Micro stub bearing end play.

onanysunday said:
Called Bob at BRP today. Super nice guy. He was the first to do these microstubs in the 90s and he gave me the history. Then everyone copied. Wheel offset and load makes a big difference how long these last. Sounds like these have a limited life span when you have a lot of abuse and load on the car. Have to say I am very disappointed I now have a setup that will need bearings every 1.5 to 2 seasons. That will be $600 each time for a pair. Wishing now I would have bought Bobs kit since his bearings are a lot cheaper. Never thought they would need replaced this often. No other choice but to buy the Jamar. On the other side of the coin maintenance is much easier. Don't touch it for a couple of seasons. Although I would go a couple season on the Funco centerboard bearings before maintenance. Those bearings that were in the car for 15 years are still good and I just need to sell those parts. Other thing is I was able to make the car a little wider with the microstubs so it does work very well. Oh well my .02. 
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Bob story is about a decade late to the game. Search mid 80’s AMC EAGLE front unit bearing , a guy named Gil George (FUNCO )saw a set being used on a trailer. At the time we had gone from a swinglaxle to type 1 (bug) to a type 181 (thing ) to a type 2 (bus) stubaxle.  The bus stuff once we built our own carrier and went to tapered roller bearing was stout enough for the race cars of the day but suffered on axle length. Gil sourced the hub then went to the Wilwood catalog and ordered up an Oldsmobile  Drag kit. To get the  5 bolt 4 3/4  hub diameter up to 5 on 205 he called his Freind a guy named Hobert Kennedy (KEP) and bought some center drops from the engine adaptor plates he was making. Stubaxle to Cv flanges didn’t exist. We were just starting to use 930’s so we would take a type 2 flange weld a ring to the OD machine  and tap to accept a 930 then weld it to a cut off eagle stub shaft. We would do the same thing to bus trans drive flanges .  Send it out to anneal and heat treat.    VOILA  we had what we called a  FUNCO MONO BEARING hub brake assembly. It didn’t take long making stub axles which was massively labor intensive until Gil called his Freind Bob Summers (Summers Bros) to build those parts from scratch. I drilled a ton of holes tapped threads bored holes when I was a youngster.  But I sold a chit ton of those kits 

The FUNCO /Summers bros relationship developed some other game changing hub and brake components to unlike some of the stuff being used today.  Some even with a TM  but that’s a story for another day. 
 

Sidebar .. once the Eagle went belly up that exact unit bearing was found on the first year Chevy S10 . 
 

 
Glamisdude said:
Where are you guys getting a $300 bearing? PLEASE TELL! 😂 I had to buy a micro stub 934 bearing. Kartek didn’t have any but said they are usually $600. Had to go to Mckenzies to get a pro am bearing that was a timken. https://www.mckenzies.com/collections/microstub-bearings/products/proam-micro-stub-bearing-ms1000hdbh-55-33-spline-hd
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You’ll be happy you did in 1 1/2 to 2 years when you don’t have to replace it.
 

Since you mentioned PRO AM . When we built the First Gen 3 we knew the mono hub was what we wanted to use. A few guys were building them as “MICRO STUB”. We dug all our old fixtures out but I immediately had PTSD so we took it to our friend Roy Debahn. He was with Kartek then. We asked  them build us hubs.   He branded that side of the business PRO AM.  What Roy has developed that brand into is a world class drivetrain systems company and currently owns Mckenzie’s as well.  He was one of the first if not the first to step up to what is now called the MS1000Hd stuff.  

 
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Grant@Funco said:
You’ll be happy you did in 1 1/2 to 2 years when you don’t have to replace it.
 

Since you mentioned PRO AM . When we built the First Gen 3 we knew the mono hub was what we wanted to use. A few guys were building them as “MICRO STUB”. We dug all our old fixtures out but I immediately had PTSD so we took it to our friend Roy Debahn. He was with Kartek then. We asked  them build us hubs.   He branded that side of the business PRO AM.  What Roy has developed that brand into is a world class drivetrain systems company and currently owns Mckenzie’s as well.  He was one of the first if not the first to step up to what is now called the MS1000Hd stuff.  
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Is this a better bearing that did not come standard in my kit? Same bolt up?

 
onanysunday said:
When I called Kartek he looked up what I ordered and said $299. I assume this one
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Not the same bearing I don’t think. The ones kartek has on the pme and jamar aren’t timken. The real timken I bought from mckenzies I put up next to my original and they are slightly different. (Mostly casting, pme one prob not made in America). I have a 15 year old pro am hub assembly sitting around and pulled the bearing off it and it’s identical to the new timken. So that’s how I kinda figured it out.  
 

Maybe I’m wrong đŸ€·đŸ»Â 

 
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It would be pure speculation  on my part.  Many people have adapted and offered their own variations of the same thing.  Couple that with the fact there are many different bearing manufacturers.All are not created equally. I’m only familiar with the Kartek and Pro Am 

 
Talk to Dave at Kartek today and he was very helpful. Sounds like that nut backing off made it very likely to cause a premature failure. I ran this thing at least a couple thousand miles without ever retorking the nuts. Everyone is saying this is important after it seats in. And to keep an eye on it. Think I will go ahead and buy two new bearings and put it all back together and go through the correct process. Learning curve. Hopefully they will last longer.

 
Well lol. The right side is now loose as well. And the cotter pin is still in it. Who knows I'll put a new set on and run it.

 
onanysunday said:
Talk to Dave at Kartek today and he was very helpful. Sounds like that nut backing off made it very likely to cause a premature failure. I ran this thing at least a couple thousand miles without ever retorking the nuts. Everyone is saying this is important after it seats in. And to keep an eye on it. Think I will go ahead and buy two new bearings and put it all back together and go through the correct process. Learning curve. Hopefully they will last longer.
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Was gonna say: if they stay tight they last. With this set, I’d retorque after the first day and check again at the end of the trip. Should be fine after that.  I always re-check whenever the wheel is off just because I saw what happens when they get loose (caliper knock back means no brakes). Go through a lot of cotter pins, but only takes an extra couple of minutes. 

 
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Great news. Kartek is engineering and working on a unit with press in races and tapered bearings. So the unit will be serviceable. Unit will be billet and more expensive. Very happy to hear there will be a better setup. I am assuming the current setup looks like this:



 
Kartek just got the new piece in and is going onto a race car for testing. Then they will produce the units. Billet and chromoly parts with Timkin replaceable bearings. I am excited!

 
No ETA on parts. Apparently Jamar is selling the kits but you can't buy replacement bearing carriers. Frustrating to say the least when it is September and I still need to tear this thing apart. Ugh. Anyone know someone over at Jamar?

 
Kartek said they had the 3.9 rebuildable ones in stock. 

 
Jtmoney714 said:
Kartek said they had the 3.9 rebuildable ones in stock. 
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Talked to Kartek and mine is a 3.9 Midboard/microstub. Rebuildable one for me won't be available until at least 6 months. They did have two bearing units so I can at least get my car back up for the season. Will be glad when I can buy a serviceable unit. 

 
onanysunday said:
Talked to Kartek and mine is a 3.9 Midboard/microstub. Rebuildable one for me won't be available until at least 6 months. They did have two bearing units so I can at least get my car back up for the season. Will be glad when I can buy a serviceable unit. 
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I think I was there when you were talking to Dave then. Your parts will be there tomorrow lol. 

 
Just FYI the 3.9 Microstub 33 spline hubs are from 2002-2008 Dodge Ram 1500 4wd front wheel hub.  Get one without the ABS sensor.

The 3.6 33 spline hubs are the rear hub from a 2014-2019 Chevy C7 Corvette.  Get the Delco brand one for $99.  The C7 hubs are based on the C5/C6 Z06 that Chevy used at LeMans.   For the C7 they removed the ABS sensor from the hub and place the ABS tone ring on the axle.

 
RonInSD said:
Just FYI the 3.9 Microstub 33 spline hubs are from 2002-2008 Dodge Ram 1500 4wd front wheel hub.  Get one without the ABS sensor.

The 3.6 33 spline hubs are the rear hub from a 2014-2019 Chevy C7 Corvette.  Get the Delco brand one for $99.  The C7 hubs are based on the C5/C6 Z06 that Chevy used at LeMans.   For the C7 they removed the ABS sensor from the hub and place the ABS tone ring on the axle.
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For the Jamar hubs there is no other hub that will work. Been round and round on this. They made proprietary hubs for my application. Yes I would have loved to be able to just buy a hub over the counter. 

 
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