davesan1

iTrader: (4)

My newly acquired ’93 3rd gen RX started out as a “clunk” nightmare. However, I've done some focused diagnosis and repair work already, (thanks to the great help from many of you on this forum, either directly or through earlier "how to" postings). This has resulted in changing out all 6 of the infamous rear pillow *****, the front sway bar mounts and the front sway bar control arms. I'm pleased to say that this has produced tremendous improvements and I have now got rid of all but one clunk. This is my so-called "bi-modal" clunk, (for want of a better description). I can now produce this "on demand” by alternately braking and accelerating at low speed. The acceleration produces a clunk then no more clunks until I brake, when I get another clunk. This repeats, ad nauseum. The suspension clearly seems to take up two stable positions and jumps between them when sufficient force is applied, (i.e., acceleration/deceleration). Hence the term "bi-modal." (I can also produce the same event by other, more random driving sequences, but the bi-modal behavior is always the same). The clunk appears to be coming from the front at the passenger side of the car.

At last, this morning, after checking, (yet again), everywhere on the suspension for looseness, etc, I think I found the source of the problem. By using a big screwdriver to leverage the rear bushing on the passenger side lower suspension arm, (the one where the eccentric "bolt" for adjusting caster and camber is located), I can produce a slight side-to-side shift between the chassis mounting bracket and the arm, (in the same axis as the hole through the bush, and thus the same axis as forward motion of the car when driving). When I reach the limit in each direction I can hear a distinct metal-to-metal contact. (Not as loud as when driving the car but, of course, the applied force with the screwdriver is much smaller than that when driving). Further more, it exhibits the same bi-model activity as my problem, and the direction of the force I am applying is consistent with the force that would be applied by the accelerating and braking pattern that I described above. Lastly, the bushing on the other side of the car does not exhibit this movement and metal-to-metal noise problem. So I think I've got it, but I have some questions before I start replacing these bushings.

1) In reading through these forums I have not seen much mention of this as a common or even as a possible cause of clunking. Has anyone else had the same problem with the same cause that I now suspect?
2) Is it reasonably viable to replace this bushing with the suspension arm still on the car, (ala pillow *****)? I note that the diameter of this lower arm rear bush is considerably greater than that of the pillow ball and I wonder whether the "long bolt + washers + nut" method that I used so successfully on the pillow ***** could yield enough force to also be used on this job. I would certainly appreciate input from anyone who's tried it, before I start trying it myself.
3) In the event that I do have to remove the whole lower arm, the only sticky issue that I see is that there appears to be a tapered press fit on the (non replaceable) “swivel bearing” on the end of the lower arm where it connects to the wheel hub structure. To break the taper, the Mazda manual recommends the usual Mazda SST tool. I'm sure that will require me to re-mortgage my house if I need to buy it! However, I feel there may be a standard puller available that will do the job. I have several tie rod end pullers, including one with the same design as this Mazda SST, (the only design that works without bending, in my experience), but it's not big enough for this job. The lack of clearance space above the nut on the taper shaft also demands a tool much like the SST, (in addition to the SST design providing superior direct pull on the taper). Anyway, if anyone has bought a "standard" puller that has successfully done this job I would really appreciate hearing from you with some detail - this will save me some time and research, to say nothing of allowing me to get the right tool "first time." Alternatively, has anyone successfully used some other tool, for example a taper fork, for this job?

That's it

Thanks for your help.

Dave

DamonB

Sounds to me like you've located the bushing that needs replaced.

To answer your questions:

1) The original front lower a-arm bushings in my car didn't seem worn and weren't noisy but after replacing them I noticed a slight improvement (my car daily driven, 100,000+ miles at the time of replacement, runs on race tires all the time yadda, yadda, yadda).

2) The arm must be removed from the car and it will take a hydraulic press to push them out. The rear bushing on the front lower a-arms are rubber encased in an aluminum sleeve that is then pressed into the aluminum arm. The guy doing it must have some sense because my lower a-arms were destroyed by a monkey with a big hammer.

3) The joint at the end of the arm is a plain 'ole ball joint. I've always used a pickle fork and a hammer ("ball joint splitter") to seperate them. Just be careful not to chew up the rubber dust boot. You can buy ball joint splitters at any auto parts store for little money.

alberto_mg

have you checked the diff bushings?

davesan1

iTrader: (4)

DamonB-

Thanks for the input.

Didn't really think I'd be able to get them out while the arm was on the car but it was worth asking! I have a pickle fork and it's good knowing that you were able to break the taper with one, so I'll give it a try

Thanks again

Regards

Dave

davesan1

iTrader: (4)

Alberto mg -

Thanks for your suggestion.

No I haven't checked the diff. bushings yet. I've not ruled them out completely, but I'm pretty sure that the clunk is coming from the front, (although I do agree that the clunks can be pretty difficult to pinpoint!). So I think I'll deal with the front lower arn bushes first and look further if, (heaven forbid!), that doesn't fix the problem.

Thanks

Dave

DamonB

Be sure to replace both rear lower a-arm bushings. If one is making noise you can bet the other isn't far behind.

davesan1

iTrader: (4)

Yep, will do. Also, I was thinking of replacing the front lower bushing in addition to the (observed bad) rear ones while I had the the arms off the car. Seems a shame to miss the opportunity once the arm removal work is done, but I'm not sure whether the front ones are also likely to be worn and worth the cost of changing out. Any comments?

BTW, just so there is no confusion with the use of "front" and "back," all of the above dialog, of course, applies to the front suspension only).

Thanks

Dave

maxcooper

I would check the toe links, as they are known to wear out and clunk. There are aftermarket replacements available, but I've had to replace the rod ends on mine more often than I would expect to have to replace the stock toe links. And the performance benefit of the aftermarket toe links is dubious. I would get new stock toe links, or get new stock bushings and press them into your existing stock links.

If you mean the rear suspension, I replaced the bushings on the lower control arm where it meets the body after finding a little play. These aren't all that likely to clunk, however, since they are ball joints surrounded by rubber. They might clunk a little, but it won't be as noticable as the bushings that don't have any rubber. You definitely have to remove the arms, and use a hack saw to cut the flange off the bushing before pressing it out with a hydraulic press. Removing the rear lower control arms is easy, and you would certainly be aware of what it takes since you already replaced the pillow *****. That makes me think you mean the front...

The front lower control arm bushings at the body side are rubber and not that likely to clunk. You can pop the taper with a $7 Pitman Arm puller from Harbor Freight.

-Max

DaleClark

iTrader: (55)

You've probably looked, but make sure the steering rack is securely bolted to the subframe. I had a customer with like 3 of the bolts BARELY in there. Re-torqued them with some Loctite and replaced one of the rack to subframe bushings - good to go. Can't remember how much/what type of clunk or if at all that made - his car was chock full o' funny noises .

Dale

davesan1

iTrader: (4)

Max/DamonB

Sorry, I may have confused everybody with "back" and "front" terminology. To clarify: the primary purpose of this thread and the questions I asked just refer to the front suspension. When I use the terms "front bush" and "rear bush" on the lower arm I am refering to the two (replacable) bushes on the lower arm of the front suspension. That is not to say that I will not do further work beyond that on improving the rear suspension but right now I am focusing on the "one remaining" clunk, (fat chance,eh!), which I have diagnosed (almost certainly) to the front suspension on the rear bush of the lower suspension arm on the passenger side. So my plan is to replace this rear bush and also the front bush, (seeing as the arm will be already off the car), on the passenger side. I will very likely also replace the same 2 bushes on the driver's side, (even though these two currently do not appear to be clunking).

Ok, now that I believe I have stated where I'm working a little more clearly, Max, your final comment, I think, where you say that the body side bushings on the lower front control arm "are not likely to clunk" in my case actually seem to be the cause of my clunk. This is why I asked my first original question 1), because noboby else on the forum seemed to have had this specific bush problem. While there is no doubt that I can manually cause a metal-to-metal clunk (by leveraging the bush longitudinally with a screwdriver), and that there is no doubt that the passenger side has got much more slop on the this bush than the driver's side one, (which is not noisy), it is still difficult for me to see how the bush in question, being rubber, could have worn in a manner that causes the metal-to-metal contact, (given my admittedly minimal knowledge of the contruction of the bush). However, because the metal-on-metal noise that I can produce is reality and because it is similar to the clunk that I get when driving, it is my best suspect, so I'm going to go ahead and change 'em out and see what happens.

I assume that the need to remove the whole arm also applies to the front lower arm that I am addressing?

Max, do you happen to know the size/part # of the HF puller you used - I'm going there this afternoon to pick up a press so I'll get one then.

One more question. The front, tapered shaft swivel on this lower arm is, I understand, part of the bar and is not repairable. The good/bad test shown in the shop manual seems a little simplistic, as it relies purely on a broad range static and dynamic friction measurement. I'll try to do the measurement while I have the arm off, but I'm dubious of getting any real conclusive result. This swivel doesn't appear to be in any way responsible for my current clunk so I really don't want to replace the whole arm, (cost!). However, horror of horrors, if it is bad and I find I have to replace it anyway AFTER I've done the bushes, then I have to throw away my new bushes and start again! So my question is, in your experience, what's the chance of that tapered swivel being bad or causing clunks?

DaleClark - thanks for your input. It doesn't seem to be loose but rest assured I'll check out the bolts, just in case!

Thanks everyone for your help

Dave

maxcooper

The only pitman arm puller I see on Harbor Freight right now is part # 36861-2VGA, which is just $3.99. I think that it is the one I used -- it certainly looks like that one, but there's a chance that it is a different size.

The front lower ball joints (near the taper-fit connection, at the botton of the upright) can go bad. And I agree the test procedure is hard to perform and hard to draw a conclusion from. I suggest jacking the suspension arm up (so that the ball joint position is close to what it is while driving -- the joint will tighten up under full droop with the car jacked up) and trying to move the upright/wheel to check for play.

The upper ball joints might be bad, too. I found that mine were bad, and then I also found that the upper ball joints on the used arms I bought were bad. So I ended up buying new upper arms from Malloy for $510. Expensive, but well worth it to have the suspension tight again.

-Max

Fritz Flynn

iTrader: (263)

If you can literally feel any front susp trouble from accelerating and braking you either have a really, really bad bushing or like Max just said you need some ball joints.

If you need some new arms let me know. Referring to the car of course hehe

Thanks,
Fritz

davesan1

iTrader: (4)

Max - Ref puller, I bought that one anyway. At $3.99 - such a deal, it will come in handy sometime even if not for this job. Ref. the taper fit ball joint, I'll try what you suggest - it certainly sounds more "real life" than the manual! Finally, I'll see how it feels after changing both lower arm bushes on bioth sides. With any luck my clunk will be gone and then we're down to tidying up the suspension - something I intend to do after I get rid of these most annoying clunks.

Thanks for all your advice

Fritz - See above, I'll check out the tapered fit ball as suggested and, unless it seems bad I'll go along with the changeout of the 2 bushes on the bottom front arms, because I can actually simulate the problem on the rear of these two bushes on the passenger side by leveraging it along its center axis with a screwdriver.

Hopefully I won't need the arms, but as your offer seems 'armless enough (sorry), I know where to go if I do need them.

Thanks for your input

Regards

Dave

davesan1

iTrader: (4)

Update

One side done today. Will know in AM whether clunk is fixed.

BTW, does anyone know why the shop manual tells you to lubricate the front lower suspension arm REAR bushing with soap and water before pressing it in? I understand why this is recommended for the front lower suspension arm FRONT bushing, because this is rubber sliding into the aluminum arm. However, in the case of the rear bushing, you are pressing metal into the aluminum arm, and something like a very light oil, if anything, would seem more appropriate than soap and water. I used soap and water, as recommended, but pressing in the rear pushing required a lot of force and produced some metal "shavings" during the pressing, even though it seemed perfectly square. The end result seems OK, but I still wonder as to the wisdom of soap and water for a metal to metal lubricant!

Thanks

Dave

davesan1

iTrader: (4)

One other item - the HF $3.99 puller works fine for breaking the lower front suspension arm taper. However, I chose not to screw the nut up partially beyond the end of the bolt when using the puller. This nut position is recommended to protect the end of the bolt from damage by the puller. Unfortunately, due to the diameter of the bolt in the HF puller, leaving the nut part way on the tapered arm does not give the required protection. So instead I took the nut off completely and used a short 1/2" gas pipe threaded nipple slid over the tapered bolt. By choosing a nipple appox 1/2' longer than the visible length of the tapered bolt, the nipple is just the right diameter to hold the puller bolt firmly in place right in the center of the end of the taper bolt, thus stopping the puller screw from slipping and/or damaging the taper bolt. Hope this helps the next guy.

Dave

maxcooper

Just moving the ball joint around with it out of the car a bit can give you some idea of the condition, too. It should be sort of tight. If you can feel play, it is obviously bad. Short of that it is a bit subjective, but perhaps someone with a bad one can chime in and tell us if you can feel the slop. I have four that are worn but not yet sloppy, so I can't feel any play.

You can tell if the upper ball joints are bad with them out of the car (or just disconnected from the upright). You just have to be careful to check for play with the joint in the position it is in while driving -- even a loose one will feel tight at other angles. You can feel the slop in the four bad ones I have just by wiggling the joint around with your hands.

-Max

davesan1

iTrader: (4)

Max -

Yesterday I got the bad arm out. The problem with the bush was very obvious on the bench. The interesting thing was that the bad bush was the front bush on the front lower suspension arm and not the back one that I suspected. It seems that my on-the-car axial leveraging on the back one also caused axial stress on the front one and that's where the slop noise was. After replaceing the two bushes I examined the (bad) front one, (this is the one with the rubber outer surface vs. metal for the back bush). The central shaft could be moved axially by about 1/4" very easily. It make a clunk at both ends of the movement when moved. Out of interest, I cut down into the bush with a angle grinder cutting wheel and removed a V section to get a cut-away view. I was suprised to find it has a fairly compex structure inside. The central swivel is "plastic" (maybe a PTFE type stuff) on metal formed by the central hollow, (for the bolt hole), metal core inside a plastic tube configuration. This area is lubricated by grease. There are also two end caps which form circumfrencial-spring-based grease seals. My limited analysis suggests that these seals also limit the axial travel of the bush assembly and that one of them had broken allowing extra travel and thus the clunk. The proof will be today when I get it back on the car!

Ref. the ball joint, I tried your suggestion while everything was still on the car, (ie jacking the car up on the ARM and looking for play by moving the wheel up and down, side to side, etc. I could feel no play. When I got the arm off the car, the ball joint seemed reasonably tight. Out of interest I rigged up a Mazda-like service tool using a long nail ground down over part of its length and inserted into one of the split pin holes at the end of the ball joint tapered shaft. This gave a 4' lever at right angles to the shaft - the same as I calculated from the Mazda SST instructions in the manual, based on the allowable torque range and the equivalent gauge reading. I attached a spring gauge to the other, (head), end of the nail and "voila" we had an SST equivalent. As expected the results were not easy to determine. The bottom line was that the static torque showed just over half the minimum specified while dynamic torque was slightly higher than the minimum specified. I very much doubt the accuracy of these measurement due both to the measurement method and the fact that the measurements were right at the start of my spring gauge range, (I really need a much more presise, shorter range spring gauge). Anyway, there it is. I decided to go ahead with the bush changes anyway and will soon know the result.

Thanks for your continuing advise and interest.

Dave

BobfisH

did the bushing change fix the clunk?