ME 109 has inspired me.

[Roy Gavin]

Isnt that seal on the wrong way round in the post with the shimming plate?

The input shaft roller is a stock outer with a special inner sleeve - BMW Boxer Supplies sells the sleeve separately so you can use a stock bearing.

I bought a replacement roller bearing for my rebuild, but when I compared old and new as close as I could measure it there was no wear on the original inner sleeve, although the new outer race was a tighter fit than the old one ,on the original sleeve.

If the box gets to to 130 degrees C in normal running , or if it is hotter than the engine, then someone has either fitted C1 bearings instead of of C3's or the shimming is a mile out, and you have an expensive rebuild coming - DAHIK.

Haynes and Clymer have the end float at 4 thou, without stating if it is to the inner or the outer race, the factory manual says two thou to the (unloaded) outer race , so if you intend loading the bearing by asking it to compress a few bits of solder before you measure it might be wiser to go for the larger end float - a bearing that has been run without sufficient end float can get hot enough to turn on the shaft and in the housing, making a mess of both!

[ME 109]

Isnt that seal on the wrong way round in the post with the shimming plate?
!

Mine was the same way Roy.

[Garnet]

Haynes and Clymer have the end float at 4 thou, without stating if it is to the inner or the outer race, the factory manual says two thou to the (unloaded) outer race , so if you intend loading the bearing by asking it to compress a few bits of solder before you measure it might be wiser to go for the larger end float - a bearing that has been run without sufficient end float can get hot enough to turn on the shaft and in the housing, making a mess of both!

Thanks Roy.

[ME 109]

I've had two people supposedly in the know, suggest 4 thou (.1mm) end play.
A bmw mechanic and a motorcycle mechanic.

Some on ADV suggest tighter is better. I don't think solder is the way to achieve tighter.
I can only see solder distorting the cover, even if it is only by a ridiculously small amount, like two thou.
Remember, if the cover is distorted by solder, and a tight clearance is determined, the clearance will be lost when the solder is removed and the cover is placed on the tranny for the final time.
Unless of course, the distortion is factored into the equation.

[Major Softie]

I've had two people supposedly in the know, suggest 4 thou (.1mm) end play.
A bmw mechanic and a motorcycle mechanic.

Some on ADV suggest tighter is better. I don't think solder is the way to achieve tighter.
I can only see solder distorting the cover, even if it is only by a ridiculously small amount, like two thou.
Remember, if the cover is distorted by solder, and a tight clearance is determined, the clearance will be lost when the solder is removed and the cover is placed on the tranny for the final time.
Unless of course, the distortion is factored into the equation.

IF IF IF the solder genuinely distorts the case, you cannot (easily) factor that in, as the distortion will be greater in the middle than close to the edge, so the distortion would not be the same for each shaft.

[dougie]

I can only see solder distorting the cover, even if it is only by a ridiculously small amount, like two thou.
Remember, if the cover is distorted by solder, and a tight clearance is determined, the clearance will be lost when the solder is removed and the cover is placed on the tranny for the final time.
Unless of course, the distortion is factored into the equation.

I have used Plasticene / modeling clay for piston-to-valve clearance measurement. Is there too much heat involved here for that?

[Roy Gavin]

Some guys on the oilhead forum have used epoxy ribbon to measure clearances, the stuff that comes in two different coloured strips and you kneed together. Apparently it stands up to the temps OK

Remember these are loose tolerance bearings - if you follow the factory workshop manual and measure 2 thou at the inner race chances are you will have nearer four at the outer race anyway.

The well document problems with oilhead final drives failing at around 30,000 km have been attributed to excess preload at the factory - I cant recall any similar failures arising from clearances being too large.

I have just stripped a box which had too little end float on the output shaft, caused by aftermarket 1st and 5th gears which were thicker than stock and the guy who built the box not checking the end float.

There was extensive and expensive damage to the box - I dont think a few thou more clearance will ever cause this amount of trouble.

And as to the benefits of less end float, well most folks wont have much idea what the end float was before the box was stripped, and if it was way over spec then a bit tightening up will make a difference, but I doubt if anyone would pick the difference a couple of thou would make.

[ME 109]

I have used Plasticene / modeling clay for piston-to-valve clearance measurement. Is there too much heat involved here for that?

I doubt plasticine would cope with the heat, and it would also stay 'Plastic' making it difficult to measure.....I think.
The putties mentioned by Roy were on my radar, but they mostly have approx 4 minute set times. Definitely useable after a bit of trial and error, with a well oiled technique.

Correcto on the distortion theory Major. Also factor in the 'pre existing' distortion I have observed in my cover.
I put one of Cycle Work's parallels across the input and output pockets. It rocks. Meaning, my cover is bowed inwards.

Anal? 'Spose so.
Two thou end play is anal.

I have experimented with the force necessary to flatten 1mm solder by pushing a bearing onto a piece of solder.
It takes about the same amount of hand pressure to distort the cover by 2 thou.
A cover heated to 80> c may indeed soften the solder sufficiently. Ideally, there should be no stress on the cover to give an accurate measurement.
Shooting for two thou clearance with solder would most likely end up with close to zero clearance. Imo, 'course.

I think it pays to make one self aware of the variables before declaring which shim/s to use.

[barryh]

I might have missed something here but instead of plasticine what's wrong with using the puka product plastigauge.

http://www.plastigaugeusa.com/how.html

[Major Softie]

I might have missed something here but instead of plasticine what's wrong with using the puka product plastigauge.

http://www.plastigaugeusa.com/how.html

Can't take the heat.