More splines - Neil Petersen's Tool and Instructions

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During the last thread I started on the subject, Neil Petersen (username=nrp) was kind enough to offer his analysis and picture of a runout measurement tool he had developed. He had problems posting the attachments, so I've done this for him in this thread. The first is a word document, the second two will be the pictures. (I've edited his document into a text (txt) file to match the site's attachment constraints.)

636390-Runout_analysis_word_V2.txt

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Picture: runout_Side viewBWD.jpg

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Picture: runout_endviewB3-4D.jpg

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It still comes up very weird.

 

Anybody e-mail me & I'll reply with the original Word file

 

Niel Petersen

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It still comes up very weird.

 

Anybody e-mail me & I'll reply with the original Word file

 

Niel Petersen

 

Regrets. The site only accepts a text file, not a "doc" or "rtf" file (which include formatting, and are quite a bit larger. I'm sure this is to reduce site storage and bandwidth requirements).

 

Copy the downloaded document (use "edit", and "select all", and "copy" from your browser, open a new text file via "Notepad" in "Accessories" in your Windows "programs" menu, and hit "CNTL-P", or control p to paste it into the window. Then make sure "word wrap" is on in your notepad window, and the formatting should be better).

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"BMW R11xx R-Series - Clutch Spline Alignment Measurement Tool"

 

By Niel Peterson

 

A poor man’s clutch spline alignment measurement tool scheme.

 

A major problem in this spline controversy is how to measure the runout between the engine crank axis and the transmission housing input bearing housing. We need a scheme that does not need expensive tools, a machine shop, or extraordinary skills to make the runout measurement. Unfortunately there is no way to make measurements without disassembling the transmission and the clutch so that the housing can be temporarily remounted to the engine for measurement purposes. But, for those experiencing clutch spline failures, this is a necessary part of the repair process.

 

I have not been able to figure out the dimensions we are dealing with to fully document a runout measurement fixture. I don't want to take my bike apart just to find out either. So this will have to be completed and modified by someone who already has his bike in pieces.

 

The pictures below show my suggested method to mount and ever-so-slightly slide a dial test indicator on the end of a 1 1/4 inch diameter oak closet pole (or something similar) with the probe oriented such that it can read the transmission input bearing bore radial runout directly. No precision parts are necessary, and the runout measurement will readout directly.

 

The scheme starts with cutting a 1 ¼ inch dia dowel or closet pole at a 45 degree angle with a bench saw. Not shown is a 2 1/2 inch diameter flange or disk made of 3/4 inch wood & glued on at the other (crankshaft) end of this gizmo to serve as surface for temporary attachment to the crankshaft flywheel bolts. The pole length will have to be cut to position the indicator probe in the middle of the input bearing bore.

A dial test indicator will have to be located or bought from Harbor Freight. They are only $20 for their item 1717-3VGA on their website. If you know a machinist, they probably have one or more in their toolboxes since they are a common tool. If you damage it, replacement is cheap. The exterior dimensions of many of them are quite similar, if not identical. This one is mounted on the end of the wooden extension to the crankshaft. The wood portion of this extension fixture assembly can be temporarily epoxied to the flywheel bolt heads with 5 minute epoxy. The transmission housing would be assembled onto the crankcase & the dial indicator mounted and positioned enough to make the measurements.

 

Why use epoxy and wood? To avoid the expense and clearance requirements etc of metal or magnetic attachment schemes. This is not a precision thing, yet it will easily offer enough rigidity to make an accurate runout measurement.

< see side view - picture 1>

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For reference, the background sheet in the pictures shows 1 inch major markings. Note that it is small enough to fit inside a 2 inch swing diameter.

 

 

The dial indicator is held to the wood rod by a small bend-and-file aluminum sheet metal (I used .050 thick) rectangular piece that has had a 3/16 inch slot sawed in it before bending. After the piece has been bent, the slot has been filed into beveled surfaces to retain the miniature dovetail in the dial test indicator backbone. Fear not - this is not a precision piece of metal. It took me about 15 minutes to cut, bend, and file it to fit. This metal indicator retainer is fastened with two screws onto the end of the wood which had previously been cut to that 45 degree angle. The mounting screws are 3/8 inch long #6-32 machine screws as they seem to work better than wood screws for adjustment. They are simply screwed into a pilot hole drilled in the wood. From the pictures others have posted, I think the 45 degree angle will allow the probe to register on the bearing bore without anything interfering as it is swung around on the crankshaft. By loosening the screws a delicate amount, the dial indicator can be slid on its dovetail enough to center the probe needle in its measuring range.

 

<see picture end view - picture 2>>

 

The two #6 screws mount the sheet metal indicator retainer

 

It would necessary to mount and carefully adjust the dial indicator after the extension has been slipped through the input shaft hole in the transmission case. The indicator has about +/- .030 inch travel capability. The probe has a slip clutch built into it that allows it to be moved over a wide range of measuring positions.

 

Once this is all set up and adjusted, the crankshaft can be slowly rotated while the indicator dial gives the runout of the bearing bore. This information is needed to establish the cause and permanent fix of premature spline failures.

 

There have been a couple of ways to correct a runout error, such as sleeving and replacing parts. I suggest using a lathe to make up special offset alignment pins out of steel, and installing them in the proper orientation into the engine block keeping the original parts. There are a number of ways these weird pins could be arranged & I would hope some others in this group could step forward to help in this area.