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Discussion Starter · #1 ·
I need to know if the front wheel bearing can be pressed out and re-used when changing the front brake rotors on a 1988 929? The shop manual says replace, but they are very expensive (the bearings) and I can't see why they can't be re-used if carefully removed.
 

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Yea, if it's anything like my 92.. it can be re-used.. even though I dont recomend.. I think you should just pay the extra dollars and put new bearings in.. My front wheel bearings were 23bucks per side.. and thats in Canadian funds :D ... more like 12 US... just make sure that when your pressing out to apply equal pressure around the whole ring or else you may cause slight warpage on random rollers.
 

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my rear wheel bearing is going I have to do that soon, it make a vibration sound when in lower rpms
 

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I changed the rotors on the front of my 88 929 and I re-used the bearings. I ended up replacing one of them 30K miles later, but then my car has over 200K so I suspect it died of natural causes.

When you press them out, press as far to the outside (not inside) as possible. They should come out just fine. New bearings for the 1st generation 929 are not as cheap as the newer ones - I paid $65 USD.
 

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Discussion Starter · #6 ·
THANK YOU! You are the only person to reply to my net posts about 88 929 front bearings. I have new rotors in hand, but haven't removed the old ones yet, so don't have first hand knowledge of the bearing assembly. However, from the looks of the back of the rotor, I have one question: is it possible to insert pipe or socket from the front and grab the OUTER race of the bearing? I don't want to press on the inner race, as I'm afraid to destroy the bearing. By the way, I have a 10-ton press to do this with, so I can be fairly precise. Do I need to grind off material to access the outer race, or drill holes in the old rotor to insert punch or anything like that? Any advice is GREATLY appreciated. Thanks. Don Scott
 

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Don - I got your email and decided to reply here so that everyone could benefit. Here's my step-by-step guide as I remember it. Please understand it's been awhile...

1. Jack up car, put on stands, remove wheel.
2. Remove dust cover from center of rotor.
3. Remove big ol' nut and washer hidden by dust cover. The nut has been deformed on the outer edge - tapped into a groove in the spindle - so that it won't loosen by vibration. This will need to be bent back out using an old flat-head screw driver and a hammer of your chosing. After removing the nut and washer the rotor will now slide off.
4. Remove dust seal from inside of rotor with seal remover. Be careful when removing as you need to re-use this seal. Neither new bearings nor new rotors come with a new dust seal. This thing is pretty easily bent out of whack, but can be reformed with a little finesse. Because of corrosion it may be difficult to tell where the dust seal ends and the rotor begins. Scrape around a bit, use penetrating oil, and gently tap with a ball peen and it should become evident where it is exactly.
5. Remove the grease from beneath the dust seal uncovering the lock ring.
6. Using a pair lock ring pliers, remove the lock ring. Be careful as this thing will want to pop off your pliers and imbed itself in your eye. I make it a habit to cover lock rings with my hand when removing one.
7. Press time! Find something pressable that *just* fits inside the hole on the outside of the rotor - a large socket works just fine if you've got some in the 1"+ range. You'll want to go as large as you can here. You may be pressing on the inner race, but it's the best you can do. Press as s l o w l y as possible as not to damage the bearing. Also make sure that you're not pressing the bearing into anything beneath, suport the rotor as close to the bearing as possible without getting in it's way as it travels down out of the rotor.
8. Catch the bearing in your hand or a stack of towels underneath the press. You don't want it to get dinged up by hitting the floor or anything. Careful as it's a little heavier than I thought it would be.
9. Take your new rotor and press the bearing back in, this time using an even larger socket such that you're pressing on the outer edge as close to the rotor as possible (hole for bearing is larger on the inside than the outside, thus the need for a larger socket). You should feel it seat.
10. Reinstall the lock ring (insert hand-over-lock-ring tip here).
11. Squirt in a healthy dose of lube and gently tap the dust seal into place.
12. Slide rotor back onto spindle and reinstall the washer and big ol' nut. Take the old flat-head screwdriver and hammer of choice from step 3 and whack the edge of the nut back into the groove in the spindle.
13. Reinstall wheel/tire and lower car to ground.

I just realized I skipped the part about taking off the caliper, but I think you can figure that out. It's only two bolts, suspend by wire not soft line...the standard operation for taking a caliper off. Don't forget to use new pads along with your new rotors. Enjoy! Hope this helps you and others...
 

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Discussion Starter · #8 ·
Once again, thanks for your posts. And I agree, the best response is a shared response!
Now, in the meantime, I've been re-reading the shop manual, and here is a couple more observations/questions before I start the job (next weekend, I think. I've ordered 2 bearings just in case, will return if not needed, as well as seals and pads).
- My new discs came without wheel studs. Did yours? Looks like I'll need to press them out and re-install in the new rotors. I'll use 2 nuts on each one to minimize risk of buggering the threads while pressing out
- I assume no heat was needed to remove the bearing. I was thinking of drilling into the old rotor, right next to part where the outer race is, then milling out to 'cut' the rotor casing and relieve all the pressure holding the bearing in. Do you think that would be overkill, as I don't know how much pressure is needed to press one out?

Now here's a comment in general about the Mazda Shop Manual procedures, which I'll post separately since it might be of general interest to many others. Using this as an example, if you go to the dealer, they'd probably follow the manual to the letter, and charge you accordingly. If I followed it, I'd be buying 2 bearings (these are $100.00CDN each, by the way), 10 wheel studs (I'm guessing $5.00 each, dealer item only), and 2 seals (about $5.00 each). This is on top of the rotors ($100.00 each). This adds up to $460.00CDN + labor (1.5 hrs @ $80.00/hr) + local tax on everything (here, 15%), for a whopping $667.00! And I haven't bought pads yet! Outrageous! I've done Mercedes cheaper than this. My point is that the shop procedures are for the Mazda shop mechanics, not the do-it-y'selfers.
So, with your experience noted, and that in mind, I'm set to go!
 

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lucky I told lotsacars too come over to this forum ? huh ?
 

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Sorry, I don't check here very often as this isn't an overly active forum...

My discs also came without studs, I forgot about that part :) Here's my procedure for removing the studs from my rotors:

1. Lay loose rotor flat on floor.
2. Tap each stud with three lb sledge.

Easy enough, eh? Just don't screw up the threads when you hit them. No need to press them out, though your double-nutting idea is a good one if you were to press them out. They pop right out and then you just tighten a nut down on them to draw them into the new rotor. It took me all of ten minutes to do all ten and most of that time was spent drawing them into the new rotors. Make sure you check your lug nut tightness a few times after you're all done (ie. tighten, tighten again, drive 2 miles, tighten, drive 100 miles, tighten, you can obviously stop tightening at any point if they are tight).

No heat is needed to get the bearings out. With your press they'll come right out. I wouldn't bother with drilling and milling and all of that - too much risk in damaging the bearing. You'll get metal shavings all over the place and those aren't condusive to long bearing life. :) Just press 'em out.

Yeah, the Mazda shop rate is pretty rediculous. Any tech worth his salt can do it in much less time. That's why Master Tech's get paid good money - they can turn jobs around quickly and bring in tons of cash at shop rate.

Here's a test of the ol' Mazda manual. How much time do they specify for a timing belt change? I know I could do it with the assistance of another in 20 minutes from driving in the garage to driving out - that's a total of 40 minutes shop time (and I'd really only need the assitance of another for about three minutes). It took me awhile to be able to do it that fast (long story - I had mine on and off like seven times because I don't have the FSM and I was misled by a local Mazda tech...several times).

Good luck and glad to see you're tackling this by yourself - most would be bringing it the the dealership and forking over the $700 :x
 

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Discussion Starter · #12 ·
Thanks for the response, lotsacars. I did the job this past Saturday. I didn't read your last response until today.
Anyway, since I have a shop press and a milling machine, neither of which get much use lately, I decided to take no chances. I pressed out the lug bolts, using a single nut, and pressed them into the new rotors.
I milled out the 1/4" of metal on the back side of each old rotor right between the lug bolt hole and the flange where the bearing is pressed in. Then, I cut the rotor in the bandsaw all the way through to the lug bolt hole. I drove a conical punch into the lug bolt hole, to expand the flange holding the bearing in, and it dropped out in my hand!
The milling took about 15 minutes/rotor, with about 15 minutes set-up time, and about 10 for the bandsawing, so in all, about an hour, total, but guaranteed to not harm the bearings.
Just in case, I bought 2 new bearings ($100.00CDN each). I'm going to drive it for a week or so to make sure the old ones are OK, then return them for a refund.
Thanks again for all your help.
Long as these posts are, I hope someone benefits from the discussion, as it just shows what can be done with good old fashioned shade-tree mechanics, eh? :)
 
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