23 replies to this topic

[RazerX]

Car, took a big hit to the RF, from the bumper of another Miata(jerk). All the damage was near the top of the wheel, as seen by what was once a fender. As such the top A-arm long bolt was severely bent. So much so I had to cut the A-arm, then cut of the bolt and pound it out. Is there any tips or tricks to see if the spindle was bent? I did lay a straightedge across the brake mounting surfaces and is completely straight there. But save for putting it all back together and trying to do a setup I want to ask the brain trust here. BTW, the LCA looks good, but will replace it and a new ball joint. Tie rod is still straight and end looks unbent, same angle a new spare one i have. Thanks

 

Link to video of hit for those who like train wrecks: 

[Johnny D]

Sorry to hear, no Brian trust comment either.

 

I would like the see the video of the guys bumper jumping up and attacking your fender.

J~

[RazerX]

I have video, just got to figure how to post and link...

[Alberto]

You won't notice a bend that way.  There are 3 connection points to the spindle - the UCA, LCA and the steering tie rod.  When something bends, it is one or more of those three points that gets bent out of alignment.  Only way I know how to check is to compare to a known straight one to see if the 3 points are all in the same plane.

 

If you can do an alignment easily, put it together loosely and check for camber loss or toe that is way out.  If you can't do an alignment easily, I'd go ahead and try to replace it if you can.  If the top took that hard of a hit, the spindle may be bent.

 

I bent one once.  Found out during a corner balance and alignment at TFB.  Wasn't sure if it was LCA or spindle until we took it apart and compared the spindle to a known straight one.  I had planned on making a jig to check but got lazy...

 

 

Post vid on youtube and link

[Tom Sager]

Car, took a big hit to the RF, from the bumper of another Miata(jerk).  All the damage was near the top of the wheel, as seen by what was once a fender.  As such the top A-arm long bolt was severely bent.  So much so I had to cut the A-arm, then cut of the bolt and pound it out.   

 

Is there any tips or tricks to see if the spindle was bent?  I did lay a straightedge across the brake mounting surfaces and is completely straight there.  But save for putting it all back together and trying to do a setup I want to ask the brain trust here.  

 

BTW, the LCA looks good, but will replace it and a new ball joint.  Tie rod is still straight and end looks unbent, same angle a new spare one i have.

 

Thanks  

I think that if you even suspect it's bent then you should replace it.  It's hard to check them IMO and a little tweak can change what your steering does even if you can get it to align statically.

[Qik Nip]

You won't notice a bend that way.  There are 3 connection points to the spindle - the UCA, LCA and the steering tie rod.  When something bends, it is one or more of those three points that gets bent out of alignment.  Only way I know how to check is to compare to a known straight one to see if the 3 points are all in the same plane.

 

If you can do an alignment easily, put it together loosely and check for camber loss or toe that is way out.  If you can't do an alignment easily, I'd go ahead and try to replace it if you can.  If the top took that hard of a hit, the spindle may be bent.

 

I bent one once.  Found out during a corner balance and alignment at TFB.  Wasn't sure if it was LCA or spindle until we took it apart and compared the spindle to a known straight one.  I had planned on making a jig to check but got lazy...

 

 

Post vid on youtube and link

Don't forget the ball joint. I bent the stem on one several years back and chased a goofy alignment issue for hours before I discovered the problem.

Rick\\

[Alberto]

Don't forget the ball joint. I bent the stem on one several years back and chased a goofy alignment issue for hours before I discovered the problem.

Rick\\

Yep.  Who knew you could bent a ball joint....

My video on how to check if you bent it:

http://youtu.be/t5KmvynFgi0

 

Excuse the mumbling.  Didn't eat my wheaties

[davew]

You should do all your homework before throwing parts at the car.

 

First- try to insert a new bolt into the upper control arm mount on the subframe. If the bolt goes in easily, you are ok, if it does not, you will need to replace the subframe. The bolt should slide through with zero effort. If you need 2 fingers to push the bolt through, the subframe is bent.

 

Second- With the tie rod assembly attached at both ends, loosen the jam nut and watch the inner tie rod as you turn it. You are looking for any wobble. Resulting from bending. If it wobbles, replace the inner tie rod. If the inner tie rod is bent, replace the outer tie rod also. All the force required to bend the inner, went through the outer!!!!!!

 

Third- Measure the distance from the alligment cam horseshoes, side to side. Not from the cam bolts, but from the tips of the horseshoe. Measure all 4 pair. They all should measure the same within 1/8". If they do not, change the subframe. I have a tool to measure the rear subframes, but not the fronts.

 

Forth- This sounds kinda silly, but it works great. Compare the normal bends in the lower control arms left and right. Lay under the car and rub your hands accross both lower arms at the same time. Close your eyes and pay attention to your fingers. You will very often be able to feel any difference between the 2 sides.

 

Fifth- just replace the lower ball joint. They take a lot of abuse and are fairly cheap. Stay away from the cheap brands (ebay specials) they are not worth what you pay for them

 

Sixth- First step on inspecting the spindle is to check the brake mounts with a straight edge, as you have already done. If that is square, then you need a comparison spindle. Put the flat surface of the lower ball joint mount on the table. Compare the height and position of the upper ball joint mount, the tie rod mount (Steering arm) and the tip of the spindle. If any do not match a known good sample, replace.

 

Good Luck

Dave

[Jim Drago]

You should do all your homework before throwing parts at the car.

 

 

Fifth- just replace the lower ball joint. They take a lot of abuse and are fairly cheap. Stay away from the cheap brands (ebay specials) they are not worth what you pay for them

 

 

 

Good Luck

Dave

 

 

 

 

All of Daves advise was spot on.. But The ball joint is DEFINITELY a throw away.  The last thing anyone needs is for them to shear and they do more often than people realize. Definitely stay away from cheapos

[RazerX]

Thanks Dave, et all;

 

Upper long bolt does pushed in w/o grease very easy, but wouldn't twist as easily.  Found the new bolt to have a very slight waver/bend.  Thanks Mazda!

 

Will check spindle against known good one.  

 

I have used the rear subframe checking tool and will rig something up for checking the front, have a good one on the side yard to calibrate on. 

 

Balljoint was already in the replacement list.  I actually cracked one a couple years back, hairline fracture around half of the shaft at the bootline.  Happy find!

 

QUESTION:  when you torque many of the suspension bolts, say the rear upper arm, it no longer rotates around the bolt due to the compression force.  Instead it twists the bushing like a rubber spring when the arm travels.   I know this partly the reason it is key to tighten them when suspension is in the "loaded position" as it would sit statically on the ground.  Should that be the same effect on all the bolt/bushing suspension points, including that long upper front bolt? 

[Glenn]

You should do all your homework before throwing parts at the car.

 

 

Fifth- just replace the lower ball joint. They take a lot of abuse and are fairly cheap. Stay away from the cheap brands (ebay specials) they are not worth what you pay for them

 

 

 

Good Luck

Dave

 

 

 

 

All of Daves advise was spot on.. But The ball joint is DEFINITELY a throw away.  The last thing anyone needs is for them to shear and they do more often than people realize. Definitely stay away from cheapos

Had one break in the 13 hour at HOGPEN....driver found the third tire wall the hard way!

[William Keeling]

Bent is not alway a bad thing

[HoneyBadger - BrianW]

Bent is not alway a bad thing

I figured someone was going to go there...

[William Keeling]

people are always telling me to get bent

[Bench Racer]

 

QUESTION:  when you torque many of the suspension bolts, say the rear upper arm, it no longer rotates around the bolt due to the compression force.  Instead it twists the bushing like a rubber spring when the arm travels.   I know this partly the reason it is key to tighten them when suspension is in the "loaded position" as it would sit statically on the ground.  Should that be the same effect on all the bolt/bushing suspension points, including that long upper front bolt?

Yes, loaded with weight included as you were scaling/alinging the car.

[RazerX]

 Yes, loaded with weight included as you were scaling/alinging the car.

 

To be clear, all arms should have enough compression from the bolts that the bushing don't actually rotate on them?  

 

What about the lower A-arm in the rear where it mounts to the upright (long bolt) when tightened to spec should that also not rotate easily?  I know the upper mount on the upright does not rotate but the bushing rubber twists.  

[Bench Racer]

If you have not been here, it's your best friend. http://mazdaracers.c...ta-setup-guide/ Click download, then click open.

ALL control arm bolts should be loose untill loaded as previously posted. All the bushings adhere to their steel center and you want the steel center to follow the rotation of the control arm with lose bolts. NO twisted rubber bushings at this point. The follow the above link.

[RazerX]

If you have not been here, it's your best friend. http://mazdaracers.c...ta-setup-guide/ Click download, then click open.

ALL control arm bolts should be loose untill loaded as previously posted. All the bushings adhere to their steel center and you want the steel center to follow the rotation of the control arm with lose bolts. NO twisted rubber bushings at this point. The follow the above link.

 

Yes, Bench I know the manual well.  But when I tighten them all down, the steel center no longer rotates with control arm and all movement after tightening is in rubber bushing correct?  

[Bench Racer]

You are correct, when the bolts are tight the steel center no longer rotates and the bushing acts like a torsion bar.

[RazerX]

As I thought.  Those rear bushings must take a beating considering there is balljoints, like there are holding the front spindle.  

 

Oh, one more question.  I have an used front UCA, but ball joint boot is ripped.  I saw that mazda sold new boots so i order some.  But upon an hours time trying to remove the old boot it appears that the boot really isn't replaceable.  Did they change that on newer UCAs?  Or is their a magic way to get all that glued on rubber off, not that there is a grove really big enough to hold the new boot on.