bobanweve Posted December 31, 2006 Share Posted December 31, 2006 I have a 1965 B-67 mack with a slow-mo rearend. I was hoping someone had a used one they could part with, that could get my truck to go near lightspeed.Maybe something with 4.17 gears. With these gears ,I could wipe the smile off Capt.Kirk's face. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/ Share on other sites More sharing options...
fuzzy buzzard Posted December 31, 2006 Share Posted December 31, 2006 Where are you located? You got a tandem or single axle? What ratio in truck now? Is drive shaft long enough to remove about 4' and a aux. trans?Tom Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9367 Share on other sites More sharing options...
bobanweve Posted December 31, 2006 Author Share Posted December 31, 2006 I live near Kalamazoo,Michigan. My truck has an single axle,and I just bought the truck. I drove it to a friends garage to work on it.He lives abought 5 miles away,and all she would go is 55 mph. It has a 3+5 trans,but I don't know what ratio I have now. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9378 Share on other sites More sharing options...
Freightrain Posted January 3, 2007 Share Posted January 3, 2007 Look on the drivers side of pig, about the middle, there should be some numbers stamped. Included in those number should be the ratio: 4.62 or 5.xxMy truck has 4.62 gears and runs 64 mpg with a 5x3. Make sure you actually pace the truck with something to comfirm your speed. My truck speedo reads about 8 slow of what it actually runs! They make two 5x3's, a single over and double over. Mines' a single over. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9457 Share on other sites More sharing options...
bobanweve Posted January 4, 2007 Author Share Posted January 4, 2007 Checked out my rearend data tag and it said the ratio was 6.26. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9501 Share on other sites More sharing options...
Freightrain Posted January 6, 2007 Share Posted January 6, 2007 Yup, that be a slo-mo-chine LOL!!Sounds like you have a single overdrive Triplex. Look on drivers side of tranny for numbers. Should read like: TRT722. The double overs were TRT7220(as the "o" on the end means double over).If I could come up with something like 4.10 air ride rear clip, I'd pass on my 4.62's. I've been wanting to convert but haven't found anything in my price range(cheap). Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9574 Share on other sites More sharing options...
mudslut28 Posted January 13, 2007 Share Posted January 13, 2007 Just wanting to tell you...as a general rule the higher the gear number the stronger the gearset. Just to throw out a few numbers here for giggles the latest truck I bought which was the R Model has an 8LL with 5.73 ratio and will run 67. The dm 800 I have has a6 speed and will run almost 50...lol..it has 5.88 ratio. On the flip side my dm690 with the 7 speed and 7.58 ratio would run 62. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9704 Share on other sites More sharing options...
Freightrain Posted January 15, 2007 Share Posted January 15, 2007 It depends on the OD in the tranny mostly. Single or double? .8, .7, .6? Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9742 Share on other sites More sharing options...
Paul Posted January 20, 2007 Share Posted January 20, 2007 Freightrain What size tires are you running? I have the same rear and I am installing a 5 X 3 single over trans. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9884 Share on other sites More sharing options...
bobanweve Posted January 21, 2007 Author Share Posted January 21, 2007 I have 11x22's on it now. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9899 Share on other sites More sharing options...
Freightrain Posted January 22, 2007 Share Posted January 22, 2007 I got 11r22.5's on it.With GPS and on the gov' it ran 65 mph. I usually with trailer run 1900 or so and it runs about 60 mph(so says buddy who usually follows me to/from racetrack with his pickup and trailer). Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9912 Share on other sites More sharing options...
Bmoto1 Posted January 23, 2007 Share Posted January 23, 2007 What, me worry? a few years ago I had the rear in my B changed from a 5:62 to a 4:??, and picked up about 8 mph to 68. The dealer did not want to install the "new" rear saying the gears were pitted. they were, some holes the size of a pencil eraser. But, been fine since- 10,000 miles- even one 600 mile day. No weight on the truck, flat bed with total truck weight of 13,800. getting ready to drive it 800 miles to Colorado Springs in June. Any way, any thing to check? I've thought of putting a thermal couple on it to see if it gets hot, but I don't know what the failure mode is. Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9917 Share on other sites More sharing options...
Lmackattack Posted January 23, 2007 Share Posted January 23, 2007 The rear end oil shoud not get over 100 deg if bobtailing empty. When I pull hils in the company truck I see 120-150 depending on the outside temps and grades. Just my.02 Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9918 Share on other sites More sharing options...
Freightrain Posted January 23, 2007 Share Posted January 23, 2007 I don't see pitting as a major issue, especially since it's a toy and won't see 80K lbs. As long as the pattern on them was still good, no howl, I think you're good to go. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9934 Share on other sites More sharing options...
Bmoto1 Posted January 24, 2007 Share Posted January 24, 2007 Thanks. Maybe my wife will hang under it and listen for the whine- I can't hear a thing in the cab. Really, I appreciate the comments, the fact that the gear face was so big it could have a pit and still have all that metal around it was reassuring. Must be getting old, when I drove a B for a living i never thought about breaking down, and never did Quote Link to comment https://www.bigmacktrucks.com/topic/1952-need-different-rearend/#findComment-9949 Share on other sites More sharing options...
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