moredawgs Posted July 15, 2014 Share Posted July 15, 2014 okay,heres my question; I have a b-61 with a 673/turbo,5speed main transmission,with a 3 speed browning behind it. I'm thinking of changing the tranny to a 3spd.axu. by 5 spd. main in front of browing.will the3x5 change the road speed? RPM'S and touque ? Quote Link to comment Share on other sites More sharing options...
j hancock Posted July 15, 2014 Share Posted July 15, 2014 Not sure what you are up to???You can change speed/rpm if you change to an aux that has different gear ratios then what is in the truck now. Changing the rear axle ratio will work also.Some Macks did have a quad box trans followed by a 3 spd aux trans giving lots of gears to play with. To answer completely would have to know the EXACT ratios in the trans, aux and rear end now plus the size tires you plan on running and how you plan on using it. Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
Freightrain Posted July 15, 2014 Share Posted July 15, 2014 Ok, you actually two boxes, not a Triplex? And you want to added a 3spd behind it. That is basically the set up I have but mine is a Mack Triplex with a 4spd aux behind it(deep under first).It all depends on the box and what over drive you have, but mine added 7-8mph to my top speed when using both OD's(triplex and brownie). I typically run the brownie in direct for most all driving until I need that last bit of road speed.What are the part numbers on the boxes? That way we can track down the ratios. What rear gear do you have? 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
moredawgs Posted July 15, 2014 Author Share Posted July 15, 2014 Thanks, I'd have to change the rears to get better mileage and more speed. Changing the tranny,adding 3more gears ,high,low and derect would only cause more shifting.and I'd have to add another gear shift. Quote Link to comment Share on other sites More sharing options...
gearhead204 Posted July 15, 2014 Share Posted July 15, 2014 in the brownie is 3td. a direct or 3td. over? if its a 3td. direct why not swap it with a 3 or 4 over brownie? Quote Link to comment Share on other sites More sharing options...
moredawgs Posted July 15, 2014 Author Share Posted July 15, 2014 yes the truck now has a mack 5 spd. [only].the browning has 3 spd. I was going to change the mack tranny to a 3 spd. aux. with a 5 spd. direct in front of the browning. now I have low hole 5 indirect 5 ,direct 5, 15 total gears, changing the tranny would give it 5 in the main ,3 in the aux.and 3 in the browning.more gears but the same to the rears,or am I wrong?????? Quote Link to comment Share on other sites More sharing options...
hurstscrambler Posted July 15, 2014 Share Posted July 15, 2014 Dont you have a 15 speed now? Quote Link to comment Share on other sites More sharing options...
j hancock Posted July 15, 2014 Share Posted July 15, 2014 If either of the aux transmissions are NOT overdrives, you won't gain anything.With specific details, road speeds can be calculated. 2 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
gearhead204 Posted July 16, 2014 Share Posted July 16, 2014 j hancock nailed it. that what I was trying to say if none of the trans. turn faster than 1 to1 you will never go any faster unless you find a hill and shove in the clutch!!!!!!!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
Brian Blaylock Posted July 16, 2014 Share Posted July 16, 2014 If what you are calling a three speed browning is a brown lipe that is a brand name of aux transmission Quote Link to comment Share on other sites More sharing options...
mrsmackpaul Posted July 16, 2014 Share Posted July 16, 2014 why dont you put the second 3 speed box in backwards it will then give two good over drives and will solve all your problemsPaul Quote Link to comment Share on other sites More sharing options...
Speed Posted July 18, 2014 Share Posted July 18, 2014 "why dont you put the second 3 speed box in backwards it will then give two good over drives and will solve all your problems" HIGHexcept then you have to build more power to use gear. Speed . Quote "Remember-ANY Gun Control is Unconstitutional!"<!--sizeo:3--><span style="font-size:12pt;line-height:100%"><!--/sizeo--><i><b>MACK-E Model Registry # 36</b></i><!--sizec--></span><!--/sizec--><a href="http://www.nvabatetravel.com/"target="_blank">http://www.nvabatetravel.com/</a> Link to comment Share on other sites More sharing options...
Maddog13407 Posted July 19, 2014 Share Posted July 19, 2014 im wondering why a B61 with a 673 turbo which wasn't available til about late 58 or early 59 would still have a 5 speed with 3 speed brownie when the quadbox and tripex were available.... Quote Link to comment Share on other sites More sharing options...
mrsmackpaul Posted July 19, 2014 Share Posted July 19, 2014 "why dont you put the second 3 speed box in backwards it will then give two good over drives and will solve all your problems" HIGHexcept then you have to build more power to use gear. Speed .yes this leads to the problem that is all these things are old trucks and most werent meant to go real fast and dont have the power to if they are geared to go quick any hill or head wind makes it time change gears Quote Link to comment Share on other sites More sharing options...
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