Tires not riding level on '88 T1550

[Merv]

The wheels on my '88 T1550 are kicked out at the bottom about 2 inches. Is there a way to adjust the caster/camber ( I think it's called ) of the tires? Already redid the bearings hoping it would solve the problem but it did not. Any input would be appreciated, thanks.

[Steve Collins]

Bob, is this the same on both sides of the trailer?

And is it really a full 2"? By that I mean looking at the tire from the front or rear of the trailer, what is the dimension that the bottom is out from the top of the tire? You may have to discount the "radial bulge" to figure this.

A couple of pictures would really help here, both of each tire, and several of the axle and springs taken from different views.

This is a very abnormal condition, but I think we'd all like to see it before offering comments, etc.

[JohnB]

Hi Bob

I have done some TT axle aligning before and may be able to help. But like Steve, man if your 2" is really a wheel that far out there are some major issues.

To aligning an axle, this post may be more then you asked for but it is how I did mine. http://www.sunlineclub.com/forums/f7...ics-10043.html

Truck shops can align them too. Pending what is wrong will dictate how they fix it. There is not actual adjustment in the stock configuration. If a spring hanger is in the wrong location (yes this is common) the repair shop will cut it off and weld on a new one. If the axle has lost camber then they can bend camber back into it. If you have a toe in or toe out condition they can bend the axle tube to align.

If you have the tools and shop space you can also buy a brand new axle tube that is in spec or suppose to be for around $100 plus all your labor and everything else you fix while your under there. A truck shop could charge $350 to $1000 pending what it is they have to do. Since you only have 1 axle it get's cheaper.

There is no caster on a TT as the wheel do not turn like the front of a car.

Hope this helps and good luck.

If you can post some pics of this 2" and how you measured it I may be able to help more.

John

[Merv]

Steve and John,

Thanks to both of you for your input. I'm trying to get pics.

Using a level, I've measured the difference top to bottom of the rim. I placed the level at the bottom edge of the rim, moved it out until it showed level, then measured in to the top edge. I measured a difference of 3/4 of an inch on the passenger side and 1/2 inch on the driver side. It seems as though they are bent.

This single axle trailer does not have an axle tube as shown in the pics, but uses a spindle setup similar to the front wheels of a car. I guess my best bet is to have it looked at by a pro.

When I got the TT, the tires on it were completely worn down on the inside tread. The outside of the tread was barely worn at all. I don't know for sure, but the tires may be the original ones since the tires were the identical bias ply size and brand shown in the manufacturer's build sheet, which came with other paperwork in the trailer. If they are they would have been 22 years old. I've since replaced them, of course, with the appropriate radial tires. I haven't gone far enough to see any wear yet.

There is nothing loose and no wobble from the wheels. The trailer tracks perfectly behind my pickup. If the only issue would be to replace the tires every few years, it would be ok with me. I was hoping to find an easy solution to the camber problem.

Thanks again, Bob

[JohnB]

Hi Bob

OK you have given some good info now, just I'm missing 1 piece of info to turn the field measurements into an actual camber angle. If I understand the measurement right on what you did you used the tire rim as a place to measure to from being plumb. Is this correct?

A few questions:

1. Was the TT on level flat hard surface when you did this? Reason is if the TT is on pavement that is tipped or uneven then it will affect the total camber angle measuring the wheels this way.

2. What is the rim OD where you took the measurements? If I know the rim OD I can then do the math to figure out the camber angle using yours 3/4" and your 1/2" from level and see how good or bad that is. Again assuming the TT is on flat level pavement when you took the numbers.

3. Also tell me, the 3/4" and the 1/2" was this gap at the top of the tire or the bottom? This will help tell me which way the wheel is tipped.

If you have an angle finder you can do this directly. If not then give me the rim diameter and I'll calulate it.

This is a cheap and quick way to measure camber at the wheel


And at the brake drum


I'm real curious on what kind of axle setup you have if there is no cross tube. I have seen that spindle type of setup you are refering to but not on a TT. This must be an older TT type thing. Maybe Sunline Fan can shed some light on this. A few pics here go a long way in understanding what it is you have.

Good luck and hope this helps

John

[Sunline Fan]

Originally Posted by JohnB

I'm real curious on what kind of axle setup you have if there is no cross tube. I have seen that spindle type of setup you are refering to but not on a TT. This must be an older TT type thing. Maybe Sunline Fan can shed some light on this. A few pics here go a long way in understanding what it is you have.

Hi John,

Every Sunline TT & FW going WAY back that I've ever seen has had an axle tube. I'm guessing a previous owner put something new on there or... I wouldn't rule out that either the tube got bent or the previous owner wanted more ground clearance, so they cut the center piece out, causing each spindle to bend outwards.

I'm anxious to see Bob's pics.

Jon

[Merv]

Gentlemen,

I hope to get the trailer up this weekend so I can get pics of the suspension.

Thanks for your insight.
Bob

[Merv]

I finally got under the TT to take some pics and discovered that there is an axle tube, but not like the one I saw in the pictures. The spindle does not come straight out the end of the tube but is set about 6 inches above center. That was causing my confusion. I've attached pics showing the tube and the inside of the wheel. Also have a couple showing the angle of the tire. I found no way to rectify this except by bending the axle tube. I don't know if it's worth the cost if the only problem would be uneven tire wear.

Thanks again for your help.
Bob

[JohnB]

Hi Bob

What you have is an older version of what they call a drop axle. The spindles and the cross tube are at 2 different elevations.

You can see here a more modern day drop axle.










If you want to know if you have a positive or negative camber problem ands approximately how much, get me the info on rim and which way the distance is in the replay I made up above in this post.

By yours pics unless there is an optical illusion going on… it looks like the tire is tipped in at the top. And if that is the case them the axle tube may have lost it’s camber settings. On the newer axles, I’m assuming the old one works this way as well, they bend the axle tube in the middle on purpose on a very shallow V. The creates camber at the wheel so the top of the wheel will pint out away from the camper. One way to loose camber is that some where in the campers life it was overloaded and the axle tube became straightened out. Even on a good working axle the shallow V decreases as the weight of the trailer goes up by the camper exerting weight at the spring seat. However if it is not overloaded it will spring back up in the middle when the camper is jacked up or the weight removed.

See this picture of mine. That is a 4 foot level across the tube centered with 2 feet each side. You can see the shallow V the axle is bent to.





Does you axle have any shallow V left? Or any traces that one ever existed? A straight edge would help confirm. If back then they did not do it on the axle tube then they would have done it at the spindle stub.

Hope this helps

John

[Merv]

John,

That is the axle I have. Did not know the correct term for it. I think, as you suggested, at some point the trailer was seriously overloaded, causing the axle to straighten out. Due to the current monsoon conditions we're having in NJ, I won't be able to check for the 'V' yet, but I will.

Aside from uneven tire wear, would this condition cause any other problems? As I said earlier, the TT tracks straight down the road, no swaying, no wheel hop, and nothing is loose. My plans are to use this one for a year or so, then get into a bigger Sunline. So, if I should expect nothing serious to develop, I may just use it as is.

Thanks,
Bob

[JohnB]

Well, if the axle was overloaded it could be bent in multiple directions. For axle camber, measure me the gap in the middle of the V if there is one and tell me the length of your straight edge that was centered left to right about the center V.

If you want to know if the axle bent at the wheel area, then do your level trick again but give me the rim diameter and the distance top and bottom from being true plumb. Just have the camper on hard level surface to use this method. Or use an angle finder like I showed you.

If you want to check the toe angle try this.

Start out marking the 9:00 and 3:00 location on each tire.


Take a tape measure and place on a tread high spot. Tape to tire. Do this at the 9:00 location on the front.


Pull tape across the camper, pull tight can read the number at the same high spot on the tread on the opposite tire at the front 3:00 position. Write the number down.






Then repeat the same process on the back of the tire. What you are doing is seeing how much toe in or out the wheels are in a general sense. This will give you a big picture look at the toe angle. Since you may be in an overloaded condition one wheel may be bent out more or less then the other. It gets a lot more complex to sort that out as you need a true straight edge the full width of the coach and set it up true to the axle tube and the determine square off of that to the wheel.

Partly like this


When you get that info we can compare it to the spec and see how far out in left field you are or not. This hand measuring is considered a rough check but done accurately can get very close.

Now is what you have OK? Since you say it tracks fine and does not wander (dog track) to one side, is must not be totally goofed up. Tire wear can be accelerated. The good thing you have on your side is your camper is not very heavy. Mine burnt up an unused spare tire from fresh no wear to only over 1/4" worn off in less then 4,000 miles. I had one wheel really messed up. Pending how many miles you have, it may be cheaper for you to just deal with the tire wear. A new axle tube is about $100, but then there is new brake plates. ~ $50, each wheel, new spring bushings while you are at it, pins and shackles, ~ $50-$75. Hopefully the brake drums are OK. ~ $65 to $80 each and then the labor to do it all and mark up on parts if you have them supply. Hoping the spring hangers are welded on right too. Your old ones may be made better then some new ones in this regard, or maybe not. To have the axle and all replace may cost ~ $500 to $800 at a truck shop/trailer dealer. RV dealer may even be more.

The main thing is to do a full inspection for any cracks in any welds on the tube or where the axle stub connects. Get a real good light and look really close. They may even be rusted now. If you have a crack, then that should be fixed as that can break down on you on the road and a single axle trailer break can be really bad. Check the springs out good too. If it went in overload to bend the axle, it may have cracked a spring. They doe sell dye penetrant to check for cracks if you really want to verify this for weld cracks.

With out seeing it myself I can’t tell you over the web. Just places to go looking. Key is, is it structurally intact?

Hope the helps.

John

[Merv]

John,

I checked for the 'V' in the axle. It is almost flat, with an additional bend in the side which leans out the most. I carefully checked for any cracks or stress fractures and found nothing. Aside from the bend and lack of 'V', all seems ok.

Took the TT on a 300 mile trip last weekend, after checking everything. I encountered no problems whatsoever. I think, as long as I keep an eye on the axle, I'm going to run it as it is.

Thanks so much for all your help!

Bob