IXLR8

Thats only 0.225 mm or 0.0088" to remove from a 12 mm ID bearing.

I'll be on this the beginning of February.

Mike J

or turn down the secondary shaft? If we can get a batch of bearing done, that would be the simpler route by far.

Cheers,

Mike

IXLR8

That would be my last choice. Since we can't get replacement bearings...yet, I certainly don't want to turn down a shaft I can't replace. I'd sooner turn down, more like grind, a replacement of a part that has already failed.

I just got an idea how to grind the ID easily.

Mike J

I could turn it on my lathe but I would have to figure out how to lock the bearing while cutting.

9 thou is not much.

Cheers,

mike

IXLR8

Same here, but we're not talking mild steel here; quite the opposite!

I think I have another method which I will relate after I try it.

nate717

Had a DD rebuild and belt change shortly after buying my car at 90,000 miles. Belt and bearings were in good shape, did this as a preventative measure.

chris walrod

Same here, but never on a 993.

Gunter

Races are very hard and impossible to cut with a tool bit.
Would have to be ground but that invites other problems.

I lean towards making a sleeve for the I.D instead.
Even a single wrap shim stock of the right size would work if cemented and crimped at the edges.

Alex:
When you go to it, you could mike out the shafts to get the right size.
And find out if all 4 bearings are the same type/size.
Plus, if you, or anyone, has an old bearing, remove the seal and check if it is an angular contact type or just a regular ball bearing.
That would be important for getting the right replacement.

IXLR8

That would require going up to the next sized ID of 15 mm.

Will do the first two. If my bearings are fine, I won't be doing the third. I will check for bearing numbers, if they are marked.

I can't see there being much axial load on this bearing other than the weight of the shaftand rotor...both hardly worth talking about. But there appears to be a circlip on the shaft. I wonder if anything in the assembly is pre-loaded. All will be apparent when I have it all apart.

dutchcrunch

i heard rennsport has the bearing for additional fee on their rebuild, has anyone contact them if they would sell them outright, i would be interested in a set.

Gunter

Go ahead, dutchcrunch, contact Rennsport and report back.

Sounds good, Alex.
Guy reported using NSK 6201-08DDU which is 12.70 mm I.D. – 32.0 mm O.D. – 10.0 mm wide.
If 0.250 mm shim stock was used, that puts the shaft diameter around 12.2 mm; an odd size.
If Schaeffer supplies specially made bearings for Bosch, the type mentioned previously is angular contact and may well be.
There is a spring washer under the top circlip effecting downward pressure, plus the total weight of the shaft, weights and electronics may have prompted Bosch to use angular contact bearings.
An old NFG bearing from a 0237503004 would solve the mystery.

IXLR8

A 0.005" shim would take it down to 12.45 mm...the reported diameter of the shaft...till I measure it myself.

When I am in Germany this summer, I will check with family and friends, some who have good connections.

IXLR8

Distributor Bearing Update...

Not a source for them, but I am confirming the inside diameter of the bearing.

My bearings are fine, so I did not remove them. As a result, the outside diameter of the bearing was not measured directly, nor was the width.

From the machined surface where the bearings are pressed into, the outside diameter is 32 mm as already stated in various threads.

The measured inside diameter of the bearing is 0.4900 inches or 12.446 mm. That makes sense as the shaft is also 0.4900 inches.

The width of the bearing appears to be 10 mm.

There are three bearings with those dimensions; one at the top of the primary distributor and two in the secondary distributor. The bearings at the bottom of the drive are lubricated by engine oil and are made up of a ball bearing and needle bearing (no dimensions taken).

Except for the bearings, I took my distributor apart to the last piece and measured all parts...

Primary Distributor Dimensioning:


Secondary Distributor Dimensioning:

IXLR8

A few more points regarding my overhaul which is still in progress.

Metal cover under secondary distributor
I wasn't about to grind away at the staked locations that hold the cover on under the secondary distributor. Instead I removed the cover by drilling it and using an awl to lift it off. The cover is made of very thin tin and deforms easily.

The replacement is a 1 1/4 inch frost plug that looks identical when in place. I bought the shallow wall type stamped with EPS110.

Distributor bearings
The distributor bearings do not appear to be a ball bearing which makes sense now that I have it apart. It appears to be a bearing that can take a side load, a load that that is placed on the bearing by the use of a Belleville washer on each shaft.

Leon993

better be safe than sorry....