nasty51ford Posted August 21, 2014 Share Posted August 21, 2014 Hi, I read somewhere in one of these posts that I could find the trans numbers on the driver sider of my trans in my 1958 B67, however, the only numbers I have found are on the passenger side, and they don't appear to be the numbers I need. The guy I got it from, told me that top gear had been turned around, (like you can do to a Fuller trans) so that 5th gear is now forward, (up against the dash) is that even possible with a Mack trans? It has a duplex in it. These are the only numbers I can find on the trans, the front box has a Patent number 267440, and a part number under that that reads 284KB5623, the rear box has a casting number 281KBK544, and a part number 281KB. I have looked all over the passenger sides of both front and rear boxes, but can't kind anything, except for the Mack logo on the front box. Quote Link to comment Share on other sites More sharing options...
Maddog13407 Posted August 21, 2014 Share Posted August 21, 2014 the trans numbers are on the left side of the front case and are stamped into the case, not raised like the patent numbers. news to me but don't think you can turn 5th gear around in a Mack. im betting its a 9 speed overgear. that was the most common after a while in a road tractor. if the case has been cracked and replaced, there could also be no numbers stamped. youll need a wire brush to find the numbers. they are right ahead of where the two cases bolt together. Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted August 21, 2014 Author Share Posted August 21, 2014 Thanks, I'll look again, they are very clean, so I shouldn't have missed them, if they are there, but the shift pattern plaque in the truck clearly shows fifth gear being back, towards the rear of the truck, and not forward, so, someone may have swapped trannies out somewhere along the way. Thanks Keith Quote Link to comment Share on other sites More sharing options...
Freightrain Posted August 21, 2014 Share Posted August 21, 2014 Should have MACK cast in the left side, plus "Hypoid gearing" or something of the such. Like mentioned, it should have a milled flat spot in the front case with "TRD72" or the like stamped into it with like 3/8" tall letters. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
nasty51ford Posted August 21, 2014 Author Share Posted August 21, 2014 Thanks, I'll go look again, must have missed it Quote Link to comment Share on other sites More sharing options...
Maddog13407 Posted August 21, 2014 Share Posted August 21, 2014 tetropoid gears should be raised, under that it should be TRDL720 or TRD720 if its a 9 speed overgear. TRDL72 TRD72 or TRD722 if its a 10 speed direct. 1 Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted September 2, 2014 Author Share Posted September 2, 2014 Thanks, I'll have to look again, didn't see an thing last time I looked, except for the numbers on the bottom. Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted October 6, 2014 Author Share Posted October 6, 2014 OK !! Finally got my truck registered and tagged today!! WOOOOHOOOOOO !!!!!!! It is one solid driving, and good running Mack! The previous owner said that ity would only run 55, I guess he doesn't know how to use a duplex trans, I had it somewhere near 60 MPH in 8th! And still had a little engine left, I only got it into 9th once, for about 10 seconds, but an overdrive trans will do about 3 - 5 MPH per hundred RPM, and this trans drops 500 RPM or better when I drop it into overdrive, and I'm wondering if it is a double over, because it drops 500 RPM when going from 7th to 8th gear! Odd thing is, this Mack does NOT SMOKE AT ALL! NOTHING !! I can't recall ever seeing an old Mack NOT roll coal, and that damn skip is still there, but it's weird, if I ease into the throttle sometimes it seems to go away, and sometimes at higher RPM it goes away, but if I put my foot in it under a good pull, it misses worse. Leaky injector? I drove it home (18 miles) and it never got over 170 degrees, and the oil pressure is 60 lbs when it's wound up,and fully warmed up. Now I just have to figure out this miss! Quote Link to comment Share on other sites More sharing options...
Joe Ditchkus Posted October 7, 2014 Share Posted October 7, 2014 Could also be a TRD 670 a lighter Duplex. I have the 670 in my B-67 it is a 9 speed go from 5th direct to 4th direct downshifting. Joe D. 1 Quote Link to comment Share on other sites More sharing options...
Bigdogtrucker Posted October 7, 2014 Share Posted October 7, 2014 Does it have a shift diagram tag? Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted October 7, 2014 Author Share Posted October 7, 2014 Hi, yeah, there is no split in the top gear, the shift pattern is what use to be in the truck, it is a ten speed direct pattern, also my back box has high range toward the dash also Quote Link to comment Share on other sites More sharing options...
Joe Ditchkus Posted October 7, 2014 Share Posted October 7, 2014 If back box has high range toward dash it could be a mono-shift duplex converted to 2 stick duplex. I found this out a few weeks ago from a well versed Mack Man. Do not know about main box turned around. Joe D. 1 Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted October 7, 2014 Author Share Posted October 7, 2014 The guy I got from was told that the main had 5the gear turned around, like in a Fuller. Quote Link to comment Share on other sites More sharing options...
Maddog13407 Posted October 7, 2014 Share Posted October 7, 2014 still don't think you can turn 5th around in a Mack transmission and I have never seen high range twards the dash in any b model or 10 or 9 speed duplex. im pondering the monoshift idea myself . 2 Quote Link to comment Share on other sites More sharing options...
HarryS Posted October 7, 2014 Share Posted October 7, 2014 My '60 B 61 has a TRD 720 with the fifth gear turned around but the hi range is to the seat. Here is a paragraph from the shop manual: "In overgeared-type transmissions, an aditional rocker and pivot pin, to operate fourth and fifth-speed sliding clutch converts the shift pattern of these transmissions to that of the direct-drive boxes. Thus, either type of transmission has the same standard shift." I was talking to Matt Phafl last year about this and he said in some cases the direct shift tower/cover had been used on the over-gear transmissions and you wind up with the 4th/5th flip. Quote Link to comment Share on other sites More sharing options...
nasty51ford Posted October 7, 2014 Author Share Posted October 7, 2014 Well, there is one other thing, all the mack twin sticks I have ever seen, are pretty much both vertical, and pretty parallel . in this truck, the main box shifter is angled towards the back of the cab, like a straight single stick 5 speed. . Quote Link to comment Share on other sites More sharing options...
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