SuzukiSavage.com - Crankshaft bearing radial clearances

kojones Full Member Offline SuzukiSavage.com Rocks! Posts: 223 Finland	Crankshaft bearing radial clearances 05/07/17 at 04:05:54 The flywheel end roller bearing in my bike has a small clearance when rocking the crankshaft up and down, how much clearance should there be in a new bearing or how much is allowed? Clymer doesn't have anything about this. Suzuki spare is very expensive, NF208 bearing from another source costs about one fifth of that
Back to top	« Last Edit: 05/07/17 at 06:53:23 by kojones » IP Logged

norm92de

Serious Thumper

Offline

SuzukiSavage.com
Rocks!

Posts: 1180
El Paso TX
Gender: male

Re: Crankshaft bearing radial clearances
Reply #1 - 05/07/17 at 13:17:16

Kojones
Suzuki's manual doesn't say anything about crankshaft bearing play.
My guess would be basically zero up and down play.

They do give con-rod deflection as 3mm and big end side clearance as 1mm. Also crankshaft run out as .05mm which may relate to your question. The balancer spring free length should be 10mm.

Hope this helps. If I had it down that far I would not be skimping on bearings.

Back to top

2014 S40. Raptor. idle mixture adj.Needle raised one notch. 4000' altitude. Stock jets. Shell Rotella synthetic.

IP Logged

kojones

Full Member

Offline

SuzukiSavage.com
Rocks!

Posts: 223
Finland

Re: Crankshaft bearing radial clearances
Reply #2 - 05/07/17 at 13:31:17

norm92de wrote on 05/07/17 at 13:17:16:

Kojones
Suzuki's manual doesn't say anything about crankshaft bearing play.
My guess would be basically zero up and down play.

They do give con-rod deflection as 3mm and big end side clearance as 1mm. Also crankshaft run out as .05mm which may relate to your question. The balancer spring free length should be 10mm.

Hope this helps. If I had it down that far I would not be skimping on bearings.

Excellent, thank you! That .05mm might be just what I need. Have to check the play with plastigauge, really hard to measure with a feeler gauge.

Not skimping on bearings, the cheaper alternative is equal or better quality than the stock Koyo Wink

Back to top

IP Logged

norm92de Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 1180 El Paso TX Gender:	Re: Crankshaft bearing radial clearances Reply #3 - 05/07/17 at 14:28:39 I have always found that spec bearings are just as good as the OEM types from any bike.
Back to top	2014 S40. Raptor. idle mixture adj.Needle raised one notch. 4000' altitude. Stock jets. Shell Rotella synthetic. IP Logged

Ruttly

Serious Thumper

Offline

Thumpers Rule

Posts: 5160
Manteca , CA
Gender: male

Re: Crankshaft bearing radial clearances
Reply #4 - 05/07/17 at 14:38:23

Is the bearing on crank or in cases ? Or is lower end still assembled ?
Only way to measure it is with a dial indicator.
Flat roller and ball bearings have different specs.
If replacing bearings get the Suzuki bearings or you will regret it.
Wrong or cheap bearings will be a bad decision.

The engine YOU build is the difference between riding it and pushing it !
When building a engine it is not the time to get cheap , unless you prefer pushing to riding !

Back to top

The Topic Terminator

IP Logged

kojones Full Member Offline SuzukiSavage.com Rocks! Posts: 223 Finland	Re: Crankshaft bearing radial clearances Reply #5 - 05/07/17 at 22:44:25 norm92de wrote on 05/07/17 at 14:28:39: I have always found that spec bearings are just as good as the OEM types from any bike. Yes, as the OEM bearings are spec bearings in 99 percent of the cases
Back to top	IP Logged

hotrod Senior Member Offline SuzukiSavage.com Rocks! Posts: 326 NC Gender:	Re: Crankshaft bearing radial clearances Reply #6 - 05/08/17 at 05:58:56 Bearings made anywhere except China.
Back to top	IP Logged

kojones Full Member Offline SuzukiSavage.com Rocks! Posts: 223 Finland	Re: Crankshaft bearing radial clearances Reply #7 - 05/13/17 at 06:28:40 Measured the play (case assembled) with a dial indicator, 0,03mm = 30um Could be a new C2 bearing when compared to internal clearance charts
Back to top	IP Logged

Ruttly Serious Thumper Offline Thumpers Rule Posts: 5160 Manteca , CA Gender:	Re: Crankshaft bearing radial clearances Reply #8 - 05/13/17 at 08:35:27 Is that with new bearings ? Be sure to take the measurement as close to the bearing as possible, not at the end of the shaft
Back to top	The Topic Terminator IP Logged

kojones Full Member Offline SuzukiSavage.com Rocks! Posts: 223 Finland	Re: Crankshaft bearing radial clearances Reply #9 - 05/13/17 at 08:38:35 Ruttly wrote on 05/13/17 at 08:35:27: Is that with new bearings ? Be sure to take the measurement as close to the bearing as possible, not at the end of the shaft Nope, with the old 50000 km driven bearings. No need to replace them as they are like new.
Back to top	IP Logged

Andy RN

Full Member

Offline

Posts: 107
Eugene, OR
Gender: male

Re: Crankshaft bearing radial clearances
Reply #10 - 05/13/17 at 20:50:30

kojones wrote on 05/07/17 at 04:05:54:

The flywheel end roller bearing in my bike has a small clearance when rocking the crankshaft up and down, how much clearance should there be in a new bearing or how much is allowed?

If you have time, please post a picture of the parts you are talking about, and how you are measuring them. I'm a beginner, and it would help me learn. Thanks, and hope you are staying warm in Finland!

Back to top

US Navy (99-03). Novice, self-taught mechanic. 2003 Savage with 44k miles. 2015 S-40 with 5k miles.

IP Logged

Armen Serious Thumper Offline Half-Witted Wrench-Jockey from Jersey Posts: 1452	Re: Crankshaft bearing radial clearances Reply #11 - 05/14/17 at 04:38:27 If the bottom end is assembled, and you are moving the flywheel up and down and feeling any play at all, I would replace the bearings. It won't be getting any better by itself
Back to top	In theory, theory and reality are the same. In reality, they aren't... IP Logged

kojones

Full Member

Offline

SuzukiSavage.com
Rocks!

Posts: 223
Finland

Re: Crankshaft bearing radial clearances
Reply #12 - 05/14/17 at 10:20:48

Andy RN wrote on 05/13/17 at 20:50:30:

kojones wrote on 05/07/17 at 04:05:54:

The flywheel end roller bearing in my bike has a small clearance when rocking the crankshaft up and down, how much clearance should there be in a new bearing or how much is allowed?

If you have time, please post a picture of the parts you are talking about, and how you are measuring them. I'm a beginner, and it would help me learn. Thanks, and hope you are staying warm in Finland!

Unfortunately I didn't take any pictures when measuring, but here's a video that explains it quite well, altough this is the axial clearance, not radial.
https://youtube.com/watch?v=tIUrVJs-iDE

Luckily it's not that warm yet, as my Savage is still under progress Grin

Back to top

IP Logged

kojones

Full Member

Offline

SuzukiSavage.com
Rocks!

Posts: 223
Finland

Re: Crankshaft bearing radial clearances
Reply #13 - 05/14/17 at 10:30:55

Armen wrote on 05/14/17 at 04:38:27:

If the bottom end is assembled, and you are moving the flywheel up and down and feeling any play at all, I would replace the bearings.
It won't be getting any better by itself Wink

There should be a small clearance in a new bearing as well, the bearing in Savage is a regular Koyo NF208 without any other markings , the first digit (2) tells that it's a cylindrical roller bearing and the last digit gives the diameter of the hole when multiplied by five (40mm)

http://www.ntnglobal.com/en/products/catalog/pdf/2202E_a08.pdf
On pages 4 and 5 are the radial internal clearances for cylindrical roller bearings, and the measured 30 um is well within the specs of a new bearing.

Back to top

« Last Edit: 05/14/17 at 11:59:55 by kojones »

IP Logged

Armen

Serious Thumper

Offline

Half-Witted
Wrench-Jockey from
Jersey

Posts: 1452

Re: Crankshaft bearing radial clearances
Reply #14 - 05/14/17 at 11:47:51

In applications such as the crank and trans bearings, the bearing would be pressed onto the shaft. The most common clearance I've seen are C3 bearings. This allows the bearing to be pressed onto a shaft, and roll without binding. Once the bearing is pressed onto the shaft, that clearance all but disappears. If I feel any up and down play on a crank end installed in a crankcase, the motor comes apart and new bearings go in.
Do as you wish. I only base my comments on 40 years of working on bikes and doing mechanical fabrication, going to factory service schools, and building bikes that won a few national championships.

Back to top

In theory, theory and reality are the same. In reality, they aren't...

IP Logged