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Differential


Rufino V
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32 minutes ago, Rufino V said:

I have a 1988 superliner dump truck I  recently change both rear differential and when I drive my truck with load it make a clucking noise looks like is going to brake the rear differential does anyone know what could be wrong?

Are they the same ratio?    terry:MackLogo:

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Ratio should be stamped in the carrier housing on the differential housing. Axle ratio is how many times the driveshaft has to spin per wheel rotation. If the ratios are different, youre going to blow up one of the rears. If they're the same, check your driveshaft for bad u-koints or a bad carrier bearing. (Rubber bushing looking thing to hold it over the lift axle) 

Power divider is a switch on the top of your dash. It forces one wheel on each drive axle to have to spin. (If it's unlocked in mud, all it takes is one drive tire to spin and you lose all power through that wheel) Never switch it when a wheel is spinning.  Never drive on blacktop with it locked.

 

If all else fails get an experienced trucker to ride along with you.

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If the front rear carrier had a spacer behind/before the yoke,  it would need switch to the new rear.  I’ve seen people leave them off, with the complaints of, vibration, oil leak or noise.  

 

Ratios are are stamped on the front right flat spot on the carrier.  To the right of input, facing forward 

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12 hours ago, Rufino V said:

What is the power divider?

It divides the power between the front drive axle and the rear drive axle

It allows them to spin at slightly different speeds that will happen as tyres ware and just thru normal driving 

When the power divider is locked both front and rear axles will spin at the same speed and hard surfaces this cause the axles to fight each other putting a lot of strain on the drive line and can also cause the axles to jump and chirp etc as they unload the tension

Paul 

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54 minutes ago, Rufino V said:

This truck does not have a divider as far as I know. I think they install different ratio on the front rear differential

If it does't have a air operated power divider, it has a inter-axle one that you can't see on the outside, to detailed to explain here, another good reason for a manual.    terry:MackLogo:

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1 hour ago, Rufino V said:

This truck does not have a divider as far as I know. I think they install different ratio on the front rear differential

Installing two carriers of different ratios is a crime. And the result would be disaster. Too probably you will learn what the divider is very soon.

Sorry to paint the picture in such dark colors but if the things are of the way you described you will get into serious dutch pretty fast. The failure of the diff gears or the power divider (which is also a part of a differential) will happen.

Vlad

Никогда не бывает слишком много грузовиков! leversole 11.2012

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10 hours ago, Rufino V said:

This truck does not have a divider as far as I know. I think they install different ratio on the front rear differential

I very nich doubt any 1988 bogie drive truck would have been built without a power divider

I dunno when Mack would have added power dividers as standard but at a guess it would have been 1930's or 40's 

I cant even think of any Mack bogie in a hwy size truck that I have seen that didnt have a power divider

Even other brands pretty much all had power dividers by the 1950's in Australia 

Does your truck have a Mack bogie or some other brand 

 

Maybe take a photo of the trucks back end, diff centers etc and we can soon recognize what brand and of it does or doesnt have a power divider

 

Paul 

 

 

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2 minutes ago, mrsmackpaul said:

I very nich doubt any 1988 bogie drive truck would have been built without a power divider

I dunno when Mack would have added power dividers as standard but at a guess it would have been 1930's or 40's 

I cant even think of any Mack bogie in a hwy size truck that I have seen that didnt have a power divider

Even other brands pretty much all had power dividers by the 1950's in Australia 

Does your truck have a Mack bogie or some other brand 

 

Maybe take a photo of the trucks back end, diff centers etc and we can soon recognize what brand and of it does or doesnt have a power divider

 

Paul 

 

 

I've seen 3.86, and  3.87 put into the same truck in the past. Can't remember if the 3.86 was built into a carrier stamped 3.87, or the other way around but it wound up going into a truck. It didn't last too long but failure wasn't catastrophic as it was caught when things were hot, not failed. However upon teardown, the differential would have needed rebuilt again. Both differentials in the truck was warrantied to make the customer happy.

These were Mack differentials with air operated power divider. Had it been the automatic power divider, the story could have been quite different.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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10 hours ago, mrsmackpaul said:

I very nich doubt any 1988 bogie drive truck would have been built without a power divider

I dunno when Mack would have added power dividers as standard but at a guess it would have been 1930's or 40's 

I cant even think of any Mack bogie in a hwy size truck that I have seen that didnt have a power divider

Even other brands pretty much all had power dividers by the 1950's in Australia 

Does your truck have a Mack bogie or some other brand 

 

Maybe take a photo of the trucks back end, diff centers etc and we can soon recognize what brand and of it does or doesnt have a power divider

 

Paul 

 

 

If he doesn't even know what a power divider is, he sure isn't going to know what to look for on a mack to figure out what he has. people sometimes get confused on the automatic power divider on a mack.    terry:MackLogo:

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16 hours ago, Rob said:

These were Mack differentials with air operated power divider. Had it been the automatic power divider, the story could have been quite different.

Mack air operated power divider is almost the same the automatic power divider with additional option to full lock.

Никогда не бывает слишком много грузовиков! leversole 11.2012

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Surprising to me you could even move the truck with that disparity in gear ratios. Normally it will shuck a tooth, or strip a gear clean. Usually not quiet when it does it either.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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1 hour ago, Rob said:

Surprising to me you could even move the truck with that disparity in gear ratios. Normally it will shuck a tooth, or strip a gear clean. Usually not quiet when it does it either.

Power divider is probably junk!    terry:MackLogo:

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11 minutes ago, terry said:

Power divider is probably junk!    terry:MackLogo:

Most likely just the start of the damage once opened up. Damage would come quick with those ratios being intermixed. I've seen it.

Somebody really got too close and inserted their complete head when they went only to kiss the backside.

Edited by Rob

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.

 

 

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The ratio is just your choice now. I would take slower diffs for dump truck operation. More power to pull and slower to crawl. But you should also check your top speed when in the highest gear to cruise down the highway. So I would go with the lowest ratio which allows you to have reasonable revs cruising at the same time.

For the best you should make calculations being based on your transmission top gear ratio, tire size and preferrable revs at the speed you would like to cruise. Look over the old threads in this section of the forum. The matter was discussed many times in the past.

Никогда не бывает слишком много грузовиков! leversole 11.2012

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