Geoff Weeks Posted April 5 Share Posted April 5 With any two speed you are not going to have lightning fast shifts. Air and Vacuum, use air pressure as a cushion, Electric needs a torsion spring. (note early diaphragm air shift also used torsion spring) that is known to break without warning. I have two single axle on vacuum shift and one tandem on air (piston type), I find both reliable and easy to "learn" My air shift is electric over air, air solenoid controls air pressure to both front and rear axle shift motors (pistons). The two vacuum shift are cable to valve with no other power needed. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549453 Share on other sites More sharing options...
Geoff Weeks Posted April 5 Share Posted April 5 (edited) 3 minutes ago, BOBWhite said: Oh Yeah, The Truck! I don't remember asking if it has airbrakes but seeing the horn made me wonder. All the Loadstars I've been around have juice brakes and since IH is gone you can't easily find rebuild kits. That is not a Loadstar, it is a V model. BTW I maintained a Loadstar school bus on air brakes, you could get a Loadstar with air brakes, just as you could a K-7 (around the same GVW range) and all "midrange" IHC's. Juice brakes were more common, but air was an option. Edited April 5 by Geoff Weeks 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549455 Share on other sites More sharing options...
mechohaulic Posted April 5 Share Posted April 5 it's unique in its own way. so different looking makes it sharp looking rig. bet if you have stopping situation ; just pull the lanyard for that trumpet on roof . will make as much noise as a jake and possibly the same hold back, LOL Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549456 Share on other sites More sharing options...
Joey Mack Posted April 5 Share Posted April 5 I found wheel cylinders last year for my '48 INT. Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549457 Share on other sites More sharing options...
Joey Mack Posted April 5 Share Posted April 5 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549458 Share on other sites More sharing options...
other dog Posted April 5 Author Share Posted April 5 2 hours ago, Geoff Weeks said: Right kind of wheels, non syncro, 2 spd rear.... Life is good! Air, electric or vacuum on the 2 spd shift motor? Air is my 1st choice, vacuum 2nd and electric last. It has the air shift, that's a first for me too. I've driven the vacuum and electric shift 2 speeds before and the vacuum shift seemed to work better. But I never really drove any truck with a 2 speed rear enough to master it. Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549467 Share on other sites More sharing options...
Geoff Weeks Posted April 5 Share Posted April 5 My Marmon has two speeds front and rear on the tandems. Air shift (piston type) and never had a problem, always shifted when I needed them to. I started out in low every time, they got used alot. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549468 Share on other sites More sharing options...
Brocky Posted April 5 Share Posted April 5 (edited) I have driven all three types of 2 speed shift.. The air was on some old Brockways and worked excellent.. The only vacuum shift was on an old GMC, with the flipper valve under the dash, it seemed you had to let completely off the gas to create vacuum enough for it to sorta force the shift.. Never had any problems with the electric ones?? Edited April 5 by Brocky 1 Quote Brocky Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549470 Share on other sites More sharing options...
Geoff Weeks Posted April 5 Share Posted April 5 35 minutes ago, Brocky said: I have driven all three types of 2 speed shift.. The air was on some old Brockways and worked excellent.. The only vacuum shift was on an old GMC, with the flipper valve under the dash, it seemed you had to let completely off the gas to create vacuum enough for it to sorta force the shift.. Never had any problems with the electric ones?? Brocky, I can see where flipping something on the dash might throw off timing. On my K's I pre-select,so on upshift there is already vacuum at the diaphragm, and once torque load is off the gears the shift takes place. downshift is a little more tricky, as you have to "break torque and quickly raise the engine speed to complete the shift.. Both ways are pre-selected. In the Marmon, with the gov diesel, it is a little easier to control the engine rpm, than it is with carb'd gas. Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549478 Share on other sites More sharing options...
66dc75 Posted April 6 Share Posted April 6 Always drove electric 2 speeds. Found out that downshifting the rear just right going up a steep hill at low speed you can snap an axle right off at the spline. One of those you learn something new everyday things. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549479 Share on other sites More sharing options...
Popular Post 66dc75 Posted April 6 Popular Post Share Posted April 6 You also learn that the driveshaft mounted parking brake and / or putting it in gear now does nothing to hold the truck from rolling away. It's fairly difficult to get a chock block under the wheel while keeping your foot on the brake pedal. 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549481 Share on other sites More sharing options...
Geoff Weeks Posted April 6 Share Posted April 6 (edited) 46 minutes ago, 66dc75 said: You also learn that the driveshaft mounted parking brake and / or putting it in gear now does nothing to hold the truck from rolling away. It's fairly difficult to get a chock block under the wheel while keeping your foot on the brake pedal. No, you learn to park in low range! Never snapped an axle shaft in 1000's of mile pulling with them. You sound like a guy at work who managed to snap the shift handle off the top of shifter rod, can break an anvil with a rubber hammer. By the mid 60's if not before, tractors and most air braked trucks had spring brakes and axle isn't even a factor, Edited April 6 by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549483 Share on other sites More sharing options...
other dog Posted April 6 Author Share Posted April 6 16 hours ago, Geoff Weeks said: Brocky, I can see where flipping something on the dash might throw off timing. On my K's I pre-select,so on upshift there is already vacuum at the diaphragm, and once torque load is off the gears the shift takes place. downshift is a little more tricky, as you have to "break torque and quickly raise the engine speed to complete the shift.. Both ways are pre-selected. In the Marmon, with the gov diesel, it is a little easier to control the engine rpm, than it is with carb'd gas. So that's another thing I was wondering about. When you shift the transmission to a higher gear they recommend that you shift the transmission first, then shift the axle to low just before you let the clutch out. I have also seen people move the button first every time and it worked just fine, real smooth. So it doesn't hurt anything to pre-select every time? Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549509 Share on other sites More sharing options...
Popular Post Geoff Weeks Posted April 6 Popular Post Share Posted April 6 (edited) In the above quote, I was talking about shifting the rear only. Like any compound shift, you need to take into consideration what is happening ratio wise. If you pre select a compound shift (moving trans and rear) like any other you can get caught with neither in gear. I will upshift the trans, and down shift the rear as I complete the shift. So double clutch upshift, when letting the clutch out when in higher gear, make the change on the rear. This means a larger drop in engine RPM to make the shift in the main but gets speeded up before load is on it. How wide the step also plays a part, My K's have a big step between 3rd and 4th, you need to downshift the rear making that jump, if you pre-select low range when you 1st break torque, there is nothing to speed the driveshaft up to match the rear low ratio to what the driveshaft is spinning. If the engine is against the gov, you can't speed up the driveshaft, so neither will go into gear. Kinda like shifting a 13 speed, make the main upshift 1st and the rear ( or in case of the 13, splitter gear)2nd. Sound more difficult than it is, but with a gas engine the ratio jumps tend to be bigger than with a close ratio box with a diesel. Most gassers have a 5 main and 2 spd rear, many diesels may have a 5 speed main and 3 spd aux. for the same ratio spread. A little time in and becomes 2nd nature. Edited April 6 by Geoff Weeks 3 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549510 Share on other sites More sharing options...
Mark T Posted April 6 Share Posted April 6 17 hours ago, 66dc75 said: You also learn that the driveshaft mounted parking brake and / or putting it in gear now does nothing to hold the truck from rolling away. It's fairly difficult to get a chock block under the wheel while keeping your foot on the brake pedal. I could see where that'd be a challenge. Thank God for those Murtys. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549514 Share on other sites More sharing options...
Popular Post mrsmackpaul Posted April 6 Popular Post Share Posted April 6 17 hours ago, Geoff Weeks said: No, you learn to park in low range! Never snapped an axle shaft in 1000's of mile pulling with them. You sound like a guy at work who managed to snap the shift handle off the top of shifter rod, can break an anvil with a rubber hammer. By the mid 60's if not before, tractors and most air braked trucks had spring brakes and axle isn't even a factor, I think the point got missed here, if you have a broken axle and transmission hand brake Your hand brake is useless whether your in high or low range Plenty of medium trucks from the 60s thru to the 80s and beyond had a 2 speed back axle and a transmission hand brake Think you blokes call them a park brake Paul 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549515 Share on other sites More sharing options...
Geoff Weeks Posted April 6 Share Posted April 6 Yes, Paul you are correct. I didn't take the two posts as one connected incident. However my comment about spring brakes stands. most all tractors will have spring brakes on the wheel ends. It was why they were retro-fitted to older equipment still operating. Thank you for pointing it out. That said, I have never twisted off an axle shaft, and moved loads in 170,000 lb range, not much for some of your Roadtrains, but for the US considered heavy, BTW that was done through a 14" organic double disk clutch. Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549517 Share on other sites More sharing options...
other dog Posted April 7 Author Share Posted April 7 8 hours ago, Geoff Weeks said: In the above quote, I was talking about shifting the rear only. Like any compound shift, you need to take into consideration what is happening ratio wise. If you pre select a compound shift (moving trans and rear) like any other you can get caught with neither in gear. I will upshift the trans, and down shift the rear as I complete the shift. So double clutch upshift, when letting the clutch out when in higher gear, make the change on the rear. This means a larger drop in engine RPM to make the shift in the main but gets speeded up before load is on it. How wide the step also plays a part, My K's have a big step between 3rd and 4th, you need to downshift the rear making that jump, if you pre-select low range when you 1st break torque, there is nothing to speed the driveshaft up to match the rear low ratio to what the driveshaft is spinning. If the engine is against the gov, you can't speed up the driveshaft, so neither will go into gear. Kinda like shifting a 13 speed, make the main upshift 1st and the rear ( or in case of the 13, splitter gear)2nd. Sound more difficult than it is, but with a gas engine the ratio jumps tend to be bigger than with a close ratio box with a diesel. Most gassers have a 5 main and 2 spd rear, many diesels may have a 5 speed main and 3 spd aux. for the same ratio spread. A little time in and becomes 2nd nature. Oh. Thanks for the info, I just need more seat time to get used to the truck now. Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549531 Share on other sites More sharing options...
66dc75 Posted April 7 Share Posted April 7 6 hours ago, mrsmackpaul said: I think the point got missed here, if you have a broken axle and transmission hand brake Your hand brake is useless whether your in high or low range Plenty of medium trucks from the 60s thru to the 80s and beyond had a 2 speed back axle and a transmission hand brake Think you blokes call them a park brake Paul Thanks Paul, that is what the sutuation was juice brakes driveshaft parking brake, snapped off axle . Oh and I did always park in low range and in 38 years of driving that was the only time I ever broke something like that. Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549532 Share on other sites More sharing options...
Geoff Weeks Posted April 7 Share Posted April 7 14 hours ago, 66dc75 said: Thanks Paul, that is what the sutuation was juice brakes driveshaft parking brake, snapped off axle . Oh and I did always park in low range and in 38 years of driving that was the only time I ever broke something like that. Then I'd say it isn't a common occurrence. I've had SP-4 spring brake valves on a trailer fail, and will not apply the spring brakes until all the air leaks out of the tank, I wouldn't use that to condemn spring brakes. It was a one off failure that can and did cause problems holding a loaded truck (tractor spring brakes were not alone strong enough on the grade it was parked on). Any truck with a driveshaft parking/E brake is subject to that failure, not just 2 spds. It was the reason that trucks got away from driveshaft brakes in general. I have repair more than a few snapped axle shafts, and most were on single speed axles, but they are more common anyway, so can't say why they snapped but it would point to operator error. Never snapped anything on stuff I owned. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549556 Share on other sites More sharing options...
mowerman Posted April 7 Share Posted April 7 On 4/5/2024 at 2:05 PM, mechohaulic said: it's unique in its own way. so different looking makes it sharp looking rig. bet if you have stopping situation ; just pull the lanyard for that trumpet on roof . will make as much noise as a jake and possibly the same hold back, LOL That thing just looks super loud have a ball Tom… bob Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549560 Share on other sites More sharing options...
mowerman Posted April 7 Share Posted April 7 I thought you were only joking about buying that thing. I still need a photo with you and Xena from Florida sitting in it to believe you.??????bob 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549561 Share on other sites More sharing options...
Vladislav Posted April 7 Share Posted April 7 The truck does look darn good in your drive way Tom! Congrats! Usually my feelings in such a case are high exciting right after purchase than light dissappointment on the day after with a thought of "What have I bought that thing for?" Than usually the things and thoughts get in order a few days later with no sorries on the done. 1 Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549571 Share on other sites More sharing options...
Joey Mack Posted April 7 Share Posted April 7 https://photos.app.goo.gl/uAGdnXacVi3Fz2Gn9 O.D. this one is for you,, and Bob, you may like it too.. O.D. got me inspired to cook over wood last year.. The jerky is Venison, the legs.... are... ...well ... chicken. homemade marinades, and glaze. thanks O.D. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549577 Share on other sites More sharing options...
mechohaulic Posted April 7 Share Posted April 7 54 minutes ago, Joey Mack said: https://photos.app.goo.gl/uAGdnXacVi3Fz2Gn9 O.D. this one is for you,, and Bob, you may like it too.. O.D. got me inspired to cook over wood last year.. The jerky is Venison, the legs.... are... ...well ... chicken. homemade marinades, and glaze. thanks O.D. I see you were smart enough to show everyone an AFTER picture not a coming soon/ or at the moment cooking all that beyond delicious food;; why of course I would have flown down for some wood fired cooking. LMAO 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73997-pictures-of-the-week/page/5/#findComment-549580 Share on other sites More sharing options...
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