Adam Geist

I also have the Sir Tools B90 and the rear wheel bearing R&R for both '86.5s is on my "to-do" list this Spring. I reviewed the instructions that came with the kit and the Porsche-specific wheel bearing R&R looks to be very straightforward.

Is it as easy as the instructions say it is?

dr bob

Bill--

Do we need to do a west-coast group purchase on one of these kits? Rear bearings are on my to-do list, and a $300 invetsment doesn't look to be steep compared with a) cost of having the local guy do it ($200/side plus bearing cost), or b) pulling the hubs and paying the local shop $50+/per side to do the work. I'm almost ready to just buy the tool, and maybe loan-it-for-a-small-fee to other folks. Thoughts?

Bill Ball

Well, that's 2 votes for the B90. Certainly, you can see from my guide that doing it the "traditional" way and w/o the Porsche tools is not exactly a walk in the park. If the hub can be extricated with the hub carrier on the car, then the rest seems pretty easy even w/o the Sir tool. I'm going to try doing this on the car and determine if the Sir tool is really needed or if more common alternative pullers will do the job.

Matt (Edco) - bring your car and bearing over. I need an experimental subject!

Bill Ball

Don't you have to pull the axle? It would seem with Stan's method you would.

worf928

Yes.

I was going to suggest that as a regional purchase it makes good sense. As long as you can "drive it over" and figure out a way that it doesn't get "lost" as it changes hands. The alternative to hand-carry is shipping and the kit is heavy enough that shipping cost plus insurance would equal the value of the kit pretty quickly.

I have the full kit with all the toys. All of the various thrust plates come in handy for other jobs in combination with a shop press. I've used them to replace bushings in our Audis, etc., and I have the right-sized thrust plates for all four wheel bearings on each of the Audis when they come due.

Yes. The e-brake and half-shaft have to come out. At that point you can use the tool to press out the old bearing (the kit can press from the front or "pull" from the back - it's very ingenious.) I heat the hub with a heat gun and chill the bearing. This allows you to get the bearing started into the hub. Then you use the kit to press in the new bearing with the correct plate.

It has been a while since I've done a RWB, so I cannot give a blow-by-blow account. But, it was way less intense that the WSM method. It's a one man job and once you figure out how to use the tool I wager that the bearing R&R will take under 30 minutes once you've exposed it and 15 minutes of that is me using the heat gun on the hub (flame wrench would be quicker but I don't like fire...) I've got about 40k miles on the last set I did, so the method seems to work just fine. I recall that getting the e-brake back together was the hardest part of the job.

Rob Edwards

Bob-

I'd put up $50-100 towards a B90 fractional ownership/timeshare plan. I've got a set of bearings sitting right here. All I need is a reason to have a bearing clinic. (May 16-17 anyone? )

Semi OT: I also got one of the front bearing cap tools, so a front bearing check clinic is also in order. FWIW, its threading is exactly the same as the shaft that comes with the POS HF slide hammer kit.

Mrmerlin

After pulling the wheel hub out of the bearing then remove the snap ring then with the carrier hot, drive the bearing out with an impact air hammer( and one of its round plates it fits perfectly on the inside of the bearing )it takes about 5 seconds, have a helper ready to catch it.
The CV axle must be removed and the inner race removed off of the hub, Looks like Bill has a good way to do this instead of cutting, Freeze the wheel hub after itsrace is removed

dr bob

I'll get the tool ordered and we'll have one to play with here in SoCal. We can do a clinic, and it will need to be somewhere near the mid-May dates you mention Rob. I have a wedding in Texas after another round in NJ mid this month, and should be home to catch a breath right about then. Unless a contract I just signed gets ahead of me then... I could be at SITM in a rental car. Feast or famine, the fun never sets!

There's a local source here for weekend dry ice too; makes the bearings and the hub really small.

Rob Edwards

I've got all the dry ice we'd need, just down the hill. Or did you mean me?

dr bob

Picking up where we left off a while ago--

The Sir Tools B90 wheel bearing kit finally arrived after a month+ of factory backorder. So we have one in SoCal for this project. I'm not available the next few weekends, but should be as we get into July and some of August. May need to do a night-time clinic to avoid the daytime heat loading. Garage doesn't have AC (yet...). We'll take lots of pictures to document the process. As Dave C mentions, the instructions are very straightforward, almost looks too easy compared with WSM process. They also mention a way to do the job with the parking brake asy in place. Just need to pull a return spring, add an included spacer before pressing with the tool, according to the instructions.

Gotta get the parts ordered, and we'll be on the way!


Oh-- The tool and its carrying case probably weigh 25 lbs or so. Might be a little spendy to ship very far for other users out of the area. Or maybe not, if it's really as easy as Dave and the instructions suggest.

SharkSkin

Great write-up and follow-up discussion. *subscribes*

JHowell37

Personally, I didn't think it was too hard to press the old ones out and the new ones in using a press, strategically positioned arbor plates and a few other odds and ends. The hardest part was removing that circlip from the bearing

dr bob

The advantage of the B90 tool is that you don't need to remove the hub carrier from the car. Remove the big nut, unbolt the inner drive flange, and remove the halfshaft. Unbolt and hang the caliper with no strain on the hose or wiring. A couple screws with the impact driver and remove the disk. Remove a return spring on one parking brake shoe. Assemble tool per diagram included with tool. Tighten bolt on tool to extract the hub from the bearing. Reassemble the tool with a different disk, and tighten the bolt to extract the bearing from the hub. There's no mention of heating the bearing carrier or freezing the bearing. We'll probably heat the hub with a heat gun some, maybe a MAPP torch. I will dry-ice the bearing before installing it with the same tool. Let the bearing warm up and expand while the hub sits in the dry ice bucket and gets smaller. Then use the tool to draw the hub back into the new bearing. Replace the return spring on the brake shoe, replace the rotor, replace the caliper. Slide the halfshaft back in, install and tighten the bolts to the flange. Tighten the big nut on the end of the stub shaft. Replace the wheel without center cap. Lower the car, tighten the nut on the stub to correct torque. Replace wheel center cap.

There's no BFHammering or impact hammer or slide hammer. The bearing carrier stays attached to the rest of the car at all times. No disassembly problems with PB cables, bent pins, stuck bolts, reversed cup/tapered washers, no risk of boogering any alignment settings.


To me it sounds a lot faster/easier than pulling the carrier out and pressing it apart and together again with spreaders, supports and pilot pins. We'll know for sure in a few weeks, hopefully, if I'm allowed to come home to do the work.

Bill Ball

Congrats on the B90, dr. bob. Edco bought one for himself and used it on his rear bearings recently.