Medium Duty Quality thread- Monroe

[murphyslaw]

So I took the early advice and had my Kodiak alignment looked at by a tractor pro--a real artisan.

He said that it was not acceptable for an alignment to be neglected by Monroe after such modifications. Mine was not tracking straight in the rear, secondary to a axle which was 1/8" off perpendicular, and you know about the steering wheel already.

Monroe drops these front ends (So-Low) about 2" and then moves the steering wheel about 2 splines one direction or another. On my truck, the wheel was still too far to the right--over corrected. Herein lies a major design flaw. It is my understanding, after my suspension clinic today, that steering boxes operate at their tightest tolerances where the factory zeros the steering wheel. There is a mark on the steering shaft at zero. By moving it 45 degrees, one side or the other, you are begging for sloppy steering and an uneven "feel" and "range" (his words.) Monroe does not install an adjustable drag link to put the steering box back to "zero" ...ever. This effectively lengthens the drag link. So they are begging for sloppy steering and again violating acceptable engineering standards. Looking at the design, I see now why I get bump steer which is worse on left wheel impacts than on the right, add that to the sloppy steering accuracy, and this shows how these could be made so, so much better.

Read: make a DOT-accepted adjustable drag link and you will sell hundreds.

We examined the new Goodyear Highway tires and there was significant tread lateral runout as well as a radial hop in each. This explains the vibration. The balance on one was still not perfect yet. I'm meeting with Goodyear tomorrow; we'll see how they will address this.

I will later measure the input and output angles on the drive shaft to see if they are within 4 degrees or whatever the spec is. This was recent advice.

I don't think the dealer would do this amount of "sorting" even if they are getting the PDI check.

dump those goodyears and grab a set of Yokohama's. just my professional opinion.

[Braveheart]

Met the Goodyear representative today. I thought this was going to be the silver bullet. I was planning my first 600 mile trip with towing (same day) and was pushing it pretty close. The intended use of the truck is to pull 4 horses in a 8k trailer and pull a double car hauler. It pulled the empty horse trailer today. To concentrate on defects:

1) OE right front tire got replaced, as it had 65 thousandths of radial runout. He was not comfortable with it. The left had 40 thousandths-- less than 70 is within spec. He was not concerned with the tread lateral jog. He tried to reseat the bead to make it go away. No change. It got rebalanced up front. They checked it first with the GM MD dealer weights, and the balancer read "0"s. It had about 5-6 oz a piece, divided inside and out. They took off the weights...made a mess of the Aluminum incidentally... and the balancer called for 3oz on the outside lip only. How can two balancer's call for a 2oz difference? And it read the 5 oz as being OK? So now I'm skeptical of the balancer. Not very accurate. Or it read the piezo and found a different solution to the harmonics with the same result.

2) Looks like the Alcoas have at least 10 thousandths of runout. I was told that is OK. We remounted the wheels with the high spot "up" so to further use the slack in the hub to minimize the runout. Thoughtful, but not terribly sceintific. Despite my request, they hit 'em with a 1" impact. Not a torque wrench in the truck shop!

3) Heard from two separate people (not employees) while the Goodyear rep was "away", that the only way to make a MD stop shaking is Michelin.

4) During the trip, at 50 mph and especially in a long, high-load turn, there is a lateral vector to the persistent vibration. It is down right awkward in a turn. I was looking at the hash marks on the speedo and they were definitely moving left to right. It still shakes violently at 70, with and without a load...8k trailer...empty. The vibration at 60 is gone mostly, but comes and goes.

5) I can feel the steering wheel pass through zero "and tighten up" on a gradual right turn. I wonder how the steering wheel shift has affected the turns to the left and turns to the right? I also wonder if the "slop" is compounding the lateral vibration while turning-- at the speed, load of a cloverleaf.

Weight definitely makes the Kodiak more behaved. I agree with those who claim this. But I've got 2.5 days tied up into making this stop shaking and still no result, with and without the load. It's awful. I mean it. If you try to talk to someone while driving, it's like you're getting a fist-pounding massage.

6) Oh, the trailer brake controller. It's not progressive like a Prodigy. Comes on and stays at the set level. I had to turn it all the way down to drive in a rural setting; The trailer was trying to stop the Kodiak before I was applying any real pedal pressure. It was set on "2" max. Am I missing something, or is this Draw-tite unit bad? All it has is a manual slider and gain knob and NO documentation from Monroe.

I don't know what to do next. Get GM to put a set of Michelins on it, and make an adjustable drag link, and buy a Prodigy? And then start all over with the shop visits and build the Kodiak the way it should have been built?

[murphyslaw]

Met the Goodyear representative today. I thought this was going to be the silver bullet. I was planning my first 600 mile trip with towing (same day) and was pushing it pretty close. The intended use of the truck is to pull 4 horses in a 8k trailer and pull a double car hauler. It pulled the empty horse trailer today. To concentrate on defects:

1) OE right front tire got replaced, as it had 65 thousandths of radial runout. He was not comfortable with it. The left had 40 thousandths-- less than 70 is within spec. He was not concerned with the tread lateral jog. He tried to reseat the bead to make it go away. No change. It got rebalanced up front. They checked it first with the GM MD dealer weights, and the balancer read "0"s. It had about 5-6 oz a piece, divided inside and out. They took off the weights...made a mess of the Aluminum incidentally... and the balancer called for 3oz on the outside lip only. How can two balancer's call for a 2oz difference? And it read the 5 oz as being OK? So now I'm skeptical of the balancer. Not very accurate. Or it read the piezo and found a different solution to the harmonics with the same result.

It matters on whether they were both dynamic balancers or static balancers. my machine will do both. if I balance a tire on one setting and spin it on another it will some times tell me its not right.(yet to have one come back for shaking) It is also possible that the dude running one of the two machines didn't know how and messed up the settings, properly running a balancer isnt as simple as most people would thing. also once a year COATS(mfg) comes in and calibrates both of my machines, when was the last time theres was looked over? I love Michelin's(but I am partial since they underwrote my store) But I push them all Toyo's BFG's Good Years Yokohama's ext.

2) Looks like the Alcoas have at least 10 thousandths of runout. I was told that is OK. We remounted the wheels with the high spot "up" so to further use the slack in the hub to minimize the runout. Thoughtful, but not terribly sceintific. Despite my request, they hit 'em with a 1" impact. Not a torque wrench in the truck shop! Yeah that is about right.

3) Heard from two separate people (not employees) while the Goodyear rep was "away", that the only way to make a MD stop shaking is Michelin. That is all I will run on my service trucks(two 5500's and one international)

4) During the trip, at 50 mph and especially in a long, high-load turn, there is a lateral vector to the persistent vibration. It is down right awkward in a turn. I was looking at the hash marks on the speedo and they were definitely moving left to right. It still shakes violently at 70, with and without a load...8k trailer...empty. The vibration at 60 is gone mostly, but comes and goes.

5) I can feel the steering wheel pass through zero "and tighten up" on a gradual right turn. I wonder how the steering wheel shift has affected the turns to the left and turns to the right? I also wonder if the "slop" is compounding the lateral vibration while turning-- at the speed, load of a cloverleaf.

Weight definitely makes the Kodiak more behaved. I agree with those who claim this. But I've got 2.5 days tied up into making this stop shaking and still no result, with and without the load. It's awful. I mean it. If you try to talk to someone while driving, it's like you're getting a fist-pounding massage. these trucks when unloaded are a killer on the back, they only soften up a bit at full load.

6) Oh, the trailer brake controller. It's not progressive like a Prodigy. Comes on and stays at the set level. I had to turn it all the way down to drive in a rural setting; The trailer was trying to stop the Kodiak before I was applying any real pedal pressure. It was set on "2" max. Am I missing something, or is this Draw-tite unit bad? All it has is a manual slider and gain knob and NO documentation from Monroe.

I don't know what to do next. Get GM to put a set of Michelins on it, and make an adjustable drag link, and buy a Prodigy? And then start all over with the shop visits and build the Kodiak the way it should have been built?

I think I would return it and get one that has not been lowered, seems that most of the problems are stemming from that modification.

I would recommend the Michelin XDE M&S retreads for the drive axle. they are a great tire, awesome tread patters will go good in the mud and snow and handle well on the road. For the steers I would go with Michelin XZA-1B's or Yokohama RY023

[Mark Rinker]

My '04 C4500 had Michelins all the way around when I bought it with 20K miles.

Wonder if the previous owner had upgraded from the Goodyears already? Or could the Michelins have come OEM factory in 2004?

[Braveheart]

Options S4L and R4L are Michelins.

My truck is brand new and has the Premium Goodyear Highway tire option.

[Mark Rinker]

Checked the visor code list and it came from the factory with Michelins. At 70K, the rears are about 35% remaining and steers about 50%. I plan to run larger diameter rear rubber to reduce cruise RPMs by 15% and am considering a swap from duals to super singles.

From re-reading your thread, I would conclude that the Monroe lowering kit is very suspect. Ever driven one without?

[Braveheart]

So here's the word from ZF engineering/Sachs:

Moving the steering wheel as a solution to the drag link geometry change upon lowering a Kodiak creates two problems.

1) Steering range different left to right--determined by release valve or wheel stops, regardless, it changes.

2) Steering feel becomes loose, as the steering gear is out of it's sweet spot--tightest tolerence.

Best solution is changing the drag link. Next best is changing the pitman angle. Changing the pitman angle creates another smaller problem for rate and effort, but much less noticable.

Remember all of this is happening in the background of Monroe denying me an alignment.