Fork Seals

[rickt]

I completely disassembled both front forks on the '78 GS750. The seals offered quite a bit of resistance, but I finally got them out with the help of my trusty heat gun. I purchase a pair of seals on Ebay and immediately noticed that they were slightly thinner. Actually, the old seals are ~13 mm thick and the new ones are ~11 mm. I was concerned and went to FlatOutMotorcycles and ordered a pair of OEM seals. Lo and behold they are also 11 mm thick. So, the question is - is this a big deal or should I just install them and not worry? There may be gap between the top of the seal and the wire spring retainer.

One other small detail - my Clymer manual says to intall the seals with the open end down. The old seals had an open and a closed end. The new seals are open and both top and bottom. Does it make a difference and if so how does one tell which side to insert first?

Thanks,
rickt

[ptm]

I completely disassembled both front forks on the '78 GS750. The seals offered quite a bit of resistance, but I finally got them out with the help of my trusty heat gun. I purchase a pair of seals on Ebay and immediately noticed that they were slightly thinner. Actually, the old seals are ~13 mm thick and the new ones are ~11 mm. I was concerned and went to FlatOutMotorcycles and ordered a pair of OEM seals. Lo and behold they are also 11 mm thick. So, the question is - is this a big deal or should I just install them and not worry? There may be gap between the top of the seal and the wire spring retainer.

The OEM ones I have are also ~11mm. I don't think the retainer spring has to be right against the seal. Who knows what the previous owner put in there...

One other small detail - my Clymer manual says to intall the seals with the open end down. The old seals had an open and a closed end. The new seals are open and both top and bottom. Does it make a difference and if so how does one tell which side to insert first?

On my OEM ones both sides have an open slot, but one has a much bigger gap. The one with the smaller gap has a thicker outside wall and that wall has some letters and numbers molded on it - AR2050G NOK 25. I'd leave that side up.

I'd also use the OEM seals - the advice around here seem to consistently recommend them over the aftermarket ones.

[Freddy]

Hi Having just done my fork seals ,they are also 11mm thick but mine were only open at one end and tappered at the top does your seal have a spring inside one of the open ends? if so put that in facing down.Over here in New Zealand it is hard to get original parts so after market is sometimes our only option. The ones I put in mine are also compatible with most the early GS's from 79 to 83 and yamaha xj 900(83)xs 1100(78-81). As with most things now a days made in taiwan EMGOart no:19-90140. They work a treat and at only $15 new.

[first timer]

install the seals spring side down