mackmodelb Posted August 23, 2006 Share Posted August 23, 2006 Can someone help me with the transmission ratios for this trans. The only numbers I can see are as seen in the picture. I am told it came out of a mid 80's R model. I am looking to see if I can use it in my B-61 to replace the TR-72. I am hoping it has a .86 final ratio. My TR-72 is 1 to 1 in the final and coupled to the 4.6 rear, my top speed is only 52mph. I am not sure it will even bolt up to my 673. Any help would be greatly appreciated as I can not sipher any of the numbers on the casting to the service manuals that I have. Thanks. Quote Link to comment Share on other sites More sharing options...
Freightrain Posted August 23, 2006 Share Posted August 23, 2006 Do I see "maxitorque" on the side towards the rear?Can't tell, is it a two stick? Maybe a 6 spd? Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
rick harper Posted August 23, 2006 Share Posted August 23, 2006 it looks to be a six speed which has a 1 to 1 last hole. if you can post the 11kb number that is on the case then we can identify it. Quote Link to comment Share on other sites More sharing options...
mudslut28 Posted August 23, 2006 Share Posted August 23, 2006 It definitely looks to be a 6 speed. Im with Rick though need a little closer look. Quote Link to comment Share on other sites More sharing options...
mackmodelb Posted August 23, 2006 Author Share Posted August 23, 2006 Hi all. It is a 2 stick. I have attached more pics. There are some numbers stamped on each side that are not the same. It has some alum grinded off of the case where the numbers I believe should be. Looks like a coat of gold paint on under the oil and grease. Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted August 23, 2006 Share Posted August 23, 2006 "gold paint" is just another reason that it is likely a 6 spd Quote Link to comment Share on other sites More sharing options...
blegh Posted August 23, 2006 Share Posted August 23, 2006 it looks to be a six speed which has a 1 to 1 last hole. if you can post the 11kb number that is on the case then we can identify it. The KB #'s are on the right rear of the pic of the stick mounts.408 KBA ?32408 KB 57RCDoes that help identify it.cheersbarry Quote Link to comment Share on other sites More sharing options...
mackmodelb Posted August 24, 2006 Author Share Posted August 24, 2006 Here are the numbers that I can not find in my service manual. Thanks.408KBA332408KB57RC Quote Link to comment Share on other sites More sharing options...
b61mack Posted August 24, 2006 Share Posted August 24, 2006 Here are the numbers that I can not find in my service manual. Thanks.408KBA332408KB57RCIf you can find a airshift 6 speed out of around 1988 mack i think they are an overdrive transmission. Quote Link to comment Share on other sites More sharing options...
HK Trucking Posted August 24, 2006 Share Posted August 24, 2006 Can someone help me with the transmission ratios for this trans. The only numbers I can see are as seen in the picture. I am told it came out of a mid 80's R model. I am looking to see if I can use it in my B-61 to replace the TR-72. I am hoping it has a .86 final ratio. My TR-72 is 1 to 1 in the final and coupled to the 4.6 rear, my top speed is only 52mph. I am not sure it will even bolt up to my 673. Any help would be greatly appreciated as I can not sipher any of the numbers on the casting to the service manuals that I have. Thanks.That trans in the photo is a TRXL 107 or TRXL 1071, both of which have 1.00 to 1.00 (direct drive) ratio in high gear.The difference between the 107 & 1071 is that the 1071 has a much deeper reduction when the compound is in LO LO, other than that they are the same.These were known as 6 speeds, because Mack recommended that lo lo on the compound only be used in first gear, then when the compound was in direct the trans was operated like a 5 speed, for a total of 6 actual usable ratios.(I've cheated quite a few times & used 2nd gear lo lo if necessary)Reverse gear was also on the compound stick, and you could use any of the 5 main gears while in reverse.Clean off the area next to the oil filler plug, the model # should be stamped in the case there.. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment Share on other sites More sharing options...
bulldog man Posted August 24, 2006 Share Posted August 24, 2006 That trans in the photo is a TRXL 107 or TRXL 1071, both of which have 1.00 to 1.00 (direct drive) ratio in high gear.The difference between the 107 & 1071 is that the 1071 has a much deeper reduction when the compound is in LO LO, other than that they are the same.These were known as 6 speeds, because Mack recommended that lo lo on the compound only be used in first gear, then when the compound was in direct the trans was operated like a 5 speed, for a total of 6 actual usable ratios.(I've cheated quite a few times & used 2nd gear lo lo if necessary)Reverse gear was also on the compound stick, and you could use any of the 5 main gears while in reverse.Clean off the area next to the oil filler plug, the model # should be stamped in the case there..Yup always like a 2 stick because of 5 reverse gears in it (ive made a lot money off bets people thinking i couldnt get across a muddy jobsite loaded & back out empty w/o getting stuck ) those ole 2 sticks made us money in more ways than 1 & they are hard to bet esp when in a hard pull have a goodone Bulldog (aka ) Quote You Cant Fix Stupid. But You Can Numb It With A Sledgehammer. Link to comment Share on other sites More sharing options...
mackmodelb Posted August 24, 2006 Author Share Posted August 24, 2006 Thanks guys for all the info. I will clean it and check to see if I can get the right numbers. Sounds like it will not give me the lower ratio than 1 to 1 that I am looking for. I will have to start looking into rear carriers with a 4.0 ratio instead. Just thought I'd try the transmission as it was given to me for free. It was in a pile with 2 other single stick 6 speeds collecting dust in my neighbors barn.Thanks again. Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted August 24, 2006 Share Posted August 24, 2006 just for refrence if you ar looking for a 4.xx ratio. Many R models with the 6 speeds (1.1 direct trans) came with high 3.xx to 4.xx rear ratiosa 4.17 rear with direct drive trans will do about 63MPH ish at 2100RPM with 24.5 rubbera 3.87 rear would give do about 68MPH at 2100RPM with 24.5 just some options there for ya. Quote Link to comment Share on other sites More sharing options...
mudslut28 Posted August 24, 2006 Share Posted August 24, 2006 Thanks guys for all the info. I will clean it and check to see if I can get the right numbers. Sounds like it will not give me the lower ratio than 1 to 1 that I am looking for. I will have to start looking into rear carriers with a 4.0 ratio instead. Just thought I'd try the transmission as it was given to me for free. It was in a pile with 2 other single stick 6 speeds collecting dust in my neighbors barn.Thanks again.LOL I have 2 worn out destroyed 6 speeds out there and like to never found a replacement a couple of years ago when the bearings got so bad they started causing gear failure. I ended up putting one with a fine spline tail shaft in which created a lot of issues in itself. Those things are hard to find around here.If you want a strong tranny with a TALL overdrive ratio try a T2070 7 speed. High gear is .60. My 88 had a 7 speed with 7.58 ratio 65k rears and would top out at 62mph.Can anyone tell me what the deal was with the fine spline tailshafts on some of the 6 speeds? Is it something changed for the later models? It sure is almost impossible to find a fine spline flat yoke for the back of one of them. Had to use a normal yoke and go to a 1810 series ujoint as opposed to the 324 mechanical joint they originally had. Quote Link to comment Share on other sites More sharing options...
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