shim plate and parallel rules G/S trans

[LBourque]

Before I go the internet road was wondering if any of youz might have a shim plate and parallel rules for reassemble a G/S transmission. Might be a long shot but you never know. Starting to get geared up to go in, I really miss riding this time of year in AZ.

[Kai Ju]

I'm in the same boat but just purchased a cracked rear cover that I'll have machined into a shim plate.
Parallel bars would be nice as well, but I've seen folks measure the bearing seat from the gasket surface.
If the cover is straight that should work, if.....
Another option might be to have a glass place cut you a strip of plate glass to substitute as parallel bar. Just a thought.

[Airhead Wrangler]

There's always this option too:

http://www.bmwboxersupplies.com/gear...g2bmue2s4hvpu3

Shipping from holland isn't nearly as bad as you'd think.

[ME 109]

The outer edges of the cover plate is the best place to measure the pockets in my opinion.
If the cover is warped, as mine was recently, measuring at the pockets will give a false reading.

Tip: To get an idea of the end play required, set a micrometre @ .05mm/.002" and hold it up to the light. It ain't much.
That is why consideration must be given to things that will vary your measurement results.

To dismiss such analyty (is that a woid?) when setting such a close tolerance is fumbling in the dark, imo.

[supershaft]

Originally Posted by Kai Ju

I'm in the same boat but just purchased a cracked rear cover that I'll have machined into a shim plate.
Parallel bars would be nice as well, but I've seen folks measure the bearing seat from the gasket surface.
If the cover is straight that should work, if.....
Another option might be to have a glass place cut you a strip of plate glass to substitute as parallel bar. Just a thought.

IMO it's pretty tough to machine the cover plates very flat.

The outside races rock. Even if your cover plate is flat the bearing boss floors almost never are. Personally, I think it helps to measure from the inside race to an depth average in the cover plate but there is always going to be an element of guesswork no matter how careful you are. Even experienced tuners disagree on whether to shoot for loose or tight. Personally, I think they shift better and hold up better on the tight side. Loose lets bearing walk IMO. I set them up snug enough that they might feel too tight after you install the input seal. Remember that they almost always loosen up quite a bit after a heat cycle or two. I forgot to add that if you set one up too tight be sure and rap it real hard a couple of more times before you take the cover back off. That can make all the difference!

[Max Headroom]

Originally Posted by Airhead Wrangler

There's always this option too:

http://www.bmwboxersupplies.com/gear...g2bmue2s4hvpu3

Shipping from holland isn't nearly as bad as you'd think.

I bought one a few years ago, and sadly it's junk IMHO.

I continue to rely on two lengths of precision ground 3/4" keysteel.

[patanga]

Jorgs MC webpage has a well designed precision drawing if you're up to the challenge and cost of having one CNC machined. http://jhau.maliwi.de/mot/gear/dist-plate.png
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[mark1305]

I don't have the link handy - its on my other computer that just died, but search for my thread "A Tale of Two Transmissions" to see the simple oversized bridge I made for my depth gauge to take the place of a shim plate. It spans the case/cover flanges sufficiently to measure each bearing at several points.

It must have worked well, cause the box shifts like buttah since the overhaul.

[Rob Farmer]

Don't forget Dan at Cycleworks.net sells shimming plates along with other tools.- $88 http://www.cycleworks.net/index.php?...products_id=39

[LBourque]

Thank you for the input gentlemen, and I use the term loosely. RF has done some amazing work on these tranys and I will probably go to Cycleworks to the necessary tools. When this thing shifts like "buttah" I hope to offer the same to other inmates. Actually it already shifted like "buttah".
Also wanted to gear up for another overhaul on another G/S I have had my eye on for about 15 years. I think it is an 1985 and a PD as well, what a huge fuel tank.

[Rucksta]

Reassemble without the shims substituing a strip of solder over the bearings.
The solder get squashed.
Disassemble and measure the thickness of the squashed solder.
Insert a shim stack of the same thickness less whatever clearance.

[ME 109]

Originally Posted by Rucksta

Reassemble without the shims substituing a strip of solder over the bearings.
The solder get squashed.
Disassemble and measure the thickness of the squashed solder.
Insert a shim stack of the same thickness less whatever clearance.

I think solder will distort the cover more than the specified end play clearance. Which would give a larger shim stack than necessary.
Resulting in a tight fit.

Just my thoughts after dissecting the solder method.
'Course, I might be completely wrong.

[Kai Ju]

The only way to determine that would be to do both methods, similar to the cover edge vs. bearing bore conundrum.

[ME 109]

Originally Posted by Kai Ju

The only way to determine that would be to do both methods, similar to the cover edge vs. bearing bore conundrum.

It would certainly give an indication as to the difference between two methods.

I found it not at all difficult to distort the cover by .002" by hand pressure.
The fact that solder will offer 'some' resistance to crushing will distort the cover. and of course the cover cannot be 'whacked' to help crush the solder because it could well go too far.
It all comes back to the ridiculously fine end play tolerance of .002" specified, that can be exceeded in a bowed cover, or from one side of a bearing to the other.

It's all good fun tho'

[robtg]

Originally Posted by ME 109

It would certainly give an indication as to the difference between two methods.

I found it not at all difficult to distort the cover by .002" by hand pressure.
The fact that solder will offer 'some' resistance to crushing will distort the cover. and of course the cover cannot be 'whacked' to help crush the solder because it could well go too far.
It all comes back to the ridiculously fine end play tolerance of .002" specified, that can be exceeded in a bowed cover, or from one side of a bearing to the other.

It's all good fun tho'

I agree with your findings. I always set them up at around .004".
These things are not the precision devices some think they are. The cases as well as the cover get distorted through heat cycles and running stress over the years. The best you can do is put them together without binding with reasonable clearance. I have put hundreds of them together over the years loose rather than tight with success. Sometimes you just have to play it by ear.