Bronze bushing change on

[MACKS]

6 minutes ago, Onyx610 said:

Plus your not gonna get any closer! So if you have the money I would do it. Then you know that whole rear suspension is good to go. Also it’s gonna make that job much easier getting it all in one piece. 

Agree one hundred percent,on a side note do u know if they make oversized bushings to compensate for a worn trunnion bar,just a thought..

[Joey Mack]

yes they do .. and even more on the heavier axles..  We used a hydraulic torque wrench. use a fork lift to hold the spring pack up-side down, and go for it....   I have used a torque multiplier a bunch of times..... Talk about ' row-row-row- your boat'...   jojo

[Onyx610]

2 minutes ago, MACKS said:

Agree one hundred percent,on a side note do u know if they make oversized bushings to compensate for a worn trunnion bar,just a thought..

You know that’s a really good question…for some reason I think not as a lot of trunnion stands wouldn’t be getting cut out. I’m sure the axle surgeons would have that answer. I’m gonna look into it. 

[Onyx610]

Just now, Joey Mack said:

yes they do .. and even more on the heavier axles..  We used a hydraulic torque wrench. use a fork lift to hold the spring pack up-side down, and go for it....   I have used a torque multiplier a bunch of times..... Talk about ' row-row-row- your boat'...   jojo

That’s how our Mack dealer does it if you order the whole spring pack. Upside down chained down on the fork lift. Then torque multiplied. 

[Mark T]

There's a lot of different ways to repair this depending how bad it is.  Springs ??  well, a spring doesn't need to be broken to be shot. The three on the bottom (mains) can have their round hole worn egg shaped. That's the hole the rubber pad's dowel goes in. If it's worn, spring is junk. The buckets ( end caps the pads go in over time can rot away and don't squish the pads like they should . Then there's the trunion bar. It could be worn  the saddles ?? the bronze bushing could be replaced and new thrust washers and seals .  That's if they aren' t worn way beyond what they should be.  Then there's torque rods that are likely wiped out if the other components are compromised .  Then the grand  daddy off it all is if the trunion stand (complete assembly containing the bar) needs to be changed. Often it goes along with the bar. In some cases the trunion stand may be rotted and you may not realize until it's inspected by someone who knows where to look. There's an aftermarket trunion stand that saves a ton of work replacing one in a dump truck, but they're not free and are somewhat heavier than the Mack trunion stand.  Without seeing it in person ?  hard to say how involved you're going to be. IDK if guys are still changing just bars in the 600 series anymore. Used to be an interesting process with dry ice and a pretty robust mobile press.

[Ricky Beals]

I guess I can get a quote from Mack dealer and Stengelbrothers on spring kits My best friend hurt his back 35 years ago torquing those u bolts on a camelback. He worked part time for a diesel repair shop after school and weekends. He was using a multiplier and long cheater bar. Sitting flat on his ass and rowing like he was in a boat. Crazy but I just remembered that story.

[Onyx610]

2 minutes ago, Mark T said:

There's a lot of different ways to repair this depending how bad it is.  Springs ??  well, a spring doesn't need to be broken to be shot. The three on the bottom (mains) can have their round hole worn egg shaped. That's the hole the rubber pad's dowel goes in. If it's worn, spring is junk. The buckets ( end caps the pads go in over time can rot away and don't squish the pads like they should . Then there's the trunion bar. It could be worn  the saddles ?? the bronze bushing could be replaced and new thrust washers and seals .  That's if they aren' t worn way beyond what they should be.  Then there's torque rods that are likely wiped out if the other components are compromised .  Then the grand  daddy off it all is if the trunion stand (complete assembly containing the bar) needs to be changed. Often it goes along with the bar. In some cases the trunion stand may be rotted and you may not realize until it's inspected by someone who knows where to look. There's an aftermarket trunion stand that saves a ton of work replacing one in a dump truck, but they're not free and are somewhat heavier than the Mack trunion stand.  Without seeing it in person ?  hard to say how involved you're going to be. IDK if guys are still changing just bars in the 600 series anymore. Used to be an interesting process with dry ice and a pretty robust mobile press.

Weren’t they just torched out in the middle and beat out with a sledge, then beat the new one in and measure each side for squareness? 

[Mark T]

Just now, Onyx610 said:

Weren’t they just torched out in the middle and beat out with a sledge, then beat the new one in and measure each side for squareness? 

I believe once the chassis is secured up  the first thing is slice through the center of the bar between the legs. If the bar tweeks at all from centered , game over. Need a trunion stand. Lots of cutting with a torch . If I remember. the legs were heated where the bar went through and the bar was put in dry ice then when it was time to get it in, you had to know what you were doing and press it in to the desired measurement .  Guy used to have a stubby press that the ram was like 9 inches wide or something like that. ( it was the same one he used to use on the spindles  on the 44s )  

[Joey Mack]

yeah, the company i have used, air arcs the bosses where the bar goes through after slicing the bar in 3 pieces,  then he welds 2 clamp plates to the bottom of the boss,'s. it has holes drilled through for bolts, 7/8" i think..  the clamps when done, are at the bottom, but the trucks I had done did not drag them through anything, and they held up good..  I only saw them after 3 years before I moved on. so I dont know about now, 3 years later..  jojo

[Onyx610]

Time for another video! Haha

 

[Mark T]

Just now, Onyx610 said:

Time for another video! Haha

That's a Superliner. Different trunion stand. They had replaceable bars and the frame was wider than a 600 series

There's a lot of different ways to repair this depending how bad it is.  Springs ??  well, a spring doesn't need to be broken to be shot. The three on the bottom (mains) can have their round hole worn egg shaped. That's the hole the rubber pad's dowel goes in. If it's worn, spring is junk. The buckets ( end caps the pads go in over time can rot away and don't squish the pads like they should . Then there's the trunion bar. It could be worn  the saddles ?? the bronze bushing could be replaced and new thrust washers and seals .  That's if they aren' t worn way beyond what they should be.  Then there's torque rods that are likely wiped out if the other components are compromised .  Then the grand  daddy off it all is if the trunion stand (complete assembly containing the bar) needs to be changed. Often it goes along with the bar. In some cases the trunion stand may be rotted and you may not realize until it's inspected by someone who knows where to look. There's an aftermarket trunion stand that saves a ton of work replacing one in a dump truck, but they're not free and are somewhat heavier than the Mack trunion stand.  Without seeing it in person ?  hard to say how involved you're going to be. IDK if guys are still changing just bars in the 600 series anymore. Used to be an interesting process with dry ice and a pretty robust mobile press.

[Mark T]

Superliner had clamps on the legs, whole different stand.  

[Onyx610]

8 minutes ago, Mark T said:

Superliner had clamps on the legs, whole different stand.  

Interesting, closest I’ve been to a superliner is just seeing one go down the road….unfortunately 

[JoeH]

Trunnion bar on our dm686SX broke probably 8 years ago. Don't remember what all was involved, I just remember the bar was about 3 to 500 lbs of solid steel. When it broke the external trunnion stand brackets sat down on the spring u bolts.

I think if I were going to go to the effort of replacing bushings (which I plan to this year on one of my trucks that needs springs) I'd replace the bar as well. I don't think it's too difficult, the rear of the truck frame should get set up on blocking or HD metal sawhorse so that the camelbacks hang. If taking the dump bed off isn't a challenge for you then I'd say that's a prudent safety move that may make access a little easier.

[JoeH]

A lot of these bolts take big torque to tighten.

[MACKS]

On 3/12/2022 at 7:26 PM, JoeH said:

Trunnion bar on our dm686SX broke probably 8 years ago. Don't remember what all was involved, I just remember the bar was about 3 to 500 lbs of solid steel. When it broke the external trunnion stand brackets sat down on the spring u bolts.

I think if I were going to go to the effort of replacing bushings (which I plan to this year on one of my trucks that needs springs) I'd replace the bar as well. I don't think it's too difficult, the rear of the truck frame should get set up on blocking or HD metal sawhorse so that the camelbacks hang. If taking the dump bed off isn't a challenge for you then I'd say that's a prudent safety move that may make access a little easier.

The bar on 44 rears is part of the stand,not removable..

[MACKS]

Rick,you should start soaking the bolts on the insulator pads with penetrating oil now..

Edited March 15, 2022 by MACKS

[JoeH]

11 hours ago, MACKS said:

The bar on 44 rears is part of the stand,not removable..

That's unfortunate...

[Joey Mack]

if the stand is good and passes DOT inspection,,, then the axle surgeon can cut out the trunnion bar and weld in a new one.  Just saying,  ive had 4 done,,  it saved a ton of labor and cost...  jojo

[JoeH]

It figures that when a thread pops up about trunnion bushings my truck would blow out the cover plate of one spring saddle!  This truck does a LOT of twisting to back into residential driveways, so the trunnion bushings have been on my mind for a while.  saw this when I was sitting in someone's driveway today. The nut stripped off so e of the threads on the spindle, blew out the cover plate and has gone by the wayside somewhere with the thrust washer, lock plate, etc.passenger side elephant pads are up on blocks, as is the driver side trunnion bar.

Torched the u bolts inside and out, jacked up the driver side elephant pads, drove an air chisel between the saddle and the springs, then lifted the spring way up so we could reach above saddle/below spring to torch the inner u bolt out so we could slide the saddle off.

Cleaned up the spindle, chased Walmart (damn auto correct, should read "what". I'll just leave that there...) was left of the threads and....

Assembly time:

Bergeys only had one u bolt, they'll have the other one in the morning.

 

About 2 hours to get all that done between my dad and I.

Edited March 16, 2022 by JoeH

[Joey Mack]

it's great that the trunnion bar was re-usable..  quick turn around..  Im also impressed that you didnt spend 2 hours knocking the saddle out..  I have to pull a Mack carrier out tomorrow,,  I pulled the side cover and gear chunks and teeth fell out,,  driver said he got stuck, then got it out, then drove to the quarry,  on the way out of the quarry,, the truck locked up...   No Sh!t...

[theakerstwo]

I grease the bushing ever other saturday plus i install the cross stabilizer bar on the rear rear and that will help out some.

[JoeH]

We had the driver side floating above the cribbing, resting on jacks on the elephant pads while we drive the air chisel in between the saddle and lowest spring, right where the u bolt passage is.  Had to cut the u bolt pretty low to get access to that spot. Took us all of 10 minutes to get the truck to drop off the spring onto the cribbing.

 

Always important to remember that Mack trucks HANG from the rear springs!

Edited March 17, 2022 by JoeH

[JoeH]

Our carriers get layered in cement, I always cringe at the idea of pulling carriers on our trucks. Access is 100% from underneath on our trucks.

[mechohaulic]

1 hour ago, Joey Mack said:

it's great that the trunnion bar was re-usable..  quick turn around..  Im also impressed that you didnt spend 2 hours knocking the saddle out..  I have to pull a Mack carrier out tomorrow,,  I pulled the side cover and gear chunks and teeth fell out,,  driver said he got stuck, then got it out, then drove to the quarry,  on the way out of the quarry,, the truck locked up...   No Sh!t...

"" I thought i heard  a strange noise; so I turned my radio up louder" . oops, think i'm dating myself again;; Not a radio; today it's headset, telephone or whatever they use.