C rear wheel bearing and seal replacement

356 Porsche-related discussions and questions.
Message
Author
Mike Grant
356 Fan
Posts: 203
Joined: Mon Feb 18, 2013 2:25 pm
Location: Aptos, CA

C rear wheel bearing and seal replacement

#1 Post by Mike Grant »

I had the rear wheel bearings replaced on 64 SC right after I bought it last March. A few months later I noticed that the left rear axle nut had lost torque (cotter pin was in place) and that there was some "wiggle" in the wheel. I pulled the cotter pin and re-torqued the axle nut and everything looked okay. No leaks at this point.

The car hasn't been driven for the last few months and I was under the car yesterday and noticed that there is a gear oil leak at the inside of the left rear wheel, dripping from the outside of the backing plate. After searching this forum, it seems very likely that the seal or one of the O-rings is damaged or unseated. A bearing failure is possible also, but I don't recall any noise that would indicate that.

I'm going to get the Stoddard seal kit and a new bearing, and I'll also get the Stoddard bearing removal tool. The tool is a bit expensive, but I suspect that this won't be the only time I'll do this task as a 356 owner.

I've read the DIY instructions in the Tech information section and it seems like a do-able task. In addition to the bearing puller I will get a 3/4" drive 40" breaker bar and a 36mm 6 point impact socket for the axle nut.

Are any other special tools or supplies required or helpful? Any suggestions or tips would be appreciated. Thanks.

Mike

User avatar
Jacques Lefriant
356 Fan
Posts: 4602
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: C rear wheel bearing and seal replacement

#2 Post by Jacques Lefriant »

Hi Mike
Good on you for attemping this.
!. disc brake seal kits or different than drum the only comonallity is the small O ring.
2. the washer in kits that imediately preceeds the small oring is usually junk maybe use Ab's.
3. the puller works only with bearings that have the correct no of balls
4. if the bearing has the correct no of balls and the plactic cage is installed wrong side out remove it then use the puller.
5. make sure you retract the screw suficientl to allow the fingers to fully grab the inner race.
6. when installing the bearing pull it out so that the oring rides on it and use the backing plate to seat the bearing.
go for it
j
BTW make sure you don't havea bent axle check the runout on the hub and if it is excessive flip the hub and check again.
 

User avatar
Vic Skirmants
Registry Hall of Fame
Posts: 9279
Joined: Tue Oct 27, 2009 5:02 pm
Location: SE Michigan
Contact:

Re: C rear wheel bearing and seal replacement

#3 Post by Vic Skirmants »

The washer in the Stoddard kits is good; the VW ones are too soft.
6. That's the large O-ring.
The small O-ring probably got damaged when the hub came loose. The hub maybe came loose because there was a soft washer in there.
I would do both sides; the bearings are probably OK, just replace the washers and O-rings.

User avatar
Albert Tiedemann
356 Fan
Posts: 1229
Joined: Thu Apr 03, 2008 2:46 pm

Re: C rear wheel bearing and seal replacement

#4 Post by Albert Tiedemann »

Jacques Lefriant wrote:Hi Mike
Good on you for attempting this.

3. the puller works only with bearings that have the correct no of balls

BTW make sure you don't have a bent axle check the run-out on the hub and if it is excessive flip the hub and check again.
The Factory tool, VW 241 A also only works with the correct number of balls--8.
Albert Tiedemann, C356C
"The Hermit"

Mike Grant
356 Fan
Posts: 203
Joined: Mon Feb 18, 2013 2:25 pm
Location: Aptos, CA

Re: C rear wheel bearing and seal replacement

#5 Post by Mike Grant »

Thanks to all for the information. I think I'll probably find a condition like Vic has described. I ordered everything today that will allow me to change the bearings, seals and o-rings on both sides.

Dick Weiss
356 Fan
Posts: 4182
Joined: Sun Apr 20, 2008 12:54 am

Re: C rear wheel bearing and seal replacement

#6 Post by Dick Weiss »

When working on bearing(s) &/or seal(s) replacements, I tilt the car sideways (via the jack spur) and keep the axle(s) INWARD so the fulcrum keys stay in place on the axle end(s)!
This also minimizes oil leaking from the opened axle tube end(s) when it's jacked up past level. I use the VW-241 tool for bearing removal.
Look in the Registry's tech section for getting the large O-ring to stay in place when reinstalling the end cap.

Dick

User avatar
Michael Aiello
356 Fan
Posts: 45
Joined: Wed Jan 05, 2011 11:31 am

Re: C rear wheel bearing and seal replacement

#7 Post by Michael Aiello »

How easy is it to dislodge the fulcrum? I fear I may have done it as recently as this morning when replacing the passenger side rear bearing. It was a bear (no pun), and I had to use 4 threaded rods in the housing to pull it into place. Now I've got a significant "thump" as I turn that axle shaft. The other side turns smooth. What's the bad news?

User avatar
Wes Bender
356 Fan
Posts: 4861
Joined: Wed Aug 27, 2008 10:54 am
Location: Somewhere in the Gadsden Purchase, USA

Re: C rear wheel bearing and seal replacement

#8 Post by Wes Bender »

If you inadvertently pulled the axle shaft out more than about 1/2", there's a very good chance that one or both fulcrums dropped out. The differential has to be dismantled to put them back in place.

No matter what method one uses to pull the bearing, you have to be very careful to keep the axle from moving out more than about 3/8" or so. (I shoot for 1/4" max and haven't had the misfortune of dropping a fulcrum.)

Maybe Vic can chime in and tell you more.....

Wes
Some days it's just not worth chewing through the restraints.....

User avatar
Vic Skirmants
Registry Hall of Fame
Posts: 9279
Joined: Tue Oct 27, 2009 5:02 pm
Location: SE Michigan
Contact:

Re: C rear wheel bearing and seal replacement

#9 Post by Vic Skirmants »

"Maybe Vic can chime in and tell you more....."
Michael, I'm chiming in here. Wes is correct; although only one fulcrum can fall in; that leaves no space for the other one. That's good news??
Anyway; I have heard that some people have succeeded in getting the fulcrum plate back into position without major dis-assembly. I never have.
I did talk to someone recently about that problem. The one thing I haven't tried; yet; is to:
Remove the axle tube, then you can see into the trans and determine which fulcrum is "missing". Rotate the axle so the missing fulcrum is at the bottom. Then using a magnet and gravity, try to pull it back. Don't know if this will work, but it's all I have.
Jon Bunin; any comments?
And Merry Christmas.
Incidentally, don't just assemble it with the fulcrum out of position. You will distort the axle tube hexagonal flange when you clamp down the bearing retainer. Bad thing.

Mike Grant
356 Fan
Posts: 203
Joined: Mon Feb 18, 2013 2:25 pm
Location: Aptos, CA

Re: C rear wheel bearing and seal replacement

#10 Post by Mike Grant »

This might be a dumb question, but since I'm probably going to be changing the wheel bearing, how much more is involved with changing the axle boot at the same time? That side has an old split boot on it that is leaking and if it's not too much more effort I might want to change that out as well.

Thanks,

Mike

User avatar
Albert Tiedemann
356 Fan
Posts: 1229
Joined: Thu Apr 03, 2008 2:46 pm

Re: C rear wheel bearing and seal replacement

#11 Post by Albert Tiedemann »

Mike Grant wrote:This might be a dumb question, but since I'm probably going to be changing the wheel bearing, how much more is involved with changing the axle boot at the same time? That side has an old split boot on it that is leaking and if it's not too much more effort I might want to change that out as well.

Thanks,

Mike
Anything that you do to replace the split boot with a solid boot will require more effort.

For starters, you will have to remove the axle tube/axle bearing housing/ flanged retainer assembly.

Then, depending upon which method you choose to replace the boot, further dis-assembly may or may not be required.

If you have strong wrists and fingers--nay make that very strong wrists and fingers you may opt for the turn boot inside out, lube,start over bell, stretch[and hope it does not tear], lube some more, turn right side out after fully clearing the bell and engaging the tube surface withe the small end of the boot technique. BTW be sure to have the orientation correct before you start the boot over the bell] This technique does not require further dis-assembly of the aforementioned assembly.

If you have a press and especially configured removal/reinstalling fixtures and aids--or even the Factory tools, you would need to further disassemble the removed assembly.
You need to start by removing the tapered retaining pin that provides positive axial and rotational restraint between the axle tube and the axle bearing housing. Be sure to strike from the correct end when removing. Fat end up on re-installation. Remove tube from the bearing housing. It is an interference fit so a press and mandrel is needed. Once removed, it is fairly simple then and without finger agony to install the solid boot by reversing the procedure as they often say in the Chilton's Repair Manual.
But, on your way back there, attention is drawn to the following points. You may want to paint--easier now that it is apart [even powder coat]. If not, surely clean the interfacing surfaces. Align the tube and bearing housing to assure taper pin insertion
ease [lots of methods to recruit here but I made shop aids to take the guess work out of alignment issues] and reinstall the tube into the axle with the press. If your alignment is good, back lighting when you are near the pin insertion matching surfaces enables the precise depth to be ascertained, and if you have not been too careful in your alignment "by eye", a chance to start again!. After n trials [n=1,j] where j is the successful try, insert the pinand you are done--Well you still have to put it back on the car.

There have been many posts touting the stretch and lube technique [someone is sure to post a link] but I and others-- to be sure follow the less finger agony technique.
Albert Tiedemann, C356C
"The Hermit"

User avatar
Michael Aiello
356 Fan
Posts: 45
Joined: Wed Jan 05, 2011 11:31 am

Re: C rear wheel bearing and seal replacement

#12 Post by Michael Aiello »

vic skirmants wrote:"
Anyway; I have heard that some people have succeeded in getting the fulcrum plate back into position without major dis-assembly. I never have.
.
Well , that's good enough for me.....Although the whole trans needs a thorough cleaning, I was hoping to leave it in place after having removed , restored andreplaced the axle tubes , all outboard equipment and installed the solid boots...#%$@@&%!

User avatar
Albert Tiedemann
356 Fan
Posts: 1229
Joined: Thu Apr 03, 2008 2:46 pm

Re: C rear wheel bearing and seal replacement

#13 Post by Albert Tiedemann »

Mike Grant wrote:


I'll also get the Stoddard bearing removal tool. The tool is a bit expensive, but I suspect that this won't be the only time I'll do this task as a 356 owner.


Are any other special tools ... Any suggestions or tips would be appreciated. Thanks.

Mike

NLA-721-262-00 Rear Axle Bearing Puller for 356 is the one that you will need.
VW 241 is the Factory tool--All but extinct as a new purchase but many abound in private and hoarded inventories. If you could get one, they would likely command a cost higher than the tool offered by Stoddard.

Regarding the two tools. Each is fundamentally the same except for the load path taken by the tool doing its job. The Factory tool VW 241, transfers the extraction force from the outer race through the rolling elements [balls] to the inner race to overcome the interference fit at the axle. Some will argue that this is bad because it may brinnell the race pathway.

NLA-721-262-00 Rear Axle Bearing Puller for 356 transfers the extraction load directly to the inner race outside the rolling pathway via the especially manufactured collet included with the tool thereby eliminating the above. This collet only works with 8 balls [VW 241 only works with 8 balls as well]

I have both tools, but in my experience I have found the NLA-721-262-00 Rear Axle Bearing Puller for 356. to be easier to use and if you are going to reuse the bearing and arguably better regarding extraction load path.
Albert Tiedemann, C356C
"The Hermit"

Mike Grant
356 Fan
Posts: 203
Joined: Mon Feb 18, 2013 2:25 pm
Location: Aptos, CA

Re: C rear wheel bearing and seal replacement

#14 Post by Mike Grant »

Thanks for the insights, Ab. I did order the Stoddard tool, it will arrive with the other parts on Monday and I'll get started. Being relatively new to 356 ownership, pretty much everything I've done over the last 9 months has been for the first time. I've found that if I get some tips from Registry members, use the manual, pay attention and take my time, I've been able to successfully complete all the projects I've attempted.

User avatar
Jacques Lefriant
356 Fan
Posts: 4602
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: C rear wheel bearing and seal replacement

#15 Post by Jacques Lefriant »

Hi Michael
If you have slipped a fulcrum plate and are removing the axle tubes anyway and if the magnet does not work remove the drivers side cover and remove the axles and diff. you should be able to relocate the fulcrum plate without removing the ring gear bolts. check the clearance since larger clearances promote dislodging of the fulcrum plate thicker plates are available but you need to replace the ring gear bolts to accomplish this.be careful to maintain the integrity of the shims that set the diff position.
Michael and Mike
With the axles off you can stretch a solid boot over the trans end of the tube.We have had this discussion in a previous thread'
cheers
j
 

Post Reply