Mack GU813E Broken Shaft

[ejuan]

Hi everyone, hope everything is doing good for you guys. This is actually my first post, so sorry if make any mistakes or violate any of the forum rules. We have a Mack dump truck (GU813E), and in three years it has broken 3 shafts. My boss is claiming that he wants to know the reason why before buying another shaft for the same truck. I've been thinking about improper operation (bad clutching, bad gear shifting...). Maybe you guys can give me an opinion and tell me what you think could be happening here.

 

[ejuan]

Well.... the idea was to post some pictures of the broken shaft..., but it seems I dont have the option to post attachments on my posts :beatsme

 

[ben46a]

When one of the moderators see this they may change your settings to allow you to post pics. Usually you need ten posts. Is it the transmission input shaft, mainshaft driveshaft or axle shaft your referring too?

 

[ejuan]

Thanks for your help Ben. It is the axle shaft, the one that goes attached to the truck´s wheel. It was cracked at a 45º angle. But it was broken not in 2 pieces, but in 4 pieces. 2 big ones and 2 little ones. Hope a moderator could change my settings so I can post a couple of pictures and show you better.

 

[ejuan]

Here you can see the pics

 

[ben46a]

The majority of broken axles are from abuse. Plain and simple. Jerking with the clutch, or bouncing the truck when stuck, etc. Domething else to think about, Does the truck have a locking differential in that axle? If its not unlocking, or being left locked in, it could cause axle breakage on a solid surface.

 

[Bob/Ont]

That axle is broken from stress cracks, likely vibration is the cause. Is it always the same axle or different ones that break.
Later Bob

 

[shopguy]

Hey Bob i am waiting on the answer too, if it is the same one could be a bent housing

 

[ejuan]

Previous two broken shafts were the ones at the rear axle, now it broke the one at the middle axle. Any ideas?

 

[oregon96pd]

Shock load failure....violent high torque impacts. As said before poor clutch engagement, stuck, or bouncing under load.

 

[willie59]

Agree with above, most of those failures are more from driver error/abuse and less from component failure.

 

[bill onthehill]

Wheel hop from spinning in mud and suddenly catching traction can do that. Usually pulling out with a load when it is mucky.

 

[heymccall]

My money is on a damaged auto power divider remaining locked. The "peanuts", if you will. Other common causes are from severely mismatched drive tire rolling diameters, or, like on one of mine, different gear ratios between the two axles (tahnks to my not so local Mack dealer). If it were from abuse, we'd break more of them, here.

 

[ejuan]

Thanks for your help guys