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View Full Version : Front wheel bearings on 1st gen



benracin
04-21-2003, 03:16 PM
Trying to get the car ready for it's first big weekend. I hear that front bearings go bad quickly in these cars. Would that be the inner, outer, or both? And what kind of grease would yall recommend using for these puppies?

Thanks.

dickita15
04-21-2003, 03:52 PM
they are a weak point, of course so are the rotors, but i am now getting a season out of them. don't overtighten. i check them every weekend at least. every session after i have screwed with them. just jack the car and give the wheel a shake and a spin. i changed to synthetic grease as it stays put better. mobil one was what i had available.
dick

rx7chris
04-21-2003, 05:02 PM
If you need any more advice on front axle, mistakes, e-mail me and i'll let you know what not to do. Had to learn the hard way on a couple things, but everything works fine now. Haven't touched my fronts since mid-last year. no wobble and they spin fine. [email protected]

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Chris
IT7 #88
PowerTrip Racing
http://www.geocities.com/ptripracing/

benracin
04-21-2003, 05:39 PM
I've found the Mobil 1 grease that comes in a long tube, like for a grease gun, is that the kind you use dickita15? All I can find for actual bearing grease is the short cans and not mobil 1.

Thanks.

dickita15
04-21-2003, 05:43 PM
yes i too could only find it in cartridge tubes. a pain but a paint stir stick makes it useable.
dick

lateapex911
04-21-2003, 09:16 PM
I can feel them when the start to get iffy. A gritty feeling in the steering. I pop the cover at the end of the session and regrease and readjust them. I've never had to replace them per se, but I do every so often, but that averages every other year.

And...they sell little grease guns pretty cheaply. But it is for the small cartrides, not sure what size the one you refer to is.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

bcarter
04-21-2003, 10:17 PM
I go through the outer bearings like crazy.

Remember that there are two different sizes. In '84 they went to a larger outer bearing. Mine are the smaller ones, probably part of the problem.

Another part of the problem is that these bearing were not designed to run at 2 - 3 degrees camber.

I think I may have been tightening them a little too much, but they are relatively cheap, and we have got the process down now so that we can change the bearings in just a few minutes. The trick is to get an old set of the races that go into the rotors, and grind them down on the outside all the way around.

You then whip off the rotor, and using a punch, you can hammer out the old races, and use the slightly smaller ground down ones to hammer the new ones in. Being slightly smaller, they will uniformly push the new ones into the rotor seat, but not stick in there. We can do a wheel in under 10 minutes.

I buy them at Napa, and get a deal, but I found out they are even cheaper at Mazdasport.

We usually have a new rotor/bearings with us in case we don't have the ten minutes.

When mine go, there is no question about it, I can hear the front wheel whinning.

Use a good high temp synthetic.

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G. Brooke Carter
Wheat Buckley Racing
# 10 Challenge Car
2002 Class Champion
Calgary, Alberta

joeg
04-22-2003, 08:36 AM
For a Synthetic Grease, try the AMSOIL Racing Grease. I experimented with many and this is the only stuff that won't burn its way out.

Cheers.

Allen Brown
04-22-2003, 10:56 AM
As Brooke made a comment to the bearing diameter. The larger size (84-85) is better wearing. I have a 85 SE, and run at the same track as Brooke (different class). I also run 3.25 & 2.75 degree neg. camber. My front bearings typically last a full season, approx. 17 hours of use.

I just put on another set of rotors and bearings as part of the safety thing at the start of each season. I'm ususally more concerned with the rotors than the bearings. Ususally by then, the rotors are starting to show early signs of heat cracking. The bearings are probably still fine, but while it's apart I just replace them.

Sorry for the long winded comment where I believe Brooke is correct in the diameter having a part in the early wear.

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Allen Brown
#36 IT1
[email protected]

lateapex911
04-23-2003, 02:33 AM
Allen, that reminded me of my stint in the eighties working with a Showroom Stock RX-7 racer at the 24 hours of Nelson....I noticed the first time we did it that the two car team had two cars come into the pits within minutes of each other. Out of brakes. and the drivers complained that the shocks were shot. Then, at eighteen hours they were both back within minutes of each other with blown bearings! Arrrrgggg!

So, fot the next year, I devised a planeed stop at 12 hours that replaced the whole strut. It was less work than it sounds, and saved an extra stop. AND the drivers were happy as they had fresh shocks. We won by about a lap. (Sorry Jeff, [a triumph guy who probably won't see this!] our main nemisis was a TR-7!)

It does appear that in racing conditions, 18 hours seems to be the magic number.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

miketrier
04-29-2003, 10:17 PM
Try Valvoline full synthetic grease in the short can. It's black and looks burned up but it stays better than anything else I've tried.

JeffYoung
04-29-2003, 10:55 PM
Jake -- I am everywhere....lol.

Seriously, if you are posting on a technical issue, I read it. Got lots to learn.

TR7 v. RX7...wasn't the TR outgunned?

lateapex911
04-30-2003, 01:55 PM
Originally posted by JeffYoung:
Jake -- I am everywhere....lol.

Seriously, if you are posting on a technical issue, I read it. Got lots to learn.

TR7 v. RX7...wasn't the TR outgunned?


Good for you, Jeff! I would say that "outgunned" might be putting it too strongly. We were faster on the track, by a little, but strangely enough, the Triumph spent less time in the pits!!! (They must have had an automatic hammer installed to hit the Lucas fuel pump twice a lap!! http://Forums.ImprovedTouring.com/it/wink.gif )
Actually, the Mazda has fuel pick up problems, and once we got down to about half or 1/3 of a tank, we had to refuel. We spent considerably more time in the pits on that issue. But we saved buckets with the "replace it all at 12 hours" strategy, which made the difference. It came down to a winning margin of about a lap or two, which in amatuer racing, is nothing over a 24 hour period.


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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

JeffYoung
04-30-2003, 07:23 PM
Hard to get people to believe it, but the later TRs, made at Canley or Soluhill from 79 to 81, can be fairly reliable. The 7s' bad rep comes from the horrible quality at the Speke factory. Hell, at my first race, an enduro, I buried my car in a lake on lap 2, pulled it out, spent an hour drying things out and taping up damage, and went back on track. Car ran fine, and made the sprint race the next day.

Showroom stock back in the 80s sure sounds like a lot more fun than today, where it is pretty much small sedans. Back then, it was, I guess, the equivalent of IT. Cheap sports and sporty cars going at it.

Jim Susko
05-30-2003, 01:00 PM
The real problem is heat. Even with the smaller bearings I used to run, I never had to replace a bearing once I added brake cooling and used a quality synthetic grease. Now I do run the big bearing struts.

I recommend the IMSA style brake cooling duct available from Mazda Motorsports. It is much better than some home brewed setups I've seen. You have to saw off one of the backing plate tabs, but it is simple to do. I could e-mail you plans if you like.

lateapex911
05-30-2003, 01:28 PM
Welcome, Jim!!

Well guys, we have a very knowlegable Mazdaphile in Jim, who seems to have a pretty good handle on, ...handling. (Sorry, couldn't resist!) (I've sung your praises before here Jim, so I'll leave it at that!)

Glad to have you here!

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]