Main Bearing Superblend installation

Using a drawing from another app, I have sketched out my understanding of a superblend bearing.
two roller bearings, one roller on each side of crank, open races allowing growth/float.
these superblend provide indexing/thrust thru the sides of the rollers/races?
clearance should be what? .005 - .040?
has anyone actually shimmed an outer race lately?
shim part number? vendor?
I have read something about a barrel shaped roller allowing crank whip....does this apply to superblend?

May not be able to understand the myth of Super-Duper-Blend terminology unless you understand the features and history that made Combat so famously imfamous. All roller bearings installed for cranks since WWII have tapered barrel shapped rollers just some are made better to tolerate higher loads and rpms. The badest non factory Nortons dragsters in their hey day used DS flat roller and TS ball bearings to allow more crank flex before breaking cases or crank and S-D-blends did not improve on that > only mileage before replacement. C-3 bearing clearance is the common code sold and about .0012-5" side shim clearances to allow for swelling. With TS 11 baller ya can skip the shiming but face the heat from others here. All the old school actual Norton parts Commando lore not covered by current crop of forum members is found in Capt. Norton Notes if time to read it all through.

p400 said:

has anyone actually shimmed an outer race lately?
shim part number? vendor?

Click to expand...

Not lately, but when i did I cut it out of a sheet of shim stock.

From the Norton Owners Club

Main Bearings:- There are so far, only two types of bearing I would recommend to anyone to use in a Norton twin (500 up anyway). These bearings are both Superblend roller bearings; one is Ransome and Marles, Norton Part No. 063906, and one from F.A.G., Norton Part No. 064118. Either should be used in 500 - 750 engines; the factory reckoned only to use the F.A.G. bearings in the 850s.

There will be some end float with the double roller bearing setup which previously was controlled by the ball bearing in the timing side. This should be between 10 and 30 thou., but don't worry if it's not, as long as there is some float. The outer rings of the bearings are glued in at the factory by Loctite Bearing Fit, so there's no reason why you shouldn't use it too, as long as you make sure that the rings are hard home before the glue sets, not when you find you haven't got any end float! Only use bearings with one of the following numbers:- NJ306E (E is very important, NJ306 is weaker) or 6 MRJA30. The 6 may be hand engraved on the bearing. The timing side bearing need not be a tight fit on the crank. Again don't use just any roller bearings, these ones are barrelled to allow crankshaft whip. Another number is NJ306E M1 (harder).

I see FAG NJ306E-M1-C3 on Amazon for $45
are these what is required?
I ordered 2 at 45........but now I see the price has changed to $134.....I see my confirmed order for 2 at 90

two day shipping has turned into delivery on June 8,, but my price was 44.58
I hope I don't get sub standard product.

The FAG bearing often referred to as: "Superblend" is "NJ" so the rollers are held captive by a double lip outer race, not single as it's drawn in the diagram, therefore, clearance will be between the inner race and rollers.



The original Superblend (R&M 6/MRJA30) was an "NF" bearing with the rollers captive on the double-lipped inner race.

p400 said:

shim part number? vendor?

Click to expand...

http://www.nortonmotors.de/ANIL/Norton% ... 005&Part=8

CRANKSHAFT SHIM.003" NMT2196A, D12/46
Part Number: 067569

Click to expand...

L.A.B. said:

The FAG bearing often referred to as: "Superblend" is "NJ" so the rollers are held captive by a double lip outer race, not single as it's drawn in the diagram, therefore, clearance will be between the inner race and rollers.

The original Superblend (R&M 6/MRJA30) was an "NF" bearing with the rollers captive on the double-lipped inner race.

p400 said:

shim part number? vendor?

Click to expand...

http://www.nortonmotors.de/ANIL/Norton% ... 005&Part=8

CRANKSHAFT SHIM.003" NMT2196A, D12/46
Part Number: 067569

Click to expand...

Click to expand...

Thanks LAB, I see the inner race is the only floating piece now. I see the shim is listed as a "crankshaft shim" but is this not a bearing shim? and not something you install on the rotating crank.
Also, the float of the crank appears to be pretty loose - the club advice - There will be some end float with the double roller bearing setup which previously was controlled by the ball bearing in the timing side. This should be between 10 and 30 thou., but don't worry if it's not, as long as there is some float.

So I take it that .005 TO .050 would be okay?

p400 said:

I see the inner race is the only floating piece now. I see the shim is listed as a "crankshaft shim" but is this not a bearing shim? and not something you install on the rotating crank.

Click to expand...

OK, try this. http://www.oldbritts.com/11_067569.html

p400 said:

Also, the float of the crank appears to be pretty loose - the club advice - There will be some end float with the double roller bearing setup which previously was controlled by the ball bearing in the timing side. This should be between 10 and 30 thou., but don't worry if it's not, as long as there is some float.

So I take it that .005 TO .050 would be okay?

Click to expand...

crankshaft-end-play-t8587.html

excessive-crank-end-float-t20924.html

L.A.B. said:

OK, try this. http://www.oldbritts.com/11_067569.html
crankshaft-end-play-t8587.html
excessive-crank-end-float-t20924.html

Click to expand...

Excellent, Thank you
I ordered a 06-7569/A kit just now

The once famous Mr. Hudson training video showed him hand sanding TS so the ball bearing slipping on/off easy but till now did not know what to make of his method, especially after he set a pump up blow torch down and caught bench rags on fire w/o noticing so cameraman had to rescue the shop with funny camera angles. As so rarely ever seen in hi performance Commandos of this forum - peek at old school lawnmower that more than held up to Peel escapades & extreme run away yet now about 12,000 more miles none the worse for wear in Wes 1971. Wes is a mentor and covered how to old school test for bearing re use or not, clean and Dry slowly roll and roll and roll and roll, ditto... sensing the slightest little tick every dozen or so turns to line everything up wrong an instant. It can be so slight must roll a bunch of times to make sure it was not just a heart beat twitch. I watched him test Peel like a lock picker till he grinned and gave em to me to try. We also did a bearing I took out of still original Trixie to feel the tick rollrollrollroll...tick-rollrollroll that almost went away with wd40 and not detectable with engine oil. i use as drift or spacer now.

Do not sand the main journals!

The bearing to shaft journal is interference/fit and ISO class m5

Suggest placing larger diameter shimming in cases only and not on crank. It is difficult to maintain the smaller crank shims centered and comnoz reported they tend to self destruct in that position. I have seen a few instances where the smaller shim was either shifted or never placed properly. It gets pinched between the crank filet and bearing inner race filet.

With the larger shims in the cases, the shims are properly nested.

Hi p400.
I recently reassembled my bottom end (same main bearings without any shims) and measured the end float at 0.007" (7 thou).
This end float 'felt' more by pushing and pulling the crankshaft but has provided good service since 1989.
Ta.

If you order original shims you will find that they fit between the shafts of the crank and the inner bearing race. The drawing of the exploded diagram in the various Norton books is incorrect.

For setting end float I use an old inner race that I have ground in the centre so that it slips on and off the shafts a bit easier. Once I have go the end float I want I then put the inner race that came with the bearing on the crank and I have the correct float. The accuracy of bearing manufacture means that there is effectively no difference in dimensions between one bearing inner and another - especially given the somewhat wide end float paramaters that we are working with. I feel this method is better than numerous heat cycles to fit and remove bearings from the case where they are shimmed on the outer race and the danger of overheating an outer race with sufficient heat to get it out again.

dave M said:

For setting end float I use an old inner race that I have ground in the centre so that it slips on and off the shafts a bit easier. Once I have go the end float I want I then put the inner race that came with the bearing on the crank and I have the correct float.

Click to expand...

Thanks Dave, It would seem the exact same tool (inner race slip fit) could be used for the outer race shim fit as well. but you would have to heat/remove/install outer portion one time.
I have revised my sketch to show captured rollers in the outer race. it is not very accurate to scale but the idea of where to place shims is the purpose of sketch.

needing said:

Hi p400. I recently reassembled my bottom end (same main bearings without any shims) and measured the end float at 0.007" (7 thou).
This end float 'felt' more by pushing and pulling the crankshaft but has provided good service since 1989. Ta.

Click to expand...

Thanks Needing, I was keenly interested in what Norton assemblers had actually found ......do you actually find a need for shims at all?

I see at least three different superblend brand offerings - FAG India, NKN Japan, RHP UK on eBay.
What brand/number did you remove and what brand/number did you install?

Hi  p400.
I did not replace the bearings this time.
They are the same FAG NJ (German) bearings since I put them in in 1989 without shims.
The endfloat was by 'feel' in 1989 but this time I put the dial indicator on to put a number to the 'feel'.
Hope this helps.
Ta.

Do not really need shims as rods and drive sprocks on either end tend to center crank to bores so a proper mechanic would measure for shims on one or both sides to leave crank centered to bores with egaul slack on either side for the thermal swellling.

hobot said:

Do not really need shims as rods and drive sprocks on either end tend to center crank to bores so a proper mechanic would measure for shims on one or both sides to leave crank centered to bores with egaul slack on either side for the thermal swellling.

Click to expand...

Good point. I recall pre shimming the TS with .005" then worked off the drive side as it was easier to deal with. Although dropping the race in and out of the driveside case causes wear to the surface, always heat to the point of drop out and drop in. I only had to do this once to add .010" to the drive side. Pulling the inner on and off the crank sucks. I recall ending with .012 endplay. Perfect!

I believe the oil pump worm gear drive on the crank actually pulls the crank over to the timing side. This is the side I nornally shim on so that the inner race cant drift out slightly and allow the shim or bits of shim to come out - which can happen.