I started tearing down my supercharger nosecone to rebuild and found that there are 4 or 5 tiny holes in the aluminum housing where the rear bearing sits.

I posted pictures of this and I am wondering if anyone has encountered this and if not could someone give me some idea if you believe this will leak and not function correctly when reassembled and the oil is reintroduced.

I would just send this in to magnusson but I am sure someone could give me some idea if you have seen this or could provide some input on what to do. Could a machine shop fill them with something??

Any help would be great!!

 

Doesn't look like anything detrimental to the supercharger to me but the pictures won't let me see them full size so can't get a good look.

 

Thanks for responding Ace

I am not sure how to post pictures that you can expand so here the link to photobucket again..

http://s1267.photobucket.com/albums/jj550/timmjk/

If you click on the pictures they should expand. It looks to me like it is the aluminium is starting to fatigue in these spots or debris was stuck between the bearing and the housing interface and created the hole.

I was thinking of filling it with some type of metal filler or epoxy to at least stop it from spreading. But I am afraid I will make it worse than they already are. Other option is to just put it back together and see if I have any issues..

Let me know if the pictures still suck

 

Those are better. It is a ballbearing race that contacts that surface right? So no moving parts are in direct contact with that?

I would not be worried about it if that is the case, the surface doesn't have to be perfectly smooth since the race is what the bearings will actually ride on.

 

Duh! Thanks Ace.. I am an idiot.. I guess since I got a decent deal I keep expecting something major wrong with it.. Thanks thats exactly right.. The bearing race spins and the outer race rests against the housing. The holes dont go all the way through so I think they are fine. I will just leave them and clean it up really well. Thanks Ace again. BTW. I picked up a MAF sensor from the junkyard and cleaned it up and stuck it in and the hesitation is mostly gone. I will still fiddle around with it while I wait for the s/c parts to come in and see if I can completely erradicate the issue but it is much better.

Thanks again!!

 

Those look like porosity holes to me. It's not anything to worry about IMO.

One a side note, does anyone know who cast and/or machined the nose housing for the TRD blowers? Those tool marks in the bore probably aren't a problem either, but they were caused my a mistake in manufacturing.

 

Magnuson. Unless they farmed it out.
http://www.gadgetonline.com/Super.htm

 

So I tried to rebuild the nosedrive today and the front bearing (towards pulley) pressed in wonderful and then the rear bearing and coupler plate pressed on the shaft good. The problem arose when when I pressed the shaft through and everything looked great. Then I spun the shaft and the rear bearing (towards the blower) is skipping on the outer race against the housing. I measured both the old and new bearings and they are the same size.

So I guess it looks like the housing has been worn to the point of allowing the bearing just to turn but just a little bit. What are my options? Is this normal? Should I be worried or just put it together? Bond it in??? Or under load will it seat with the oil in in?

 

From the pictures it looks like the bearings had been spinning in the bores at least to some degree before.

Far as how to fix it, I would call up a supercharger rebuilder and get their opinion. Not sure what would work long term.

 

You mean the outer race is spinning in the housing?

 

My questions are...isn't that some type of RTV/sealant? And if so, wouldn't that mean that somebody tried to seal the outer bearing race to the housing once before? I swear it looks like those holes are filled with it too.

a. Buy a new/overhauled nose drive and/or housing. Or have the housing repaired, sleaved, or rebored to accept a bearing assembly with a slightly wider outer bearing race.
b. Normal? No. That's a bad thing, surely.
c. Worry or just put it together? Worry, atleast a little bit(if not a lot). Don't just put it together.
d. Didn't somebody try that already? Well, did it work? Maybe it did until you came along? You tell me.
e. Will it seat with the oil in it? Quite the contrary. It will seat less with the oil in it actually.

 

Thank you for the input - So unfortunately I did not get your reply until just now. Here is what I did.I purchased a new bearing (this time SKF brand) and a loctite compound made specifically for seating bearings that are pressed in housings that will not seat correctly (oversized housing). Followed the instructions I put a thin coat of the bearing retainer compound on the inside of the housing. The new bearing spun freely and did not catch like the other bearing (which was one reason it was causing the outer race to skip). I pressed in the new bearing and let the compound dry a full 48 hours and then tested it out and the outer race did not move at all. I put in the charger and drove it lightly and tested the shaft play once installed and driving on it. It seemed to have worked thus far. It has been on the 4runner for about a month and I had a little oil leak out of the nosedrive right after the install (about three or four drops). But nothing after a few days. I will have to keep watching it but it seems like this is at least a decent short term fix. I did pick up a used gen 3 housing off a bonneville and I know that magnesson is using these to rebuild for the TRD gen 3's. I will keep watching for a housing though to replace it since I really don't like doing the mickey mouse installations. If it comes down to it in the future I will just buy the gen 4 or have the nosecone I picked up machined down to match the one I have (except for the oversized area of course).. Or like you said have it bored to mate with a larger outerdiameter race bearing.Cheesy but it seems to be working for now.. My main worry was that the oil would eat away at the compound and dissolve it. I checked out the specifications and talked with Loctite and they did not feel it was an issue and it was made to withstand solvents once it is cured. You have to buy a specific compound to remove it. So I am hoping it will work for thousands of miles while I keep searching for the long term solution.Thanks again..

 

BTW- Yes when I tore into the housing it was chuck full of grease. I am talking the entire area between the bearings was completely full. You never know what you are going to get off of CL unfortunately. But for a total of $400 the SC is on and functioning (including all the damn bolts and crap I had to piece together since he had nothing for the install). Now need the fuel mods as well. Just need to figure out what I can do and still pass inspection here in Cali.