Definative main bearing thread

[bushmechanic]

Lol pics please

We just had a 450 with 0.5mm axial play chew up SKF mains

Orangeberg proved in Australian desert racing that the special Ntn nj206 handles the situation better

And we have another member here running zero axial play on his ntns in a 644

It's Still going after nearly 2 years

 

[Borgschulze]

That's how I got my bearings out, used various old bearings...

It's really interesting how a bunch of the bearings fit in various seal holes just right so you can press them out.

Today I'm nearly done my motor too, just need to use some old clutch plates (bolt them together) to lock the hub so I can torque the hub nut.

Thanks for all the help guys, I learned a lot doing this rebuild so far.

If it lasts a few hundred hours I'll be happy

Might take a couple years to get there for me though!

 

[bushmechanic]

Nice one Borg

There is an easier way. Heat the case to 150c in an oven and tap it on the bench

Bearing falls out

 

[Borgschulze]

I did that, but I used the other bearings as guides.

Almost done!

 

[abarth]

Anyone used *** NJ206-E-XL-TVP2 ? Local bearing shop offered this as alternative.

 

[bushmechanic]

weed used them I think ..... im not 100% sure on that

he and i used them in 20mm wide C4 nj2206 for the drive side. i used an orangeberg ntn on the other side, not sure what weed did his user name is "pop up" you might be able to find something.

they were good in 20mm and at C4 not sure if that helps

 

[abarth]

It seem that *** has slightly better static and dynamic load ratings (37.5&46KN) compared to NTN (37.5&39KN) and SKF(36.5&44KN). Also axial displacement is 1.5mm compared to 1.3mm on SKF.

 

[gery]

I put the *** x-life bearing as main last time. I will see (hopefully) in the winter how they deal with husaberg shaft.

 

[abarth]

I put the *** x-life bearing as main last time. I will see (hopefully) in the winter how they deal with husaberg shaft.

Do you know exact model number?

 

[gery]

I do not, but I think it was NJ206-E-ETVP2-C3 equivalent of NTN or SKF.

 

[abarth]

Will try ***...

 

[abarth]

Here are some pictures of *** berings.

And old skf

 

[Jonteri]

Hello! I have a question about NJ206 bearings. Me and my friend both have KTM EXC 450's yearmodel 2005. I did engine rebuild few weeks ago and my friend is doing it atm. I accidentally bought 2006 Exc 450 crankshaft bearings( Thought my bike was 2006 until i checked yearmodel by a serial number). And the thing is that 2005 has NJ206ECP/C3 and 2006 NTN NJ206 ET2XCS46.

Someone explained here few pages earlier the difference's between these bearing( Different cages, different clearances etc.) NJ206ECP/C3 should be smaller clearance than the other, right? But somehow when i was measuring crankshaft's axial clearance, u had to hit crankshaft gently with rubbermallet to move it from side to side inside the enginecases. I didn't worry about it until yesterday when we were doing the same axial clearance measurement's to my friend's engine. His crankshaft weren't even near as thight that mine was, you could just move it around case's with your bare fingers. So... What's the thing? Mine bearings should be with greater clearance's and somehow it's much tighter than my friend's bearings. Is it possible that my "wrong" bearings do some damage over time?

Thanks for reading this. My english isn't that good, so ask me if you have problems understanding some part's of my text.

 

[Taffy]

perhaps the crank seals were very grippy?

did you remove all your shims?

Taffy

 

[WArdogG]

For what it's worth, I have used those *** X-Life bearings in a KTM 520 rebuild about 2 years ago, I saw that bike last week and it was still running fine at 150+ hours.

 

[WArdogG]

To the suitably knowledgeable, what should I be looking for as the root cause of the failure?

Left Side Crank Bearing
2005 FE450E
90 hrs
5800 km's
SKF Bearing

[/URL][/IMG]

I have a 2004 FE 450 which chewed up it's mains like this. Initially when the bike was bought it had a broken valve spring, but I opened the cases anyway to see what's going on inside. All seemed well, except for the crank runout, so I had it trued and re-assembled, I use 0.5mm endfloat.

Engine ran about 20hrs before chewing up the drive side main. These were the OEM SKF mains. So I replaced the mains, and had to have the crank trued again, at this stage maybe alarm bells should have started ringing, but I assumed that the crank runout may have gone out due to the hammering from the worn main bearing. This time I used Rollway nj2206 on the drive side and an NTN(the Pro-X one) on ignition side.

Once again about 20hrs running, bike started sounding noisy, so I took the ignition cover off to feel the main bearing there, and I could move the magneto up and down ever so slightly.

So I pulled the engine apart again, and this time it was the ignition side main that was starting to go. Looking at the Rollway 2206 inner race on the crank, the roller 'track' mark is right in the center of the race, which I would consider to be a good thing, but the race on the ignition side, the 'track' is right up on the inside, against the lip, and I can clearly see the marks on the rollers and the lip of the inner race where they ran against each other. This is also where the inner race had started to deteriorate, right against the lip the edges of the little raduis there was starting to flake. Also, the crank runout was once again waaaay out.

So it seems to me that the interference fit between the bigend pin and the crank webs is too little and the crank starts wobbling and destroys the main bearing. I suppose welding the pin will sort this problem, or maybe heating the web and quenching in oil may cause the hole to 'shrink' a bit and get the interference right? I don't know if this heat treatment will affect the crank in a bad way?

My real question here, is wether the crank tends to push to the left, or to the right side when under load, so if everything else is correct, will the crank use the drive side or the ign side bearing as a stop? Or is it supposed to run in the center with a little bit of endfloat on each side?

I know as mentioned in another post, the use of a locating bearing on one side is meant to keep the crank locked in place on one bearing, and allow a little bit of movement on the other, which is what the Jap bikes use.

 

[Sicco]

Hello,

i am building a Big Bore RFS engine. 102x78mm 637ccm

I maschined the driveside bearing seat to 30x62x20mm. I will install a SKF 22206E spherical bearing but i have no idea on ignition side. Ball, Roller or second Spherical bearing? (NTN TMB206 JR2 / NTN NJ206 ET2XCS46 or *** 20206 TVP) Should i honing the bearings out and what axial play is good?

On my Husaberg FS650 08 i use two Roller bearings 20mm and 16mm wide from SKF 0,65mm axial play without balancer. Headwork and Dual Akrapovic system, 100 hours on street, most time full throttle. Every 5-8 hours oil and Filter Change (Motul 15W60 Offroud) Works very good but i think the RFS Crank spreads wider?

Best Reguards Max

 

[Dr_C]

 

[Sicco]

Okay thank you. Do you honing out both bearings or the only one on the ignition side? What axial clearence for the crank are you using?

Thank you very much!

Best Reguards Max

 

[bushmechanic]

Hey there wardog

The crank just spreads as it spins so both sides get almost the same axial load. The different wear patterns are due to the different shaped rollers and lips

What is the exact code on the prox bearing ?

The crank can be all kinds of wrong and still read as though it's within limits. It could be twisted slightly . Also welding the pin doesn't stop crank spread it just reduces it.

I use a slip fit between crank and bearing inner to avoid the crank moving when the bearings are hot then getting locked with no axial play when the bearings cool off.