Hi,about to change the fork seals on my TY175,what weight oil is best - manual says 126cc 10 - 20 - 30w?I am 13st ,also any tips on stopping the damper rod turning while dismantling.Thanks

an air impact tool may help you remove the bottom screw, but I have had ones that doesn't even work. Sometimes they loosen partially, then just spin in the bore.

Attached is a pic of two tools: small modified socket for the TY175, and fabricated tool for the TY350, question on another post.

also inserted some notes from my .doc files on seals and replacement.

TY175 FORK SEALS

Fork inner damper removal: To hold the inner rod, need a 5/16 square socket, grind the sides out, weld to end of tubing about 18 inches long. Basically there is a cast alum spud with 5/16 across flats, 2 flats milled on it. I was able to get bottom bolt loose, but could not thoroughly tighten it later without making this tool.

FORK SEALS FOR TY175 are 30 x 40.5 x 10. TCM does not have 40.5

One supplier lists 30 x 40.5 x 10.5 B&J has 40.5.

SEAL REPLACEMENT

Seal removal is tough, the wire retaining ring was rusted into place and tapered ends were broken off. Had to hack saw a small slot on outside of slider, in line with the groove, then use fine screwdriver tip to punch wire retaining ring inward. Occasionally, the hacksaw blade catches the ring when finishing the cut and spits out the wire ring like a bullet. Used small rolling pry bar, the 90 degree end, under the seal. Hooked my slide hammer vise grip tool onto the pry bar and pull seal slightly outward. Pull with one hit, then move tool 90 degree increments around the inside of seal and pull again. Work around and around and the seal comes out. If hit too hard, seal cocks and wedges in tighter, may damage ID of slider.

Installing: B&J seal has garter spring on both sides with lip on both sides. One direction has a slight molded backup lip/groove, so I put that towards the oil side. I use the fork socks over the seals and dust boots. Dust boots NLA from Yamaha.

TY350

in response to the post on other thread, the second item in pic is for TY mono forks. 7/8 inch, 22? mm, hex nut welded to end of stainless steel tubing, fits right into the hex on top of damper innards.

I welded a 3/8 drive socket to the top end of tube so a ratchet fits it to turn.

FRONT FORK SEALS 36 x 48 x 10.5 mm rubber case two lip. KYB 43 13361 01509 73S 36-48 was on originals. Assuming made for KYB forks.

Can't get from TCM, has single lip only. TCM TC4 rubber case, 'linear' seals for mc forks. 2 lips + dirt wiper. May be high friction?

B& J had 36 x 47, too small, is sending 48. 48 appears correct.

ps: the spots on the stainless tubing are not part of functional feature, are only weld flash on the tube. Before the days I had an auto darkening welding hood.

Also, the hex nut appears much larger in the pic than the top of the damper rod, only due to distance from camera. It's an old picture. Hex nut fits into the recess in top of damper rod.

kcj

Edited October 13, 200619 yr by kevin j