[TwoWheelTim]

This is a warning to all the DIY guys and gals like myself.

I replaced my tire on my B 400 L1 before my recent trip. I didn't notice a problem until I returned, when to my horror I noticed the bottom swing arm bolt was missing and the top was only still in the hole by the grace of God and the fact that the parking brake cable ran over the top of the bolt head preventing it from coming out and providing just the slightest bit of bolt still in the hole preventing the swing arm from separating from the engine.

Facts, I torqued the bolts to 36 PSI but they still came out.

I will be replacing the bolts and and putting Lock-tite on them both. Lesson learned, all critical bolts will be chemically secured.

One the plus side the bike got me home safely, and the ride was not bad as far as I could tell. Lucky for me, I was riding with my fiend who owns a Harley Fat Boy, so we were riding no where near the limits of the Suzuki.

 

[InfernoST]

There is no swing arm so too speak on the 400 the engine and final drive are one cast unit, the engine is what is acting as the swing arm. On an another note bolts are not tightened to PSI rating but ft-lb/lb-ft or Newton Meters rating using a torque wrench. Double check your service manual for the correct torque values for the bolts in question and try again. Using thread lock is a good practice but necessary on every bolt, just stay away from the high strength/permanent red stuff unless the manual calls for it, use the Blue removable stuff (Med strength). I never had a problem with a bolt working its way out on my when it was torqued to the specified value outlined in the service manual.

 

[Mike337]

I know the part you mean. Wow, scary. I sometimes will put a magic marker line across the bolt head onto the part in problem areas so I can take a quick visual check to see if the bolt head moved/loosened.
Great post, glad you're safe! Lucky, or a good guy? lol. God was watching.

 

[TwoWheelTim]

Thanks guys. Man, sometimes I think I need a proof reader. The brain and fingers just don't connect.

Yes I meant lb-ft. I am still a little shaken by my lapse in double and triple checking the bolts.

After the fix today, I noticed the soft rear brake feel had gone away, and the ride was indeed more precise.

Well out to the garage to check them again. :thumbup:

 

[Chatman128]

Great post, timely information. Unfortunately, I replaced my rear tire on 6/22. The day before your post. Did not torque the bolts that hold the rear caliper properly and lost the top one. The bottom was loose so when I applied the rear brake I heard a little clunk. Fortunately, Lowes stocks an exact size replacement flange bolt (probably a pretty common part M8-1.25x30mm), $3.09. Still annoying.

 

[Mike337]

So what's the cure? Loctite? Blue or red?

 

[TwoWheelTim]

Here is what I did.

I didn't want to remove the muffler/O2/brake lines etc to apply Permatex Blue (medium strength). So I repaired it in place.

I have used, with success, the GREEN Permatex Penetrating Grade. It is designed to wick into the threads, and can be applied after assembly. I used it a little differently though, by applying it to the bolt before assembly and then torqued it down. As the bolt screws in, an excess will built up on the shank, the excess will later will wick in and do its job.

My reason for not using the Blue, was I couldn't get to the recessed engine threads because I did not have a long straw applicator.

I found perfect match bolts at ACE hardware. I let set overnight.

 

[Mike337]

This post may have saved our lives!
I just checked mine because the dealer just did a rear tire change for me and the top one was loose, and the bottom one was GONE!
Thank you for posting this!:salute::salute:

(Just under 100 miles)