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914World.com _ 914World Garage _ Rear Wheel Bearing wobble

Posted by: paintguru Nov 12 2017, 11:08 AM

Has anyone experienced excessive play in a newly installed rear wheel bearing? During the restoration of my 72 I installed new bearings. The left rear has no play and the hub rotates smoothly. The right side seems to have excessive play and with the car on the lift I can wiggle the tire and wheel left and right about 1/8th of an inch. Thinking I might have damaged the bearing during install I ordered another one. Yes I bought decent quality from Pelican and not a made in china cheapie. Again I carefully pressed in the bearing feeling confident it was not damaged but once again the hub rocks while the other side doesn't. Thoughts?

Posted by: 80cap Nov 12 2017, 11:14 AM

What torque value did you use on the nut? I had the same thing until I torqued it to the spec.. I can't recall the amount but it is around 260 Lb.Ft.
Brian

Posted by: paintguru Nov 12 2017, 11:26 AM

QUOTE(paintguru @ Nov 12 2017, 09:08 AM) *

Has anyone experienced excessive play in a newly installed rear wheel bearing? During the restoration of my 72 I installed new bearings. The left rear has no play and the hub rotates smoothly. The right side seems to have excessive play and with the car on the lift I can wiggle the tire and wheel left and right about 1/8th of an inch. Thinking I might have damaged the bearing during install I ordered another one. Yes I bought decent quality from Pelican and not a made in china cheapie. Again I carefully pressed in the bearing feeling confident it was not damaged but once again the hub rocks while the other side doesn't. Thoughts?

I've not yet torqued either side. I was hoping the pressure from the nut would remedy this but I'm troubled by the left side being firm without the nut being tightened.

Posted by: paintguru Nov 12 2017, 11:27 AM

QUOTE(paintguru @ Nov 12 2017, 09:26 AM) *

QUOTE(paintguru @ Nov 12 2017, 09:08 AM) *

Has anyone experienced excessive play in a newly installed rear wheel bearing? During the restoration of my 72 I installed new bearings. The left rear has no play and the hub rotates smoothly. The right side seems to have excessive play and with the car on the lift I can wiggle the tire and wheel left and right about 1/8th of an inch. Thinking I might have damaged the bearing during install I ordered another one. Yes I bought decent quality from Pelican and not a made in china cheapie. Again I carefully pressed in the bearing feeling confident it was not damaged but once again the hub rocks while the other side doesn't. Thoughts?

I've not yet torqued either side. I was hoping the pressure from the nut would remedy this but I'm troubled by the left side being firm without the nut being tightened.

I guess at this point I'll torque the nuts and see where I go from there. Thanks for the reply.

Posted by: 80cap Nov 12 2017, 11:42 AM

The Haynes manual states the torque at 217 to 253 Lbs. Ft.
Brian

Posted by: porschetub Nov 12 2017, 02:12 PM

Wasn't there a thread on here about some bearing having a slightly smaller I.D.,seem to remember it was the SKF ones that were the issue and the FAG ones were ok ??.
This would certainly seem to be the OP's problem,I would think if it wasn't a tight fit into the trailing arm this would be an issue.
I read replies with interest as I have a bearing to replace myself and it is an SKF one sad.gif .

Posted by: MarkV Nov 12 2017, 02:52 PM

I had a new FAG bearing made in Slovakia or some place that had play in it. It wasn't loose in the bore the bearing center was loose in the race. I could move the wheel back and forth 1/4" and it made noise when driving. Replaced it with an ebay $15 bearing made in China and it has been fine ever since.

There is this Boxster youtube..... said there was a batch of bad bearings and that they had very little grease in them form the factory. Same part # as 914 bearing.

https://www.youtube.com/watch?v=-A5kf5pXl4w

https://www.youtube.com/watch?v=l9P1R2clGAU

Posted by: 914Sixer Nov 12 2017, 04:53 PM

I discussed this very thing earlier this year. I went through 4 bearings until i got good ones. I made sure I got some NOS old style. There is major differences in the thickness of the inner bearings. The good ones that worked for me was FAG 545495AD. This is a BMW bearing but it is universal.

Posted by: cary Nov 12 2017, 07:24 PM

1. Same thing happened on my 911 many years ago.
2. Have you put it on the ground yet ? If not, lower and torque to spec. Torque to 217 then dial it in till you line up the next cotter key slot.Then see what you have.
Maybe. But I kind of doubt it.
3. Ditto on FAG

Posted by: porschetub Nov 12 2017, 09:26 PM

QUOTE(914Sixer @ Nov 13 2017, 11:53 AM) *

I discussed this very thing earlier this year. I went through 4 bearings until i got good ones. I made sure I got some NOS old style. There is major differences in the thickness of the inner bearings. The good ones that worked for me was FAG 545495AD. This is a BMW bearing but it is universal.


Hopefully that's helpful to the OP,in my case the bearing I have is a BMW SKF kit,includes self locking nut and snap rings,my friend @ SKF told me it will fit a 914,the kit number is VKBA1460, the bearing is listed as SKF FW109 for 914 fitment.
I trust my bearing guy so hopefully all will be good as its not a job you want to be doing too often.
Thanks Mark.

Posted by: ThePaintedMan Nov 13 2017, 08:34 AM

The double row bearings are very difficult to over-torque. In fact, they rely on a great amount of torque to seat the balls and extend the life of the bearing. Went through 3 of them on a client's racecar till he trusted me that 100 ft lbs wasn't enough rolleyes.gif

I'd be willing to bet that once you torque to 217+ ft-lbs, you'll see the slop disappear,

Posted by: McMark Nov 13 2017, 09:18 AM

Getting the slop to disappear requires that the stub axle be fully seated into the hub, and the hub to be fully seated against the bearing. Rust, dirt, or damage can keep things from seating fully by hand. Most of the time those factors are irrelevant against 200+ft/lbs of torque, so it's not a problem once torqued. If you really want to go the extra mile, make sure those components are clean and smooth.

I always do a little cleanup with a fine ScotchBrite pad as well as taking a dental pick to each and every groove in both sides of he spline joint. Also a thin layer of grease on all surfaces. You want to make sure this stuff will come apart again later.

Posted by: worn Nov 13 2017, 09:23 AM

QUOTE(paintguru @ Nov 12 2017, 09:08 AM) *

Has anyone experienced excessive play in a newly installed rear wheel bearing? During the restoration of my 72 I installed new bearings. The left rear has no play and the hub rotates smoothly. The right side seems to have excessive play and with the car on the lift I can wiggle the tire and wheel left and right about 1/8th of an inch. Thinking I might have damaged the bearing during install I ordered another one. Yes I bought decent quality from Pelican and not a made in china cheapie. Again I carefully pressed in the bearing feeling confident it was not damaged but once again the hub rocks while the other side doesn't. Thoughts?


They wobble like crazy until the stub axle is tightened. Scared me to death when I did them.

Posted by: 76-914 Nov 13 2017, 10:14 AM

I remember Cap'n Krusty saying that if you rolled the car around before tightening you could ruin them. confused24.gif

Posted by: Dave_Darling Nov 13 2017, 10:27 AM

QUOTE(76-914 @ Nov 13 2017, 08:14 AM) *

I remember Cap'n Krusty saying that if you rolled the car around before tightening you could ruin them. confused24.gif


Yup, that's been known for a long time. They're usually OK for just sitting, and maybe for pushing across the shop once or twice, without the stub axle in and torqued. But if you're doing anything more than that, the stub has to be in there and it has to be torqued up properly.

--DD

Posted by: mepstein Nov 13 2017, 12:00 PM

always insert the stub and at least snug it down. even for rolling around the shop.

Posted by: jim_hoyland Nov 13 2017, 02:56 PM

QUOTE(MarkV @ Nov 12 2017, 12:52 PM) *

I had a new FAG bearing made in Slovakia or some place that had play in it. It wasn't loose in the bore the bearing center was loose in the race. I could move the wheel back and forth 1/4" and it made noise when driving. Replaced it with an ebay $15 bearing made in China and it has been fine ever since.

There is this Boxster youtube..... said there was a batch of bad bearings and that they had very little grease in them form the factory. Same part # as 914 bearing.

https://www.youtube.com/watch?v=-A5kf5pXl4w

https://www.youtube.com/watch?v=l9P1R2clGAU


Great videos ! I just replaced both rear bearings and now i’m Hearing one again. Is it too late too late to regrease the noisy bearing ?

Posted by: colingreene Nov 13 2017, 02:59 PM

Jim its a sealed bearing, i dont think you can re grease it.

Posted by: mepstein Nov 13 2017, 03:20 PM

QUOTE(colingreene @ Nov 13 2017, 03:59 PM) *

Jim its a sealed bearing, i dont think you can re grease it.

You can. There’s even a good video.

Posted by: Spoke Nov 13 2017, 03:34 PM

QUOTE(mepstein @ Nov 13 2017, 01:00 PM) *

always insert the stub and at least snug it down. even for rolling around the shop.


I read somewhere or from someone here that you should never roll a 914 without the rear hubs attached to prevent bearing damage.

Posted by: MarkV Nov 13 2017, 03:57 PM

I found the old thread:

http://www.914world.com/bbs2/index.php?showtopic=284907

The part # on the loose FAG bearing that I had was 545495AWD. Made in Slovakia. I took it apart after I replaced it and couldn't see what was wrong with it. It seemed like the two halves of the inner race would meet before they were tight to the bearings.

Posted by: jim_hoyland Nov 13 2017, 04:14 PM

QUOTE(colingreene @ Nov 13 2017, 12:59 PM) *

Jim its a sealed bearing, i dont think you can re grease it.


That was my impression too; but, see:
https://www.youtube.com/watch?v=-A5kf5pXl4w

Posted by: mepstein Nov 13 2017, 05:33 PM

QUOTE(jim_hoyland @ Nov 13 2017, 05:14 PM) *

QUOTE(colingreene @ Nov 13 2017, 12:59 PM) *

Jim its a sealed bearing, i dont think you can re grease it.


That was my impression too; but, see:
https://www.youtube.com/watch?v=-A5kf5pXl4w

Sealed bearings are usually a press fit bearing that is self contained vs loose bearings that use a cup and cone. Many sealed bearings have an easily removable plastic seal that lets you get to the bearings. Sealed doesn’t always mean non serviceable.

Posted by: euro911 Nov 13 2017, 08:41 PM

Wow yikes.gif

Good to know that new ones need special attention and are 'serviceable'. The '71 has been rolled around extensively since the axle shafts were pulled out, but I was planning to replace the old bearings anyway. Just didn't know new ones were coming out of the factory with a built-in defect mad.gif

Has anybody chided their QC department?

Posted by: mepstein Nov 14 2017, 07:07 AM

Here's my theory on why the boxster guys have trouble with the bearings while most of us do not. I think the brand new bearings are filled with a bead of grease from a machine instead of having grease worked into the bearing retainer. The boxster spec cars are getting used on the track. So the guys take out there cars and immediately start driving some hot laps. This sudden increase in speed doesn't give the bearing much chance to warm up slowly so the grease can soften and flow to the bearings. So for at least a while, there is hot metal on metal. The bearing gets trashed before it ever has time to get lubricated. Most non track cars would be driven slowly for a while and the grease has time to warm up and flow around the bearing before any one part gets too hot.
The boxster guys are not modifying the bearings, just making sure they are completely lubricated.

just a theory...

Posted by: paintguru Nov 14 2017, 11:41 AM

QUOTE(ThePaintedMan @ Nov 13 2017, 06:34 AM) *

The double row bearings are very difficult to over-torque. In fact, they rely on a great amount of torque to seat the balls and extend the life of the bearing. Went through 3 of them on a client's racecar till he trusted me that 100 ft lbs wasn't enough rolleyes.gif

I'd be willing to bet that once you torque to 217+ ft-lbs, you'll see the slop disappear,

I'll do this. The bearing is an FAG unit.

Posted by: paintguru Nov 14 2017, 11:43 AM

Thanks for all the help. I'll torque on it today and let you know what happens.

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