Shredded edge of tag axle tire

[CAllingham]

My wife and I were at the mall today practicing the alley dock backing maneuver for our upcoming California Non-Commercial Class B 45' Housecar driving test, a requirement here for coaches larger than 40 feet.

We completed the 90 degree back-in from the left quite a few times, and while standing outside the coach while my wife was backing, I noticed the phenomenon where the tag axle does not lock in the straight position and I could see the left rear tag axle tire rolling over on the outside edge of the tire. What I didn't notice until we were all done was how much damage this caused to the tire.

Attached are some photos. Before running down to the truck tire store, I thought I'd ask the experts here for some opinions. Have we ruined the tire?

[mahdi]

Did you have your tag switch on "auto" or did yo have it off? As far as the tire is concerned, I would get the opinion of a truck tire expert preferably Michelin.

Hopefully, more experienced tire members would give more detailed opinions.

[CAllingham]

Originally Posted by mahdi

Did you have your tag switch on "auto" or did yo have it off? As far as the tire is concerned, I would get the opinion of a truck tire expert preferably Michelin.

Hopefully, more experienced tire members would give more detailed opinions.

Tag switch was set to "Auto".

I am sure there were several instances where we did not pull forward enough for the tag axle tires to straighten out before going into reverse so they could lock in place, and there were several instances where we really had the front tires cranked hard to the left to swing the back end into the 12' wide box, resulting in this scrubbing action.

[Dutch Star Don]

To some degree, that happens every time you turn the coach while driving. However, you make a turn and then go straight for many miles, smoothing off what was torn/shredded during the turn. In your situation, you made repeated turns without driving on the highway in between.

I'm also very cautious about forcing the tag the wrong direction after turning and then trying to back up with the tag still turned. It puts a lot of stress on the steering unit.

[Suburbazine]

You have illustrated why steerable tags are a terrible option. The tire isn't shot, but you've shortened its lifespan and weakened that section to puncture damage.

Lift tags get you exactly the same steering benefit without scrubbing the heck out of the rubber when you back up.

[Dutch Star Don]

I have to disagree. My steerable tag has over 35K on it and is no more worn than what the front tire sees from steering. The dumping/steerable tag increases the turning radius by 10%. I just don't see the downside. Lifting tags had plenty of issues.

[NXR]

Originally Posted by Dutch Star Don

I have to disagree. My steerable tag has over 35K on it and is no more worn than what the front tire sees from steering. The dumping/steerable tag increases the turning radius by 10%. I just don't see the downside. Lifting tags had plenty of issues.

Increases or decreases? I'd see anything increasing the turning radius as a downside. I really do not know.

Our 38' gasser on a 242" wheelbase only has a 42 degree wheel cut. The Ford manual says it has a 72' turning diameter, so 36' radius. I sure wouldn't want to increase it anymore.

On the plus side, we worry less about tail swing.

Ray

[UMXHAULER]

I have found that with these steerable tag axles it is very important to make sure the coach is going straight for a few feet before attempting to back up so the tag has time to lock in the straight position. Also, point a mirror so you can see the tag and if it starts turning when you begin to back up, it is not in the locked position-move straight forward a few feet and attempt back up again. For example, it you are trying to turn in a culdisac that is too small and you begin the left turn but then need to back up in order to do a three point turn, make sure you turn the wheel straight the last few feet going forward before you put in reverse to lock the tag and then back up. I can imagine a situation where you would not have the room to do this and in that case, you will be forced to drag the tag tires in the wrong direction and that is what I think you did but it is what it is.

[CAllingham]

Originally Posted by UMXHAULER

I can imagine a situation where you would not have the room to do this and in that case, you will be forced to drag the tag tires in the wrong direction and that is what I think you did but it is what it is.

Yes, this was exactly our situation, and I could see it happening in real time and knew it was not a good thing.

I guess what I'm really after here is an assessment of the damage to the tire. I visited a commercial tire place and show him my photos, he said he'd need to see the tire in-person. Not sure when I'll be able to do that. In the meantime, I think I'm going to snip off those thin little danglers hanging off the edge of the tire.

[96 Wideglide]

Originally Posted by Dutch Star Don

Lifting tags had plenty of issues.

I've had zero with mine!

[Rd1]

I have observed the tags on my own unit as well as others during backup literally lay on their side at full lock! These were both at Freightliner dealer as well as Newmar dealer when their own drivers were not familiar with the backup procedures. However, I have never observed tire damage to this extent. There is certainly tire edge damage as is obvious in your picture number 3, less the chunk falling off. The tag tire edge wear is very common on these passive steer tag axles, some worst than others.

It would help to see the tires surface and not just the side view. From your write up, it seems this damage is only present in your driver side tag tire? And not the passenger side? At least tire chunks falling off.

When the coach is backing up, do you actually hear the air from the airbags getting dumped? The switch maybe in auto, but there could be problems with the airbag solenoid not releasing the air from the airbags.

You can also perform a simple test. Drive dead straight forward. Stop and go on revers dead straight for a few feet, then hard right and observe if the tag wheels maintain their straight lock. Do same steps with a hard left. If you are standing behind and observing, you should see if the tag wheels loose their integrity in maintaining dead straight position. There could be problem with one of your lock straights for either of the tag wheels.

The ride height on your tag axle/rear axle maybe off.

[Dutch Star Don]

I meant to say decreases the turning radius by 10%, I believe the actual number is 12%.

[Dutch Star Don]

Originally Posted by CAllingham

Yes, this was exactly our situation, and I could see it happening in real time and knew it was not a good thing.

I guess what I'm really after here is an assessment of the damage to the tire. I visited a commercial tire place and show him my photos, he said he'd need to see the tire in-person. Not sure when I'll be able to do that. In the meantime, I think I'm going to snip off those thin little danglers hanging off the edge of the tire.

That tire has a boatload of rubber on that edge. It will be fine.

[Dutch Star Don]

Originally Posted by 96 Wideglide

I've had zero with mine!

What's your point, my turning tag has had zero issues. But people have had issues with lifting tags in the past and will have issues with turning tags in the future. Neither are bullet proof as one poster suggested.