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2009-2011 Diamond Drive Bearing Failure

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I talked to Ray today at BD-xtreme and he said this isn't a concern on the reverse diamond drives. He was very helpful in answering my questions and getting the new bearing on the way.

Wish this was actually the case, we have an 08 m8 with the reverse case that wrecked the entire drive because of this same bearing failure in about 4000 miles. retail is 1400 on a new case!!! Just opened up an 07 CF with just over 4k miles and it was falling apart, seal was pushed back and worn and the bearing cage was falling apart when we were taking it out. Regardless of year, this bearing is too cheap and too easy to change to ignore replacing it. Nachi Taiwan bearings from new will be replaced with japanese bearings on mine.
 
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Wish this was actually the case, we have an 08 m8 with the reverse case that wrecked the entire drive because of this same bearing failure in about 4000 miles. retail is 1400 on a new case!!! Just opened up an 07 CF with just over 4k miles and it was falling apart, seal was pushed back and worn and the bearing cage was falling apart when we were taking it out. Regardless of year, this bearing is too cheap and too easy to change to ignore replacing it. Chinese Peer bearings from new will be replaced with japanese bearings on mine.


4000 miles! Thats damn good life if you ask me. Its CHEAP to rebuild the case every 1000 to 2000 miles if you ride hard.
 
i finally got the 5203 bearing installed along with new bdx gears. i found the cover still didnt go on but much closer than with the stock cat gears. i found before i did any grinding that the sun gear wasnt in full contact with the planet gears. i could have taken the driveshaft out and machined some off but the way the planet gears are running in the ring gear it would have not been flush with the driveshaft moved over 0.050" or more. so i just grinded down the bearing stop on the bottom gear so that the 5203 bearing sat around 0.065" lower than flush. now the sun gear is pretty much in full contact with the planet gears and the cover goes on and doesnt spring back or wobble at all like it did with the bearing flush on the shaft. so it should work good.
 
Caught just in time!

Thanks to the information on this site, my son and I checked our M8 153 & M8 162 1300 mile sleds. The 153 sled had failed the seal and the bearing cage. Rollers were still intact. Caught it before any real damage had occured. A few pieces of bearing cage were floating around, but were easy to clean up. All gears were OK. if you haven't checked yours yet get it done.
 
drained the oil today to put in fresh for summer storage and guess what i saw!
DSC04243.jpg

metal in the oil
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from this
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with only 1717.7 mi. on 09 M8 LE
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Update on one years running of 5203 Brg.

Well I started this thread just over one year ago when I was servicing my then new 09 M8 SP. I was just doing prevenative maintenance when I found the bad bearing in the diamond drive. I now have 1100 miles on the new 5203 bearing and it looks and feels just like new, I had changed oil 500 miles ago and today when i serviced the DD oil looked good, no signs of foreign material. So the 5203 bearing did its job for me.

For next season I have installed the 4203 bearing which is aprox. .050 narrower than the 5203, If any one was having tight issues with the case this will help and not put side pressure on the cover. My case cover was snug if not just a little tight with the 5203 so I chose to use the 4203 this year. Its the same double row bearing just a little narrower.

All other bearings and gears,thrust washers were in excellent cond. I feel that by changing to the double row bearing and regular oil changes will make the DD last a long time. I now have 2120 miles on the diamond drive.
Hope this updated post helps everyone out. RickM
 
Well I started this thread just over one year ago when I was servicing my then new 09 M8 SP. I was just doing prevenative maintenance when I found the bad bearing in the diamond drive. I now have 1100 miles on the new 5203 bearing and it looks and feels just like new, I had changed oil 500 miles ago and today when i serviced the DD oil looked good, no signs of foreign material. So the 5203 bearing did its job for me.

For next season I have installed the 4203 bearing which is aprox. .050 narrower than the 5203, If any one was having tight issues with the case this will help and not put side pressure on the cover. My case cover was snug if not just a little tight with the 5203 so I chose to use the 4203 this year. Its the same double row bearing just a little narrower.

All other bearings and gears,thrust washers were in excellent cond. I feel that by changing to the double row bearing and regular oil changes will make the DD last a long time. I now have 2120 miles on the diamond drive.
Hope this updated post helps everyone out. RickM

why change to another bearing now? if the 5203 has 1100 miles on and is in excellent condition... everything else being good... why change anything?
there must not be no issue with your cover being " alittle tight ".
 
Killerrf

Thanks for the question on why to chg to the 4203 brg.
If you have read all the posts of people having problems with having to machine the drive shaft etc. because of the cover not fitting properly and being to tight. When I initially installed the 5203 my cover was snug if not just a little tight. I was concerned of having a side load on the bearing from
"maybe" being tight. As it turned out the 5203 felt good. I had the 4203 so I just decided to run it. The cover went on easier with no end load. I may have not needed the added end clearance but I will run it and see how it holds up.
RickM
 
:face-icon-small-sho Well,I finally took my DD apart to check out the bearing and guess what. The stock bearing was toast. took every thing apart and cleaned well,lots of metal from bearing cage. Replaced with A 5203A bearing made in the good ole USA. Every thing looks good now. This is in a 2010 HCR with 238 miles. Thanks for all the info on here. Looked A little more and found the primary clutch spring broken about 2 coils from the cap end. New spring # superseaded to old yellow white spring, must have had quite A few fail. Thanks to all again. Dave.
 
Also, just to be clear. Machine the drive shaft to take the load off the little bearing in the gearcase if your tunnel is too narrow. Machine the transfer gear or install the 4203 bearing to provide clearance inside the case itself. Two issues, two different fixes.
 
hi guys,im decide to chek my dd bearing after read this post.
the bearing and seal was broken,1 or 2 run more and my dd ...........
i only 1000m on my m8 2009,i had to machine 0.017 of the shaft to put
as before whith the 5203 bearing.
ty at all for this post:face-icon-small-win

bearing.jpg
 
guess what "F**KED BEARING"

i was thinking about this alot and i was just thinking it must be just another one of those things. didn't think it could happen to my sled! so yesterday went out and took the diamond drive out of the sled (taking the diamond drive out of the sled was about 30 mins work. and it was my first time ever doing it! why leave it in?)popped the cover off and WOW, guess what! bearing was F**ked 1600 kms on the sled and i bet i wouldn't of made it too 2000 Kms. i'm going with the 4203 bearing i don't see why anyone would go with a 5203 bearing if it doesn't fit or is tight. the 4203 is still a double row bearing and will take alot more than that garbage bearing that came stock. just change it out every year! anyways people

CHECK YOUR DIAMOND DRIVE'S, ITS A HOUR'S FIX AND COST'S ABOUT 40 BUCKS INCLUDING GEAR OIL.

Troy
 
I bought both bearing but have yet to install them to see which one provides the best fit. I do agree that either the 4203 or 5203 would be an improvement over stock, but I do prefer the 5203 as it is a true Angular Contact bearing which is designed to take more side loading at differing angles than the 4203's on the market.

John
 
Also, just to be clear. Machine the drive shaft to take the load off the little bearing in the gearcase if your tunnel is too narrow.
Sounds like some sleds have worse width problems than others, I just picked up a '10 M8 with 290 miles so we'll see if that one is bad already. If so it looks like I will need to put the shaft on the lathe...
 
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So whats our verdict on this? Sealed or non sealed bearing... Can this bearing get lubricated by the DD oil in the case? Putting a sealed bearing inside a gear case you have the risk of the oil getting in, and washing the grease out, but not having great splash lubricity with the seals in place. Obviously theres variables, just looking for a 100% sure answer here. Thanks guys
Brian
You want a sealed bearing in there for sure, they came with one (a cheap one for sure though) for a reason. Anytime you are moving, all oil is slinging centrifugally away from the center of that shaft robbing that bearing of oil. It is buried inside the planetary so until you come to a stop and the lube levels out it will not see gear oil. The end bearings benefit from the washing down of slung oil against the cases so they get plenty of lube. This bearing needs it's lube sealed inside to keep it from slinging out. That shaft probably sees 6-8000 rpm on a regular basis assuming clutches shifted out 1:1 and the gear ratios are about 1:1.
Anyone trying the unsealed bearings will probably find this out soon enough.
 
You want a sealed bearing in there for sure, they came with one (a cheap one for sure though) for a reason. Anytime you are moving, all oil is slinging centrifugally away from the center of that shaft robbing that bearing of oil. It is buried inside the planetary so until you come to a stop and the lube levels out it will not see gear oil. The end bearings benefit from the washing down of slung oil against the cases so they get plenty of lube. This bearing needs it's lube sealed inside to keep it from slinging out. That shaft probably sees 6-8000 rpm on a regular basis assuming clutches shifted out 1:1 and the gear ratios are about 1:1.
Anyone trying the unsealed bearings will probably find this out soon enough.

I treat this bearing just like a wheel bearing on a MX bike. Pull the seals out, pack it full of a high quality grease and reinstall the seals.
 
http://www.vxb.com/page/bearings/PROD/Kit9704 I just ordered mine, these are Nachi Fujikoshi Japan as opposed to Nachi Taiwan. Not sure what the difference is but mine went 4200mi without kersploding, so either way these should be at least as good if not better. These are the same part number as what's in there.

For 3.40 ea I will just change it since the inconvenience is getting at it, not the cost of the new part.
 
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