Hobert62 Posted September 14, 2015 Share Posted September 14, 2015 Trying to help a guy out with a gear swap. I first thought the rad 5291 stamped into the axle housing meant it had a 529-1 ratio. Then I found all the other numbers stamped into the carrier section of the rear. Please mack gods help me out with the ratio. Thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/ Share on other sites More sharing options...
The Fireman Posted September 14, 2015 Share Posted September 14, 2015 Thanks for posting, I'm the guy working on the swap into my 1963 B42. right now I still have the gas job rear end with what I believe are 7.85's. The truck has a 673P with either a TRDL 720 or TRDL 7220 I know its one or the other but for the life of me I cant remember right now and its a bit wet right now to go crawl under the truck to verify. Shes on 22" rubber, I'm going to put on some new 24.5's in the spring so tire size will stay the same. With my currant set up I top out around 40 or so, I'd like to get to 55-60 but I would settle for 50-55 as the truck wont be seeing the interstate. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303707 Share on other sites More sharing options...
Maddog13407 Posted September 14, 2015 Share Posted September 14, 2015 Rad5291 is the housing series. it usually meant the difference between 6'' or 7'' brake lining, aluminum backing plates and some had the cheaper axle without the centering cones behind the axle nuts. the rear ratio is stamped on the driver side of the hogs head below the round side cover. usually has an R in front of it. id say with an overdrive trans on 22'' rubber you need a high 4.xx to low 5.xx ratio. most single axle b models I have seen with directtrans and 22'' rubber had 4.66 or 4.62 ratio. you gotta watch changing out the hogs head because if you have the cheaper housing, it wont have the webbing inside to support the ring gear.the better rear housings were the Rad508 or Rad512 Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303710 Share on other sites More sharing options...
j hancock Posted September 14, 2015 Share Posted September 14, 2015 With the overdive trans and depending on what you are doing with the truck, something in the 5's would be better for you and get you into the 50-60 range.A CRD78 in a B61LT had optional ratios of 4.28, 4.60, 5.30, 5.74 and 6.26. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303711 Share on other sites More sharing options...
fifth wheel Posted September 14, 2015 Share Posted September 14, 2015 I read 4.60FW Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303713 Share on other sites More sharing options...
The Fireman Posted September 14, 2015 Share Posted September 14, 2015 Ok so the botom number on the hogs head is the ratio, learned something new today. thats good news as 4.60 would be perfect for what I'm doing. I'll have to check my housing to see if the series is the same otherwise I might have to swap the housing and all. Thanks for the info you guys are a wealth of knowledge. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303716 Share on other sites More sharing options...
Maddog13407 Posted September 14, 2015 Share Posted September 14, 2015 yup, 4.60 is the ratio. usually has an R in front of it or some actually say 'ratio'. looks like that ones been reworked with different gears and someone made it a 4.60 as the numbers looks scratched out and restamped. id probably just change the whole housing. if you have the original rear in your B42, it most likely has the smaller brake lining anyways. if the other rear came from a diesel it usually has the 7'' lining. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303752 Share on other sites More sharing options...
Hobert62 Posted September 14, 2015 Author Share Posted September 14, 2015 I just measured and it does only have 6" lining. It has a 7" drum on the one side but both sides have 6" lining. It's from a 1963 b67 single axle tractor. Is there a way to tell if it has the centering cones? Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303761 Share on other sites More sharing options...
Maddog13407 Posted September 14, 2015 Share Posted September 14, 2015 just take one axle nut off, the cone/wedge should be under the axle nut. im know they used the cheaper axles and housings in some B42's just not sure what the cutoff was. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303762 Share on other sites More sharing options...
Hobert62 Posted September 14, 2015 Author Share Posted September 14, 2015 I took it out of my 1963 b67. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303763 Share on other sites More sharing options...
Hobert62 Posted September 14, 2015 Author Share Posted September 14, 2015 I don't think it has them. The one side I know just has a nut against the axle flange. The other side has a drain plug in the end of the flange and it may but it doesn't come out very easy. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303767 Share on other sites More sharing options...
Vladislav Posted September 14, 2015 Share Posted September 14, 2015 It wouldn't be a lost time to make some prop shaft flange turns and count how many the hubs do. Than make a math and get the actual ratio. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303771 Share on other sites More sharing options...
The Fireman Posted September 14, 2015 Share Posted September 14, 2015 I'll pull one of the axle nuts of my truck when I get home to check for the cones. I'll also measure my brakes. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303772 Share on other sites More sharing options...
Hobert62 Posted September 14, 2015 Author Share Posted September 14, 2015 I turn the front yoke 2 1/4 turns for the hub to go around 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303779 Share on other sites More sharing options...
The Fireman Posted September 14, 2015 Share Posted September 14, 2015 I just checked and I have the centering cones under my axle and I have 7" brakes (that are new too) so I would say I have the heavy housing in my truck so if I understand everything I've read correctly the hogshead above will work in my housing. I sent you an email Hobert thanks again for everything. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303795 Share on other sites More sharing options...
Phase 1 Posted September 14, 2015 Share Posted September 14, 2015 I turn the front yoke 2 1/4 turns for the hub to go around 1Then 4.60 is probably correct. Quote Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303800 Share on other sites More sharing options...
Vladislav Posted September 14, 2015 Share Posted September 14, 2015 Then 4.60 is probably correct.I agree.If more sure is needed just make ten full revs and divide the result to get the sharp figure. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/41774-help-with-s-stamped-in-rear/#findComment-303809 Share on other sites More sharing options...
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