Engine seal replacement / part 3 crankshaft seal & driveshaft seal

[Mailman]

In this installment of engine seal replacements I shall be tackling the big dogs under the left side case, the crankshaft seal and the driveshaft seal. For both of these seals I’ll be relying on using my seal puller. Available online or through Harbor Freight, and probably auto part stores.

In the past I have just placed the tip against a seal and drove it into the seal with a hammer, but I thought I would try to be a little more precise by drilling an entry point into the seal exactly where I want it.

So I started with the drive shaft seal. I drilled a small hole right in the lettering on the outside of the seal. I’ve discovered that if you go right into the lettering it puts you in just the right place on the seal, you’ll see in a moment. It turned out I needed a slightly larger hole due to the awkward angle I had to enter from. So I opened it up a little and then drive my puller into the hole with a small hammer, and pried against a block of wood so I didn’t mar the case.

Same position viewed from below.

Here you can see how it entered the seal from the front ( I cut the rubber away to view ) and then an inside view to show you how the puller hooks into the inside of the seal. There is a steel band that is penetrated.

The case opening for the driveshaft is a machined edge and is sharp. It will need to be beveled with a deburring tool prior to installing the seal. This tool is available on eBay or at your local hardware store.

Be sure to clean up the case opening thoroughly. I vacuum out the opening just to be sure there is no debri.
Wipe everything down so you have a clean surface , and if needed , I used an Xacto knife to carefully scrape old sealant off of the case opening. This seal and the crankshaft seal will get a thin smear of Yamabond around the outside edge, before installing.

Once again I am forgoing any sort of driver in favor of a small 1 X 2 block of wood to slowly , lightly tap the seal into place. I find the block of wood gives me a great feel and view of what’s going on.

The seal is now in, just wipe it clean and I’m done.

There really is no point in doing a separate write up for the crankshaft seal , since it is another large seal that goes in the same way. The only thing I would add is that since the crank seal will be sliding over the crankshaft, I wiped the shaft and the inner seal with silicone to get a smooth installation and avoid damaging the seal. Also the crankshaft seal opening in the case has a relieved edge and does not need to be deburred.
So, all my seals on the left side have now been replaced. It’s really not hard and you don’t have to have a lot of fancy tools. The only ones I bought specifically for replacing seals was the puller and the deburring tool.

I hope someone, someday finds this helpful.
-Bob

 

[MaxPete]

Excellent - excellent - well done Bob.

Thanks SO much for doing such a thorough and well presented write-up.

Pete

 

[Mailman]

Excellent - excellent - well done Bob.

Thanks SO much for doing such a thorough and well presented write-up.

Pete

Thanks Pete, it was fun to put together.

 

[Superjet]

Nice write up! I recently have replaced the output shaft seal. I did all mentioned above except the yamabond. It has developed a leak again and will try it with it on the new seal. Thanks again. JC

 

[highboy_coupe]

Brilliant, thank you

 

[5twins]

Just a couple notes or additions about the countershaft seal. That steel sleeve over the splined shaft will slide right out. Then you may not need to do any hole drilling, the seal puller will hook right into it. And to make this one leak-free, you have to install the countershaft sprocket nut really tight, like 90 ft/lbs tight. Many leaks here aren't the seal at all but rather just a loose sprocket nut. If the nut isn't tight enough, oil can run out between the steel sleeve and the splined countershaft, and it does. You're attempting to seal the back end of that steel sleeve against the inner race of a bearing inside the motor and the outer end of it against the back of the coutershaft sprocket. You're attempting to make 2 steel to steel seals here so that's why the nut has to be so tight. A small ring of Yamabond on the back of the sprocket where it contacts the sleeve can sometimes help.

 

[Mailman]

Just a couple notes or additions about the countershaft seal. That steel sleeve over the splined shaft will slide right out. Then you may not need to do any hole drilling, the seal puller will hook right into it. And to make this one leak-free, you have to install the countershaft sprocket nut really tight, like 90 ft/lbs tight. Many leaks here aren't the seal at all but rather just a loose sprocket nut. If the nut isn't tight enough, oil can run out between the steel sleeve and the splined countershaft, and it does. You're attempting to seal the back end of that steel sleeve against the inner race of a bearing inside the motor and the outer end of it against the back of the coutershaft sprocket. You're attempting to make 2 steel to steel seals here so that's why the nut has to be so tight. A small ring of Yamabond on the back of the sprocket where it contacts the sleeve can sometimes help.

I’m glad you weighed in here 5T. I didn’t realize that collar slid out until after I was done, you are quite correct , that would’ve simplified things greatly. Also I was trying to remember what you had said about applying a little Yamabond to the backside of the sprocket. Thanks for chiming in!

 

[Superjet]

Thanks guys for clearing up a few things. I did remove the sleeve, sprocket and polished up all mating surfaces to remove any thing on there for a good contact. I also did thr yamabond behind the sprocket as suggested on another thread. My manual shows sprocket nuts (22mm) at 47 ft. Lbs. 90 ft lbs is what most have been doing? If that's the case, I gotta re-visit my torque wrench and start torquing!!

 

[5twins]

Yes, this is one of the torque values that Yamaha changed several times, and for no apparent reason that I can see. If you look through the torque charts from the different year shop manuals, you'll find a value as low as 36 ft/lbs for some of the early Specials, all the way up to near 95 ft/lbs in some of the early model year manuals. Through experience, many of us have found really tight to be best for avoiding leaks. And this is something you should check periodically. Even with the lock washer bent up against it's side, this nut still manages to loosen up sometimes. If you develop a leak from under this cover, this is the first thing I'd check.

 

[kshansen]

Through experience, many of us have found really tight to be best for avoiding leaks. And this is something you should check periodically. Even with the lock washer bent up against it's side, this nut still manages to loosen up sometimes. If you develop a leak from under this cover, this is the first thing I'd check.

I was thinking that countershaft leak was some engineer at Yamaha trying to "reinvent" the Scott oiler!
https://www.scottoiler.com/us/

 

[Superjet]

Lol i like that scott oiler reference. Well I found it was low considering my Roadstar is up in the high values 85ft lbs. I will start by re-torquing to 90 ft lbs and see. I may even take it all apart and start over again to ensure all is done right. I've read on a thread gggGary was going to try a a oil seal kit from ebay by a canadian seller. Any word if any good? I see they are still available from them ( out in Vancouver) and price is good.

 

[5twins]

ARS was the original seal brand Yamaha used, so you really can't do much better than that. That ARS seal kit Mailman got seems to be about the best deal around at the moment. That eBay seller is reasonably priced and ships fast. MikesXS gets $49 for the exact same seal kit. I'd rather save $18 and have it to spend on other 650 parts.

I looked up that kit from Canada and I would pass on it. The seal brand isn't ARS, it has 3 less seals than the ARS kit (7 versus 10), and on top of all that, it costs almost $5 more, lol.

 

[MaxPete]

Bloody Canadians.....

First - the White House, then the Olympic Hockey - and now the seal kits!!

What will these snowy b@stards do next?

 

[xjwmx]

A piece of plastic sink drain pipe fits the crank seal well as a driver. Available as a repair piece in a blister pack.

I would mention just one thing -- before removing the old seals pay close attention to the surface in relation to the case, and on the new seals compare the ridge to the groove in the case. Both of those things to keep from driving the seal in too far, which is easy to do. Also, a key thing is keeping the seal square as it goes in -- take your time. And a final thing -- 5T's advice to burnish the shaft where it meets the seal with a little piece of household scotch brite to keep the seal from leaking has improved my success a lot.

 

[CoconutPete]

Great write-up. I'll refer back to it when I tackle my engine build # 1.