Problem with my finned nuts!!

[Gallinazorey]

Hello everyone,

I also noticed my 1979 R65 is leaking oil, every time worse. Close inspection shows its from the pushrod´s seal and perhaps the sump gasket. Now as I have said in many forums I HAVE 2 LEFT HANDS
but I certainly love it and do my best to fix things myself, but what I am about to do is BY FAR the most ambitious ever; to change the seals myself and thus take out the cylinder head and barrels. I have bought the whole kit full of gaskets and rings for this. I understand from a friend (who has NO BMW bike , shame on him) that I should put sealer between the barrel and the crank case, do you agree??
Any other common pitfalls to look out for??

But now the real problem: I cannot figure out how to open the finned nuts to get the exhaust out. I have read through my bible manual and they show this should be done with a funky tool, but the only one I have (came in the tool box with the bike) is in the picture below, but it does NOT fit. I must be doing something wrong...please give me a "how to take the exhaust out for dummies" lesson with pictures if you can! Maybe its the wrong tool but I find this hard to believe as the previous owner (28 years) included it in the tool bag.
On the tool are the numbers 40/42

Thanks guys

Eric

[Bob_Roller]

The tool you need is made specifically for this purpose, it actually mates up to about 3/4 ths of the fins on the exhaust nut.

Also, if the nut has not been removed before, and had anti seize compound applied to the threads, getting the nut off is going to be next to impossible without damaging the threads on the head.

First you need to get an exhaust nut wrench tool.

Attempt to remove the nut, if it loosens up, and then re tightens, you need to cut the nut off.

If the nut won't move, cut it off.

[Gallinazorey]

Looked for a couple on the internet and they all look like the one in my picture! Like I said, why would they previouse owner have it among his tools?

Anyway, got this from my neighboor? Any thoughts? Should I attempt it or will it harm the nuts/thread?

[Bob_Roller]

The first tool that you have a picture of, looks like an adjustment tool for the rear shock absorber spring preload.

You could try the second tool, but I would be quite surprised if it worked without taking off a fin or two on the nut.

Just to give you an idea of the force you may need to apply, the BMW shop manual states a torque of about 100 ft/lb to secure the nut, it's not hand tight.

[Gallinazorey]

so were is the best place to get an exhaust nut wrench tool? My BMW parts supplier? If not, what specifications am I looking for?

[Bob_Roller]

If I remember correctly, you are in the UK, try Motobins, do a search for exhaust nut wrench, or spider nut wrench.

Motobins part number is : 99100.

[Gallinazorey]

great stuff, thanks Bob, too bad I wanted to do it tomorrow!! I guess I will have to go on my weekend trip the way it is, cant be too bad

Cheers

[Bob_Roller]

If by chance you need to replace the exhaust nuts, they are specific to the R65, no other model exhaust nuts will work.

[Ed Miller]

You need some variation on this.  If the nut won't come off or starts coming off then seizes up, you will need to cut through it with a hacksaw blade or (very carefully Mr. two left hands) a power cutting tool like a die grinder or dremel, or you will mess up the threads on the cylinder heads.



Some helpful articles:

http://bmwmotorcycletech.info/exhaustnuts.htm

http://bmwmotorcycletech.info/break-in.htm

[montmil]

San Jose BMW http://www.sjbmw.com/ had the best price for the R65 exhaust nut tool that I found. I bought one and got one nut loose but the other required surgery with a drill bit and cold chisel.

If you have additional problems with your nuts, may I suggest the old standby Blue Star Ointment?  

Monte

[MrRiden]

Two left hands and finned nuts eh? Sounds like a 50's monster movie. Fun aside. Go get the tool one eyed Monte [this is scary] recommend. Don't screw 'round with other stuff. Sure there are other ways to get it off but with 2 left hands don't invite misery. Try to loosen the nuts [righty tightie / lefty loosey] using the tool and yr hands alone. If it wont budge, stop. If you want to whack it with a hammer, stop. If you think a length of pipe on the handle will give more leverage, stop. It should brake loose with only the tool in yr hand. If it does come loose see if you can remove it with your hand only, if it binds, stop. Ok, if you stopped at any point you are going to need a hacksaw blade [8 tpi] and a short handle like this
Ace hardware has 'em. You are going to cut the nut almost all the way down to the exhaust spigot. Once you have cut almost all the way through [nut only] you can use a suitable screw driver to spread the nut open for removal without galling the threads on the head
spigot. Order up a new nut [R65 specific] slather with silver anti-seeze and reinstall. repeat as nessary. May take several attempts.
Here is the pretty picture part.

[Justin B.]

Eric, the wrench you pictured looks very much like the one that I remember from my /5 toolkit.  The "hook spanner" end was for adjusting the steering head bearing pre-load and the other wnd with the two pins fits the caps on top of the fork tubes which are removed to add fork oil.  The second tool you picture looks almost like a basin wrench but they normally have a swivel head.  I think this is one of those "universal" wrenches that's supposed to fit any/every nut or bolt it can fit over but as Bob stated probably all it will accomplish will be to make it easier to break off the cooling fins...

Heed the warnings put forth by the membership.  If you get the nut to turn and it then starts to feel like it is tightening up stop immediately or you start pulling/galling threads on the head.

[Rob Valdez 79 R65]

http://www.sjbmw.com/parts.asp#mid=54
Go to this link, and type in "exhaust nut" in the search field.  It will come right up.

$20 US, and well worth waiting for.

And it doesn't take that long, these days, even with the cheap rates.


(Is he in the U.S.?)

[drewboid]

The first tool looks similar to the exhause not wrench for a /2 - only the R69 series had the finned nuts. (and maybe the R50S)

As many have stated - if it is too hard to remove cut it off so the cylinder is not damaged. Replacement exhaust nuts are cheaper than rethreading the exhaust spigot.

Also be aware the R65 exhaust nut is unique and will not interchange with the other airheads.

[not-so-fast-ed]

Soaking the nuts with a penetrating "Liquid Wrench" or "PB Blaster" oil may help loosen the nuts.  Squirt, squirt, tap, tap, wait, & repeat several times during dis-assembly.

I had to work mine off with a back & forth, oil soaking, series of steps.

Yeah, I remember his wrench fitting rear shocks to pre-load the amount of stiffness.

Ed