shawn Posted April 15, 2006 Share Posted April 15, 2006 Hey truckers! Just registered on this site! Glad to be here among all you Mack lovers. Getting ready to purchase my first Mack this week. It's a 2000 RD690S tandem axle dump, with a 16 ft steel body. It has the E7 300 mated to a Maxitourque 7 speed. I am impressed with this ride but the 7 speed has caused some concern for me. She seems to be a bit stubborn even when double clutching. Is she an extended range tranny in so that it should be around 1200 rpm for downshifting and against the peg for upshifting. I am used to an Eaton 8LL. In my trial run with the seven speed I ground the gears alot when I first took off but as my run went on I was getting a little smoother. If you have any tips at all I would truly appreciate your feedback. Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/ Share on other sites More sharing options...
theakerstwo Posted April 15, 2006 Share Posted April 15, 2006 Hey truckers! Just registered on this site! Glad to be here among all you Mack lovers. Getting ready to purchase my first Mack this week. It's a 2000 RD690S tandem axle dump, with a 16 ft steel body. It has the E7 300 mated to a Maxitourque 7 speed. I am impressed with this ride but the 7 speed has caused some concern for me. She seems to be a bit stubborn even when double clutching. Is she an extended range tranny in so that it should be around 1200 rpm for downshifting and against the peg for upshifting. I am used to an Eaton 8LL. In my trial run with the seven speed I ground the gears alot when I first took off but as my run went on I was getting a little smoother. If you have any tips at all I would truly appreciate your feedback.Yes just dont get in a hurry and let the rpm come down and dont put your foot on the clutch. you will get good as time goes by. Glenn Akers Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5361 Share on other sites More sharing options...
fullfuel01 Posted April 15, 2006 Share Posted April 15, 2006 this make me laught. We own a 1987 R model tractor 300Hp with a 7 speeds. This Mack is simply undestructible. not the way you should shift a truck but sometimes when me and my brother get crazy and think that we are at the races this tranny can be the best one. from second to third it's a powershift. keep the pedal to the metal, the other boots right under the clutch pedal and swing that stick... yess it works! pretty sure the wheel come off the ground sometimes. all the big bird and Cummins are impress how this little Mack pull. Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5367 Share on other sites More sharing options...
Lmackattack Posted April 15, 2006 Share Posted April 15, 2006 the 7 speed is a fast transmission (.60 overdrive? will have to check my books.)you likely will have slow rears so it wont be 2 fast. I think it was David that said that the fast drive train speed helps reduce stress and shock in the mud? The 7 speeds I have driven were all pretty good and the 2 low gears did help startup on a hill, at least a little better than the 2 stick 6 speeds Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5368 Share on other sites More sharing options...
mudslut28 Posted April 17, 2006 Share Posted April 17, 2006 Yes..it is an .60 overdrive. My 88 with 65,000 lb rears and a 7.58 ratio will top out at 62 mph. 1200 is about right on the money for down shifting.....however tight you can get it to turn is good for upshifting I have ran one hauling coal (35-45 tons) in the southern West Virginia Mts sinc eit was new in 88 with 1 bearing kit. The things are unbreakable. Mackattack was right in the fact that the 2 low gears are a dream for pulling out in bad places and hills. It is definitely an extended range tranny. You cant get in a hurry with them but they usually get a lot better over time on ease of shifting. High gear seems to be loud in everyone of them also.My only kick was the darned splitter...you had to make dang sure you were in neutral before you flipped ranges are it grinded like it was gonna explode but after 17.5 years it still hasnt Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5400 Share on other sites More sharing options...
jeff20878 Posted April 17, 2006 Share Posted April 17, 2006 Good choice on the Mack! Mack's are made for dirt work...I've been driving Mack dump trucks for 21 years and there's nothing better for on-off road work!The shift troubles you are experiencing is common for people who move from Fuller transmissions to Mack transmissions. With a Fuller transmission, the timing between gears is the same for each gear, but with a Mack transmission, the timing between gears gets a little longer as you shift up through each gear. For example, 2nd to 3rd is a longer wait than 1st to 2nd, etc. The old joke with the shift from 4th to 5th took so much time that you could take it out of 4th, go get a cup of coffee, and come back and shift into 5th! If you are in a real bind, you can shift with the Jake on, which will bring the RPM's down quicker and you can upshift quicker. I don't recommend this as a daily practice, as it's too much "shock" on the driveline.Practice the timing and you'll have no trouble! Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5409 Share on other sites More sharing options...
kevin mccune Posted April 30, 2006 Share Posted April 30, 2006 Hey truckers! Just registered on this site! Glad to be here among all you Mack lovers. Getting ready to purchase my first Mack this week. It's a 2000 RD690S tandem axle dump, with a 16 ft steel body. It has the E7 300 mated to a Maxitourque 7 speed. I am impressed with this ride but the 7 speed has caused some concern for me. She seems to be a bit stubborn even when double clutching. Is she an extended range tranny in so that it should be around 1200 rpm for downshifting and against the peg for upshifting. I am used to an Eaton 8LL. In my trial run with the seven speed I ground the gears alot when I first took off but as my run went on I was getting a little smoother. If you have any tips at all I would truly appreciate your feedback. Keep at it, you will figure it out-these things are tough-just remember these things are designed to pull & last-just use low range in bad situations -dont buck jump her-these are not the fastest trucks in the world but you sure can make money with em.If you mess up dont cram start over-Kevin Quote Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5582 Share on other sites More sharing options...
rsmartyn Posted April 30, 2006 Share Posted April 30, 2006 Some key words there from Kevin and why most of us love Macks - "You can sure make money with 'em" Bob Quote Ain't a Mack? Take it back! Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5583 Share on other sites More sharing options...
HK Trucking Posted May 13, 2006 Share Posted May 13, 2006 this make me laught. We own a 1987 R model tractor 300Hp with a 7 speeds. This Mack is simply undestructible. not the way you should shift a truck but sometimes when me and my brother get crazy and think that we are at the races this tranny can be the best one. from second to third it's a powershift. keep the pedal to the metal, the other boots right under the clutch pedal and swing that stick... yess it works! pretty sure the wheel come off the ground sometimes. all the big bird and Cummins are impress how this little Mack pull. Ouch!!!!!!!!!!!!! Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/1043-mack-7-speed/#findComment-5754 Share on other sites More sharing options...
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