Tandem Axle Alignment Issue

[Gearhead62]

Inspecting my tandem Shoreliner recently. I suspected something when observing the front (or rear) axle might be out of "true". I held a straight bar horizontally against the left tires, then the right tires...sure enough, there is a measurable difference of 1/2" gap (off plane) between fronts and rears, on both sides. Would this create extra wear or would I feel a pull while towing?________

I have axle system where the U-bolted "dual spring / tandem axle assemblies" will slide fore and aft, but also have the spring centering pin at the U-bolt clamp to axle...Won't that pin prevent me from adjusting left / right? Or do you just muscle it back to even plane?__________

Maybe sliding the spring / axle assembly on one side fore or aft will correct it? Square it up?

I gotta get the tape / line out and start measuring from ball / tongue to frame points, hubs, and get some readings, but just inquiring on those axle assemblies, as I'd like to try and tackle this myself. Will get some pix also if I'm not explaining correctly.....Thanks in advance for any advice

 

[smokeonthewater]

Re: Tandem Axle Alignment Issue

If the trailer was being pulled in any sort of a curve when parked the axles would be out of line.

If you want to measure you will have to jack the trailer up by the frame till the tires are off the ground to let the suspension unload

 

[UncleWillie]

Re: Tandem Axle Alignment Issue

Are both sides out in the same direction or are the front tires pointing Inward on both sides.
The axles are pinned to prevent anything going out of alignment unless something gets bent.

I don't know if they do it in trailers, but you will see the same thing on your auto.
The front tire will be "Toe In" compared to the rear.
Dead straight ahead will cause the tires to flutter like a shopping cart in some circumstances.
It also compensates for the crown on the highway surface.

If the tires are not wearing out the right edges on both fonts and left edges on both rears, or vice versa, I would not worry about it.

 

[Gearhead62]

Re: Tandem Axle Alignment Issue

Thanks for responses... Just for clarity on what I measured, axles are not tracking in-line perfectly........

If I'm standing above the trailer looking straight down, front axle is out 1/2" to the left of rear axle, and rear axle is 1/2" offset to the right of front axle, or maybe both are a 1/4" off dead center. I have to measure and closely examine the geometry.. something is out of whack

 

[T_Herrod]

Re: Tandem Axle Alignment Issue

As stated earlier be sure to jack up the trailer to allow the suspension to unload.

 

[UncleWillie]

Re: Tandem Axle Alignment Issue

Now I get it!
The axel are offset laterally.
If they are both pointing dead ahead and the tire wear is normal, the offset would be of little concern.
Make sure any side load is relieved and check again.
Measure the distance between the centers of each axle on both sides. Should be the same.

 

[buckhorn7]

Re: Tandem Axle Alignment Issue

Run a string line down the center of the frame to help with measurements.

 

[lckstckn2smknbrls]

Re: Tandem Axle Alignment Issue

Flip one of the axles, which ever is easier to do.

 

[Thalasso]

Re: Tandem Axle Alignment Issue

Trailer Tire Problems & Tips
You don't jack the trailer up.

Trailer Tire Problems & Tips

Trailer Tire Problems? Check the Axle Alignment. It's easy!! Does your trailer eat tires? Are you frustrated because no one knows why? If you’ve checked all the ...

 

[smokeonthewater]

Re: Tandem Axle Alignment Issue

You don't jack the trailer up.

With a tandem you absolutely HAVE to so the suspension will unload and center... then let it back down to do the measuring

 

[Thalasso]

Re: Tandem Axle Alignment Issue

With a tandem you absolutely HAVE to so the suspension will unload and center... then let it back down to do the measuring

You didn't say this in your original post. It leaves someone (at least me and i know better) to believe that measurements are done with suspension hanging.

 

[bruceb58]

Re: Tandem Axle Alignment Issue

I would get a measuring tape and measure the distance between the 2 axles at the springs on each side. This will tell you if they are parallel with each other. They should be identical. Even better would be to measure center to center of the axles at the axle nut threads if you can do that.

Don't bother measuring the tires as there is too much variance between 2 tires.

 

[bruceb58]

Re: Tandem Axle Alignment Issue

Now I get it!
The axel are offset laterally.
If they are both pointing dead ahead and the tire wear is normal, the offset would be of little concern.
Make sure any side load is relieved and check again.
Measure the distance between the centers of each axle on both sides. Should be the same.

I agree. This won't matter one bit if this is the case.

 

[Gearhead62]

All good feedback... Measured and did some adjustments.....Think its straighter / better,..............

Now for last adjustment, I'm need to slide my tandem axle assemblies back 4-5", to get some more tongue weight and I need some guidance, tips. Of course my boat is on the trailer. Might be crazy to try and move axles while on trailer, but it needs to happen. I have plenty of jacks and stands. Appears I'll have to support both sides of trailer to get clearance and then move it. Any experience out there that can give me some instruction and guidance? Each side assembly has 4 U-Bolts (thread down) supporting the sliding tandem axle / springs on rails, and even with all tires off, its damn heavy.......Thanks

 

[Gearhead62]

Anyone?

 

[Bondo]

Anyone?

Ayuh,.... Jack up the trailer frame, loosen the u-bolts, 'n slide/ roll the tandem back, retighten the bolts, 'n remove the jacks,...

 

[Thalasso]

Anyone?

If i were doing that i would have slid them back before aligning. You will probably going to need to adjust after it's done

 

[Gearhead62]

Completed... I was really looking for some helpful procedures or methods on the process...

....I won't recommend attempting this while a 21' boat is on trailer. I had the trailer hitched to a truck for stability purposes, and had 2 jack locations on each side, supporting frame. That's where it got challenging and that's the guidance I was looking for - trying to find jack locations (frame, cross-member, axle?) and then raise frame, mid and rear simultaneously, so frame wouldn't arc or sag, but it made some crazy noises under stress....then walked tandem assembly back, re-tightened, test drove, etc

Have adequate tongue weight now - rodeo effect is gone
GH62

 

[smokeonthewater]

when I last did this I didn't jack anything up... removed bolts (mine didn't have ubolts... oiled the parts, and used two come alongs to slide the subframe back with the full weight of the oat on it all the time...... lined up bolt holes with a drift and replace the bolts