New 914 rear wheel bearing, No to very little grease from manufacture Options

[Luke M]

So, I just purchased a set of New FAG wheel bearing (made in Germany) so I can install a set of the later (74-89) 911 rear hubs on my 914 control arms.
I saw a few you tube videos about how the bearings for the Boxster where being shipped with little to no grease in them. I figured before I install them to check the grease. Well sure enough one side had little grease and the other side had very little to no grease on the bearings. I should've taken a few pics but didn't have my phone handy. I still have another new bearing to inspect so I'll take pics of that one. I'm sure it will be the same way. Now to go pick up some grease and repack them.


So if anyone of you out there plan on replacing your rear bearing I would inspect them.

Here's a handy video which shows how to do this.

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

[Superhawk996]

Can’t tell for sure but it appears from YouTube (here we go again !) that 06’ CRV rear bearing as GEN1 double row ball bearing. In was 07’ it looks like they went Gen3 wheel and hub. I can’t tell for sure what they are doing on 2wD versions but I assume you are AWD given your location.

So again, like 914; torque on the rear hub is what establishes Pre load.

The other thing up for discussion is seal life. A contaminated bearing won’t live long.

[bbrock]

but I assume you are AWD given your location.

Well, it's April 12 and I've been watching it snow outside my window all day. I'll let you decide if your assumption is correct.. (IMG:style_emoticons/default/happy11.gif)

I didn't know what Gen1 etc. meant but yes, double row of ball bearings just like the 914. I would assume the factory trained mechanics knew to torque the hub properly when they did them. I know I did when I did them myself last time. I'm not saying they are wearing out prematurely because I don't know what the acceptable service life is defined as. I'm just saying they don't last nearly as long as every other car I've owned which is basically, forever.

[Superhawk996]

"I would assume the factory trained mechanics knew to torque the hub properly when they did them."

(IMG:style_emoticons/default/av-943.gif)

Now that's funny! (IMG:style_emoticons/default/lol-2.gif)

No offense to dealer Tech's. Most are great and diligent. However they are paid on flat rate more often than not. I've witnessed bearing hub nuts go on with the impact wrench and no more thought than that. Hard to blame them if under the gun and they don't get billed back for parts if the repair fails. Since bearings with too much pre-load won't fail immediately there is little risk of it coming back to bite them personally.

Gen 1 -- is simple bearing that presses into knuckle. Or trailing arm in our case. bearing pre-load is controlled by torque across the joint.

Gen 2 -- is bearing and hub as integral assembly - not meant to be disassembled; service as an assembly. These are very problematic in service since it takes knowledge to recogniize them 1st and 2nd to use the proper special tools for installation that only applies pressure to the outer race. Mechanics often unknowingly press in via the hub and that damages the bearing.

Gen 3 is integral hub and bearing assembly with mounting flanges. Bolt and unbolt. Bearing pre-load is typically established by orbital forming of the hub to the bearing controlling to a pre-determined deformation that holds the hub & bearing together as an assembly. These are often used on the rear of 2WD since there is no CV & axle assembly to hold the hub and bearing together. These are typically very very reliable and are the ones that hold up for life of vehicle.


So onto seals. Engineering seals is a whole field unto itself. Single lip seal, double lip seal, with or without Garter spring. With or without an external Flinger?

Seals are designed with a bit of springiness to hold them into the bearing. After the 1st assembly at the plant, that is supposed to be it. Pulling the seals and then reinstalling them means they go in with just a little less spring force and a bit less of a seal to the outer race than they originally had. Minimal . . . yes. However, there will be just a little bit less sealing force to the outer race than it had initially none the less. We won't even talk about the potential for bending the seal slightly.

Likewise, in the case of lip seals (especially double or triples) it's easy to get a lip folded over. That will wear out the folded lip in short order and fail. I've even seen single lip seals fold. Again, minimal risk but I assure you it can happen.

Seals are what keep the water and dirt out. You could have the best bearing steel, the best manufacturing tolerances, and the best grease but if a seal lets in dirt & water, it won't live as long as it otherwise would have.

This is why I cringe seeing the bearing seals pulled for a little look see, just to be sure.

Aftermarket bearings are typically made to a lower standard than OEM and they cheap out on seals, grease, and steel quality.

So your best chance is with the bearing delivered with the vehicle. I've had several vehicles go to 200,000+ before a bearing went south. And that is inclusive of Michigan winters + salt + lots of corrosion. On the other hand I've had the OEM bearing fail at 90,000 miles and then had to put aftermarket on for tail end of the vehicles life when a $300 OEM bearing would have been 1/2 the vehicles value.