Rufino V Posted January 19, 2019 Share Posted January 19, 2019 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? Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/ Share on other sites More sharing options...
terry Posted January 19, 2019 Share Posted January 19, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413608 Share on other sites More sharing options...
Hayseed Posted January 19, 2019 Share Posted January 19, 2019 is your Power divider stuck in the engaged position?? Quote "Be who you are and say what you feel...Because those that matter...don't mind...And those that mind....don't matter." - Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413612 Share on other sites More sharing options...
mrsmackpaul Posted January 19, 2019 Share Posted January 19, 2019 Measure the new tyre diameters and as Seed has said make sure the power divider isnt engaged Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413618 Share on other sites More sharing options...
Rufino V Posted January 19, 2019 Author Share Posted January 19, 2019 What is the power divider? Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413622 Share on other sites More sharing options...
Popular Post terry Posted January 19, 2019 Popular Post Share Posted January 19, 2019 (edited) 19 minutes ago, Rufino V said: What is the power divider? You have a dump truck and don't know what a power divider is? Are you brand new to this line of work? terry you better get you an older mack manual. Edited January 19, 2019 by terry 3 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413624 Share on other sites More sharing options...
Rufino V Posted January 19, 2019 Author Share Posted January 19, 2019 I am not sure if they are the same ratio. How can I find out the ratio? Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413626 Share on other sites More sharing options...
Rufino V Posted January 19, 2019 Author Share Posted January 19, 2019 Yes I am new on dump truck job Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413627 Share on other sites More sharing options...
JoeH Posted January 19, 2019 Share Posted January 19, 2019 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. Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413634 Share on other sites More sharing options...
mrgumby Posted January 19, 2019 Share Posted January 19, 2019 Just a thought since you had the drive shafts out don’t know what else you did. Have you checked the drive shaft phase Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413635 Share on other sites More sharing options...
Challenger Posted January 20, 2019 Share Posted January 20, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413645 Share on other sites More sharing options...
mrsmackpaul Posted January 20, 2019 Share Posted January 20, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413674 Share on other sites More sharing options...
Rufino V Posted January 20, 2019 Author Share Posted January 20, 2019 This truck does not have a divider as far as I know. I think they install different ratio on the front rear differential Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413702 Share on other sites More sharing options...
terry Posted January 20, 2019 Share Posted January 20, 2019 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 1 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413710 Share on other sites More sharing options...
Vladislav Posted January 20, 2019 Share Posted January 20, 2019 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 Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413712 Share on other sites More sharing options...
mrsmackpaul Posted January 21, 2019 Share Posted January 21, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413755 Share on other sites More sharing options...
Rob Posted January 21, 2019 Share Posted January 21, 2019 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. Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413756 Share on other sites More sharing options...
terry Posted January 21, 2019 Share Posted January 21, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413767 Share on other sites More sharing options...
Vladislav Posted January 21, 2019 Share Posted January 21, 2019 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. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-413804 Share on other sites More sharing options...
Rufino V Posted January 24, 2019 Author Share Posted January 24, 2019 This is what I find out the Rea front differential ratio is 4.64 and the other is 4.17 this could be the problem . When I drive the truck made the clucking noise Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414019 Share on other sites More sharing options...
Rob Posted January 24, 2019 Share Posted January 24, 2019 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. Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414022 Share on other sites More sharing options...
terry Posted January 24, 2019 Share Posted January 24, 2019 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 Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414027 Share on other sites More sharing options...
Rob Posted January 24, 2019 Share Posted January 24, 2019 (edited) 11 minutes ago, terry said: Power divider is probably junk! terry 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 January 24, 2019 by Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414030 Share on other sites More sharing options...
Rufino V Posted January 24, 2019 Author Share Posted January 24, 2019 I have to call the shop who did the job and fix it . Because they replace both differential. now I have to find out what is the ratio for this truck? Quote Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414032 Share on other sites More sharing options...
Vladislav Posted January 24, 2019 Share Posted January 24, 2019 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. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/55351-differential/#findComment-414039 Share on other sites More sharing options...
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