Sliding Rear Axle - 1984 VF700F

So this has been an ongoing and annoying issue I've been having.

I have had this bike for almost two years now and I still can't figure it out. For some reason the rear axle slides back whenever I use the rear brake. I have it set up correctly as far as I know. All the spacers are on the axle and it is torqued down really good (I don't know the torque specs, but I have it fairly tight, tighter than any other axle I've encountered) But it still moves.

Does anyone else have this issue? Or a way to fix it?

 

Do you have your chain adjusters/tension-er set properly? to keep the axle from moving forward?

 

The axle nut could be bottoming out on the axle threads before pinching to the swingarm, so try placing a big thick washer under the nut......

 

Yes the Chain Tension is set correctly. I'm not having problems with it sliding forward. The Axle is also not "over-tight" from what I can tell. The issue is with it sliding backwards under breaking. This typically happens when I use the rear brake (which is not often). When it does slide it unseats the right side (brake side) adjuster bolt from the crater that it rests in.

It seems odd to me that Honda would have a system that keeps the axle from moving forward under power, but doesn't prevent it from moving backwards under breaking. Does anyone have pictures of their first gen axle nut/ chain tension area that I can compare to?

 

I don't have a close-up pic like you asked for of the axle nut/chain tensioner area on your '84 VF700F k2them. Best I can do for you is a parts breakdown pic. Maybe this might be helpful to you.

Do you have all the parts shown in the pic?
Are the spacers (part numbers 5,6,and 8 in the pic) installed correctly?
Are you using the correct factory Honda axle nut to pinch that axle tightly?

 

I've seen that schematic before. I've only had the axle off twice in the two years I've owned it. As far as I know everything is there. I didn't omit any of the spacers and didn't notice any obvious holes that indicate a missing one. The Wheel itself is in there solid. There isn't any play laterally. The only issue is the axle sliding backwards when the rear brake is applied.

Is it possible that it is sliding on the dirt and grime that has built up? I know that sounds bad, but I ride it almost all year round so it can get fairly dirty down there between the rain and whatnot.

 

IF the axle is properly tightened and ALL spacers are in place it should not move....are the axle threads clean and undamaged ??

are the spacers #5 and #6 on the correct sides?? and is spacer #8 in place or missing ??

Try to rock or detect movement in the sprocket hub.

when was the last time you had the wheel off??

I love a mystery, and this is one !

 

There is a step in the axle just passed the threads, is anything hanging up on the step?The only time I have seen this a washer was in use and the hole in the washer would fit over the threads but snagged up on the step on the axle.

 

The only thing I am not 100% sure on is how tight the axle is supposed to be. I've tightened it down to where the rear wheel is hard to move by hand, but figured that must be to tight. I don't have the service manual, but probably should, so I don't know the torque spec for the axle nut. I'm just taking shots in the dark, and that is probably my problem.

I suppose it is possible that I swapped the spacers... But the wheel isn't misaligned as far as I can see. The last time I had the wheel completely off was when I changed the rear tire, about a year ago. I've tightened and loosened the axle nut several times since then in search of the magical tightness. I even did a track day with it like that...

I won't have a chance to work on it till Wednesday, so let me know of anything else I can try...

 

wheel should not get hard to turn even with high torque....your wheel or hub bearings could be be worn out or damaged.

be sure the internal spacer between sprocket hub and wheel (#8) is properly mounted and that the sleeve # 10 is in place.

proppa torque on the nut is about 75 ft.-#, and you need a 1/2" drive setup for that.

 

Ditto to what squirrel said!

 

I'm planning on pulling the axle and inspecting things at lunch today. I'll update when I'm done. Thanks for the info!

 

Well, I've got good news and bad news... I figured out what was wrong, but it isn't good.

Turns out I've been using the bike for the last two years without spacer #8. Numbers 5 and 6 were properly located. I don't know when spacer #8 went missing. I haven't taken the cush drive off the entire the time I've owned it, and since the axle was misaligned when I got it I'm guessing that it has been missing since then.

So now what to do. My Boss is skilled at machining and says he can make one. I got the measurements to him and we'll see how it goes. If it doesn't work out I'll be needing to track one down.

 

I was guessing something was missing !! Might be a good idea to replace all 3 bearing in the assembly cuz something could have been damaged.

Don't make the part !!

Try salvage yards or new from a dealer. There are HUNDREDS of these items sitting in junkyards awaiting reuse.

 

I'll try making it first. If it doesn't work I'll get one from BikeBandit.

 

The Honda part number for the rear axle sleeve (part number 8 in the pic) is 42605-393-000 K2them.
My parts price list isn't current,but it says that part should be about $18.00.

 

+ good info, stosh, and that means a junkyard would want about $10 for it.

At that rate, building the part makes no sense at all....except to prove some obscure point??

 

It is in fact $18.00 I can get one from Bike Bandit (+$6 shipping...). The only issue with that is that I am at work currently and somewhat without a way to get home (I commute ~12 miles in to work). If worse comes to worse I'll just put it back together, ride it home and park it till the part comes.

 

WHY not.....you've been riding that way for months !!

I believe the bearings are shot because without the spacer they were taking clamping loads they were not designed for.

 

I'm just riding it gently till the part comes. It's been working for literally years now so a few more days wont be bad. I've noticed that it actually is working better now that I have the proper torque specs on the bolt (thanks Squirrel!).

I've checked all the bearings and all are in good shape. The only note of concern is the bearing on the sprocket/cush-drive assembly. It is an open bearing and needs re-packed. No biggie though. It still has grease in there, amazingly, but it needs to be changed.