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Broken rear axle Mack dump truck

T

terex herder

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Nov 10, 2017
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Kansas
1980 Mack twin screw dump truck. Drive shaft turns going into front differential, but no go. Truck was trying to dump full load in soft ground. Bang when the driver let out the clutch. Canadian built Mack if it matters, top load differential. No axle weight on door. Just wondering if anyone has any words of wisdom or relevant experience to share.
 
J

Jumbo

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I bet it is an axle. At Weyerhaeuser with the Macks from '73 into the '80s, we broke axles regularly. They were a weak link. All the trucks carried a set, you could change an axle in about 5 minutes if you had a shop modified axle. The truck shop had the machine shop score each axle about an inch from the spline. thus giving it a "weak point" to shear. It saved trying to retrieve chunks of axle from the differential. Keep the scored end out by the hub and it was really easy. The DM 8000s were notorious for eating axles.
 
I

IceHole

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Jumbo said:
I bet it is an axle. At Weyerhaeuser with the Macks from '73 into the '80s, we broke axles regularly. They were a weak link. All the trucks carried a set, you could change an axle in about 5 minutes if you had a shop modified axle. The truck shop had the machine shop score each axle about an inch from the spline. thus giving it a "weak point" to shear. It saved trying to retrieve chunks of axle from the differential. Keep the scored end out by the hub and it was really easy. The DM 8000s were notorious for eating axles.
Click to expand...
Axle shafts you mean? Axle is the whole shabang, no? Ie Mack top loader axle.
 
DMiller

DMiller

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Having internally splined Axle shaft end caps instead of flanges made broken axles on DMs somewhat easier, IIRC those had Mack 48k tandem ratings.
 
kshansen

kshansen

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Just remember that if one of those shaft/axles broke the chance there aren't some bits that won't come out when shaft is removed. I would hate to just slip a new shaft in and hope the other bits will not get some place they could do some more harm.

I suppose one could inspect the two broken parts and determine what might be missing then flush the housings with fuel oil and play around with a magnet and hope everything comes out.
 
J

Jonas302

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If you can lock the power divider and see what spins usually shorts out pretty quick what area is broke I usually have to pull both to knock the stubs out thank goodness we don't need as many as Jumbo did
 

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Truck Shop

Truck Shop

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Depending on where it broke if that's what it is--if it broke near drive unit a piece of
pvc that fits the tube can be used as a receiver to remove broke stub.
 
Truck Shop

Truck Shop

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The thing everyone loves--lockers--till it's driven on dry asphalt for a couple hundred.
We had a series of Freightliner Classics with front lockers, drivers kept for:)getting to
flip the air switch to disengage-then a sharp snap would be heard. After replacing
about 6 axles-two in parking lots--those got disconnected.
*
Next everyone will say {didn't they hear the buzzer or see the light} they taped over the
light and pumped the buzzer full of silicone. Drivers are some scheming buggers.
 
DMiller

DMiller

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Third member, pot, pumpkin, drop in, carrier, is just a name and spoken differently around the nation. Axle tube, axle housing, Banjo housing, axle shaft, etc. we all here been around long enough to have heard 95% of the variables.
Pop, Soda, Coke, soft drink!!
 
C

cuttin edge

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1980 would be old enough to have t 2 part axle, axle shaft, long splined on both ends thingy the makes wheels go. Would it not. Not sure when Mack went wit the one part
 
DMiller

DMiller

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Flanged and or Double Splined have been around for a LONG time at Mack. Caped Dbl Spl were seemingly always on Heavier Axle arrangements, lighter got the Fanged sets, OLDER Trucks(Pre 70) many had Double Splined.
 
Truck Shop

Truck Shop

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DMiller said:
Third member, pot, pumpkin, drop in, carrier,
Click to expand...
Yes I understand that----but pumpkin does not fit in that sentence.
cuttin edge said:
1980 would be old enough to have t 2 part axle, axle shaft, long splined on both ends thingy the makes wheels go. Would it not. Not sure when Mack went wit the one part
Click to expand...
Two piece axles--I don't remember.
 
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