Problems with inner race bearing removal off an 850 Mk3 crankshaft.

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Soundbite

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I’m having a wonderful time trying to remove these inner race bearings off my 850 Mk3 crank.

These are standard size Superblend bearings (FAG X-life NJ306-E-XL-M1 INDIA R059-163952) which were purchased in error and are now being swapped out for 3C bearings (NJ306E.M1.C3) with more clearance. Unlike the original German manufactured FAG bearings which were easily removed, these Indian made FAG bearings (currently on the shafts) have less of a groove cut into the back of the races to allow sufficient grip for the extractor jaws to pull. Instead the jaws continually slip off the race, even under extreme tension. I’ve reshaped the jaws for a better fit and tried heating the races with a blow torch but they just won’t budge. Plus, no room between the race and the crank-cheek for sufficient purchase.

Here's a diagram illustrating the problem and method of extraction… http://gtdc.co.uk/norton/850-mk3-bearing-race-removal.pdf

Have you ever had this problem, if so, how did you successfully remove your races without damaging the shafts please?

Any advice would be highly appreciated. Cheers!
 
Perhaps you can use a sharp chisel between the crank and the bearing to move it enough to get the puller in behind the bearing?
 
You need the right tool

Problems with inner race bearing removal off an 850 Mk3 crankshaft.


Beware the ones made from Chinesium.
 
www.accessnorton.com

Main Bearing Removal

I am trying to remove the main bearings from the crank cheeks. In the Mick Hemmings video, he removes the ID Race with a specialized tool which he reiterates of it being quite rare and expensive. The issue with mine is that the roller bearing (center piece) part of the bearing did not come off...
www.accessnorton.com www.accessnorton.com
 
You have to make room, thin the edge of the tool to a knife edge like a Stanley knife.
 
kommando said:
You have to make room, thin the edge of the tool to a knife edge like a Stanley knife.
Click to expand...
Absolutely… I’ve milled the leading edge of the jaws right down to a sharp profile but it still slips off. I may have to resort to taking it to my local engineering works and have them machine the races off. Happy days!
 
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Gents, many thanks for your feedback. I did sharpen the pullers to fit on the back of the race but no joy. Sadly I don't have access to welding gear so I've sent the crank over to my local engineering works who are confident they can sort. Cheers!
 
Rats, I'm to late to help. I recently had the same issue trying to remove the carrier bearings off the differential of a Dodge truck rear end. I used my 3X Chicago Pneumatic rivet gun [think air chisel with a throttling trigger] and a long straight chisel. Use a chisel with the end dulled, so there is less chance of doing damage if the chisel slips. Best to tape some thin wood over the machined surface of the crank. Place the chisel onto that outer lip of the inner race. I then start hitting that lip while slowly increasing the throttle pressure on the rivet gun. You only need to move it outboard far enough to get the proper puller behind it. Send me a PM [conversation] with your email address if you would like to see this set up.
 
Once you SLIGHTLY thin the edges of the puller, you need to carefully, slowly, tap them into place between the race and the crank cheek.

It's a "SLOW AND STEADY" process, applying heat to the race, with several sets of vice grips GENTLY clamped to the crank with soft alloy shims, and wrapped with wet rags to keep the crank as cool as possible.

One you can clearly see that the tool edges are sufficiently in place, crank down on the vice section, then torque down on the center drive, then smack it sharply with a hammer to get the race to break free.

(for others, of course, @Soundbite; too late for you)
 
I do it from behind with a modified puller as I said earlier. I had one that didn't want to move so I used an angle grinder with a cutoff wheel to cut the slot larger on both sides CAREFULLY, and then cranked down on the jaws of the puller and pulled it. In that case, you want to grind the half moons of the puller so they fit your new slots and are not slanted. Lot of work to get right so make sure the first way doesn't work first.

Also, once you have tension on the puller with either method, apply the heat, not before setting up the puller.
 
You can use a "hot dismount" - a large machined piece of steel that is heated, dropped over the bearing, clamped and tapped up.
I made one for the 961 Balance shaft bearing a smaller NJ305

Problems with inner race bearing removal off an 850 Mk3 crankshaft.
 
bushman said:
You can use a "hot dismount" - a large machined piece of steel that is heated, dropped over the bearing, clamped and tapped up.
I made one for the 961 Balance shaft bearing a smaller NJ305
Click to expand...
Seems almost counter-intuitive; clamping down enough to get a good purchase would seem to bind it to the crank.

Although, pretty cool if it works...
 
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