Thread Count on 8 mm Tranny Bolt?

[mieczkow]

Comrades:

I am about to launch my clutch spline lube project and will follow the IBMWR instructions. I intent to buy the recommended 8 mm x 125 mm bolts to act as guides in sliding the tranny back. No one specifically mentions the thread pattern and 8 mm comes in both 1.25 and 1.0. I am guessing that the tranny is 1.25 but can someone let me know for sure so I can make only one trip to the bolt store?

:scratch

[RUDYJO]

They are M8x100mm. Ijust did my first clutch spline lube on my 92 K75RT, I
followed the check list on IBMWR by Bryan Lally. The use of the sawhorse
through the frame was well worth the little bit of extra time, there was no way
for the bike to fall over. I did the whole thing by myself and found that I had
to jack up the rear frame with some 4x4's and a couple of bottle jacks to lift
the bike a couple of inches to get the sawhorse in. I ended up leaving the back
jacks in along with the sawhorse, so the bike was suported at 5 separate places
along with the front wheel. Do yourself a favor and buy a set of hex sockets to
put on your rachets and extentions if you don't have some already. I got mine
at Home Depot for $13.00. I found that when you pull the transmission back
and when you push it back in, to measure the gap between the transmission
and the engine. There must be an even gap top and bottom or it won't slide back
in. Have no fear about doing this, there is nothing hard about it, but it does take
some time. I did mine over a course of 5 days, but was in no hurry. Make your
own check list as you go and then check things off as you put it back together.
I used 4 of the M8 bolts, two on the bottom and two on the sides. Let us know
how it goes.

[Bobmws]

I just looked on the parts fiche and they show the length but not the thread pitch. Safest bet would be pull one bolt and take it with you, though I'm sure someone will be along soon with the correct thread pitch.

[98lee]

Tom,

You need the 1.25 pitch. :thumb (Just measured mine).



:dance:dance:dance

[mieczkow]

Thanks, Lee. that was my guess without taking one off the bike. I'm running over to my local bolt shop to pick some up tomorrow. I'm pretty close to starting the project, I just need to get a few things in place.

My wife got me a nice ATV type lift for Christmas which will pick the bike up nicely, but I want to build set of stabilizers to clamp across the front wheel to make sure the bike is secure. I'll also use some tie downs, as I will place the K75 between the rails of my quick lift.

I've got Monday off next week, so I'll devote the day to getting the lube done.

On another note I posted earlier, I just got a call from Hap's BMW that my pump rebuild job is complete and ready for me to go pick it up and re-install it on the bike. In addition to the seals they replaced the main shaft. So the total bill came to $350 - $50 for the seals and o-rings, $180 for the shaft, the balance for labor. Not too bad by BMW standards... The guys on the forum who have a lot of mechanical skill strongly urged having the shop press in the seals and I think that is a wise thing to do. And about half the price of a new pump...

Thanks again for confirming the thread count!

:buds

[kbasa]

Tom,

You need the 1.25 pitch. :thumb (Just measured mine).



:dance:dance:dance

:nod

Take a bolt down to the hardware store and you can easily compare the threads. Hold one bolt upside down in relation to the other and see if the threads match up.

If they're a decent hardware store, they've probably got a reference card or tools. My hardware store has a card that measures the size 8mm, the pitch and the length. You can also find a nut that screws onto your example bolt to make sure your new bolt has the proper thread pitch.

[roncooper]

[QUOTE=DRUDOLPH148006;536109]They are M8x100mm. Ijust did my first clutch spline lube on my 92 K75RT, I
followed the check list on IBMWR by Bryan Lally. The use of the sawhorse
through the frame was well worth the little bit of extra time, there was no way
for the bike to fall over.

I used the same checklist with the sawhorses. When I started pushing the transmission in place, the bike rolled forward! I tied a bungie cord around the front brake lever to keep that from happening again.

[dbrick]

You can also find a nut that screws onto your example bolt to make sure your new bolt has the proper thread pitch.

An excellent tactic, as you never know for sure if the store's gauge is accurate, or if a previous customer might have mis-sorted nuts or bolts when putting them back. If the bolt you're looking at fits the nut (which itself fits the bolt you removed from the bike), then you know the bolt you're looking at will fit, no matter its label.

Another tactic I've used is buy both sizes, as sometimes a few extra bucks is worth not having to drive to the store again.

[RUDYJO]

Roncooper; If I have this bike long enough to do another clutch spline lube, I
think I will also get a sheet of 3/4 inch 4x8 plywood and use some carriage
bolts to mount my wheel chock to it, then ride the bike into it and strap the front
wheel to the chock. For the bike to move forward or backward, it would have
to take the weight of the chock and plywood with it. Maybe even put some
8x8x16 building blocks on the plywood.