Rob Posted March 7, 2010 Share Posted March 7, 2010 Through the years I've read where the 34,000 pound tandem Mack rears were of the five spoke design, and the 38,000 pound rears had six spokes. Well, upon cleaning my B67 rears I noticed the stamping into the rear rear housing of SWDL56 denoting the series of suspension under the truck. This, suspension according to my service manual that resides right next to my bible, equates to a 34,000 pound rated suspension. I then march across the shop to look at another B61 series and it to is stamped SWD56, (minus the "L"). These too, according to the good book is also a 34,000# rears. Both of these have six spoke hubs so I'm thinking the earlier analogy of the number of spokes is misdirected to identification. Both of these trucks have the same brake setup installed with aluminum brake shoes and shoe mounting adapters. Even the same Mack part numbers are cast into the aluminum brake shoes. Both suspensions look identical to me so I can't figger our why the "L" designation is not stamped into the second trucks' axle housing. I know stranger things have been solved but I know both suspensions are original to their respective chassis. Does anyone know how wide an R model axle housing is and if it will readily go under a B series truck? I've never actually measured this dimension from axle tube end to axle tube end and do not have an R model apart. One of my B model has a busted housing and it has been poorly welded back up, (I didn't do it) and leaks.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/12930-camelback-rear-suspension/ Share on other sites More sharing options...
HK Trucking Posted March 7, 2010 Share Posted March 7, 2010 Hi Rob.My 1972 DM685s triaxle had 38k Mack rears with 5 spoke hubs, as did all of the 38k rears in Van Handels fleet when I worked there.Regarding the width of the housing, I believe it would be the same.. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/12930-camelback-rear-suspension/#findComment-50844 Share on other sites More sharing options...
Rob Posted March 7, 2010 Author Share Posted March 7, 2010 Hi Rob.My 1972 DM685s triaxle had 38k Mack rears with 5 spoke hubs, as did all of the 38k rears in Van Handels fleet when I worked there.Regarding the width of the housing, I believe it would be the same..Hi Herb, I'm going to assume this earlier depiction was inaccurate due to your experience. The six spoke design must be for strength I would think. Would you think the bearing sizes would be the same given an R model and B model if the suspension rating were the same? I have an R model with 34,000# suspension and no bends in the reservoir bowls so would like to keep them if useable. My 58 B model has a caved in bowl, but doesn't leak. Otherwise I was planning on knocking it back out sometime.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/12930-camelback-rear-suspension/#findComment-50846 Share on other sites More sharing options...
HK Trucking Posted March 7, 2010 Share Posted March 7, 2010 The six spoke design must be for strength I would think.Of the ones I've dealt with over the years the 44k rears and the later style 87? on up 38k had 6 spoke hubs. Would you think the bearing sizes would be the same given an R model and B model if the suspension rating were the same?I honestly can't answer that as I have never made that comparison. I have an R model with 34,000# suspension and no bends in the reservoir bowls so would like to keep them if useable. My 58 B model has a caved in bowl, but doesn't leak. Otherwise I was planning on knocking it back out sometime.RobIf they're the pressed steel housings, check real carefully for cracks in the area at the left front of the bolt circle. I've had several that developed cracks and resulting oil leaks in that area. If that's the case the housing can be welded up and ground down and filed flat at the mating surface. Is that what happened to the housing you spoke of earlier? Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/12930-camelback-rear-suspension/#findComment-50848 Share on other sites More sharing options...
Rob Posted March 7, 2010 Author Share Posted March 7, 2010 Of the ones I've dealt with over the years the 44k rears and the later style 87? on up 38k had 6 spoke hubs. I honestly can't answer that as I have never made that comparison.If they're the pressed steel housings, check real carefully for cracks in the area at the left front of the bolt circle. I've had several that developed cracks and resulting oil leaks in that area. If that's the case the housing can be welded up and ground down and filed flat at the mating surface. Is that what happened to the housing you spoke of earlier?Hi Herb, no this one is cracked up between where the spring end box and tube meet from impact with something as the area is really pushed in too. 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/12930-camelback-rear-suspension/#findComment-50849 Share on other sites More sharing options...
Superdog Posted March 7, 2010 Share Posted March 7, 2010 I don't know what year they quit and went to the 5 spoke,but the 6 spoke wheel was used on all the 34k rears,they had the small wheel studs that used same nut as steer axle. Quote Link to comment https://www.bigmacktrucks.com/topic/12930-camelback-rear-suspension/#findComment-50851 Share on other sites More sharing options...
Swishy Posted March 8, 2010 Share Posted March 8, 2010 FWIWMy 2 cents worth from the udder side of the world (tax free)Ifn I'm readin me Mack info rightthe 'L' part of number = L for light as in Aluminiumthe 5 spokes coulda been swapped for 6 spokes in aprevious life6 spokes puts less stress on wheel rims than a 5 spoker under full loadQ?: Has it walking beam suspension?ButEyeDoSt&2BCorrectedcya§wishyHasBeen Quote Link to comment https://www.bigmacktrucks.com/topic/12930-camelback-rear-suspension/#findComment-50861 Share on other sites More sharing options...
Rob Posted March 8, 2010 Author Share Posted March 8, 2010 I don't know what year they quit and went to the 5 spoke,but the 6 spoke wheel was used on all the 34k rears,they had the small wheel studs that used same nut as steer axle.Thanks Mike, mine do use the 5/8ths studs which are the same size as the front spiders.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/12930-camelback-rear-suspension/#findComment-50863 Share on other sites More sharing options...
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