Passive Steer Tag Axle chassis and front tire wear?

[Rd1]

Does any one with freightliner passive steer tag axles experience front tire wear?

The wear appears on the edges of front tires. It does effect both sides of the tire. and it does so on both front tires. see picture (not sure why the picture is up side down).

If you do, please specify year model mileage, thank you.

17 LADP 16K miles

[MisterT]

confused?

are you asking about your Tag Axle 'front tires', or are you referring to your front 'steer' tires?

[Rd1]

sorry for the mixup.

the front tires (steer) on a chassis with passive steer tag axle experiencing very peculiar tire wear.

[MisterT]

I don't see how they could be related

[tom chelbana]

As a 25 year plus shop owner I would be first looking at toe-in/toe-out settings. Is the wear the same on both front tires? Are we looking at the inside or outside front tires? Kind of looks like might have been a little low on tire pressure.

[fixit1957]

You need to get you coach realigned after you load it with all your stuff. Recent post on that. Maybe 2 weeks ago.

[Rd1]

Originally Posted by tom chelbana

As a 25 year plus shop owner I would be first looking at toe-in/toe-out settings. Is the wear the same on both front tires? Are we looking at the inside or outside front tires? Kind of looks like might have been a little low on tire pressure.

Tom thank you for your comment. have had 6 attempts at alignment and related issues. FCCC claim has always been all is in spec. This is one of the units with the tag axle mounted of center. among many other flaws.

I have scaled all corners. tire pressures are based on Michelin recommendation. Which I feel it may be low as well.

What got my attention was, observing most hi-line units displaying the same wear, with varying degree. The wear is very similar on 4 corners of the fronts. However, the roll over is different. The VT and DS do not show this wear. However, MA, LA, and EX with some mileage (mostly 2016 and some 2017) seem to show this wear. The one difference I see is the front tires. Hi-line is using the 365, which is kinda wide. not sure if the VT, DS use 315? or similar size tire.

Of other interest, the Front tires show noticeable roll over. LF about 1/4" and RF about 1/8". which could be due to road camber and also the unit is about 200# heavier on the LF. Likely due to BATT compartment on LF. Can't imagine 200# extra weight would cause the additional 1/8" roll over on the LF.

The one issue I can imagine, as you suggest, if the contact patch is collapsing in the middle due to weight!?!? Hence causing roll over and wear on the 4 edges of the fronts. However, there could be other reasons(s).

Randy, it has been re-aligned and scaled after load. thank you.

[db7512]

Rd1 my 2016 VT has 305's on the front. I have the steerable tag axle but only about 2K miles no noticeable wear on the fronts.

[Mr_D]

I have the DynoMax chassis, liftable tag, 365/70 tires on the front and tag and after 9 years and 47,000 miles they didn't show any excess wear. Must be something in the chassis as the 365 tires should not wear like that.
Our 40' '02 DSDP no tag MH had the 305 tires on the front and it also didn't have any strange wear.

[bonesaw]

wonder if it has to do with comfort drive system and not chassis

[Rd1]

The problem is only evident in the hi-lines, MADP, LADP, EXDP with passive steer chassis. Just about anyone I have seen at newmar camp has this wear, except the new 2018 unit (EXDP) that was at the show.

I had a 3 hour trip yesterday and took the tire temps at the end. The outer edges were cooler than the middle surface of the front tires. @110 psi, they are more than what Michelin recommends for my weight. Which corresponds to higher tire temps in the middle. I'll take more temps to establish matter of fact.

This pic is from another 17 hi line with only about 6k (5 mo old). this unit had similar issue with tag axle of center, front toe off and wondering problems from FCCC. You can see a line just starting to show at the first thread. You have to expand the picture to see the line. Although, I don't know if this issue is related to only units with tag axle mounting problems. Even though, I see quite a few units with tag axle off, which is a surprise for me. Most people just do not know their tag is off, let alone their front tire wearing of.

It will be curious to see what happens in another year when some of these units hit 20-30k miles.

I'll take more temps this week and report back. Tires do tell what the story is with the chassis.

[palehorse89]

From the looks of the tire, your driveway has a good thick layer of gravel on it??? Kinda looks like marks from driving through loose thick gravel......Just taking a guess on your last photo......

[Rd1]

Originally Posted by palehorse89

From the looks of the tire, your driveway has a good thick layer of gravel on it??? Kinda looks like marks from driving through loose thick gravel......Just taking a guess on your last photo......

The second pic is not from my unit. it belong to someone else I know. Most newmar parking lots of gravel. the line is there by running your hand over it. it is obvious starting to wear.

[ghaynes754]

RD have you thought about sending your photo to customer support at Michelin for an opinion?