2008 M8 Diamond drive gear

[sheebansavage]

Hey guys, I was just doing my preseason DD removal/open up and oil change when the I found the bearing on the end of the splined transfer gear in pieces. It didn't even stay pressed on the shaft. This has happened once before. I use SKF 6203-2RSJ bearing.

So my question and concern is this bearing was only in the sled approx 320 miles. Not that long and it's destroyed. I also notice that it seems like the bearing is spinning on the shaft and then the washer that's next to it, heats up and penetrates the seal on the bearing and the rest is scrap metal.

Am I using the wrong bearing and this is causing the spinning on the shaft or is the shaft a little smaller now from all the spinning (worn down) and there is not enough of a pressed fit. I can easily press on pretty much by hand and every year when I change it, I can pull it off by hand if its even attached to the shaft. This particular failed bearing is not one bit snug on the shaft. This is the second bearing failure I have had. First was the original cat bearing to my knowledge. It also was totally wrecked and off the shaft.

Also, there is now some marks on the shaft of this transfer gear. Even up close looks like the weld is cracked. If anyone has a transfer gear near by or know what they look like can you see if mine looks normal.

I am leaning toward buying a new transfer gear and hope for the best. What do you guys think?

 

[Lund]

There should be a thrust washer, thrust bearing and another thrust washer up against the gear your showing. Then the 6203 ball bearing. Are parts missing, looks like the thrust bearing and washer assembly was missing?
This will cause the 6203 to fail as it is not design to handle side loads.

 

[sheebansavage]

Thx for the reply. We may be talking about a different gear. Looking at my pic below, the bearing that fails is #22. The stack up you mention is in item 24. If I am missing something here or not understanding you right please show me the way. lol


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[sheebansavage]

Thx for the reply. We may be talking about a different gear. Looking at my pic below, the bearing that fails is #22. The stack up you mention is in item 24. If I am missing something here or not understanding you right please show me the way. lol


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[sheebansavage]

Also, 25 and 26 are there as well

Also I believe that when the bearing went years ago (original), when it quit it locked up and spun on the shaft and screwed the shaft up.

That's just me thinking out loud only !!! Lol


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[Lund]

Yes bearing #22 is the one i'm talking about. If the thrust assembly is all there as you said #25 and 26. Then are your torquing the axle bolt to spec. (the bolt that is on the inside holding the planetary assembly together) or just making it tight or like some would do ....super tight. The axle bolt has to be torqued to spec with loc-tite. Over tightening that bolt will cause that bearing to fail as it will side load it.

BTW the wear on the shaft won't cause that bearing to collapse.
Use green loc-tite bearing retainer when you reassemble the shaft and bearing, this will help lock the bearing on the shaft and fill the gouge. Don't use any in the housing though, just the shaft.

 

[sheebansavage]

Thx for the reply. I am assuming the axle bolt you are talking about is the big one you access through the brake rotor? Your comment about the green loc-tite for retaining the bearing, Thats a good idea, can that stuff be used to fill the gouge like I have next to the gear?

I also would assume that I have been over torquing that axle bolt. Do you know off hand what that torque is?

Thx again

 

[Lund]

Thx for the reply. I am assuming the axle bolt you are talking about is the big one you access through the brake rotor? Your comment about the green loc-tite for retaining the bearing, Thats a good idea, can that stuff be used to fill the gouge like I have next to the gear?

I also would assume that I have been over torquing that axle bolt. Do you know off hand what that torque is?

Thx again

Yes the green loc-tite will fill the gouge.
As for the bolt, yes i'm referring to the one you access through the brake rotor. Use the blue loc-tite and torque to 55ftlbs. This is the bolt that if over torqued will put a side load on the bearing and can cause failure. In some cases the bolt will break and then the diamond drive comes apart (blows apart) Then the guy blames A/C and the junk drive system, mean while the real problem was the so called mechanic F'ed up.

 

[sheebansavage]

Lol. That's funny. I found the welds on my gear cracked today so I ordered a new one from BDX and it will be made to for the double row 5203 bearing.

I appreciate your help!!

Cheers.


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[Lund]

The upgraded bearing is the way to go, make sure you torque the bolt to spec though because it can poop also if side loaded and that still doesn't prevent the bolt from breaking. They are known to do if over tighten.

 

[sethier]

2011 crossfire 800. I put in the 3203 angular double row bearing in 2012. The original factory bearing disintegrated in no time. Pulled the DD out last week, took off cover and did full inspection. Everything was as good as new.


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[sheebansavage]

That's awesome. I will inspect my new double row end of this season or during the off season. Hopefully I can put this issue on my sled to rest.


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[sethier]

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[sethier]

This helped me out a lot working on my sled.


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