Bushtec Road Star with broken Torsion bar, Help

[M61A1MECH]

On my way to WingDing I thought I heard some clunking frommy trailer, I did not see anything obvious and passed it off as the hitchclunking. Today when I stopped at Spartanburg, SC on the way home fromKnoxville, I grabbed the left wheel and it was "floppy", I found thetorsion bar is broken at the weld where it attaches to the frame. The trailerpulled fine all the way up to Knoxville and down here to Spartanburg, so now Ihave a couple of questions.

 

1) Has anyone else had this issue? If you did what did youdo to repair it? Looks like it could simply be welded back in place.

2) Any thoughts on how safe it is to tow this the 480 or somiles back home.

 

Thanks for any thoughts and inputs.

[SpencerPJ]

If the torsion bar is where the spindle is, that holds the wheel on, and it's cracked or needed a weld back to the frame, I sure wouldn't drive 480 miles. Stop at a truck stop, they'll weld it quickly for you.

[M61A1MECH]

Not at the spindle, but at the aft end of the trailer where there is an L bracket where both left and right torsion (sway) bays are anchored. I pulled it home today from Spartanburg, SC to Edgewater, FL, 490ish miles. Set my mirrors so I could see the trailer and the left wheel for any funny stuff starting, no issues, ran at interstate speeds and checked it at every stop. Tomorrow I will take the cargo box off and photograph the issue. If I have room to get tools in the space I think I have a fix worked out, but still want to talk to Bushtec first, but they are not open again until Tuesday.

More to come.

[M61A1MECH]

OK, I did some more research over on the Goldwing site and then reinspected my trailer and here is what I found.

What I originally thought were solid cold rolled rods with turned down ends running fore and aft parallel to the main frame tube are actually hollow tubes with a long "pin" running down the center, the pins are what go though the frame supports and are welded in place. There are supposed to be bushings in each end to locate the pin and tube relative to each other. Looks like the bushings on the left side of my trailer disintegrated and that allowed the tube and wheel to flop around.

 

Evidently the fix is to remove the welds and remove the "pin", replace the pin with a new one and install new bushings and weld the pin back in place.

 

I need to talk with Bushtec on Tuesday to see if I can purchase the parts I need to do both sides, also want to know if it is possible to thread the ends of the pins and secure them with nuts instead of welding. That would make future replacements much easier.

[djh3]

When you get some pictures Steve I would be interested in a look see. If it has a pin through it, I think you may be able to work out a plan to use a grade 8 bolt or some way to sleeve it and bolt. The axles on my Legends car were a shortened OEM Toyota. They cut the solid axle shaft and welded a tube/sleeve over it. Best way use racers figured out how to do this was drill a hole thru the tube, so when you had it together you could weld around end and at drilled hole fo a bit of extra.

[M61A1MECH]

Dion, look at this link this the same issue as I have, http://www.sheriart.net/honda/bushtec

I am thinking that if the SS rod is a standard size that can be threaded I can skip the welding of the rod to the frame and make any future replacements easier.

[M61A1MECH]

I have the trailer upside down, found out the wiring harness is threaded inside the tongue, so no taking the cargo box off to make this repair. The pins are removed, was not to bad once you figure the best way to do it. I took a dermal with a cut off blade and cut the welded ends off as close to the support plate as possible. I then ground down the residual weld until I could see the outline of the pin. Once both ends were done, I simply took a drift punch and hammer and knocked the pin out as far as possible , then pulled it out the rest of the way with some sturdy channel locks. On the side that was loose and making all the noise , there was nothing left of the bushings, on the other side that was still tight and quiet, the bushings came out in pieces. I have decided to forgo talking with Bushtec and I am going to replace the pins with 5/16" 316 stainless steel all thread, install some marine grade bronze flanged bushings from McMaster Carr and shim up the gaps with PTFE and 316 SS washers as needed to get a proper fit. The all thread will be kept in place with double heavy duty 316 SS nuts and a generous application of blue Locktite.

I expect that I will need to re-size the locating holes in the frame to accept the 5/16" (.3125") all thread as the current holes are sized for a .310 rod, but that will come after I receive my threaded rod and check the fit.

I am taking photos as I go, so if it all works out swimmingly I will post a DIY Bushtec Bushing repair manual.

 

Attached are some photos of the disassembly.

Edited September 3, 2018 by M61A1MECH
Spelling

[Flyinfool]

SS threaded rod is not very strong, and certainly weaker that solid steel rod.

 

I would put a new 5/16 solid rod welded in with new bushings but add a grease Zerk to each side and fill the tube up with grease after welding to lube and prevent rust. Then it will likely outlive most of us.

Edited September 3, 2018 by Flyinfool

[Freebird]

So what you are saying is that SS threaded rod is weaker than SS threaded rod?

[Flyinfool]

Oopie, brain cramp, I went back and fixed it.

 

My brain knew what it was saying but my fingers went ahead and did their own thing anyhow.

[M61A1MECH]

SS threaded rod is not very strong, and certainly weaker that SS threaded rod.

 

I would put a new 5/16 solid rod welded in with new bushings but add a grease Zerk to each side and fill the tube up with grease after welding to lube and prevent rust. Then it will likely outlive most of us.

 

Thanks for the input.

 

And I thought about all of that before making my decision. I may investigate a place to put a zerk fitting in, just not sure there is enough wall thickness to get sufficient thread engagement in the tube and no guarantee the grease will go where it needs to go, it is a2 foot long tube to fill up, that is a lot of grease. I plan on sealing the ends of the tubes with compliant spacers to keep moisture out, and will lube the bushings and tube prior to assembly, if needed I can easily remove the tension on the threaded rods and apply lube to the bushings and then re-tighten the whole affair.

 

Just for clarification, the rod that came out is not stainless (based on my very crude magnet test) and it is only .310 in diameter. I looked at the rating of a carbon steel shaft in the McMasterr Carr web site it is 70,000 psi, the rating for 5/16 316 SS threaded rod is also 70,000 psi. The effective areas are different for a solid rod verse threaded rod. I calculated the tensile strength of the .310" steel rod to be approx. 5283 lbs, the 5/16 SS Threaded rod worked out to 4200 lbs, Using a basic rule of thumb that the shear force rating is .70 of the tensile the original steel rod worked out to be 3698 lbs in shear and the threaded rod to be 2940 in shear. So I think I may have lost about 20% of the safety factor.

 

The loaded trailer probably weighs less than 500 pounds and each of the rods support 1/2 of that in a static condition, not sure what implied loading could be when the trailer hits a pot hole, but in my mind there is enough safety factor.

 

But I agree with your hypothesis and would have gone with solid rod if I had a welder handy, but I do not, and cannot move the trailer without the rods being secured. If I find out my plan does not work, I could simply purchase the 5/16 solid rod later and tow the trailer to a local welder and have the all thread swapped out for solid rod and welded in place.

[Flyinfool]

The other thing to consider is that the tips of the thread make a lousy bearing surface for inside of the bushings. I wonder if you could fill the threads up with brazing rod for the area that will be in the bushing and sand it smooth using a drill as a lathe?

[M61A1MECH]

The other thing to consider is that the tips of the thread make a lousy bearing surface for inside of the bushings. I wonder if you could fill the threads up with brazing rod for the area that will be in the bushing and sand it smooth using a drill as a lathe?

 

Yes , I was having that same thought, the crest of the thread may create fretting and point loading on the ID of the bushing, the other issue will be getting the threads through the bushings and spacers without damaging the bushings and such. The control arm does not have a very large range of motion, but depending on the road conditions, there may be a lot of high frequency oscillation.

If I can fill the threads, I can most likely jig the rod up in my wood lathe and get a nice finish.

[Flyinfool]

As for getting the new rod thru everything, did you notice that one end of the original rods was ground to a point to help it find its way thru everything?

[M61A1MECH]

The other thing to consider is that the tips of the thread make a lousy bearing surface for inside of the bushings. I wonder if you could fill the threads up with brazing rod for the area that will be in the bushing and sand it smooth using a drill as a lathe?

 

Well that got me thinking a bit more, here is a new plan. I will buy the "axle" rods from Bushtec and thread the ends of them and secure the "axle" rods with the nuts and Loctite.

I can then make the trailer road worthy enough to pull it to a local welder and have him tack the nuts to the frame member to ensure they will not come off. If I ever have to service the bushings again, it is a simple matter to cut the tack welds and remove the nuts and rods.

 

I just went out and took one of the rods I removed yesterday and threaded one end pretty easily with a hand held die, if I had some real cutting fluid it would have been even easier, WD40 and honing fluid is only so good, but allowed me to prove out a theory.

 

"As for getting the new rod thru everything, did you notice that one end of the original rods was ground to a point to help it find its way thru everything?"

 

Yes I saw that, I figured I could manage the square end, I am sure the point is more to facilitate speed of production than anything.

[djh3]

Quickly reading thru this and I got kind of lost in description. But I get your going to install brass bushings in the A arms in front instead of the rubber ones. I would do the same in the back if it was me. I dont know if you have access or can get the arms out. But what if you had a threaded "bung" essentially its a nut inside a tube at the point you would need and use a shanked hardened bolt thru the bushing. Sounds like you have a plan anyways. Rubber bushings are both cheap and quiet. But long lasting they are not, and it dont look like they wanted to make them very replaceable either. Try tractor supply for your brass bushings. We have some NOS bushings from a store that closed out and I have several floating around at the school.

[M61A1MECH]

Quickly reading thru this and I got kind of lost in description. But I get your going to install brass bushings in the A arms in front instead of the rubber ones. I would do the same in the back if it was me. I dont know if you have access or can get the arms out. But what if you had a threaded "bung" essentially its a nut inside a tube at the point you would need and use a shanked hardened bolt thru the bushing. Sounds like you have a plan anyways. Rubber bushings are both cheap and quiet. But long lasting they are not, and it dont look like they wanted to make them very replaceable either. Try tractor supply for your brass bushings. We have some NOS bushings from a store that closed out and I have several floating around at the school.

 

My plan is to replace all 4 bushings, (front and rear , in the left and right A arms). I am going to get new "axle" rods as Bushtec calls them, they go through the fore and aft frame members, the bushings inside the A arm tube ride on the rod. I am going to thread the ends of the rods, shim up between the ends of the bushings and the inside of the frame members with nylon and stainless washers / shims to get a proper fit then secure the rod in place with nuts. With the nuts holding the axle rods in place I can take the trailer to a welder and have the nuts tack welded to the frame to ensure they do not come loose. Should I ever need to service the bushings or shims, I can cut the tack welds off, saving the rods and replace the wear items and reassemble and repeat the tack welding.

 

As far as longevity, much will depend on how quiet the aluminum/bronze bushings are over time, everything that moves will be lubed up as I reassemble, just not sure how long the lubrication will last, the bushings may get to making noise after a while if I can not manage to keep them lubed.

 

The trailer was not designed to easily service those bushings, that is for sure.

[djh3]

you could drill end of rod and use an R clip,or a cotter key or brush off them aircraft skills and drill nut and safetywire.

[M61A1MECH]

you could drill end of rod and use an R clip,or a cotter key or brush off them aircraft skills and drill nut and safetywire.

 

All good methods, but not a lot of real-estate on the ends of the rods for cotter key or R clips, plus do not want to weaken the rod any further, threading them will reduced the effective diameter and reduce the tensile load numbers. Safety wire, maybe, if I can drill the 316 SS nuts I am getting, but still not as secure as a tack weld

[djh3]

I think I am grasping how this goes together now. The pointy rod gizmo is secured at the end (both maybe) the bushings go on and the "A arm" is supported by the rod/bushing combo. You can buy some solid rod at tractor supply or probably any welding/metal fab shop you have there in your area. Get long enough you could thread or pin. You could double nut end also.

[M61A1MECH]

I think I am grasping how this goes together now. The pointy rod gizmo is secured at the end (both maybe) the bushings go on and the "A arm" is supported by the rod/bushing combo. You can buy some solid rod at tractor supply or probably any welding/metal fab shop you have there in your area. Get long enough you could thread or pin. You could double nut end also.

 

Yes you have the idea now on how it goes together, I searched McMaster Carr and did not find the rod I wanted, Bushtec has the axle rods ready to purchase so I ordered those, not to expensive and I am sure I have the right material, other than knowing they are some type of steel I have no idea exactly what grade of steel they are or what the hardness is, I am guessing the OD is work hardened to give a robust surface to resist wear and the ones I took out are dead straight to boot, not all rods that diameter are straight. If the Bushtec rods do not work out, I may try tractor supply or other supply houses around town.

[djh3]

some type of wearable, lubeable bushing VS rubber will probably end issue

[M61A1MECH]

I heard back from Bushtec today, the bushings they use are urethane impregnated with graphite. According to Andrew Preston the GM they do not normally see those bushings fail like mine at the age and miles of my trailer. He thinks they were contaminated with a chemical or some sort of heat issue. Still think the design leaves a lot to be desired as far as serviceability.

[Flyinfool]

Since he said they do not normally fail so soon did he offer to warranty them????

[M61A1MECH]

Since he said they do not normally fail so soon did he offer to warranty them????

 

No, but did not expect it, the trailer is more than 20 years old.