Push-rod Oil Seal Question

[bcware]

1978 2e SOHC

I've had an oil leak on the left side of the engine behind the sprocket cover for a while now which stops when the bike is not running. I replaced the gasket on the stator cover and sealed it with Threebond, but it didn't help. SO, I am pretty sure it is the push-rod oil seal.

I replaced the seal previously with some no name brand oil seal from Ebay. The packaging literally said "xs400" and nothing else. I'm assuming it wasn't the highest quality seal available and who knows how old it was.

Anyway, I pulled out the leaking seal and took a photo. I just want to be absolutely sure what I am seeing is not the metal backing plate from the OEM seal. The replacement seal sat flush with the engine and didn't stick out at all, but there is a metal ring in there with 4 grooves which are 90 degrees apart.

I have an OEM Yamaha seal waiting to go in. I am just looking for confirmation.

 

[XSLeo]

I can'r be sure but what you might be seeing is the end of the transmisson input shaft. This shaft is hollow so the clutch push rod fits through to operate the clutch.
I might see if the local dealer can get on. Or order one from a parts seller like boats.net, they list the stock one as available. $10.25. Not sure what the shipping would be. The MSRP is $12.48
How that compares to the one you got was i don't knoe but even at the MSRP it ain't to bad.
Leo

 

[bcware]

I already have an OEM Yamaha seal to put in. I just wanted to be absolutely sure what I am seeing is not part of the old seal.

 

[16VGTIDave]

What did you remove? The entire old seal or just the rubber at the end?

Got something you could measure the OD of the new seal and the ID of the hole?

 

[bcware]

There have been a total of 2 seals in this bike as of right now (the third new one is sitting in a bag waiting to go in).

I can't remember if the original one I pulled out a year ago had the metal backing intact.

The one I just pulled out tonight is intact with the metal back and all. I did notice that it was very easy to remove. I remember the original being a bear to get out. This seal sat flush with the engine; it wasn't sticking out at all.

I can measure the ID/OD but probably not accurately enough.

Are the numbers on the seal a size reference?

 

[esmith87]

yes the first number should be OD, the second is ID, an the third is thickness of seal,

example: 42 20 07....... 42mm OD, 20mm ID, 7mm width

 

[bcware]

The old cheap one:

SHTCR 8.8 22 6 1857 1

The Yamaha OEM one:

C 24 S07 8.8 22 6-1 R KS

On these seals it looks like 8.8 is the ID, 22 is definitely the OD, and 6 is probably the thickness.

 

[esmith87]

sounds about right for a pushrod seal.

 

[jayel]

put the bike in gear and rotate the rear wheel, if what you can see in the hole rotates it's the end of the shaft.... chamfer the edge of that hole for easier seal insertion and pack the inside of the seal with heavy grease... BC a common leak on these bikes is a loose sprocket, oil migrats down the output shaft thru spacer #33 pack those spines/spacer with grease and tighten sprocket nut to spec

 

[bcware]

Good idea on chamfering the opening for the seal and rotating the rear wheel; it's possible I damaged the last seal with a sharp edge during the installation.

I've been trying to knock off one item at a time. If this new seal makes no difference I will check out that sprocket.

I did just put on a new set of sprockets and a chain, so the front sprocket should be tight enough at least.

Edit:

Should what I am seeing inside rotate when the bike is in neutral or in gear? It isn't rotating in neutral, but the more I look at it the more it looks almost like a bearing seal.

I just looked more closely as the edges of the opening too and they are definitely a bit jagged.

 

[jayel]

Should what I am seeing inside rotate when the bike is in neutral or in gear?

in gear, maybe someone has a pic of the end of the main shaft? or a pic from the service manual?

 

[Kdog]

did you ever decide whether there was the metal cup still in there or not?