trailer alignment

[OldCoot]

Originally Posted by rgmiller32

Our trailer was still under the warranty also. The thing you must check is if you weight equally on both sides both empty and loaded with your stuff. When loaded and ready to roll we were heavier on one side. Still within limits but this causes the springs to flatten more on one side and change the aliagnment more on one side.

On a solid/straight axle, I don't think the load affects the alignment. It does on a steering axle, but not a solid/straight axle like on a trailer or a rear drive vehicle.

[davel1971]

Originally Posted by OldCoot

On a solid/straight axle, I don't think the load affects the alignment. It does on a steering axle, but not a solid/straight axle like on a trailer or a rear drive vehicle.

I'm with you on this one. If load on a solid axle changes alignment, you need heavier axles

[ResQfrog]

If the spring did not change length as it is loaded, you would not need a rear spring hanger. As a leaf spring is loaded it becomes flater and longer. This also causes the center spring pin to move back some. Causing the center line of the axle to move back slightly. So if one side of the trailer is loaded more than the other, you can have one end of a axle pushed back slightly more than the other.

This is one of the reasons truck arms and coil springs work better in oval racing. The rear axle stays in a truer arc when in travel. With a leaf spring you need to figure in the loading and length changes.

All this length changes might not be a great amount but every little bit adds up. 1/4" can cause a tire to wear.

[davel1971]

Originally Posted by rgmiller32

If the spring did not change length as it is loaded, you would not need a rear spring hanger. As a leaf spring is loaded it becomes flater and longer. This also causes the center spring pin to move back some. Causing the center line of the axle to move back slightly. So if one side of the trailer is loaded more than the other, you can have one end of a axle pushed back slightly more than the other.

OK, you got me there. Didn't think that far into it. Lets just hope the manufacturers don't build them that lop-sided and people are mindful of how they load them.

[OldCoot]

The springs are fixed in the front and the axles are positioned closer to the front on the straight/flat section of the spring to minimize movement front to back. Also the springs are relatively short to also decrease axle front to back movement. I would venture to say the front to back axle movement from a full load to full relax is less than 1/16".

[davel1971]

movement will not be determined by spring length, but by length of hanger, plus any bushing movement

[1Texan]

I just saw this post and am wondering if alignment could be my problem. I have a 29 ft. 5er with a dry weight of about 6850. The right front tire is wearing on the outer and inner edges almost like it had low air pressure. I know it doesn't because I always check it. This is the second tire that is wearing like this in about 3000 miles. Other 3 tires show normal flat wear. The trailer is about 2 1/2 inches high off level in the front. I first thought this could be from tire squirm on corners but that is a lot of wear.

Any ideas????

[davel1971]

since you have had 2 tires do this, you have eliminated being a bad tire. Only thing left it axle/align issue. My dealer is still being very uncooperative, but I have been communicating by E-mail with Forest River Warranty Administrator and so far seems very willing to help. Have been sending him lots of pics. Should get my next reply today. I will post what their decision is.

[AquaMan]

Originally Posted by 1Texan

I just saw this post and am wondering if alignment could be my problem. I have a 29 ft. 5er with a dry weight of about 6850. The right front tire is wearing on the outer and inner edges almost like it had low air pressure. I know it doesn't because I always check it. This is the second tire that is wearing like this in about 3000 miles. Other 3 tires show normal flat wear. The trailer is about 2 1/2 inches high off level in the front. I first thought this could be from tire squirm on corners but that is a lot of wear.

Any ideas????

Were both tires mounted to the same wheel? I'm just guessing here, but could it possibly be a wheel issue? Right front would take all the abuse if you were to have hit a curb or something. Also, do you have torsion axles, or leaf spring mounted? Alignment is fairly easy to check with 2 people.

[davel1971]

may be making progress with my tire wear issue. Since dealer was not willing to do anything, I contacted Forest River by email. Responded next day. Sent them lots of pictures of tires. He forwarded all stuff to Lippert. Now I have been emailing them back and forth a few times a day. I have a reference number for dealer to contact them with to get this settled when I take TT there on the 11th.

[BigBaron]

FR customer service IS good, isn't it? I'm a PITA to them, but they have worked hard to take care of me. I'm glad they are taking care of you, too!

[Thurman]

UM, UM, UM. Having worked for a company that built custom order trailers I can say this: ALL pull type trailers we made regardless of length, width, weight load, number of axles and other factors were constructed taking into consideration that the axle(s) had to be in alignment with the coupling point within 1/8" period. Consider that we made trailers with ball type couplings, pintle hitch couplings, drop-in pin couplings ALL trailers had to have the axles aligned within 18" of the coupling point. Measurements were taken from the center of the coupling point to each end of each axles spindle (where the spindle nut screws on). If the measurement was over 1/8" between the spindle ends of an axle the necessary adjustment was made to correct this--on each axle of every trailer. Also-the axles we bought had built-in camber which we checked after trailer construction. These axles were bent slightly into an upward arch which causes the top of the tire to measure 1/8" to 1/4" depending on the trailer. Now--can one end of an axle get ahead of the other end and cause tire wear on one side only? Yes. Can the camber of an axle change over due time causing strange tire wear on a trailer? Yes. I've seen each of these on trailers with odd tire wear. Can the alignment of a pull type camper axle measuring from the coupling point to the end of each axle be checked? You betcha, even in your driveway, but a truck/bus shop can do it easy and quickly. Can this measurement be changed? Yeppers. Unbolting the axle from the spring hanger and using "persuasion" can move the axle into proper alignment. IF the camber changes on an axle can this be corrected? Not unless you find a shop that can remove the axle, strip the axle down, measure the camber arc and re-arc the axle. The camber arc does not change too often on axles though. So the bottom line question seems to be: Can the alignment on my pull trailer be checked and/or corrected? Yes.

[davel1971]

Thurman, thanks for all the info. Good to hear what I knew was true from someone that was in the business. Luckily for me, Forest River and Lippert have been very willing to want to help me. Unlike my dealer. As long as the manufactures are behind me, I should come out good in the end.

[GOTTOYS]

I wouldn't spend any money on a Correct Track. That system will only adjust the axles front to back, called tracking. It will not allow any adjustment for camber, or individual wheel toe in or out. A quality alignment shop can adjust all 3 of these. I recently had mine done and both axles were tracking to the left, making my trailer pull slightly sideways, one wheel was also towed in more than the others and the camber was off on one wheel. Don't waste your time at an RV dealer they don't have the equipment for this and will only try to sell you a new axle which still will not always make it right. I don't doubt that mine was off when delivered new. I cost about $200.00 form a shop that does, big trucks/trailers, buses and RVs. Money well spent...

[davel1971]

They aren't selling me and I'm not buying anything. It's only 10 months old. It's under warranty, that's why I contacted customer service.