What is the general consensus regarding the specified torque of 220 Nm for the output flange nut on a 5 speed tranny? There sure wasn't that much torque when I undid the nut on two trannies recently. Is 220 Nm excessive?
Go with the spec. Remember, the output flange is a taper fit and the preload from the flange nut is critical. --Bill
+1 on what bill said I did one recently, it's a big pull but it's one of the few places I'll use a torque wrench, you don't want that coming off
I've had a couple that wern't torgued properly allowing the flange to spin. With the right torque wrench it isn't that difficult to achieve the torque.
Thanks blokes, 220 it is. Just need to find a bigger torque wrench. I cleaned and dried the shaft and flange tapers with degreaser. Does that sound ok?
Make sure that the tapers are absoluteky oil-free. Even fingerprint-free. Use a spray brake cleaner or acetone or the like. --Bill
I suspect a lot of people think the threads are stripping and stop short of the spec torque. No, that's the flange stretching. That's how they work. I use torque wrenches all the time but it isn't to make sure things don't come loose. It's to make sure things aren't too tight!
Is degreaser oil free? I spoke to a German bmw motorcycle mechanic (factory trained? Dunno) who said the torque value was too high and stretched the output shaft. He suggested using a lower value, of which I don't recall him saying. But, as he had not heard of an oil filter bypass spring breaking and chewing out main bearings, I figured you guys know more than him.
Factory trained? Who cares? I am factory trained. I asked. The graduation rate had been 100% for years and years when I went. What does that tell you? Pay money, get certified. I know of quite a few factory trained 'master technitions' that are anything but! It doesn't necessarily mean you don't know much but at the same time it is no guarantee that you do. The flange stretching is how they stay tight. That is what insures enough static friction between the two parts.
I think you mean the output shaft is stretching. The flange is being compressed by the nut, the output shaft is being stretched. No? When I convert Nm to ft/lbs I get 162.26. I have been told it was OK to use slightly less than this. Like 150 ft/lbs. I was told by a guy that's not around to defend himself anymore. This is the figure I have used. I've had no problems but I really don't have the amount of experience that some others on this list have. I don't think I'm alone though. I think there are others that use a slightly lower figure? Anybody else? Or I should change my ways? Clean and dry is important. Taper joints are found in several places on Airheads. Rotor on the end of the crank shaft, bell on the end of the drive shaft, transmission output. I use brake cleaner or carb cleaner. Must be a type that leaves no residue so electric contact cleaner would work.
No. I am sure the shaft stretches some but most of that is the flange. It's hollow, not solid. I get 159.06. I have always used .723. 10flb? Is there a difference? Besides wrenches? I'll stick with the spec since it has never given any trouble and I have seen a lot of those nuts come loose.
Rats! I knew I should have looked that up. I always use this genius converter I got at BMW tech school. .737!
You talking about the BMW Kitchen Calculator? With the teaspoons and so forth? My wife loves it but I still don't trust BMW to convert mechanics' units.
That one. It converts about everything. I have never caught it out. What I don't trust from BMW is a lot of their diminsional specs. A lot of them come from la la land.
To be honest, I'm unsure, but the guys at BM Motorcycles use it as a non residue cleaner. It evaporates pretty quick and a further wipe with metho might be reasonable insurance. I think carb cleaner can leave residue...not for use on the brakes!
