R80RT Speedo Cable gearbox seal

[MikeO]

During the overhaul of the R80RT, I noticed that the speedo cable gearbox seal had seen better days...

I've read that this can be a cause of water entry into the gearbox oil etc and the last owner had used a cable tie to help to tighten the fit of the seal, but a new one was the clear answer...

Now, there's almost certain to be a right way and a wrong way to replace this. Is it as simple as undoing the gearbox end, removing the old one and pulling the new seal over the end of the cable? I've not taken the old seal off, so haven't had a look at the size of the fitting it would have to stretch over - is it a snag at all?

Does it need a cable tie? Any type of sealant?

Any advice appreciated...

Mike

 

[(RIP) Proff]

Hot water soak, bit of rubber grease and hope the fecker slides on
I ALWAYS use a cable tie as well, thinner the better..

 

[Kenny]

Yup, thin cable tie as proff says, plus load of vaseline inside rubber cap

 

[(RIP) Proff]

Also, don't forget to make sure the special breather bolt [ holding cable in g/box] is clear.

 

[MikeO]

Also, don't forget to make sure the special breather bolt [ holding cable in g/box] is clear.

Will this be obvious when I remove the seal?

Thanks for all the responses.

I'm considering using some heatshrink to make a seal between the cable and the top of the seal - probably over the top of the cable tie. Any reason you can see this not being a reasonable idea?

Mike

 

[andyfrizzle]

The applied heat needed to shrink the heatsink 'may' damage the seal.

I would be more inclined to use a polyurethane sealant if you wanted to ensure a waterproof joint.

I you combine Proff and Kennys advice you shouldn't have any problems.

 

[(RIP) Proff]

Will this be obvious when I remove the seal?

Thanks for all the responses.

I'm considering using some heatshrink to make a seal between the cable and the top of the seal - probably over the top of the cable tie. Any reason you can see this not being a reasonable idea?

Mike

It's the bolt that holds speedo cable in the g/box...
It's "special"

Plus no heatshrink, it can feck up the lining of outer cable.

 

[toadjam]

vaseline

don't use vaseline on rubber , it's oil based and with knacker the seal . rubber grease like prof said or silicone grease .

 

[thornley]

don't use vaseline on rubber , it's oil based and with knacker the seal . rubber grease like prof said or silicone grease .

Same advice with condoms

 

[MikeO]

Job done.

Thanks for all the advice. I now have 30 years supply of rubber grease...

I asked the guy at my motor factors if they sold this in an any other size and he said "Yes, but I can't lift it"

The old seal looks horrible...

...but actually isn't badly perished...

...and I wonder whether it had a textured finish when new...

Anyway, clearly worth replacing. I could see daylight through the middle of the breather bolt and after a hot soak, the new seal slipped on without too much of a struggle. I packed it with a load of red grease, pushed and twisted it firmly over the plastic flange, before finishing off with a thin cable tie at the top...

I think that might become an annual service item - it's no great drama to replace and if it keeps the gearbox oil uncontaminated it has to be a worthwhile use of time, I reckon...

Whilst I was working there, I made a pleasant discovery...

The bike has a K&N air filter, which I hadn't been aware of until then.

Thanks again for all the input.

Mike

 

[VAL. H.]

Now then. Let me get this straight.

The rubber cap is to prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

It is recommended to add rubber grease and a thin zip tie to further prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

Ok, now this is my quandry:
If I have filled the cap with grease and zip tied it tight shut. How's the breather bolt going to breath and why would I need to bother checking the hole in the breather bolt is clear, if I'm just going to block it up with grease?


Val.

 

[(RIP) Proff]

The rubber cap is to prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

It is recommended to add rubber grease and a thin zip tie to further prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

Ok, now this is my quandry:
If I have filled the cap with grease and zip tied it tight shut. How's the breather bolt going to breath and why would I need to bother checking the hole in the breather bolt is clear, if I'm just going to block it up with grease?


Val.

JEEZ the breather bolt "breathes" thats it !!! no magic

Breather is in the bolthead and it's thread.., the bolt that secures the earthwire as well as the speedo cable


Nowhere has anyone suggested Blocking said 'ole...


HTH ... now piss off and let me sell some pork !!!!

 

[MikeO]

The rubber cap is to prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

It is recommended to add rubber grease and a thin zip tie to further prevent water ingress to the area where the cable goes into the gearbox and to the breather bolt. Right?

Ok, now this is my quandry:
If I have filled the cap with grease and zip tied it tight shut. How's the breather bolt going to breath and why would I need to bother checking the hole in the breather bolt is clear, if I'm just going to block it up with grease?


Val.

This...

...is the breather bolt. It is unaffected by the seal.

Mike

 

[fayeslane]

Whilst I was working there, I made a pleasant discovery...

The bike has a K&N air filter, which I hadn't been aware of until then.

My preferred BMW repairers strongly advise against using K&N or other 'free breathing' air filters. They recommend sticking with the standard BMW filter.
Their comment is based on what they see when they open up motors. Probably a can of worms comment but I thought I'd mention it.

 

[Kenny]

I agree...standard air filter is the best !


Hey, this thread ( rubber grease/vaseline/breathers) is getting like the ones in the 1200 section

 

[MikeO]

My preferred BMW repairers strongly advise against using K&N or other 'free breathing' air filters. They recommend sticking with the standard BMW filter.
Their comment is based on what they see when they open up motors. Probably a can of worms comment but I thought I'd mention it.

I agree...standard air filter is the best !


Hey, this thread ( rubber grease/vaseline/breathers) is getting like the ones in the 1200 section

OK, let's open that can of worms - why is this inadvisable?

Mike

 

[MikeP]

OK, let's open that can of worms - why is this inadvisable?

Mike

Because they're not as good at filtering.

I don't wish to claim any special knowledge, it just seems logical to me that if a manufacturer needs to balance longevity against performance, they will do their damnedest to fit something that filters to an acceptable level, while not restricting performance too much (and risk losing-out to their competitors).

It's all well and good for those involved in motorsport, who have absolute performance as their objective and who can often justify rebuilding an engine or its fuel delivery system, on a regular basis but for the rest it may not be worth the few extra ponies.

 

[MikeO]

Because they're not as good at filtering.

I don't wish to claim any special knowledge, it just seems logical to me that if a manufacturer needs to balance longevity against performance, they will do their damnedest to fit something that filters to an acceptable level, while not restricting performance too much (and risk losing-out to their competitors).

It's all well and good for those involved in motorsport, who have absolute performance as their objective and who can often justify rebuilding an engine or its fuel delivery system, on a regular basis but for the rest it may not be worth the few extra ponies.

Thanks Mike.

I have no particular desire for extra performance, but the idea of a filter that you can service, rather than replace does appeal. I have seen plenty of evidence (particularly on later BMWs) where an expedient solution has been used rather than that which encourages longevity against performance.

If someone could give me a logical reason why the OEM filter is better, then I'd probably replace it. Otherwise "it's not OEM" sounds a little like a mantra. It's a 10k mile service item after all, and that'll mean replacing it every few years (this being a second bike), so the cost isn't a factor...

Mike

PS Your bike is freakishly clean (pic in my 'broken exhaust stud' thread)

 

[fayeslane]

There will be differences in after market filters and some servicable oil foam ones probably do a good job depending on what's available for an airhead. Anything called 'free flowing' lets more air through through bigger holes therefore more crap. There will also be an effect on the fuel/air mixture (if no other adjustments) causing leaner running -significant? dunno.

We do dust pretty well in Oz so the problem may be accentuated here. The guys I spoke to pull down plenty of BM engines and their reccomendation was based on the observed engine condition- K&N air filter vs standard.

Always have run OEM in mine couldn't see any advantage in changing. Tried oiled paper once in my R100RSR thanks to a loose air cleaner box bolt , not recommended

 

[MikeO]

There will be differences in after market filters and some servicable oil foam ones probably do a good job depending on what's available for an airhead. Anything called 'free flowing' lets more air through through bigger holes therefore more crap. There will also be an effect on the fuel/air mixture (if no other adjustments) causing leaner running -significant? dunno.

We do dust pretty well in Oz so the problem may be accentuated here. The guys I spoke to pull down plenty of BM engines and their reccomendation was based on the observed engine condition- K&N air filter vs standard.

Always have run OEM in mine couldn't see any advantage in changing. Tried oiled paper once in my R100RSR thanks to a loose air cleaner box bolt , not recommended

So what were they finding that was attributable to the air cleaner?

As you say in your last paragraph, I'm going to have to see an advantage in changing - if I had an OEM fitted I wouldn't look to fit a K&N, but that's not where I'm starting from...

Mike