Gonna pull transmission

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Bamboo812
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Re: Gonna pull transmission

Post by Bamboo812 »

The tab has a thick washer between it and the transmission housing. The longer end with the two bent edges go up, with the bent edges pointing toward the back of the bike. This serves to guide the edge of the air box tighter to the trans housing when installing..
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jagarra
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Re: Gonna pull transmission

Post by jagarra »

Thanks for the info. I don't recall a thick washer, I had it upside down too. I can fit it while the right top cover is off so I can see how it fits.
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
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Bamboo812
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Re: Gonna pull transmission

Post by Bamboo812 »

Look at the thickness of the cover where the tab fits in the notch; that is how wide the gap must be.
Rob
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Re: Gonna pull transmission

Post by Rob »

http://www.realoem.com/bmw/enUS/part?id ... 4213060174

they call it a shim, but give no dimensions.
Rob V
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Airbear
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Location: Oz, lower right hand side, in a bit, just over the lumpy part.

Re: Gonna pull transmission

Post by Airbear »

jagarra wrote:...
Adjusted the swing arm to center, torqued the pivots to about 10 ft. lbs. (won't go any lower)
I reckon it is best to hold off on fitting the shocks after fitting the swingarm. That way I can test the ease of movement and confirm the lack of free play as I'm adjusting the pivot preload. You need hardly any preload but the lock nuts need to be firmly locked down. This can be tricky since you don't know if the pivots are tightening as you tighten the lock nuts - if you are using a socket, that is. The swingarm should move freely up and down before and after the locknuts are tightened.
Charlie
and Brunhilde - 1974 R90/6
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Graduate, Wallace and Gromit School of Engineering and Design (Pending)
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jagarra
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Re: Gonna pull transmission

Post by jagarra »

I am also going to replace shocks, but they haven't arrived yet. I was looking at Snobum's site for the adjustment procedure. He has you torqueing the pivots to 15 ft. lbs., backing them off and then torqueing them to 7.5 ft. lbs. Checking for clearance as you work one side then the other. Mine is within .004, so that part is OK. Since my clicker torque wrench only goes as low as 10 ft. lbs. I am sort of stuck at that figure unless I go and buy a beam type wrench.
Since I am in a holding pattern waiting for a few bits to get here, pulling the wheel and the shocks can be done to get a feel of how it adjusted.
Had a bit of a misunderstanding when I ordered new scrapper rings for the internals of the forks. Book said I need 6 of them so I ordered 6. turned out that 1 was equal to a set of 3 rings, so I have plenty of spares. :shock:
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
Duane Ausherman
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Re: Gonna pull transmission

Post by Duane Ausherman »

We replaced hundreds of badly worn swing arm bearings due to incorrect tightening by the factory and others. The life of those bearings isn't very long in the best of cases. There is a lot of incorrect information about how to adjust the swing arm pivot bolts. The whole thing about adding in pressure in order to get longer life out of the taper bearings doesn't apply to this application. This is a very poor use of taped bearings due to the fact that they don't rotate far enough for one roller to go to where the next one was. This is why they notch so quickly in the best of cases.

The whole thing of measuring the torque on the bolt is fraught with error. How much of that "torque" is just in the threads themselves? Did you check to see if the bolt is totally free in the threads of the frame?

The next common error is tightening up the locking nut. The play between the threads of the pivot and frame is such that the locking nut will actually pull the pivot bolt away from the frame when locked down. What ever preload is on the taper bearings will reduce when the locking nut is tightened up. This means that things are not as you assume they are.

In real life, nearly everybody's method results in too much preload on the bearings. Incorrectly tightening the locking nut actually does a good thing, but it is by accident. That isn't acceptable to me, I wish to "know" just how it has been adjusted.

One really only needs to have the play gone from the swing arm. There is no advantage to having preload on the bearings for most types of riding. Note, a hack will provide serious side loads on the box section that holds the swing arm and that distortion will greatly affect the preload on the bearings.

The whole clearance issue of the swing arm from side to side is greatly misunderstood. It is far more important for the driveshaft to ride in the center of the swing arm than for the swing arm to be centered. It would be ideal if both happen with the same adjustment and they probably did when new. You bike ain't new and the box section is commonly not perfect. We always centered the driveshaft, not the swing arm. We learned this from the time that a driveshaft broke because it had been rubbing on the swing arm housing during heavy compressions caused by bumps in the road. Several times we found a shiny wear mark on a driveshaft that was hitting slightly.

Next, be sure to grease the pivots often, several times a year if one rides often. It only needs a single pump to put new grease in the bearings and that shoves out the old dirty grease. Then, don't wipe it out from the space between the frame and swing arm. That excess grease is a far better seal than the actual seal. Use thin grease, not the thick stuff.

If you can resist the temptation to follow the BMW method of tightening the pivot until the swing arm drops slowly and some of the methods offered by "experts" and just make sure that the play is gone with the minimum amount of preload, you lube it often, then you will get a longer life out of those bearings.

However, it is your motorcycle and you are free to do as you wish.
Ask the Indians what happens when you don't control immigration.
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Airbear
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Re: Gonna pull transmission

Post by Airbear »

Thanks for that Duane. You have increased my knowledge yet again.
Charlie
and Brunhilde - 1974 R90/6
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Graduate, Wallace and Gromit School of Engineering and Design (Pending)
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jagarra
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Re: Gonna pull transmission

Post by jagarra »

Duane, I heeded your advise and undid the lock nut and backed off the pivot bolt . I had removed both pivots in order to swing the swing arm out of the way, held it back using the board as recommended in my manual, so I knew they were free all the way till contact. I had already given each side a good blast of grease before I seated the pivots. My manual said to bring it up to touch and give it another 1/8 of a turn, I just brought it up to touch, snugged it and left it there . Figure I will not be able to check for free play unless I drop the wheel and remove the bottom shock bolts to free up all the weight. Didn't get around to that as my kits for the calipers came in so I did them, installed the clutch arm. Had no bolt for that pivot, so I made a locking collar so it wouldn't fall out if the clip went away.
1974 R90/6 built 9/73
1987 BMW K75S
1994 BMW R1100RS
1964 T100SR Triumph
1986 Honda XL600R
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