Medium Duty Quality thread- Monroe

[murphyslaw]

[rant] Just another example or why lowered rigs suck[/rant]


even if you replace the draglink with a smaller one to get the wheel centered you will not have the turning radius as stock, as the steering box will limit out before it has moved the pitman arm a sufficient length for push/pull to move the wheel fully.

[Braveheart]

I don't think that is true, and I'm getting off topic. But when the drag link is nearly level, the end of the pitman arm is moving the knuckle in a 1:1 relationship. If the gear moves the pitman end 6 inches, it's going to move the knuckle 6 inches regardless of the drag link length. If the pitman was changing length, then the range would change, but that is not the case in Monroe's build.

I'll concur that the shorter drag link may move the knuckle ever so slightly less at the extreme throw, because its angle may change more acutely there and in effect appply less longitudinal movement, but it would be minimal. They chose the least messy way to get the steering wheel centered and left it at that. If it ended up between splines, like in my case, Monroe just left if off-center.

Anyway, it's not engineered like it should be. Simply put.

[Mark Rinker]

'Off topic' around here isn't when someone offers up a differing opinion - its when you are talking about Medium Duty Quality Problems and somebody starts contemplating the benefits/drawbacks of bio-diesel.

How did your first haul go with the new rig?

[Braveheart]

The first tow went OK--not great. One problem got worse: the lateral vibration at 50. The ride improved somewhat and the confidence behind the wheel reinforced why I got a MD. I still think the steering is a bit sloppy, and I'm still mystified with the Activator II Drawtite unit. I looked for a ramp feature and could only find a gain control. There was no happy medium with it. Nothing like my old prodigy.

But I also dug deeper into the front steering issues:

I found out from Monroe yesterday that GM's engineers assisted with the development of the "So-Low" suspension. GM informed them at development that: the steering geometry changes induced by the lowering were negligible. Monroe was suprised to hear that ZF (steering gear) disagreed. The 50 or so degrees that the wheel changes means the gear has changed position--it' simple and it's bad. Monroe is going to verify their information from GM and call me back. (Monroe also said that if I did not have an after-market steering wheel that they did not move it. This is untrue, and is not consistent with the information that I got elsewhere at Monroe. My wheel stamp is no longer on center, so they did move it.) I really cannot believe they were unable to provide me test data showing that were actually thinking about it and measuring the effect THEMSELVES.

To see how that equates in steering performance while turning, I discovered that my truck has one-half more wheel turn capability in one direction. This in not negligible. It also behaves differently, both in sound and feel at the extreme. I will see how that translates in turning radius when the weather improves. That means it is over-running on one direction.

So make that quality complaint #12 for me...data to come.

For those that are counting: GM and Monroe are about tied on the responsibility for my 12 quality and design issues. GM's problems are about fixed and Monroe's are going to be difficult, because there are inherent design issues.

[DmaxMaverick]

On the Drawtite A-II controller, there is a timer ramp adjustment on the left side, near the screw mounting hole (toward the driver). It's a tiny slider button. Depress the brake and move the button a tiny bit (while stationary, or you can adjust it while moving, but reduce the gain so you aren't applying the brakes hard during the adjustment, then reset the gain after the adjustment for testing). The number display should change, and you can adjust the value. Let off the pedal, and press it again, the ramp rate should change according to the rate you set. They take some getting used to, but are pretty good once you do. I have one, and prefer it over the Tekonsha controllers. The only better controllers, IMO, are the older direct pressure line controllers, like the KH's, or the electronics that connect to the brake pedal linkage.

The Drawtite A-II controller has the same internals as some of the Reese models, with a different label.

[Duramaster]

Have you had the tires balanced ON THE VEHICLE? Or on a tire balance machine? Was it a ROAD FORCE type balancer? Is this truck a 4WD model? I forgot if you had posted that and there is too much to read here now.

[Braveheart]

Tires have been balanced off the truck only. It is 2wd. Supposedly the first time around, they were done on a Hunter "road force." The second time it was a Coats basic.

[Duramaster]

Does anyone in your area have the "TECHNOLOGY" :::snicker::: to balance the front tires on the vehicle?

[Braveheart]

Rear axle was balanced today. Required at least 2 oz per wheel on the Hunter Road Force. The vibration at 65 is solved, I think. Traffic was heavy during the test. Lateral shake at 50 mph still present (worse with payload and lateral load), but very subtle in a straight line. May be the Goodyears; may be the steering play...

Monroe still has not owned up to the responsibility of the steering issues, and is still denying the alignment reimbursement. The Gen Mngr. has not followed up. I have no idea how I'm going to make that right if they don't see the error in the design. They should have designed and installed a shorter drag link, and performed an alignment starting from a centered steering gear. No one has disputed this fact outside of Monroe.

A full half-turn difference (L to R) in the wheel range and a steering gear 1/4 rotation off-center is not acceptable.

Anyone with a non-lowered Kodiak care to measure the steering turns to the left of center and right of center? Lowered Kodiak owners please verify too.

I've got 2.5+ left and 2 turns right.

The other Kodiak pickup like mine was still at the shop today, but no one would check the steering. The owner has left it there, disgruntled.

[Mark Rinker]

Have you spoken with the owner of the other truck?

[Braveheart]

I don't know what confidentiality exists, but they are hesitant to divulge owner info. The mechanic was more than happy to tell me that the owner did not like driving his rig, and that they have fixed many of the same issues, and that he was in no hurry to get it back.

[Mark Rinker]

Is it a Monroe conversion as well?

[Braveheart]

Truck says Monroe on it.

I have also spent some time doing some trig on the steering geometry. It looks like the pitman arm was displaced by about .230" during lowering which equates to about 1.4 degrees of steering gear output shaft movement to keep the wheels going straight.

I also just got an email from ZF engineering. Here is what I know:

1) the steering gear has hydraulic limiters which are set one-time only when the steering wheel is turned to its axle stops. If you change the pitman arm range, you have to replace the self-adjusting limiters and then reset them. If you don't set them, the gear will run full hydraulic assist into the axle stops and who knows where that energy is going. For me that would be on right-hand turns. Monroe did not reset them.

2) the gear also has a self-centering feature. So , when you take your hands off the wheel or in a bump-steer situation the wheel wants to come back to straight ahead. If your gear is 45 degrees off like mine, the truck will naturally pull opposite the direction of the displacement.

3) The gear has it's absolute most sensitive "feel" by having its tightest tolerances at "zero."

The solution: I think there is enough play in the gear mounting bolts to get 1.4 degress of rotation and get the steering gear back where it belongs. If that is not enough, there is probably enough play in the shackles or axle to move the gear the rest of the way.

Monroe asserts that GM told them that the changes from lowering were trivial, as I said before. I am working on a solution that Monroe can implement for everyone.

It would be interesting to see where other's gears are centered at the steering wheel. If you have a factory non-airbag steering wheel, just work your fingers under the horn pad and it comes off shockingly easy. Just four rubber posts hold it down using friction. Note whether your rig is lowered or not and where the chisel mark on the steering shaft is in relation to the steering wheel's center.

My bet is that the lowered Monroe rigs will have the mark to the left of the wheel. My bet is that non-lowered rigs will have a steering shaft pretty close to straight ahead. .

[Duramaster]

If I think about it Braveheart, I will try and take the time to compare steering wheel revolutions from center to stop and even stop to stop if you would like.

[Braveheart]

Because the pitman arm is not perpendicular to the drag link, the arm has to rotate more on left turns than on right. There might be some further geometry at the knuckle that is in play. Anyway I think you'll find about 2.3 turns left and 2.1 right if the suspension is stock.

If I can verify when that chisel strike is placed during Assembly, it will save me taking off my steering shaft to find the steering gear's center. I think it is a safe assumption to say that it reflects the steering gear center though.

Looking under the pad for the strike and seeing how that compares to the steering wheel is the best way to determine if it is centered, unless the strike means something else.

[Braveheart]

Note the steering wheel chisel strike about 45 degrees left of center.

SteeringIII.JPG

Note the arrow in the plastic dust shield and the fat arrow cast into the gear housing.

GearIII.JPG

This causes three difficulties: 1) the gear's "return to center" function is constantly trying to turn the truck to the right. If you doubt this, take your hands off the wheel. This makes you work harder to keep the truck straight. 2) in a bump steer situation, it may amplify one vector 3) the gear is looser anytime you are off zero, making you work harder again to keep it in a straight line. It could be soooo much better if this was in line.

[Braveheart]

So, I've got the major problems narrowed down to some wheel waddle and the steering gear.

I had the chance to examine the other Kodiak with So-Low and his steering gear is displaced by the same amount. I've heard from others with stock trucks that their gears are mostly centered, and the lowered rigs are "off". But it would be nice to hear some data here.

If you don't think this is a problem, take you hands off the wheel if the gear is not centered, and see which way the truck wants to turn.

The word from the gear manufacturer is that the gear needs to be centered for best driveability and that the steering limiters should be replaced if the pitman range was changed---like when lowered.

Monroe is currently working on a fix, but I think they are still in the data collection mode. If you've got a C4500, check your gear and post it!

More data can only help. I'm sure that by now they are watching this.

[murphyslaw]

I will check both of my 5500's and my 6500 tomorrow, it can only help right

[Braveheart]

Well I'm pretty close to wrapping up my saga with this new truck. The dealer has been less than helpful and has renigged on his offer to pay for the initial alignment and tire swap. So I've resigned myself to eating $125 and a lot of fuel.

I have also come to the determination that the Goodyear G647RSS's are have enough lateral runout that they are inducing the remaining vibration which is worse with a load on the rear. I can see the tread blocks waving left to right in the side view mirror. That's bad, right? The dealer has voiced that he will look into the horrible factory fisheye repairs, the leaking seat, and the oil which was 15 months old at delivery, but I'll have to drive 450 miles to get him to do it. He's probably betting that I won't.

The front Goodyear to Michelin swap which resulted in a better ride and reduced vibration, and unfortunately, demolished rims still has a remaining to do list....Raben tire thinks they can polish out the deep gouges that their tire man left in my brand new Alcoa's, so I'll have to drive 100 miles to see what comes of that. I cannot remember if I posted pics of that.

Monroe has agreed to look at the rear axle and fine tune the airbags, as well as repeat the wheel balance. They helped me find a solution to the steering gear issue, among others. I cannot say enough about how they stepped up during all of this. They put the dealer network to shame.

Please keep this thread going as it will continue awareness for those to come. Regards.

[Mark Rinker]

Glad to hear you are getting the the end of your driveability issues/concerns. In conclusion - how many of your issues were due to the conversion and how much were straight from the factory?