Insulator Pads

[ropensaddle]

What will normal re-bush cost if done in a shop verses done at home? And how much better does the truck Handel afterward? Guess should include 81 mack camelback!

Edited June 27, 2010 by woreoutmack

[rhasler]

What will normal re-bush cost if done in a shop verses done at home? And how much better does the truck Handel afterward?

If the metal plates in the load cushions are exposed or there are marks on the buckets caused by contact with the "T" on th espring leaf it is time to replace your load cushions. This is not a difficult job but it does require some large tools. If the trunnion bushings (bushings on the suspension crossmember between the axles) are worn it gets much more complicated. Depending on the suspension rating the u-bolts will be either 1 1/8" or 1 1/4" for the 34,000-46,000 lb suspensions. These tighten down to 1,100 lbft for the 1 1/8" and 1,500 lbft for the 1 1/4". These must be tightened down or you will break spring leafs when loaded. There are three different trunnion bushing types: brass/greasable, one piece encapsulated rubber trunnion bushing, and two piece rubber trunnion bushing. If you have the brass bushing or the one piece bushing they will have to be pressed in. Also the one piece pushing can sieze to the dead axle making removal very difficult. When installing new insulators I would recommend installing urethane replacements as they seem to last much better than the current standard rubber type supplied by Mack. I will find a picture of the different trunnion bushing types so you can figure out what you have.

[ropensaddle]

If the metal plates in the load cushions are exposed or there are marks on the buckets caused by contact with the "T" on th espring leaf it is time to replace your load cushions. This is not a difficult job but it does require some large tools. If the trunnion bushings (bushings on the suspension crossmember between the axles) are worn it gets much more complicated. Depending on the suspension rating the u-bolts will be either 1 1/8" or 1 1/4" for the 34,000-46,000 lb suspensions. These tighten down to 1,100 lbft for the 1 1/8" and 1,500 lbft for the 1 1/4". These must be tightened down or you will break spring leafs when loaded. There are three different trunnion bushing types: brass/greasable, one piece encapsulated rubber trunnion bushing, and two piece rubber trunnion bushing. If you have the brass bushing or the one piece bushing they will have to be pressed in. Also the one piece pushing can sieze to the dead axle making removal very difficult. When installing new insulators I would recommend installing urethane replacements as they seem to last much better than the current standard rubber type supplied by Mack. I will find a picture of the different trunnion bushing types so you can figure out what you have.

Thanks I think the actual trunnions are ok But I can't find a grease sert. I could buy a big torque wrench I usually use a six foot cheater and 1 inch drive breakover for my heavy stuff and get all I can get bouncing lol. I may just get it done at the spring shop but would like to have an understanding of the process. We have a good spring shop, wander how much it will hurt my pocket?

[rhasler]

Thanks I think the actual trunnions are ok But I can't find a grease sert. I could buy a big torque wrench I usually use a six foot cheater and 1 inch drive breakover for my heavy stuff and get all I can get bouncing lol. I may just get it done at the spring shop but would like to have an understanding of the process. We have a good spring shop, wander how much it will hurt my pocket?

It depends on if you use OEM or aftermarket vendor parts. You'll probably have to shop around. Here are some pictures of the trunnion setups from the Euclid parts manual so you can see the difference in them.

Trunnion Type Comparison.pdf.

[ropensaddle]

It depends on if you use OEM or aftermarket vendor parts. You'll probably have to shop around. Here are some pictures of the trunnion setups from the Euclid parts manual so you can see the difference in them.

Trunnion Type Comparison.pdf.

Thanks I would rep you but I am neutral is it 50 posts before you add rep? I either have the two piece or one piece cause I don't have a cap like the bronze! I will probably get the red aftermarket insulator pads I know they cost a lot more but if the are similar to the radius arm bushings like on my ford its worth it doing it once!

Not a mack but I like my lil one ton dump

Edited June 27, 2010 by woreoutmack

[Lmackattack]

I have seen alot of guys use the torqe multiplier on the trunion U bolts to get them tight. run the truck for a few days and then check them again. I agree that the urathane lasts longer. I think you can get them for the trunion and pads that are between the main spring at each axel end.

you should notice that the rears track better in hard turns and dont dog track going down the road. IMO Ride comfort is not noticed after new bushings and pads are installed...

[theakerstwo]

Does anyone know if you can get the offset lower pads in urathane?I got some lower pads that was after market rubber and did not last one year. They give me new ones of the same brand and they strech in a turn bad.

[rhasler]

Does anyone know if you can get the offset lower pads in urathane?I got some lower pads that was after market rubber and did not last one year. They give me new ones of the same brand and they strech in a turn bad.

I've never seen them in urethane but I've never looked.

[rhasler]

I went back and looked. I don't see an offset urethane replacement in Euclid or PAI. Mack may have one but I'm sure it's really high priced if they do. ATRO offers an offset polyurethane insulator. The part number is MA36000-OFF. It cross refrences to several competitor numbers most of which are rubber. We use ATRO insulators pretty regularly for various applications, they seem to last pretty well and they have a good selection. Their replacement saddle bushings for torque rods and Hendrickson suspensions are excellent because the bar saddle rotates freely in the polyurethane which means you won't have to align the bar pin when pressing it into the walking beam or torque rod. I'm not sure of the price on these offsets, they're probably not cheap but they're probably worth the price.

[ropensaddle]

I have seen alot of guys use the torqe multiplier on the trunion U bolts to get them tight. run the truck for a few days and then check them again. I agree that the urathane lasts longer. I think you can get them for the trunion and pads that are between the main spring at each axel end.

you should notice that the rears track better in hard turns and dont dog track going down the road. IMO Ride comfort is not noticed after new bushings and pads are installed...

It feels more stable then thats what I am after. Mine feels too top heavy going in turns, of course the grapple is heavy so; it actually is lol. I am wondering if I can break it loose with my cheater too! I am going to call the spring shop and see if they have done enough of them to give me a worst and best scenario; knowing that they at least will be changing insulators!

Edited June 27, 2010 by woreoutmack

[theakerstwo]

It feels more stable then thats what I am after. Mine feels too top heavy going in turns, of course the grapple is heavy so; it actually is lol. I am wondering if I can break it loose with my cheater too! I am going to call the spring shop and see if they have done enough of them to give me a worst and best scenario; knowing that they at least will be changing insulators!

The spring shop here cuts the old u/bolts on all springs.And on the pad boxes bolts they are also replaced with new every time they are taken down. I guess it is a libilty thing with bolts.I know with freightliner only factory replacement bolts are only used in frames and things like that.

[HK Trucking]

Does anyone know if you can get the offset lower pads in urathane?I got some lower pads that was after market rubber and did not last one year. They give me new ones of the same brand and they strech in a turn bad.

Glenn, how about if you put a set of those metal stabilizer blocks in each spring box, you know, the ones that go between each side of the spring and the inside of the box.

I had those in a few of my trucks and it kept the rears in line when cornering.

Otherwise, how about retro fitting a transverse torque rod on the back rear, like the later models (86 on up) use? Yeah, I know that may eventually cause a cracked banjo housing if you have the pressed steel housings, but it would also keep things straight in the turns.

Just some thoughts.

.

[Rob]

The spring shop here cuts the old u/bolts on all springs.And on the pad boxes bolts they are also replaced with new every time they are taken down. I guess it is a libilty thing with bolts.I know with freightliner only factory replacement bolts are only used in frames and things like that.

I would never reuse the fasteners that one's life depended upon. I'd rather refuse the work that have the liability exposure that reusing the old fasteners and Ubolts could entail.

Rob

[rhasler]

I would never reuse the fasteners that one's life depended upon. I'd rather refuse the work that have the liability exposure that reusing the old fasteners and Ubolts could entail.

Rob

Absolutely right, especially with U-bolts. U-bolts are typically made from a softer steel that stretches as tightened in order to provide the proper clamp load when torqued to specification. Mack also recommends a mixture of white lead and oil as a lubricant while tightening U-bolts. It should be applid to the threads of the bolt, the contacting face of the nut, and to both sides of the washer. I use anti-sieze and 15w-40 as white lead is (as far as I know) not something typically found anymore. Mack also says the rubber two piece trunnion bushing should be lubricated with "edible mutton tallow". I tried ordering some once, my request was met by blank stares.

[HK Trucking]

Absolutely right, especially with U-bolts. U-bolts are typically made from a softer steel that stretches as tightened in order to provide the proper clamp load when torqued to specification. Mack also recommends a mixture of white lead and oil as a lubricant while tightening U-bolts. It should be applid to the threads of the bolt, the contacting face of the nut, and to both sides of the washer. I use anti-sieze and 15w-40 as white lead is (as far as I know) not something typically found anymore. Mack also says the rubber two piece trunnion bushing should be lubricated with "edible mutton tallow". I tried ordering some once, my request was met by blank stares.

For lube on those rubber trunnion bushings, I always put some Mr. Clean in a spray bottle, wet the bushing with the Mr Clean, then smear a coating of D&L or GoJo waterless hand cleaner on them too. That combination makes things slipperier than shit. I use that for a lube on the Chalmers suspension bushings nowadays on the Internationals where I currently work.

Regarding the camelback U bolts, I have seen them break in service, also have seen the spring box attaching bolts snap, so it's cheap insurance to use all new hardware.

.

[rhasler]

For lube on those rubber trunnion bushings, I always put some Mr. Clean in a spray bottle, wet the bushing with the Mr Clean, then smear a coating of D&L or GoJo waterless hand cleaner on them too. That combination makes things slipperier than shit. I use that for a lube on the Chalmers suspension bushings nowadays on the Internationals where I currently work.

Regarding the camelback U bolts, I have seen them break in service, also have seen the spring box attaching bolts snap, so it's cheap insurance to use all new hardware.

.

I was mostly just trying to see if our parts man would call around to some butcher shops and grocery stores looking for mutton tallow, but only the edible kind. I thought it was funny anyway. I do the same thing with the hand soap for installing the bushings.

[HK Trucking]

I was mostly just trying to see if our parts man would call around to some butcher shops and grocery stores looking for mutton tallow, but only the edible kind. I thought it was funny anyway. I do the same thing with the hand soap for installing the bushings.

Wonder why they spec'd "edible" mutton tallow. Did they think you're gonna spread it on your sandwich at lunchtime too?

LOL.

[ropensaddle]

For lube on those rubber trunnion bushings, I always put some Mr. Clean in a spray bottle, wet the bushing with the Mr Clean, then smear a coating of D&L or GoJo waterless hand cleaner on them too. That combination makes things slipperier than shit. I use that for a lube on the Chalmers suspension bushings nowadays on the Internationals where I currently work.

Regarding the camelback U bolts, I have seen them break in service, also have seen the spring box attaching bolts snap, so it's cheap insurance to use all new hardware.

.

I understand new fasteners are the way to go impacts heat them up and sometimes u bolts get hot just wrenching. I however have seen idiots in trucks that it would not matter if you replaced every bolt daily they would still break them!