Topic: cb550f1, tampered seal above oil pump

[BigBird]

Hi
I have a sealing rubber above the oil pump i wonder what function/name has. It´s been tampered with probably because of an oil leak, and goofed up with metal paste. The chain seams to have been chewing on the block and seals at some point. The sprocket seems solid and barely moves when I wiggle it. I removed the metal paste as it was crisp and porous to have a look what the previous job had been, as it is leaking oil again. I´m looking to do a temporary fix, so I´d appreciate knowing how the seal is fitted and what it is called to find replacement.

Cheers, Simen

[carnivorous chicken]

If I'm not mistaken, that seal is no longer available, and you'd have to split the case to replace it. These leaks are caused by using o-ring chains or others that are too wide. Best bet is to try to seal it up again as best as you can (hylomar, hondabond). If you need to, put a thin washer behind the sprocket to move it out just a hair to prevent the chain from rubbing anymore.

[carnivorous chicken]

Might be, but Honda OEM has it as 34X8 not 34X9...

I should add: still have to split the case too.

[BigBird]

Thanks for the feedback!

I´m not into splitting the cases yet, that´s in the distant abyss of future.

Does anyone know locktite 5922, flange sealant, and if it can do the trick? It sounds like the same as hondabond. It´s a rubbery elastically hardening material which is usually used as sealant between surfaces or on a gasket.

Just have to clean everything up nice first and use a plate to make a flat surface with the bonding. Thanks again!

[DaveBarbier]

When I did my rebuild this part was available from Partzilla and was labeled as 39X8, even though it said it was obsolete. I know you're from Denmark but I'd call around...although I may have gotten the last one!

Now that seal doesn't have any lips or anything so it may be possible to change it out without splitting the cases. But I've looked around the site and can't find anyone who has actually done it. You might just end up ruining a seal as you try to force it in.

Usually that kind of damage is done with putting an o-ring chain on a 550 which it can't take without modification. Might want to make sure you don't still have that chain or it'll be getting damaged after the fix.

Not sure about the loctite stuff, but I think I'd avoid making a metal plate to go over it because even a normal chain doesn't have that much room between it and the cases. There's no oil pressure behind that so just some sealant might do the trick.

[lajos]

I assume you are looking for the oil seal with part number 91207-374-000, size 34x9.

I purchased a 550 seal kit on ebay that has it in it. The marking on the seal is NE D3203 34x9. The kit seems still available:

Honda CB550 CB550F Engine Oil Seal Kit! 1974 1975 1976 1977 1978 550 Four!
http://www.ebay.com/itm/Honda-CB550-CB550F-Engine-Oil-Seal-Kit-1974-1975-1976-1977-1978-550-Four-/361300299900?vxp=mtr
The seller's name is dream305: http://www.ebay.com/usr/dream305?_trksid=p2047675.l2559

My engine is being completely rebuilt so the crankcase is open, but I don't see why you'd need to open the crankcase just to replace this seal. It doesn't have a lip and it doesn't look tapered.

[DaveBarbier]

I assume you are looking for the oil seal with part number 91207-374-000, size 34x9.

I purchased a 550 seal kit on ebay that has it in it. The marking on the seal is NE D3203 34x9. The kit seems still available:

Honda CB550 CB550F Engine Oil Seal Kit! 1974 1975 1976 1977 1978 550 Four!
http://www.ebay.com/itm/Honda-CB550-CB550F-Engine-Oil-Seal-Kit-1974-1975-1976-1977-1978-550-Four-/361300299900?vxp=mtr
The seller's name is dream305: http://www.ebay.com/usr/dream305?_trksid=p2047675.l2559

My engine is being completely rebuilt so the crankcase is open, but I don't see why you'd need to open the crankcase just to replace this seal. It doesn't have a lip and it doesn't look tapered.

Be aware, Lajos, the crank main seals in that kit don't have lips like they're supposed to. I got one of those kits and sent it back and got OEM from David Silver Spares and Partzilla. Without the lip there would be a possibility of the seals to creep out over time. Just a heads up!

And yeah, that's the right part he's looking for, and they indeed don't have a lip nor is it tapered but the cases squish on it a bit so I'm not sure how easy it would be to install. I think he should try and report back, haha.

[lajos]

Thanks for the heads up on the crank seals Dave! I've noticed that they don't have a lip, but I saw somebody on this forum use the ones without the lip to replace the crank seal without taking the motor apart. I'm planning to add some hondabond there to make sure the seals stay in place.

[DaveBarbier]

Thanks for the heads up on the crank seals Dave! I've noticed that they don't have a lip, but I saw somebody on this forum use the ones without the lip to replace the crank seal without taking the motor apart. I'm planning to add some hondabond there to make sure the seals stay in place.

Yeah, I guess that's a benefit to not have lips, ha. I'll be lurking around your build thread and see how it goes.

[BigBird]

Replies appriciated!

Removing all the old bonding used when the PO probably mounted an o-ring chain(which it has´t got enough space for), i found a dented metal surface within the ring of the seal. Unlike all the pictures i´ve seen elsewhere, which has a circle rubber surface. I tap it with a screwdriver and it feels solid, so I grind the area and surface lightly and making the rifts and dents deep and wide to be better applicable for the metal paste i´m putting on. It seems like a butcher´s upsdate, as i probably won´t be able to get an original seal to fit as the case is slightly grinded from the chain and again by me to ease the rifts and make clearance to the chain. So hopefully the putty would stay in place after I sand it down to smooth edges tomorrow : tampered seal v2.0

Only worry now is why there is a seal there and not a case wall, because now i basically created a case wall. Maybe the hole without the seal has a shaft mounting purpose?

[carnivorous chicken]

It's at the end of the trans main shaft.

[DaveBarbier]

The 650, which is very similar to the 550, doesn't have this seal. It actually has a wall. I don't really know why these have the oil seal there anyway. It's like when they drilled these holes from the right to the left they just kept going completely through the entire case coming out the left side. With the 650, they smartly stopped before it breached.

[nicks2319]

Old thread bump: Has anyone actually replaced this without splitting cases yet? Seems nobody has a for sure answer yet. About to try it on my spare engine before trying it on my bike.

[flybox1]

If there is no oil pressure there, why not scuff it up, wipe it with acetone, and give it a few thin coats of non hardening sealant? 
Yeah, its temporary, but why split open an engine when you dont have to?  Its not visible, anyway 

[BomberMann650]

Would an epoxy and metal coin hold up?

[flybox1]

Would an epoxy and metal coin hold up?

with the appropriate chain....probably.

[carnivorous chicken]

Would an epoxy and metal coin hold up?

This is essentially what I did three years ago or so. My CB550 in Seattle came with an o-ring chain when I got it around 1990. It slowly developed this leak, but since I moved to AZ in 1997 and kept the bike in Seattle, it wasn't a priority, just something I dealt with (and rode with #$%*ty shoes that could get a little oily). I also thought it was the shifter seal, but after replacing that it didn't do the trick. Eventually the leak got worse so I removed the front sprocket, cleaned up the area, drained my oil, and slathered on a thin layer of hylomar or something similar. As I wrote in a previous post on this thread, I put a thin washer behind the sprocket, put everything back together, filled the oil the next day and since 2013 or 2014 when I did this I haven't had so much as a drip. Mind you, I ride my 550 only when in Seattle, so that's 2-3 weeks in the summer, a week or two around X-mas and the occasional other trip I make up there. I do ride it to Portland every summer so it's got some solid and fast freeway miles, but like I said -- it's held up just fine.

[nicks2319]

For those searching:

Yes, you can replace the mainshaft oil seal on the 500/550 without cracking the cases. Just did it on two. Drill a small hole in the exact center. Used a screwdriver and hammer to widen the hole and then pliers to pull it out. A little hondabond and tapping to get it back in.