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R model front springs

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Why do R model front springs cause such a bad ride? I drove a 2000 freight liner again today and it barely made the front end move when going over a pot hole. I then got in the R model and drove over the same roads and it made me kringe when I went over a man hole cover .

I love Macks and the duribility but why oh why do they ride like crap??? can i simply swap some pete or Freightliner springs under it?

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Why don't you just get a Pete or Freightliner?

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Why don't you just get a Pete or Freightliner?

why would I do that? I dont need more problems. :rolleyes:

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If you only use it for show or light loads, take some of the spring leafs out. Assuming you have a multileaf pack like 11 or 13 leafs. Just put a spacer block in of the same thickness as the leafs you took out. That will keep the front end the same height.

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If you only use it for show or light loads, take some of the spring leafs out.  Assuming you have a multileaf pack like 11 or 13 leafs. Just put a spacer block in of the same thickness as the leafs you took out. That will keep the front end the same height.

It has the standard R model 3 leaf 12K

I replaced the shocks after I posted the message and found one of them were frozen. I noticed a improvement but the cab still shakes on smooth roads?

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I have a 72 R model that had stacked springs , i used 3 leaf springs out from a u model and the spacers,and the rear spring hangers , every thing bolted in place, rides alot better , since your R model is a western i dout it would work, but dont know. ron

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My western has the 3 leaf right now. I noticed the newer trucks have the 2 leaf so that itself will make the truck ride a little harsher. I am hoping to get my front wheel balenced soon. the front tires on the truck are new drives. I removed the old steers as the MO state gave me a ticket for low tread ware and made me get them replaced with recaps!!! go figure :wacko:

The drive tires may make the ride harsh also??

As far as the cab shaking I am thinking that the rear shocks are shot and the tires may be not balanced properly?? one thing I never under stood was why Mack only used 2 shocks for the rear I have gathered the parts for 2 more shocks and hope to install them when I rebush the rear end..

Trent :MackLogo:

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After the recent accident, i had to get two new sets as the originals had sagged,and she was on a bit of a list (all that v8 power torque) I checked the shocks, and they are about 80% efficient, So hopefully this week, Ill be able to prove if the ride improves or is the same, I have a reasonably short wheelbase as well as air bags on the rear, so I havent noticed how severe they can ride, its been a while since I drove a Camelback.

regards, Nigel :SMOKIE-LFT:

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:wacko: you are running drive tires on the steer axel? are they all position tires? if not I wouldnt leave them on there very long, that might be your problem also I cant figure why any one would run caps on the steers! Doug :huh:

My western has the 3 leaf right now. I noticed the newer trucks have the 2 leaf so that itself will make the truck ride a little harsher. I am hoping to get my front wheel balenced soon. the front tires on the truck are new drives. I removed the old steers as the MO state gave me a ticket for low tread ware and made me get them replaced with recaps!!! go figure :wacko:

The drive tires may make the ride harsh also??

As far as the cab shaking I am thinking that the rear shocks are shot and the tires may be not balanced properly?? one thing I never under stood was why Mack only used 2 shocks for the rear I have gathered the parts for 2 more shocks and hope to install them when I rebush the rear end..

Trent :MackLogo:

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I agree Doug!! recaps on the steer is a big no no!!!! MO DOT thinks diffrent however. I was suprised when the scale master let me leave his station with a recap on the steer axel??? but after a 3 hr delay I just wanted out... As soon as I got back from the trip to pick the truck up I put the 2 drive tires I had at home... Correct steers will come soon. All my drives are currently 40%

trent

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men, I really like the way you think :thumb: it's not just the front spring, tire, wheelbase, cab kind of suspension, seat... knock off a spring or two and put an air ride kit on the front!

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Why do R model front springs cause such a bad ride? I drove a 2000 freight liner again today and it barely made the front end move when going over a pot hole. I then got in the R model and drove over the same roads and it made me kringe when I went over a man hole cover .

I love Macks and the duribility but why oh why do they ride like crap??? can i simply swap some pete or Freightliner springs under it?

My 1985 U688t model bounces between 29 and 39 mph. below or above that it is fine. I just dropped it off to have a few things done to it and I mentioned the bouncing. I will let you know what the verdict is on it when I get it back. I hope they can fix or at least minimize it without to much work involved. The type of bounce that it has is real aggravating. Aside from that it goes down the road streight and smooth ,no pulling or wandering .

JIm !

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sounds like we have simmilar issues Jim.

I drive the druck once a week some times more and its exactly like you discribe between 30-40 mph. I have (2) steers that went on the front axel today and the drives went to the rear axels. I still notice the cab shacking but not as violently as before. I am thinking the rear cab rubbers(non air ride cab ) might be worn so thats the next thing I will look at. So far I have replaced all the shocks. 2 front tires and 2 drives. I may try lowering the front tires to 85psi and see if that helps? a friend of mine has his at 85 psi on his B model and said it helps a little?

let me know if they find something. hope its a cheep fix :unsure:

Trent :MackLogo:

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sorry guys, new springs, 40mm higher in the front but no ride improvement, I drove a K124 a couple of years ago with the bounce problem , and traced it to the rear engine mounts which were solid instead of rubber cushion, some dork had done a quick fix, once all the engine mounts had been replaced , the bounce dissapeared, it was powered by a NTC 400 Cummins.

Nigel :chili:

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Well Trent and Nigel

The Mack is back and the mystery continues. The mechanics and Myself for that matter didn't see or find anything jumping out at us and I didn't want to turn it into a million dollar pursuit. My shocks are fine , the front end is tight , tires are brand new . I will just cope with it for now . Nigel the truck was already in the shop by the time I got your post. I'm glad you found , and were able to fix the source of your problem ! Looks like me and Trent will still be making scrambled eggs on the way to work between 30 and 40 mph !! Thanks for your help guy's :thumb:

JIm :SMOKIE-LFT:

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Well  Trent and Nigel

  The Mack is back and the mystery continues. The mechanics and Myself for that matter didn't see or find anything jumping out at us and I diddn't want to turn it into a million dollar pursuit. My shocks are fine , the front end is tight , tires are brand new . I will just cope with it for now . Nigel the truck was already in the shop by the time I got your post. I'm glad you found , and were able to fix the source of your problem ! Looks like me and Trent will still be making scrambled eggs on the way to work between 30 and 40 mph !!  Thanks for your help guy's :thumb:

                                                                                     

                                                JIm  :SMOKIE-LFT:

sorry you dident find the issue Jim. I went to mack today and ordered the cab bushings to see if that helps any?? I will reply back when they are installed.

P.S. I had big time "scrambled eggs" doing the semi truck pull last night LOL

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sorry you dident find the issue Jim. I went to mack today and ordered the cab bushings to see if that helps any?? I will reply back when they are installed.

P.S. I had big time "scrambled eggs" doing the semi truck pull last night LOL

A shot in the dark,but I would have your trucks Vis-checked.Most Kenworth and Peterbilt dealers have them.They can detect everything from worn motor mounts to spring bushings to loose u-bolts and check the efficiency of the brake system.Peterbilt of Joplin ,Mo charges a fee to do so but does it as a curtiousy if you are getting your truck worked on anyway and they will give you a printout of their findings. Tim

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Thanks for the advice Tim. I will be looking into that for sure. I 'm sure that will be good news for Trent also!

Thanks

Jim !

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Thanks Tim. I did not know such a machine was availible. I was at my local Mack dealer tonight and they do have that machine you speak of. I might have a go at it after my rearend gets rebushed.

Update on the shaking problem.

Tonight I installed the new rear cab rubbers and it has improved the ride BIG TIME!!! i still get a slight shake but it will go away as soon as I knotice it.

The old rubbers were smashed pretty bad and the hole in the steel cab support is oval so it looks like the shaking has rounded the hole and was not helping the problem. one thing I noticed is that when I removed the old rubbers the nut was not very tight. When i put the new rubbers in I tightend it untill I could see it begine to squezz the bottom rubber. the cab now sits maybee 1/4 inch higher and rides much better. i did a few laps around the yard and i could hold 2nd gear to the floor and still see straight LOL. I then did a quick 6 mile trip over a concrete hwy and thats where I noticed it did not shake like it used to in the 30-45mph range.

hope this helps :thumb:

Trent

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Whats your wheelbase? I stretched 2 of my ol dogs out and i feel nothing with the steering axle now

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glad to hear that you got most of your shake taken care of. I thought it might be doing the camelback dribbling as i call it. Thats my only downfault to camelbacks is usually empty at a certain road speed they will start dribbling. I usually have to back out of the throttle a bit when mine starts to dribble. I have a east enddump with a propar suspension thats bad for the same thing. Stout suspension but thats the downfault to a singlepoint suspension.

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