DragoMack Posted February 2, 2022 Share Posted February 2, 2022 Today I realized that the front axle of the tandem on my 97 Ch613 dump truck shifts. It appears to move left and right 2-3 inches on turns and I wonder if its the cause of uneven tire wear. My guess is that the shifting is not normal. Any opinions on what’s causing this? Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/ Share on other sites More sharing options...
DragoMack Posted February 2, 2022 Author Share Posted February 2, 2022 I should note that it’s a 46K camelback suspension. And the leaf springs also appear to move. Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488342 Share on other sites More sharing options...
Onyx610 Posted February 2, 2022 Share Posted February 2, 2022 Check the condition of your torque rod. Also Mack allows for a couple of inches of travel. Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488343 Share on other sites More sharing options...
Popular Post Onyx610 Posted February 2, 2022 Popular Post Share Posted February 2, 2022 I believe worn trunions will cause excessive play. Someone correct me if I’m wrong. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488344 Share on other sites More sharing options...
DragoMack Posted February 2, 2022 Author Share Posted February 2, 2022 8 minutes ago, Onyx610 said: I believe worn trunions will cause excessive play. Someone correct me if I’m wrong. What do you mean by “worn trunions”? Do you mean the trunion bushings? Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488347 Share on other sites More sharing options...
Popular Post Joey Mack Posted February 2, 2022 Popular Post Share Posted February 2, 2022 take a look at the box rubber's.. i bet you can wiggle them with the truck sitting normally... ATRO makes a descent kit and it's affordable... jojo 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488348 Share on other sites More sharing options...
Onyx610 Posted February 2, 2022 Share Posted February 2, 2022 Bushings/shaft…take your pick. Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488349 Share on other sites More sharing options...
Onyx610 Posted February 2, 2022 Share Posted February 2, 2022 3 minutes ago, Joey Mack said: take a look at the box rubber's.. i bet you can wiggle them with the truck sitting normally... ATRO makes a descent kit and it's affordable... jojo Are the elephant pads more for forward and back movement? From what I have seen anyway. If that’s the case you will see The “T” marks on the front and or backside of the “buckets”. Sometimes the big centering dowl on the springs rusts away to nothing. Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488351 Share on other sites More sharing options...
Popular Post Joey Mack Posted February 2, 2022 Popular Post Share Posted February 2, 2022 when they wear out the can move any direction, and if there arent any 'twinkies' in the boxes,, even more movement, enough so that ive seen the A-Frame bolts/hucks polished by the tires, due to movement... Way way worn out at that point.. what happens is the steel plate on the bolster breaks loose from the rubber, and well.... it moves.. jojo 4 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488353 Share on other sites More sharing options...
Mark T Posted February 2, 2022 Share Posted February 2, 2022 ( lol ) this poor guy is going to get his $5000.00+ education about what causes his problem 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488355 Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 yep.... hopefully he can do the job himself... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488356 Share on other sites More sharing options...
Mark T Posted February 3, 2022 Share Posted February 3, 2022 If he doesn't know what's wrong with it ? I'm guessing he's not about to take on changing the trunion stand 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488364 Share on other sites More sharing options...
DragoMack Posted February 3, 2022 Author Share Posted February 3, 2022 (edited) I appreciate the feed back and info. Just took a quick look and the bushings are shot. So I guess that’ll be the next fix in the next few weeks. I have all the tools and space necessary to do the job. The biggest problem I have is time. I have a lot of work on my hands that the whole process might take a week or two. Edited February 3, 2022 by DragoMack Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488366 Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 Its a bit of work. Do you have to replace the A-Frame? or are you talking about the bolsters in the spring boxes? just curious. I know full well what is in youre future.. Wish I was there to help you get it done.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488369 Share on other sites More sharing options...
DragoMack Posted February 3, 2022 Author Share Posted February 3, 2022 7 minutes ago, Mark T said: If he doesn't know what's wrong with it ? I'm guessing he's not about to take on changing the trunion stand Two years ago I changed out the whole trunion from the original to a 3/4” thick steel trunion. I’m not afraid of doing the work and I would consider myself new to heavy trucks. I’ve only had about 2 years experience with them. For me the biggest issue I’ll have is time. I’ve got more than enough work on my hands that changing bushings isn’t the biggest priority rn 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488370 Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 If the A-Frame is not rusted out at the bottom where the trunnion is mounted, and not cracked real bad inside the frame, and all you have is 'D' shaped trunnion ends... I have actually hired an axle surgeon company that will cut the trunnion bar out and weld in a new one.. I have hired this service 4 times and the work is pretty good. and it was $1500.00... I had to strip the wheels and spring packs off, but so what, gotta do it anyway, then I got new pivots from Mack and built my spring packs on the side. then put it all back together the next day. My guess is the company in youre area will have the name of your state followed by Axle surgeon. jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488372 Share on other sites More sharing options...
DragoMack Posted February 3, 2022 Author Share Posted February 3, 2022 6 minutes ago, Joey Mack said: If the A-Frame is not rusted out at the bottom where the trunnion is mounted, and not cracked real bad inside the frame, and all you have is 'D' shaped trunnion ends... I have actually hired an axle surgeon company that will cut the trunnion bar out and weld in a new one.. I have hired this service 4 times and the work is pretty good. and it was $1500.00... I had to strip the wheels and spring packs off, but so what, gotta do it anyway, then I got new pivots from Mack and built my spring packs on the side. then put it all back together the next day. My guess is the company in youre area will have the name of your state followed by Axle surgeon. jojo I’d have to check tomorrow. It’s night time now. 2 years ago I changed out the whole trunion. As a newby it never occurred to me to check the condition of the bar. But as I get into it I’ll see how much damage I’m really in. Thanks for the info! Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488375 Share on other sites More sharing options...
Onyx610 Posted February 3, 2022 Share Posted February 3, 2022 Yea when you need a shaft that’s when it becomes a big job….Mack usually sends it out too Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488376 Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 to check the wear on the ends, I used to put a magnetic dial indicator on the bar and the pointer on the pivot, (wheels still on the truck) then jack the truck off the ground to get a reading,, at 100 thousanths, i knew the bar ends were likely worn out. you can pull the caps and clean the grease out of the way to see the movement, bring a friend to help.. you can raise and lower the truck until you feel you have the answer.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488377 Share on other sites More sharing options...
Mark T Posted February 3, 2022 Share Posted February 3, 2022 1 hour ago, DragoMack said: Two years ago I changed out the whole trunion from the original to a 3/4” thick steel trunion. I’m not afraid of doing the work and I would consider myself new to heavy trucks. I’ve only had about 2 years experience with them. For me the biggest issue I’ll have is time. I’ve got more than enough work on my hands that changing bushings isn’t the biggest priority rn Maybe there's hope. Don't forget the springs might be worn where the dowels go in on the ends. Didn't mean to sound offensive, but guys are often reluctant to accept that when they start " walking " it's usually not just the pads ( the cheapest easiest thing ) 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488383 Share on other sites More sharing options...
JoeH Posted February 5, 2022 Share Posted February 5, 2022 So some Mack camelback trucks have a torque arm on the rear differential going to the right frame rail. It prevents the axles from walking. Check to see if you have one, check condition of the joints at either end. Replace if worn. Also, elephant pads aren't a terrible job, doable in a day, but they do take some serious torque to tighten down. Expect to replace all bolts, you will likely be torching some off. Few different styles of pads I believe. Some use a metal side insert some don't. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488660 Share on other sites More sharing options...
Popular Post Joey Mack Posted February 5, 2022 Popular Post Share Posted February 5, 2022 yes JoeH.. you nailed it.. I can do a full set on a tractor in 2 hours. of course I have done at least 50 of these jobs. a truck with a body on it adds an hour or so, based on room to move and tooling because of the extra weight.. always use new hardware, and yes to torches,( they save time) I also have the 7/8" tap to clean the threads on the right side so that the bolts go right in.. (with anti seize) jojo 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-488662 Share on other sites More sharing options...
Popular Post fjh Posted February 14, 2022 Popular Post Share Posted February 14, 2022 (edited) On 2/2/2022 at 3:33 PM, Onyx610 said: Are the elephant pads more for forward and back movement? From what I have seen anyway. If that’s the case you will see The “T” marks on the front and or backside of the “buckets”. Sometimes the big centering dowl on the springs rusts away to nothing. Correct the T leafs hitting the buckets indicate the pads are fubar! also there are steel spacer shims either side of the spring that are sometimes omitted on the 38 suspension they NEED TO BE there! If you step up to the 44 suspension these are always required ! If your walking out 3 inches the trunnion is defiantly suspect If its a grease trunnion You got a huge project on your hands! If its all rubber your looking at 8-12 hrs of toil to do everything! If your changing the chair recommend doing this setup Like Joey recommends NEVERSEASE IS Your friend lots of it! Gaumer Industries - Gaumer Trunnion Stands for Mack Camelback Applications These are offered by several supplyers ! I also recommend converting to all rubber if your going this route if your dump application just because its and easy fix next time ! most guys forget to jack up the truck when they grease! for proper! most guys don't know how to care for the greased version Just sayin Edited February 14, 2022 by fjh 3 Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-489391 Share on other sites More sharing options...
Mark22300 Posted December 17, 2022 Share Posted December 17, 2022 hey did you ever fix this? sounds like i have the same issue with my truck. any pictures of that you replaced? Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-518483 Share on other sites More sharing options...
Joey Mack Posted December 17, 2022 Share Posted December 17, 2022 Welcome Mark, If you post some pics of yours we can point you in the right direction. Camel back bolster replacement is easy to understand, just laborious.. ATRO makes an excellent kit that is a lot cheaper and more complete than MACK's kit.. and is found at many truck part's stores. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69145-axle-shifting/#findComment-518507 Share on other sites More sharing options...
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