1979 GS750L: Fork Oil Seal Cross-Reference

[DannyMotor]

The front forks are ODD-BALL, 1-year forks. If you notice, the drain bolt is toward the rear of the fork, not on the side, and it has a speedometer guide loop that has it's own bracket off the front brake mount, rather than a singular bolt. It also DOES NOT have a 50mm ID of the lower tube as 99% of other Suzuki leading fork, 37mm tube bikes do.

Here's a picture:







They are a leading fork, 37mm OD shock tube, 48mm inner diameter of the lower tube. The bike also has a small spacer-seal below the oil seal which is now discontinued.

As you can see in the diagram below... part number "5" is the spacer seal... The seal itself has the dimensions of 37x48x10.5.





Having run a cross-reference on the Sudco website, the seal dimensions lead to part number 516-1027, or 516-1028. The difference between the two is the little spacer seal. 1027 is 10.5mm tall, where 1028 is 12mm tall and does not require the use of the spacer seal.

Continuing to search through parts manifests and cross-reference the fit of seal 516-1027, I found that this is a COMMON Honda seal, however is only used on 1 or 2 models of Suzuki motorcycles.

Furthering my quest... I found that the 1975-1979 Honda GL1000 Gold Wing, uses the 516-1027 seal. Having looked up a parts manifest, I found that this bike, too uses a "spacer seal".

SO... if/when you need to re-do your fork seals... you will need the following Honda part numbers:

(below diagram #4) "Ring Backup": 51412-371-003 (quantity 2)
(below diagram #23) "Oil Seal": 51495-467-405 (quantity 2)

Everything can be had for under $30 through most dealerships directly.





Hope this helps... I know I wish I had this when I started this project!!!

-Danny

[BassCliff]

Hi,

Great sleuthing! Thanks for sharing!



Thank you for your indulgence,

BassCliff

[daturat100r]

Thanks for the info,have you come across any fork oil volume in your searching?.As the 79l was never sold new here in nz info is a bit hard to find so I asked the question on here but got no definitive answer and i had suspected the forks were different to the 4 valve models.I started with the least volume recommended 185ml then increased by 20 ml but they still clash a little will try another 20ml and see how it goes

[DannyMotor]

I have the capacities in my clymer manual. Ill post them up when I get home.

Pyramid-parts out of New Zealand sold me the wrong seals twice already. I got an email from them stating they are 100% sure they sent me the right parts. Nope. I just checked the top of the seal itself and it even says 37 48 on it. The Sudco parts manifest is wrong still stating it should be a 37 50.

So every source Ive checked is wrong. Thank god for calipers and the internet. Hahah. That and I never realized the seal size was printed on them.

So yea. Honda GL1000 75-79 Seals and washers from here on out. weird.