Fixed more things now more oil leaks :(

[dz]

Well, I installed a new shock on the back of my 1st gen. That went well. I also decided to grease the splines on the drive shaft while I was there, now low and behold I have an oil leak at the rubber boot which according to the parts diagram looks like the drive shaft seal right before the u-joint. Anybody have any insight on the replacement of that seal? Also, my twinkie has started leaking. I'm sure a lot of curse words (Even some I may have to make up) will be used. I also have a little leak by the clutch slave cylinder or stator cover, not 100% sure yet. Any help would be greatly appreciated.

[frankd]

If you have an oil leak on your slave cylinder or alternator stator wiring gromet, fix that before you worry about the driveshaft seal. The forward leak may be blowing back and looking like a leak out the intermediate gear shaft.

 

On my 83, I did have a leak from the intermediate gear seal. To pull that apart, you have to remove the drive shaft. You may have to pull the rear swing arm, it's been a while and I don't remember if I had to pull it to get enough room to slide the intermediate gear out. Then you loosen the 2 engine case bolts (if you have to do this job, I'll take a picture showing which bolts) that are near the intermediate gear. Remove the 3 bolts that hold the intermediate gear and be carefull of the shims that are between the engine case and the intermediate gear. Now you can slide the intermediate gear out. The Yamaha manual wants you to measure the force required to spin the gear so you can adjust the bearing preload to the same place. Mine had over a 100K on it when I did this job, so it spun freely. So freely you couldn't measure the force required to turn it. I marked the nut and the shaft with a punch mark and counted the turns required to spin the nut off (I seem to remember it went 14 1/2 turns). I replaced the seal and a slightly worn U-joint, and installed the nut, turning it the same number of turns and to the same position (also re-aligned the punch marks). Then you put everything back together, making certain to re-install the shims correctly.

 

That's why I say fix the other leak first!!!

[dz]

Frankd,

Thanks for the heads up. I didn't drive the bike yet, I just let it warm up in the driveway testing out the new used starter I also replaced (out of a 2006). After two minutes of running I had a puddle of oil right under the driveshaft boot (I never had oil leak there before during the previous year and about 2000 miles last year). That sure sounds like a pain but I really can't drive it right now anyway for other reasons and would just like to do it right the first time.

[frankd]

Before you tear the whole thing apart, pull the boot off and verify that the oil leak IS the shaft seal. When mine went bad, it wasn't a big leak, it just made a mess in the garage. I ride it a couple of years with the seepage.

 

My 83 (my brother's been riding it) has developed a pretty big leak on the left side. I sure do hope it's not the intermediate gear again. I've got to install a stator anyway, so I'm hoping that it's the clutch slave cylinder or something else easy.

[greg_in_london]

A couple of the screws in the casing have a copper washer under them and omitting them or reusing a damaged one can lead to a surprisingly prodigious leak too. It's worth checking anyway.