dragonwagon Posted March 25, 2012 Share Posted March 25, 2012 My R model is lacking in gears , 5 speed trans . I know Mack made multi speed rear ends . The rear end has side plates that remove , did the multi speed units just bolt on or like GM and Ford was it a different housing for a multi speed rear ?Worse case i may need to find a 2 speed out of a LN800 Ford or something of that sort . Not much aroun here for Mack parts to find . If the multi speed was a bolt on then maybe i can find one and have it shipped . Quote Link to comment Share on other sites More sharing options...
Rob Posted March 25, 2012 Share Posted March 25, 2012 My R model is lacking in gears , 5 speed trans . I know Mack made multi speed rear ends . The rear end has side plates that remove , did the multi speed units just bolt on or like GM and Ford was it a different housing for a multi speed rear ?Worse case i may need to find a 2 speed out of a LN800 Ford or something of that sort . Not much aroun here for Mack parts to find . If the multi speed was a bolt on then maybe i can find one and have it shipped .You would be better off changing the transmission and recalibrating the injection pump to "Thermodyne" settings.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
slpwlker Posted March 25, 2012 Share Posted March 25, 2012 Listen to Rob. They are a pita if not used all the time. Very,Very finiky if tires are not matched like changing one axle before the other. they will let you know. Like to take the ones in mine out Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted March 25, 2012 Share Posted March 25, 2012 I would like to hear more about the multispeed mack rear ends. glenn Quote glenn akers Link to comment Share on other sites More sharing options...
dragonwagon Posted March 25, 2012 Author Share Posted March 25, 2012 drove a number of 2 speed elec shift rears , other then a motor burning out now and then they werent an issue . Never used the Mack multi speed though . Thanks for the input .Next question then , does the Mack use standard 10 spline clutch , in other words can i drop a 9 speed out of some other truck in there ? Would have to alter the drive shaft but thats not a big deal . This is a working truck and needs help . Not interested in repowering the truck . 9 speed would be smaller and lighter then the current trans . Quote Link to comment Share on other sites More sharing options...
slpwlker Posted March 25, 2012 Share Posted March 25, 2012 Really have no experience with the electrical 2 speeds. Mine is on Air and is an Eaton Quote Link to comment Share on other sites More sharing options...
WHITE9064TD Posted March 25, 2012 Share Posted March 25, 2012 If you are talking about the 3 speed set up, I would suggest another route. I have the 3 speed Eaton setup and bobtailing it is a pain. Sidetracking a little, did Mack make a 3 speed setup or did they use Eaton 3 speed tandem? Quote Link to comment Share on other sites More sharing options...
Rob Posted March 25, 2012 Share Posted March 25, 2012 drove a number of 2 speed elec shift rears , other then a motor burning out now and then they werent an issue . Never used the Mack multi speed though . Thanks for the input .Next question then , does the Mack use standard 10 spline clutch , in other words can i drop a 9 speed out of some other truck in there ? Would have to alter the drive shaft but thats not a big deal . This is a working truck and needs help . Not interested in repowering the truck . 9 speed would be smaller and lighter then the current trans .Most trucks use a 2" 10 spline input shaft. I've replaced several Mack five speeds with both Mack, and Fuller transmissions without replacing the clutch but strongly prefer to change it also when apart. It is a maintenance type thing and expensive to take a truck out of service a second time. This is especially true when the "well shit", why didn't I just do it right the first time factor is accounted for. The original clutch is prolly working very hard right now to start off heavy loads so will have considerable wear from the start of your changover.I've never seen Mack built multi speed rears. Most I've been around are Eatons. I too prefer the air shifted as opposed to electric. If a guy opens up the air flow orifice they will shift very fast in either direction. The electric shifted axles I've been around are fine but become "finiky" after they age if they are used regularly.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
dragonwagon Posted March 27, 2012 Author Share Posted March 27, 2012 Thanks Rob , yes i would change the clutch while i had it down . Just had no idea if id find something standard or some odd " mack only " clutch set up . A 9 speed is smaller/lighter then the Mack trans . Man that thing is HUGE . I didnt know who made the multi speed rear under a Mack , i just new they had them .I think a 9 speed would really help that little 237 Mack motor pull the large loads . Quote Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2012 Share Posted March 27, 2012 Thanks Rob , yes i would change the clutch while i had it down . Just had no idea if id find something standard or some odd " mack only " clutch set up . A 9 speed is smaller/lighter then the Mack trans . Man that thing is HUGE . I didnt know who made the multi speed rear under a Mack , i just new they had them .I think a 9 speed would really help that little 237 Mack motor pull the large loads .I would go with a Mack nine speed myself.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
bullhusk Posted March 27, 2012 Share Posted March 27, 2012 I would go with a Mack nine speed myself.RobRob's right, the Mack T2090- 9 speed would be a good trans, just make sure if it's pre 1990 you might want to check an see that it has the up-grade on the top shifting cover (heaver forks) My 89 Superliner had a 2090 and I broke one of the main shafts twice, when the shifting fork would break and put the trans. between 2 gears and BANG!! That truck had 4.64 rears-24.5 tires and would run about 80 mph. I did in fact get a ticket for 77 mph an that was when the speed was 55!!BULLHUSK Quote Link to comment Share on other sites More sharing options...
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