1st Gen. Rear Wheel Wobble Please HELP
 

So I'm new to the Mazda scene so bear with me on these questions lol... But I was driving home today and a buddy of mine said he noticed some rear wheel wobble on the drivers side of my new Rx7 (1st gen). He said about a 1/4" to a 1/2" in each direction. I had thought the lugs might be loose due to me balancing the tires in my highschool auto shop today. But I had torqued the lugs to 85 lbs all around. Does anyone have any suggestions on what might be going on here? I would love to resolve this problem asap.

Also, the previous owner of my car had a set of tires on it which are worn differently tread wise. When I first bought the car it had slightly pulled to the right, today I rotated the low tread right front wheel with the left front wheel with more tread. It now pulls to the left. Any thoughts on this anyone?

Hi Culp:

Did the headlight bucket suggestions help you fix your problem?

First of all, wheel torque is 65-80 lbs.-ft., no reason to go any higher, you don't want to strip a flange, not as easy to fix as pressing in a new stud on a vehicle with nuts instead of our bolts.

Wheel wobble can only be one of 2 things: Bent wheel or bent mounting flange. Your description of the alignment issues indicate a "hit a curb" type accident, which can bend wheels as well as flanges.

Pull all the wheels & check your rotor runout in the front, and your axle flange runout in the rear. Check all four. There should be essentially none, a few thousandths at the most. If this checks out fine then a wheel is bent. Check all four wheels for runout, should be very little as well. Then take to an alignment shop & have them do a four wheel alignment, if any issues have them check for bent suspension components. Replace and align as need & you should be good to go. Parts should be available to fix any problem whether you get them new or used. If the front crossmember or a rear axle are bent, you might have to go used, all other components are available new from Mazdatrix, among others. Let us know what was wrong & how you fixed.

Bruce

welcome. :)

this.

Bent wheel ,, or bent flange .. or possibly something as simple as a tire gone out of round quite common when hitting pot holes or sharp uneven surfaces . before spending a bunch of money jack up each wheel and spin it and see weather the wheel is in a wobble or if the tire itself is in a wobble , sometimes the steel belts break up inside causing a uneven tire ,, Just a thought that costs nothing to check .

pdxgen1 is right for sure ,over tightening wheel nuts can also cause the brake rotors to warp and cause uneven brake surging.

Culp:

Good point, Gerald is correct, if you impact a curb or pothole hard enough, you can damage the tire & cause it to internally delaminate, bulge, and get wobbly. He's right, jacking each wheel up & spinning the wheel/tire assy. is sure a quick easy check to look for a bad tire. Do this B4 pulling wheels & checking for rotor & axle flange runout.

While you are looking @ the tires, check the DOT date code for week & year of manufacture of the tires & replace any that are 7 years old or older.

Bruce

Jesus Christ, you know a lot about tires. :D I never knew about these codes. you've taught me something today.

Thanx Diabolical - -

I was in the wholesale tire & rubber supply business for quite a while, not any longer, you learn a lot when you're in the business day to day.

This issue of tire age has started to become known in the classic car world, a few of the mags have written articles about it. Classic Motorsports and Auto Restorer have both featured good articles in the past few years about tires for old cars, and covered the age and DOT date code issue well in both cases.

Take a guess what other hobby has vehicles that stand around a good part of the year, get driven infrequently, and have tires that don't get many miles over a period of many years? Yup, RVs, both trailer and over the road types. There have been well documented cases of horrible accidents caused by blowouts because these things are so big & heavy. As tires age they continue to vulcanize, they harden and separate from the fabric casings, blowouts or catastophic failures are the result frequently. A few years back a guy driving his Sunbeam Tiger on Mullholland drive in the LA area with old tires suffered a blowout, went off a cliff I believe, & was killed. A tragedy that could have been avoided with a bit of information.

Save your bacon & check your DOT date codes.

Bruce

So today in the shop I did a few things... First I had a new tire that the previous owner had given me and decided to put it on the front left tire that was low on tread causing the pulling to the left. I then noticed that the car had mismatched tires on the front (one 175/70r/13 and one 185/70r/13) and rear (the same as the front). So I replaced the 185 low tread tire on the front and moved it to the rear with the other 185. The new tire now sits where the previous 175 and different rim had sat. It fixed the pulling issue but even with the differerent rim and tire combo on the left rear I am still having the wobbling problem. I have drum brakes on the rear and this is my first car I have owned (atleast import wise). So where and how would I go about checking the flange on the rear?

oh believe me ... I pay much closer attention now. the very thing that put my FB off the road now for 6 years was a blowout. and one of the hardest things about the whole ordeal is the fact that I washed the car about 2 weeks before the accident and decided that the front tires were garbage. I ordered 2 tires and they were home waiting for me. :(

Culp:

To check the axle flange, pull the wheel back off, release the handbrake, remove the 2 phillips screws holding the drum to the axle, and slide the drum off. It should slide right off with both screws removed & the brake off.

To do a rough check, have a partner turn the wheel on the opposite side of the axle & hold a machinist's rule or other accurate small ruler butting up against the drum backing plate and watch for movement of the axle flange in & out. Keep in mind it will be only a few mms. of movement at the most. Should be none. Shops measure more acurately by mounting a dial micrometer with a magnetic mount somewhere near the flange or rotor and measure the amount of runout. If your flange is bent you'll have to source a used axle or a whole used rear axle/diff. assembly. Let us know what turns up.

Bruce

Thanks for all your help man! It turned out to be a bent axle. I however sourced a used axle from a junkyard and am in the process of installing it now. Just need to press the new bearings on the junk yard axle and I'm ready to put her in. I'm just praying to God that this junk yard axle is not bent too. Has anyone had bad luck with junkyard parts of the sort?

its a 50/50 shot, usually a reason a car is in the J-yard to begin with.