Self oiling rear tyre...

[bungbung]

I was riding the vtr up Lewis pass on Thursday, the rain beginning near the summit. I stopped to put on wet weather gear and noticed an oil drip on the ground. (The vtr is normally oil-tight).

On closer inspection, there is oil coming from behind the front sprocket cover onto the chain, then flicking off the chain onto the rear wheel and then being flung round onto the tyre.

The left edge of the tyre has a thin film of oil on it.
I checked the oil level, plenty left, so I take left-handers easy to Greymouth, where the only Honda agent on the West coast is closed until the 7th.

I use a mates gargre and tools to whip off the cover and have a closer look, nothing much to see. It's definitely coming from behind the front sprocket.

I cruise to Chch on Friday. Popped in to Casbolts, the mechanic hasn't had a vtr bottom end apart before, so cannot guarantee a repair in time for my ferry trip home on saturday.

Checked the sight glass, no sign of any oil, so I buy a litre and bung in 500ml.

Cruising up to Picton on Saturday I stopped for gas in Cheviot and top up another 500ml. More gas in Ward and another litre of oil purchased and 500ml in. The back of the bike has a black film all over it and I'm leaving dark lines out of left handers.

Back at home, check out the photos:

[bungbung]

My guess is that I've picked up a stone which has been trapped between the urethane damped sprocket and the counter-shaft seal. This has been around and around and around until it has worn through the seal outer face.

Funny thing is at no time were there any funny noises, extra vibrations or anything out of the ordinary. If it wasn't for the rain on Lewis pass, it's possible that the first time I would have noticed the problem is after I had a lie down on a left hand bend.

Checking the Honda manual, I'm lucky that it's a seal replacement only, although you need to split the cases to perform that job.

I'll also want a new chain and sprockets, but I did anyway.

[James Deuce]

Far out!

Well spotted that man!

[RantyDave]

Back at home, check out the photos:
Euuuww, gawd, that is *not* good and full marks for not dropping it with that quantity of oil spewed all over the place. So, the thing that has a hole in, that's just a cover/seal/whatever and not part of the engine casing?

Dave

[Katman]

Checking the Honda manual, I'm lucky that it's a seal replacement only, although you need to split the cases to perform that job.



Are you sure? I would be highly surprised if you had to split the cases. Just lever the old one out and press (or tap) the new one in with a thin smear of threebond around the outer surface.

[Maido]

I think you will find he is right, the seal has a flange around the outer part, mainly cos it is such a large seal. with the oil pressure from piston pump inside the cases, it would be easy to force a normal seal out.
Quite common on large honda road bikes.

[bungbung]

Euuuww, gawd, that is *not* good and full marks for not dropping it with that quantity of oil spewed all over the place. So, the thing that has a hole in, that's just a cover/seal/whatever and not part of the engine casing?

Dave

Yeah, I'm pretty sure it is just the seal affected. I asked the local honda dealer for an estimate of the labour involved in doing this job, 8-12 hours @ $80/hr.

I'm going to do it myself.

[jonbuoy]

I have heard of people cutting off the flange on the internal side tapping in place with a hammer and securing sealant, its probably a bitch to get in and out even without sealant - I wouldn't think there is a huge amount of oil pressure behind the sprocket seal. If its holed now and only weeping out that would confirm theirs no pressure involved, not sure if this will work on that particular type of seal though - might be worth trying - only the price of a seal to loose.

[Tony.OK]

If it wasn't for the rain on Lewis pass, it's possible that the first time I would have noticed the problem is after I had a lie down on a left hand bend.



Thank goodness for the rain aye?
Never thought I'd ever say that:(

[What?]

I have heard of people cutting off the flange on the internal side tapping in place with a hammer and securing sealant....

Yep - I know a few Honda shop mechanics who do that. The odd failure happens, but overall it seems successful.

[bungbung]

The Honda man was on the money for the amount of labour involved, it took 5 hours to get the motor out of the frame, including making a couple of peg spanners out of old sockets.

Another hour passed and I had enough of the bits removed to split the cases or so I thought. Some gentle tapping here and there with a soft faced hammer hasn't produced anything like the gap I'd hoped for.

I must be missing something, according to the Honda workshop manual (thin on fine detail) and the Haynes (assumes you want to completely strip down everything) I have removed the correct number of bolts.

The only thing I can think of is the clutch. I'd left it in place, as I had assumed that it wouldn't be necessary to remove and I'd require a couple more tools to remove it which I will need to make.

Does anyone know (in a general sort of way) whether this might be somehow holding the halves together, or am I needing to use a bigger hammer?

[bungbung]

New seal $15

[Ixion]

Don't know your bike, but you almost always need to pull the clutch. Never encountered one yet where it could stay on.

[jonbuoy]

Possibly gear change mechanism too? There are a few places on the interweb you can download the VTR honda service manual in PDF format. Can't remember where I downloaded it from last time.

[Ixion]

Yeah, there's usually a fair bit of stuff behind the clutch.

[bungbung]

Cheers for the replies,

I'll pull off the clutch and have a look.

[Maido]

Cheers for the replies,

I'll pull off the clutch and have a look.

Behind the clutch there is a chain that runs between the clutch shaft and the oil pump, this is what is preventing the separation.

[bungbung]

I have removed the oil pump, it's not the chain.

[Katman]

It will probably be hooking up on the camchain guides. You need to remove the cam chain tensioners and the bottom bolt that holds the front cylinder chain guide to the lower crankcase.

[bungbung]

Thanks Katman, that sounds promising.

[Sketchy_Racer]

Does the motor split vertically or horizontally?

I know in a lot of the kwaka motors (the split horizontally) that there is a hidden bolt under the oil filter/sump

[F5 Dave]

Yeah I've replaced this seal on a mate's Bandit couple of months back. Fortunately you just remove the bush then you can lever the seal out. The only reason you would have to split the cases is if the seal has a dirty great ridge on it which would be a sucky design. If they got paranoid they'd just have to put a seal retainer screwed onto the outside &/or make sure the case is vented properly.

There is often a small o-ring behind the bush to shaft, that should be replaced too.

[bungbung]

The only reason you would have to split the cases is if the seal has a dirty great ridge on it which would be a sucky design.

Dirty great ridge?

check.

Sucky design?

check.

[Squiggles]

Might pay to check and poss replace any other bearings that are weak on the vtr's while you're at it (on tl's its bottom end bearing shells & the countershaft sprocket one) I'd say check as a precaution if she was off the sight glass by that much, though i am sure others will disagree :)

[Patch]

Depending on its life and mileage, might as well do the bearings, hone and new rings.

It sucks having to pull a motor twice and fix something that broke, when it could have been replaced a month earlier before it broke.


Your bike, your call.

[awayatc]

Hi I have pulled engines apart where the cases were held with 1 bolt behind bearing flange (which was bolted on).......don't know your setup though....
Good luck

[bungbung]

I've replaced the seal, what a mission!

The case was held together by three more bolts: 2 bolts for cam chain blade pivots and one directly holding the halves together behind the clutch.

You can see from the photos how much of the bike, and then the motor needs to be disassembled to get to the point where the the seal can be replaced.

I'm now waiting on a clutch cover seal to turn up, although I can reinstall the motor into the frame without that.

[F5 Dave]

Vukin' 'ondas.

As kids we found out that you had to remove half the bike to get to anything. Haven't changed in philosophy it seems. Perhaps it is to keep Honda dealers in business through their service departments & simultaneously make them uneconomic to repair once a few years old.

Oh well good on ya for persevering.

[vifferman]

Perhaps it is to ... make them uneconomic to repair once a few years old.
Think about it: vehicles are ditched in Japan after 4 or 5 years (?), so who cares if it needs serious work after that? This seal is unlikely to crap out until after the average bike is past its 'lifetime'.
It's the same with other defects Honda (and presumably other manufacturers) don't address: if it's not likely to result in a string of lawsuits, why should they give a crap? That's why Hondas have had crap camchain tensioners and gearboxes for umpty-squillion years, and why it took them until 2001 to properly address the R/R problems, even though their manufacturer (Shindengen) had better R/Rs available since the early 90s.

[vifferman]

I've replaced the seal, what a mission!
You can see from the photos how much of the bike, and then the motor needs to be disassembled to get to the point where the the seal can be replaced.
An excellent opportunity to stick some aftermarket goodies in?
You know you want to...

Just remember that the VTR cases can't take more than 125hp before they explode.:blank:

[F5 Dave]

Think about it:. . .
I thought I did.:cool:

[vifferman]

I thought I did.:cool:
Oh.
Yeah, I suppose you did too.

Just an excuse for me to have a wee rant.

[bungbung]

So far so good. The motor is back in the frame, suspension/swing arm/back wheel on. Looks a lot more like a bike now.

[Dino]

.
Starting to look like a bike again.

:clap:Well done.:clap:

.

[bungbung]

My side cover gaskets finally showed up, and she's back together again.
Oil tight once again.
Many thanks to those who offered advice.