mrsmackpaul Posted September 19 Share Posted September 19 Got asked a question this morning If your back diff on a bogie drive (twin screw) is buggered Can you pull the axles, drop the jack shaft and engage diff lock and drive home Truck has to travel 500 miles bob tail On Eaton back ends this can be done I can't think of any reason it shouldn't be done Is my thinking correct ? Paul Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 19 Share Posted September 19 You can.. Quote Link to comment Share on other sites More sharing options...
tjc transport Posted September 19 Share Posted September 19 yup. done it a few times when the low boy trailer, or float as you call it over there was not available to haul it back home Quote when you are up to your armpits in alligators, it is hard to remember you only came in to drain the swamp.. Link to comment Share on other sites More sharing options...
cruiseliner64 Posted September 19 Share Posted September 19 6 hours ago, mrsmackpaul said: Got asked a question this morning If your back diff on a bogie drive (twin screw) is buggered Can you pull the axles, drop the jack shaft and engage diff lock and drive home Truck has to travel 500 miles bob tail On Eaton back ends this can be done I can't think of any reason it shouldn't be done Is my thinking correct ? Paul Interesting....iv no experence of anything like this as twin screw tractors are not common over here.im thinking of my Cruiseliner here...so remove jack shaft pull the half shafts put on diff lock.now iv no diff lock switch and i know you guys will know much better than me but how would oil get to the wheel bearings? Im only asking as i want learn more.thanks Paul Quote Link to comment Share on other sites More sharing options...
Popular Post Joey Mack Posted September 19 Popular Post Share Posted September 19 There is a small amount of oil that stays in the hub. However oil does need to circulate via the axle shaft.. 3 Quote Link to comment Share on other sites More sharing options...
Geoff Weeks Posted September 19 Share Posted September 19 I have done it, even have some "dummy" axle shafts cut off to cap off the hub (recommend packing bearing with grease). You need a good PDL and I wouldn't rawhide it with all the power going though the bull gears on the front axle. If air ride, you can cap off the air to the bags and chain the axle up. Then no worries on bearing lube. I am not as up on Mack Bogies do they all have an air operated PDL that can be locked? Rockwell, IHC (spicer) Dana and Eaton all do. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 19 Share Posted September 19 They do not come standard with pdlo.. you have to order it. Yes its air operated 1 Quote Link to comment Share on other sites More sharing options...
BOBWhite Posted September 19 Share Posted September 19 Do the new truck even have locking power dividers as an option anymore or do they have some sort of auto system now? A switch that could grenade the powertrain if used improperly seems like a bad idea, just like expecting drivers to shift their own gears and have common sense. 2 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 19 Share Posted September 19 Yes, electric over air is what ive seen. There is a light and audible warning, and i think the newer macks wont run over 25 mph too... So really the driver IS doing less driving. Quote Link to comment Share on other sites More sharing options...
Geoff Weeks Posted September 19 Share Posted September 19 (edited) PDL can't grenade the power train. All they do is lock out the interaxle differential. The only time they could come close to doing damage is they were on a truck with 2 spd rears (I have such a truck) and one rear failed to shift with the PDL locked. The other way is to try and shift it in when one wheel is spinning. Never in my time, did I ever have a problem having both 2 spd rears and a PDL From the factory I believe that they have it set up such that the PDL is only active in low range rear axle. I had mine set up that I could lock in both. Often I would put a set of 3 railers on the back axle and lock the PDL when climbing a snowy grade. A little common sense goes a long way. Edited September 19 by Geoff Weeks 2 Quote Link to comment Share on other sites More sharing options...
Mark T Posted September 19 Share Posted September 19 49 minutes ago, BOBWhite said: Do the new truck even have locking power dividers as an option anymore or do they have some sort of auto system now? A switch that could grenade the powertrain if used improperly seems like a bad idea, just like expecting drivers to shift their own gears and have common sense. I bet you posted this not even try'n to be funny. It's one of those things, it's funny cause it's true. Quote Link to comment Share on other sites More sharing options...
Mark T Posted September 19 Share Posted September 19 I'd have to imagine a Mack with no air lock (regular Mack power divider) would move the truck, but free wheel when it's not being powered by the engine output. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 19 Share Posted September 19 Auto matic power divider in Mack rears SUCK!!!!, the wholething about how it divides the traction power to each wheel 25% per wheel is hogwash.. the wheel with the leaste traction spins... the only way to make that system work good is if you had 4 seperate trolley brakes to engage any drive wheel you choose, individually.. to stop it from spinning, and then the wheels on the ground wil grab.. of course you will need to let the brake off once you are on all fours.. Just more of my crazy sh!t.. 1 Quote Link to comment Share on other sites More sharing options...
The Heinz Posted September 19 Share Posted September 19 3 hours ago, BOBWhite said: Do the new truck even have locking power dividers as an option anymore or do they have some sort of auto system now? A switch that could grenade the powertrain if used improperly seems like a bad idea, just like expecting drivers to shift their own gears and have common sense. I know it was a joke, but they still do. Like Joey said, it's air over hydraulic. The connectors going to the actual switch are not very tolerant of harsh chemicals, so we see a lot of cement mixers need the switch and pigtail. Something about the cleaning chemicals a specific company was using was killing them left and right. We have a 2023 Granite needing an entire rear chassis extension harness because of this. Same customer even though they had their cleaning crew stop using that chemical, guess this one was just waiting to fail. Quote Link to comment Share on other sites More sharing options...
Mark T Posted September 19 Share Posted September 19 Newer trucks have them on that modular valve in the back. I could see acid for cleaning mixers killing those. Mack power dividers work pretty good.....when they're not worn out. Lots of them were worn long before making noises. Gotta remember some of these new trucks with traction control do things you wouldn't expect when you try things that worked 40 years ago. Like juacking one wheel end up and trying to make it spin with the engine . We won't get into how I stumbled on to this 🤣 1 1 Quote Link to comment Share on other sites More sharing options...
Mark T Posted September 19 Share Posted September 19 Yeah Jojo....don't try it at home. Funny thing was the switch wasn't even on. I was looking for a leak. cleaned the housing, figured I'd jack up the one wheeel and let the tires spin to see what was wet. Luckily I was in it, and it did the brake thing and the truck tried moving. Nothing really happened, but I was certainly surprised to find that happen. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 19 Share Posted September 19 well thats what having more under wear in the dresser drawer is for.. Man, every so often I remind myself of a Boo Boo or dumba$$ move I've made that could have been BAD.. However, the lessons I learned made me much smarter.. 1 1 Quote Link to comment Share on other sites More sharing options...
mrsmackpaul Posted September 20 Author Share Posted September 20 Well thanks for the replies The truck is CH type Elite, 470, 18 speed Mack on Mack axles on airbag with a intergrated bunk If some photos ever come my way I'll bung them up here Paul 2 Quote Link to comment Share on other sites More sharing options...
Popular Post mrsmackpaul Posted September 23 Author Popular Post Share Posted September 23 Said beast has arrived at it's new home Looks the goods to me, first intergrated bunk I have ever seen Paul 2 1 Quote Link to comment Share on other sites More sharing options...
Adkat Posted September 27 Share Posted September 27 Saw that for sale Paul, was cheap enough. Reckon he's got a good truck there. Was 2 IT bunk CHs for sale last week. Don't think there was too many made over here. I've got a Trident about the same year with one. 1 Quote Link to comment Share on other sites More sharing options...
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