Fork Seal Direction

[holysmoke]

Hey,

I'm in the process of replacing my fork seals. I have the newer replacement seals with spacer:


51168-30B00 (replaces 51168-45031) front fork seal spacer
51153-19D10 (replaces 51153-34200) front fork oil seal

My question is, does the new seal go in with the deep channel into the fork, or face out of the top? The service tech stated that the deeper channel should go down into the fork. Any experts out there that can chime in? Thanks in advance,
Ron

[Coyote]

[Suzsmokeyallan]

Also, if you look at the seal you will notice theres a tension spring fitted around the behind lip, that side always faces towards the source of the fluid.

[holysmoke]

Wow, you guys are on top of it. I appreciate the info. The service mechanic's input corresponds with this. If that isn't amazing...

Another thought. I've got the replacement dust seals, but they're the type that fit without the metal jacket. They'll fit over the lower fork, but you can tell it's not quite right. Would you go with the older periodically correct dust seals, or the new ones that are a better seal, but not period right?

Ron

[Suzsmokeyallan]

The 74s had a different dust seal and the fork leg was casted to accommodate this design. Fitting the later style seals over the body does not look right but is best to have a seal than none at all.
Whats wrong with your original dust seals and the metal band from your forks.
If you are handy with a Dremel you can cut down the raised lip inside the dust seals you have so it fits a bit flatter onto the 74s lower leg.
If you look through ebay periodically the 74 specific ones do show up and you can fit the correct ones in later once you find them.

[holysmoke]

Allan,
I guess I could use one of my old dust seals. I've got a set that doesn't look too bad. I was just thinking that I should have fresh ones with the rebuild. What would you do, use a "pretty good" older set?

What type of dremel bit would you use?

[holysmoke]

What weight oil would you use?

[oldjapanesebikes]

What weight oil would you use?

I usually use ATF, which is around a 15 to 20 wt typically. I also posted a couple of links to fork oil and oil viscosity charts here which will provide you some other alternatives. Just scroll down to the bottom of the page.

[holysmoke]

Very good. Thanks. Does the GT750 take 1600 cc per fork?

[Coyote]

1600cc? That's more than my 550 gear box holds. If you meant 160cc, that is correct for the L, M, A, and B. GT750 J and K hold 235cc.

[holysmoke]

lol, right 1600 cc is like a car engine...

[Suzsmokeyallan]

Sorry for a late reply but I've been away traveling so not up to speed on visiting the board as often as I do.
If the little dust seals on your 74 specific fork covers are still good I'd reuse them since you cant find any that easy to buy.
To use the later ones you would use the rubber sanding drum in the dremel kit with the sandpaper roll on it to grind down the lip inside the rubber where it would normally sit in the later style fork leg casting.

I like to use fork oil as I find its slicker than ATF and in these old forks you need as much smoothness as possible for sliding the stanchions in the legs.
Maxima fork oil or any similar product in a 20 wt works as good as can be expected for reducing the stiction as much as possible.