1998 YZ250 Swing Arm Bolt Stuck

[areeda94]

Hey everyone, so I just finished replacing the case half on my '98 YZ250, and now that I'm trying to get the engine mounted back in the frame, I cannot get the swing arm bolt through the rest of the way. It's lined up, but appears to be getting stuck going from the left side case into the left side swing arm. I have tried any and all adjustments to the positioning, mounted up the other 3 mounts, but for some reason this thing is NOT budging. I tried greasing it up upon assembly, however this thing is so tight the grease is taken right off before it even reaches that side of the case/swing arm. Any suggestions?

[ohiodrz400sm]

Is there any fretting corrosion on the shaft? If so clean it off with scotch brite. What condition are the bearings in? Got any photos?

[YZDOC]

All of the other engine bolts are to be loose while trying to install the swingarm bolt. Make sure your swingarm bolt has a lot of grease on it, and there is a lot of grease and both bushings on the back of the engine. You do have the correct bushings in the back of the engine case, correct?

[areeda94]

There is a little rust formation on the shaft, I'll try out the scotch brite tonight and see if it does me any good. The bushings are correct, and it has no problem going through the engine, it's just getting stuck at the left side of the swing arm. After I clean it up with scotch brite I'm going to get into the engine and swing arm itself with some grease and hopefully my trusty rubber mallet can convince the bolt to make it through. I had to use an air hammer to get it out when I was disassembling the bike if that says anything. Previous owner had the bike for quite some time and didn't ride it much, so I'm guessing this is the 1st or 2nd time the bike has ever been taken apart. However, the bearings, spacers, and seals all were in great condition. Maybe it's just dry in there and needs some assistance. I'll update tonight after work once I've had a chance to give it another go. Thanks for the advice guys!

[Biff Tannen]

Once had to grind a swing arm in half to access a seized arm pin with the angle grinder, removed my engine last week & it was much easier reinstalling the arm pin with the shock absorber removed. I found that with copper grease the stick version sticks to brake pad backings & pins/bolts a lot better w/o running off quickly unlike softer tinned versions, specifically the Loctite C5-A  Anti-Seize Copper Stick, applies a bit like cold butter on warm toast.

 

[CaptDan]

Just for fun, try running the swingarm pivot shaft through from the 'wrong' side. This should help you identify exactly where the hangup is.

 

While the motor was out, did you re-grease/replace the swingarm & linkage bearings? If so, the pins can get out of place in the bearing cage and cause some binding. In this case, any hammering may just make things worse.

 

Good luck, and keep us updated with what you find.  ?

[areeda94]

I did not replace the bearings, they all looked to be in good condition so I didn't bother, however I did not grease the swing arm itself, which is where I'm thinking the hang up is. It was a son of a b***h getting the shaft out in the first place, and when I did it was damn near bone dry.

Edited November 2, 2016 by areeda94

[Spooge]

Yep!  What they said  ?

[areeda94]

Alright guys so I pulled the engine back out, looks like I'm getting stuck on this collar, the one in the new case I receive is too narrow. How do I go about freeing the collar so I can pop it out? I have the old case half as well so I can salvage the other one.

[YZDOC]

You can get a punch from opposite side and "tap" it out, or a blind bearing puller.

[YZDOC]

All of the other engine bolts are to be loose while trying to install the swingarm bolt. Make sure your swingarm bolt has a lot of grease on it, and there is a lot of grease and both bushings on the back of the engine. You do have the correct bushings in the back of the engine case, correct?

Last sentence summed it up.

[areeda94]

Yeah rookie mistake, shoulda listened to ya lol the heat and beat method worked on my old one, now to get out the other one..

[areeda94]

SUCCESS. Got the old one into the new case. Now, to mount the engine up.

[areeda94]

Engine is mounted up, radiators, carb, and airbox in, hopefully I can finish the bike tomorrow! Pictures to come tonight or tomorrow morning.

[areeda94]

Finished the rest today [emoji106]