Red Horse Posted September 4, 2007 Share Posted September 4, 2007 My B-68X was built with TRQ 720 quadbox and 9.05 rears. At some point, someone put a 673 and a duplex in it. I have not driven it on the road but I tracked it down to the last guy who had it registered and he said it did about 35! I have the opportunity to get a quad box out of a B-42X but I'm assuming the quadbox in a gas job had a much lower torque rating and is a different animal. I will get the vin out of the B-42 but just curious if anyone had any ideas??I have to believe that getting a quad will be a lot easier then finding a gear set for a RAD 111 rear.Bob Quote Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/ Share on other sites More sharing options...
other dog Posted September 4, 2007 Share Posted September 4, 2007 My B-68X was built with TRQ 720 quadbox and 9.05 rears. At some point, someone put a 673 and a duplex in it. I have not driven it on the road but I tracked it down to the last guy who had it registered and he said it did about 35! I have the opportunity to get a quad box out of a B-42X but I'm assuming the quadbox in a gas job had a much lower torque rating and is a different animal. I will get the vin out of the B-42 but just curious if anyone had any ideas??I have to believe that getting a quad will be a lot easier then finding a gear set for a RAD 111 rear.BobWOW,9.05s! Now that's slow all right.I doubt if a quadruplex would give you much more road speed-it'll give you some because the duplex,if it's a ten speed and not the 9 speed overgear,is direct in high where the quad is a double overdrive. But if it only does about 35 now,I just don't know how much more the quad. would get you with those rears.My mixer has A 673 and A quadruplex and it'll only do about 55,but I don't know the rear end ratio. So I didn't really tell you anything,but that's my specialty here-B.S. and nonsense...somebody's got to do it! Meanwhile,there are some very smart people here and somebody will have A real answer for you. Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13757 Share on other sites More sharing options...
terry Posted September 4, 2007 Share Posted September 4, 2007 The Quad box in the B422 won't even bolt up to the diesel flywheel housing, with a 9.00 rear even a double over tri plex or quad is not going to get you any road speed,You need a rear with at least a 6.00 or under ratio. Being it was a B68 it had a higher turning gas engine that is why the deeper rearend. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13762 Share on other sites More sharing options...
HK Trucking Posted September 5, 2007 Share Posted September 5, 2007 That would be a TRQ77 or TRQ770 quad box from that B422.It's a much lighter duty transmission used behind the smaller gas engines and END 465 and END475 diesels. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13768 Share on other sites More sharing options...
b61fred Posted September 5, 2007 Share Posted September 5, 2007 Hi, I have seen the tr 67 series trans behind the 673 engines before, the trans that I would use would be a tr 72 series, I think what hapened when the former owner installed the diesel engine and removed the gas, the gas engine would rev much higher than the diesel, inturn droping the max rpm of the whole drive line. The solution is to install higher gear ratios in the rear to get some road speed. I have some differentals that may help you out, I would sell them reasonable price. I live in Indiana, but with our new part transit system we could get them to you... Fred Quote 15 gears...no waiting! Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13777 Share on other sites More sharing options...
Red Horse Posted September 5, 2007 Author Share Posted September 5, 2007 Hi, I have seen the tr 67 series trans behind the 673 engines before, the trans that I would use would be a tr 72 series, I think what hapened when the former owner installed the diesel engine and removed the gas, the gas engine would rev much higher than the diesel, inturn droping the max rpm of the whole drive line. The solution is to install higher gear ratios in the rear to get some road speed. I have some differentals that may help you out, I would sell them reasonable price. I live in Indiana, but with our new part transit system we could get them to you... FredGuys, thank you all for the feedback- No doubt the gas engine (3000 RPM) made a big difference vs a 2100 rpm diesel. It does have big rubber (11:00-24) but 9.05 is a killer.B61Fred, emailme at fd68brnco@aol.com with what yo have for gears. Rear is an RAD 111.Bob Quote Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13779 Share on other sites More sharing options...
other dog Posted September 5, 2007 Share Posted September 5, 2007 See what I mean? Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13785 Share on other sites More sharing options...
RC51 Posted September 12, 2007 Share Posted September 12, 2007 9:05,that just barely beat the B-62SX I had that ran 9:02's in SWD-54's.On 11:24 tires,with a 3 spd brownie,the poor C-180 Cummins was wound tight to 2,600,barely made 45 mph. Quote Link to comment https://www.bigmacktrucks.com/topic/2823-quadbox-conversion/#findComment-13914 Share on other sites More sharing options...
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