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-   -   New Flappy Bearings not tight when installed (https://rennlist.com/forums/928-forum/953958-new-flappy-bearings-not-tight-when-installed.html)

1979928 09-16-2016 03:17 AM

New Flappy Bearings not tight when installed
 
Hi all,
I'm at the stage of replacing the flappy bearings on MY89 intake refresh.
The originals were a PITA to remove but the new ones I purchased from Roger can be pushed in without much effort with my finger.
I wouldn't say they are loose but they are definitely not as tight as the originals.
I was careful when removing the originals and no damage was done to the bearing seats in the manifold.
Should I be able to do this? I’ve searched on Rennlist and have only found one other with the same issue and he resolved it by using loctite on the bearing race then installing.
Should I give them a smear of Loctite 574 when installing?
Not sure whether I’m over thinking this but just wanted to make sure before I button it up.

Dave928S 09-16-2016 07:40 AM

Check the bearing outer dimension with a caliper and see what you get. It may be a bearing dimensional issue, or you may have, despite your care in removal of the old ones, enlarged the bore a little.

First check dimensions of the outer of new and old bearings, and the bore, and post back here.

If you had to use loktite, I'd use the one specifically for taking up interference fit slop ... can't remember the code.

Ed Scherer 09-16-2016 11:21 AM

Are the bearings labeled INA HK1012.2RS FPM? I remember them fitting pretty well and I certainly didn't have any concerns about them spinning or otherwise moving in their seats. That was six years ago, though, so I don't really remember my exact impressions.

In case it's of use, I posted some hi-res photos and specs of the bearings.

GregBBRD 09-16-2016 12:28 PM

Normally a press fit.

1979928 09-16-2016 09:00 PM


Originally Posted by Dave928S (Post 13607682)
Check the bearing outer dimension with a caliper and see what you get. It may be a bearing dimensional issue, or you may have, despite your care in removal of the old ones, enlarged the bore a little.

First check dimensions of the outer of new and old bearings, and the bore, and post back here.

If you had to use loktite, I'd use the one specifically for taking up interference fit slop ... can't remember the code.

Thanks Dave,
The new bearings are 14mm (the originals were also 14mm) and the manifold bore measures 14.05mm.
I think you're right in saying I must have slightly enlarged the bore of the manifold during removal. I used silicone spray on the bores prior to installing to help thinking they would be very tight which they were not. They are not loose when installed and certainly couldn't be rotated.

1979928 09-16-2016 09:09 PM


Originally Posted by Ed Scherer (Post 13608005)
Are the bearings labeled INA HK1012.2RS FPM? I remember them fitting pretty well and I certainly didn't have any concerns about them spinning or otherwise moving in their seats. That was six years ago, though, so I don't really remember my exact impressions.

In case it's of use, I posted some hi-res photos and specs of the bearings.

Thanks Ed,

Yes they are definitely the right bearings HK10122RS.
They certainly don't spin or move in their seats but my concern was the relative ease of the installation. As Dave has suggested I must have slightly increased the bore diameter when removing the originals.

GregBBRD 09-16-2016 11:37 PM


Originally Posted by 1979928 (Post 13609464)
Thanks Ed,

Yes they are definitely the right bearings HK10122RS.
They certainly don't spin or move in their seats but my concern was the relative ease of the installation. As Dave has suggested I must have slightly increased the bore diameter when removing the originals.

They are not going a anywhere....there's a thin thrust washer against both of them.

1979928 09-17-2016 12:15 AM


Originally Posted by GregBBRD (Post 13609707)
They are not going a anywhere....there's a thin thrust washer against both of them.

Thanks Greg,
I suppose I'm most worried about potential false air due to the bearings not needing to be pressed in. That's why I'm asking whether I should use some type of Loctite on the bearing race and or manifold bore.

GregBBRD 09-17-2016 11:31 AM


Originally Posted by 1979928 (Post 13609778)
Thanks Greg,
I suppose I'm most worried about potential false air due to the bearings not needing to be pressed in. That's why I'm asking whether I should use some type of Loctite on the bearing race and or manifold bore.

Doubtful you are going to get a significant air leak around the outside of the bearing and then around the 90 degree corner of the seat for the bearing in the manifold.

Loctite makes a stud and bearing mount, if you are really that concerned. A film of any kind of silicone sealer would also do the job.

Of course, the top has a rubber cap that fits over the entire assembly, so no air is going to get in there.

1979928 09-17-2016 07:41 PM

Thanks Greg


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