

Should I look to replace or repair something to fix this condition?

Thanks in advance.

[MACKS]

Might be time for cab mount bushings,not a big deal if that's the problem.

[Keffer inc]

We have a 1987 DM series dump truck at work, and its a total piece of crap! we have cracks running all over the rocker panels and firewall too. We've welded several times to try and fix it, and it always splits open again. If moneys not an issue, I would find a cab that was air-ride, and swap the cab and air equipment over.

[GreenGiant2]

dont think you can dod an air ride cab on a dm mack

[Keffer inc]

You're probably right, just figured theres a newer year that could have them. "If you can't buy it, fab it"

Edited February 26, 2013 by Keffer inc

[hicrop10]

We had 15 1979 DM600 triaxles dump truck that we had brought new.They had to be the worst riding truck I think Mack ever built.They were noisey,bouncey and just plain rough riding.

[Ardenmack]

Thank you all for your responses they provided a good insight to what the problem can be and perhaps ways to fix it. I took it for a short drive and paid closer attention to where the noises where coming from. One was the passenger door not closing right or tight, the other was the air intake cap loose. I expect that after correcting them and others like the ride noise well reduce.

After seeing the body cracks on the cab our mechanic suggested replacing the cab with another, perhaps a salvage one. He also explained that this would be relatively simple. I'm not sure, can someone with more experience add their comment.

Thank you

[umodelnut]

We replaced the cab on my U model. The U model used the same cab and hood as the DM, but the DM has a thicker frame, and heavier axles and such. Let me tell you there is alot of wiring. There's also quite a few air lines but that's not to bad. But, when you change the cab make sure you tag all of the wires and tape them and write on the tape what the go to, you know what I mean? Do this because it'll be easier to know where everything went and you probably won't get an identical cab to yours so wiring will be a little different in some places.

[Ardenmack]

Thanks umodelnut I sure know how rewiring can go real bad if you don't take the time to tag the lines.