607t1173 Posted February 2, 2013 Share Posted February 2, 2013 The problems that the unishift caused.I only had two or three trucks with this transmission and all that anyone had to say about it was negative.The first was in a '62 H-67 and it lived up to it's reputation,leaving me on a 700 mile trip stuck on the low side not being able to split the gears and only being able to get 45 mph ln 9th gear on down grades. That little 673 must have thought that I had mistaken it for a 675 as much as I lugged it.But it gave me a greater appreciation of what the older drivers driving gas burners on the two lane highways had to endure.And also that if you are hauling a time sensitive load in sub zero temperatures that you needed to keep the alcohol evaparator full. After learning that lesson and a little tweaking on my part I never had anymore problems with the Unishift and actually came to like it. Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/ Share on other sites More sharing options...
Bigdogtrucker Posted February 2, 2013 Share Posted February 2, 2013 I drove one in a friends B61 wrecker a few years ago,it worked great.It was summer time though... Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161272 Share on other sites More sharing options...
Milaca Posted February 3, 2013 Share Posted February 3, 2013 My 1964 Mack C-609 originally came equipped with the Unishift but it was replaced with a Triplex somewhere along the way. It still has the Unishift shift pattern plate on the sun visor. Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161513 Share on other sites More sharing options...
thermodynediesel Posted February 3, 2013 Share Posted February 3, 2013 The truck I am restoring right now has the unishift in it, Always worked good when out driving it, Hopefullyit stays that way. Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161681 Share on other sites More sharing options...
Maddog13407 Posted February 4, 2013 Share Posted February 4, 2013 never heard of any problem with them. Doug Fetterly has run one behind a 237 in his integral cab B61 for years. long as you keep your air tank clean and drained, i think youd be ok. kinda like a Roadranger Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161726 Share on other sites More sharing options...
dockmen027 Posted February 4, 2013 Share Posted February 4, 2013 never heard of any problem with them. Doug Fetterly has run one behind a 237 in his integral cab B61 for years. long as you keep your air tank clean and drained, i think youd be ok. kinda like a RoadrangerHis is blocked off in high range, he runs it like a five speed, been that way for a while. Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161736 Share on other sites More sharing options...
607t1173 Posted February 4, 2013 Author Share Posted February 4, 2013 One of the other problems with the Unishift was having to depress the clutch pedal so far before it would shift. I bought an F Model that had a C motor backed by a Unishift and it didn't want to change out of hi into low,until I took the clutch linkage arm off and built up the surface that came in contact with the air actuator and then adjusted it till all you had to do was just tap the clutch pedal and after that it became a pleasure to drive. Quote Link to comment https://www.bigmacktrucks.com/topic/29752-unishift-transmission/#findComment-161858 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.