Rear Wheel Bearings Loose Options

[DennisV]

Should the rear wheel bearings be able to move within the trailing arm and contact the housing flange?

The bearings went in pretty easy after being frozen. When I put in the rear wheel hub, using the technique suggested by Ian and PMB, they seem to have broken free. I can slide them back and forth. Maybe that's the whole purpose of the housing flange, but seems sloppy.

[930cabman]

(IMG:style_emoticons/default/popcorn[1].gif)

We will be crossing this bridge soon

[bdstone914]

@DennisV

Do you have the stub axles installed and nuts torqued?

If not they will be loose.

[bdstone914]

@DennisV

Do you have the stub axles installed and nuts torqued?
Did you install the bearing retainer plates?

If not they will be loose.

[mepstein]

@DennisV

Do you have the stub axles installed and nuts torqued?

If not they will be loose.

(IMG:style_emoticons/default/agree.gif) that’s why you never move the car without stubs installed

[Superhawk996]

Outer bearing race should not be freely rotating within the trailing arm with or without the flange tightened.

The bearing is normally a light press fit into the trailing arm and shouldn’t allow the outer race to rotate or move laterally freely.

The retaining flange is basically a belt and suspenders safety to prevent the bearing from ever migrating laterally and to put a hard stop on how much it can move laterally.

If that bearing is truly able to rotate the outer race in the trailing arm, or if the outer race is free to move laterally, I’d remove it and replace with another bearing and/or measure bearing OD and trailing arm ID to make sure there is a light .001” - .002” press fit.

[Superhawk996]

@DennisV

Do you have the stub axles installed and nuts torqued?

If not they will be loose.

(IMG:style_emoticons/default/agree.gif) that’s why you never move the car without stubs installed

This is true - but pertains to the inner races.

Rolling the car or even putting static weight on the the car without the stubs installed will permanently damage the bearing due to the dual row, split inner race design.

[technicalninja]

I agree !

Works great to break free the old bearings, easier to remove after.

[DennisV]

Do you have the stub axles installed and nuts torqued?

If not they will be loose.

Nope. Trailing arms are not back on the car.

Outer bearing race should not be freely rotating within the trailing arm with or without the flange tightened.

The bearing is normally a light press fit into the trailing arm and shouldn’t allow the outer race to rotate or move laterally freely.

They are new bearings in freshly refurbished arms. I froze the bearings and they went in without issue. I didn't test how tight they were, but they weren't falling out.

Is it possible that I over tightened the hub using the impact wrench and pulled the bearing out of the housing? I thought the hub was meant to fully seat. I can rotate the hub with one hand, but it does have some resistance.

It sounds like I need to unwind all this? Remove the hubs, flange housing, and start over? What a PITA. (IMG:style_emoticons/default/headbang.gif)

[Superhawk996]

Tightening the stub / hub on puts tension (pre-load) across inner split races. Tightening the hub but has no way to apply force laterally that would cause the outer bearing to migrate laterally.

After that tightening is done you shouldn’t have any lateral movement of the hub.

Rotation will have some light resistance due to bearing / grease / seal drag.

Can you post video to YouTube if you have lateral movement going on? It’s not clear to me exactly what you’re describing.

[DennisV]

Can you post video to YouTube if you have lateral movement going on? It’s not clear to me exactly what you’re describing.

I can post a video in about a week when I'm back with the car.

The hub and bearing can move in the direction of the red arrow. When pulled outward, the bearing contacts the back of the flange as noted by dotted line.

[bdstone914]

@DennisV

' date='Jan 4 2024, 10:27 AM' post='3121785']
[quote name='Superhawk996' post='3121781' date='Jan 4 2024, 08:13 AM']
Can you post video to YouTube if you have lateral movement going on? It’s not clear to me exactly what you’re describing.
[/quote]
I can post a video in about a week when I'm back with the car.

The hub and bearing can move in the direction of the red arrow. When pulled outward, the bearing contacts the back of the flange as noted by dotted line.

[/quote]


It sounds like you have the wrong bearing that is not wide enough. Bearing should be flush with the top of the trailing arm. What exactly did you buy?
Or the bore for the bearing is oversized. But it should have no clearance to the bearing retainer.
You will have side to side movement until you install the stub axle.

[DennisV]

It sounds like you have the wrong bearing that is not wide enough. Bearing should be flush with the top of the trailing arm. What exactly did you buy?
Or the bore for the bearing is oversized. But it should have no clearance to the bearing retainer.
You will have side to side movement until you install the stub axle.

I bought 999-053-035-00 per the parts catalog from Stoddard. Ended up being a FAG bearing.

I didn't take a photo before installing the retainer, but here is one from before the hub. It is not a lot of travel, but I was surprised it could be moved at all.

[Superhawk996]

Are you sure you have 914/6 or early 911 stubs / hubs?

Just thinking out loud (dangerous); weren’t there some 944 stub or hubs or something that folks were using back in the day to get 5 lug hubs but they needed a 5mm spacer or something like that on the stub axle?

@914sixer
Do you remember any weird stub or hub setups from back in the day when it would have been much harder to find a 914/6 hub?

[Superhawk996]

Also with respect to the impact wrench:

Without actually having something to prevent rotation of the hub an impact isn’t going to give you enough torque to tighten properly.

The hub nut needs to be tightened properly to set pre-load in the bearing. You need to do this with a real torque wrench and a breaker bar to keep hub from rotating and to get the high torque needed (217 -253 lb*ft per Haynes). It takes a LOT of torque to tighten the hub nut properly.

Failure to properly torque the hub nut will result in premature bearing failure.

[914Sixer]

This topic has been covered several times. The short version is the quality of the bearings. NEW bearings now seem to come in good, better and best. Original German bearings were in tight tolerance. I try not to use any bearings made after 1990. I only try to use FAG or SKF NOS original German, Spainish and Italian bearings.

As far as 911 or 944 hubs go, check all the info in the Classic section that cover the combinations.

[Krieger]

I have some used rear bearings I removed you can have or use to measure. I wrecked them installing 5 lug hubs. I also have a pair of NOS wheel bearings you can measure out. Also one rear trailing arm laying around you could mess with. The hub has been removed.

[DennisV]

Are you sure you have 914/6 or early 911 stubs / hubs?

Our car was a factory 914-6. Pretty darn sure they are 914-6 hubs.

Without actually having something to prevent rotation of the hub an impact isn’t going to give you enough torque to tighten properly.

Not sure what you're referring to regarding the rotation and torque. All I did was install the hub into the bearing in the trailing arm as pictured. Using the all thread rod, nuts and impact wrench method referenced in my initial post to pull the hub into the bearing.

If you're talking about the nut that secures the cv joint / drive shaft, I haven't gotten that far yet.

Is it wishful thinking that this problem goes away once the drive shafts are installed?

[rjames]

Is it wishful thinking that this problem goes away once the drive shafts are installed?

Yes. Unless I'm misunderstanding the situation you've described, they shouldn't move once installed.

When I installed mine (after freezing them) they slipped right in by hand and then immediately warmed up and were firmly in place such that I wouldn't have been able to remove them without pressing them out like I had to do with the old ones.

[porschetub]

Also with respect to the impact wrench:

Without actually having something to prevent rotation of the hub an impact isn’t going to give you enough torque to tighten properly.

The hub nut needs to be tightened properly to set pre-load in the bearing. You need to do this with a real torque wrench and a breaker bar to keep hub from rotating and to get the high torque needed (217 -253 lb*ft per Haynes). It takes a LOT of torque to tighten the hub nut properly.

Failure to properly torque the hub nut will result in premature bearing failure.

(IMG:style_emoticons/default/agree.gif) I wouldn't put and impact wrench near them ,the chattering could easily damage the new bearings , real simple answer is they don't fit and must be undersize OD or even worse too narrow but not likely ,how the bearing is torqued up won't cure that sadly.
I have a bad RH side one to do and was always intending to measure the bearing OD and the trailing arm bore to be safe,I can return the bearing anytime as have a mate @ SKF where I purchased it ,cheers.