Axle Replacement Question

[John and Jaci]

We have a 72 Boler. We are considering changing to a different axle and adding leafsprings. We would also like to change from the orriginal 13 inch wheels to 15 in if possible. It appears that we will have to shift the axle backward on the frame 4-6 inches to accomidate. Has anyone else done this? If so what did you do. Any information would be appreciated. Any pictures to show the process would be a help.

[Roy in TO]

If we knew the reasons why, we might better be able to give an opinion.

[John and Jaci]

There are several reasons that we are toying with changing the axle and wheel size.
1. Better ground clearance which gives the ability to drop the center floor for more interior height. This would also give possible room for a black water tank and plumbing. (we plan to remove the kitchen and replace with a wet bath.)
2. Leafsprings reportedly give a smoother ride with less bounce.
3. Larger wheels and tires provide better handling and safer in the event of a flat.
4. Larger wheel/tire would match the tow vehicle, ie the spare for one could be the spare for the other.
5. A wider axle would bring the fenders exterior and allow for more interior space. (we are terribly concerned with keeping it with the original look)
6. A longer wheel base on the trailer would provide better tracking and easier backing of the trailer.
7. We plan to add surge brakes, which requires changing the wheel/axle hardware.
8. The existing suspension appears to be at the end of its useful life
These are our reasons for wanting to do this, however our plans are not written in stone. We are working on taking it off the frame currently. Once we have it off the frame we will see better what we are working with. We are asking the questions since many of you have already done many of the modifications we are looking for and we would like reasons for and against our ideas. Any and all help is appreciated.

[Don N]

My Boler had 235/75R15 tires on it and I just replaced them with 205/65R15. Trailer sat too high. Didn't like the looks of it that high and it made for a higher step into the trailer. Think there was about 4-5" difference in height between these two sizes. Would the electric brakes not be easier to hook up than the surge brake?

[Donna D.]

3. Larger wheels and tires provide better handling and safer in the event of a flat.
4. Larger wheel/tire would match the tow vehicle, ie the spare for one could be the spare for the other.

I went with 15" tires for both of these reasons. Boy was I wrong on one of them.

Hoping to go down to one spare and use for both was wrong. I have disc brakes on my tug and the offset on the wheel that's necessary won't work for the trailer... the wheel rubs on the frame. And to fit on the trailer, it won't fit on the tug. So, I'm back to two spare.... sigh.

[Dana T]

Donna, even though the idea of using the same spare for the tug and trialer didn't work for you, it can for John & Jaci D. if the new axle they order has the proper hub to hub spacing.

However, another thing they have to watch out for is the pilot hole size (the center hole in the wheel) -- it needs to match the hub on the new axle. So when they order the new axle they need to specify the hub that matches the tug's wheel pilot hole size.

[Donna D.]

You could be right Dana, in my case it wasn't going to work because the Scamp has fender covers. An open fender would have made it easier. But the wheel and tire had to fit between the frame and fender cover. Too much of a back space on my Tug wheels to fit and it wouldn't be possible to order an axle to make it work as the axle would then be too wide.

This diagram may help those considering this "one spare" option:
Wheel Cross Section

[Roy in TO]

There are several reasons that we are toying with changing the axle and wheel size.
...
We are asking the questions since many of you have already done many of the modifications we are looking for and we would like reasons for and against our ideas. Any and all help is appreciated.

John and Jaci, I'm not sure I agree with all your reasons etc.. I'm very happy having gone with electric brakes on mine when I swapped the axle on my boler American. I did raise my trailer and I could have gone with a slighty larger tire without modifying the wheel well. But I was trying to keep everything looking stock while raising the trailer a bit. You can tinker with the wheel sizes and down angles of axles to get just the right fit. Once you've raised the trailer you will have at least 6-8" height below the dining area to place a water tank between the frame rails. Here is a link to what I did on mine. Let me know if you want the excel spreadsheet where I plugged in numbers for various down angles and wheel sizes and the effect on wheel height.

[Michelle A]

I'm also quite curious about this modification. The bounce in my 75 boler is a bit rediculous. The constant shifting has caused some cracking in the fiberglass, not to mention the fact that the closet doors come open and spit the contents all over the floor. We would like to have it painted, but my father (autobody mechanic) thinks we should fix the suspension first to prevent further damage to the fiberglass.

I'm curious if a leaf spring suspension would be more stable than a new torsion bar suspension. Any thoughts??

Michelle

[curtis c]

wow... where to begin on this little number.. torsion is far smoother than leafs. Shifting the Axel back will change the entire hitch weight geometry ... A wider wheelbase will not (noticeably) change how it backs up. length from tongue to axle changes backing track. Also making the rim tire size the same as the rig to use as a spare is kinda overkill. Not to mension you would have to use the same rim style as your vehicle. Go with a torsion and save yourself a headache. Leafs are garbage... unless you plan on taking it through the Rubicon or some kind of expedition trail even a leaf with shocks is not as smooth as a dexter torsion. just my 2 cents tho.

[Roy in TO]

Michelle,
The new axle made a major difference in ride on mine. All but one of the cupboards stays closed and most things remain where we put them. The one exception is the tall closet door and I know the reason for that. When I did my body sag fix I squared up the closet from its original twisted install. That put the latch just enough out of alignment that it does not always fully latch. One of those little things I've got to get around to fixing.

We now know the early axles were under rated. The specs on my boler American were 850 Lbs. with a 1200 Lb axle which gives a 350 lb payload. Jean L weighed his boler American and it comes in at 1450 Lbs without a load. Add 350 Lbs of gear to that and the axle was overloaded by 50% for 30 plus years. Upgrading to the 2200 Lb axle should compensate for that.

The cracks might be due to flex, have a real close look at your frame for cracks and double check the floor for integrety. Jean L reports a difference in body rigidity after replacing his floor.

[james kent]

Like Roy, we replaced our axle last summer and upgraded it as well. What a difference! The higher capacity axle doesn't bounce near as much. Using proper trailer tires and not just automotive tires will also make the trailer more stable. It would be easier to raise the trailer by adding a spacer between the axle bracket and the frame than to go to larger tires and cutting a larger well opening.
When I towed with a Safarri van I had a lot more sway than with our present Dakota pick-up. I think that the different ratio of hitch to rear vehicle wheels has made the difference. Now it tracks better and even backs better. [or I'm just getting more practice] Changing your axle position may give you a whole new set of headaches. How handy are you at doing FG work? You may have to cut out and relocate your wheelwells. A tongue extension might be easier if you really need the extra length.

[John and Jaci]

This is exactly the information and discussion we were hoping to generate with our questions. We have lots of ideas none of which are set in stone, but wanted to hear the good and bad from the folks who may have actually tried some of the ideas that we are toying with.
Roy, we would love to have the spreadsheet that you have developed with the information related to down angles, wheel size and the effect on wheel height. If you could email it to us at jad1547[at]aol.com we would appreciate it.
A lot of what we decide will be based on information from this website besides our own additional research. We know that some of our ideas are a bit different than most such as the wider axle, but thats part of the uniqueness we are searching for. We had considered building a fiberglass trailer completely from scratch before finding this boler for sale. John has all the welding, fiberglassing and mechanical skills needed for us to complete the task. He was an aircraft mechanic in the navy for 21 years and he figures that if his fiberglass repairs did not break on aircraft going 600 mile/hr it should hold just fine on a camper going 60 miles/hr. Thanks again for all the comments. Keep the ideas coming.

[Roy in TO]

File Sent. Sorry for the delay, we were at bolerama for the weekend.

[John and Jaci]

Thanks for sending the file. We got the camper off the frame and the axle will definately need to be replaced. In John's naval aviation terminology, the wheels were in the up and locked position...... No wonder why the step up into the camper was only about 5 inches.... amazing that we didn't bottom out and drag the frame on the way home. Thanks again

[Roy in TO]

We got the camper off the frame and the axle will definately need to be replaced.

You are welcome. Don't forget the numbers in the spreadsheet also include the 4" lift required to install a trailing arm axle.

When you get the axle off please try to cut through the main beam and get a picture of the shape of the rubber. I'm sure we would all like to see the effects of 37 years.

In my excitement of finally getting my new axle installed, I forgot to get a picture until it was too late.