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-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   Rear wheel offset problem, looking for help from rx7 gurus !! (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/rear-wheel-offset-problem-looking-help-rx7-gurus-1165104/)

Lex89 02-02-24 11:04 PM

https://cimg4.ibsrv.net/gimg/www.rx7...0bc640df29.jpg
Right side
https://cimg6.ibsrv.net/gimg/www.rx7...69c8104420.jpg
https://cimg5.ibsrv.net/gimg/www.rx7...5f47f48af5.jpg
Right side
https://cimg7.ibsrv.net/gimg/www.rx7...bbb60ab444.jpg
Left side
https://cimg8.ibsrv.net/gimg/www.rx7...7c89a3318b.jpg
Ppf
https://cimg9.ibsrv.net/gimg/www.rx7...9093674b1d.jpg
Diff/subframe

Subframe
https://cimg2.ibsrv.net/gimg/www.rx7...5e55959776.jpg
Subframe locating pins
https://cimg3.ibsrv.net/gimg/www.rx7...c551fecf49.jpg
Diff/subframe
https://cimg5.ibsrv.net/gimg/www.rx7...18beef9114.jpg
Diff/subframe
https://cimg7.ibsrv.net/gimg/www.rx7...d807afcc2b.jpg
Left side
https://cimg8.ibsrv.net/gimg/www.rx7...96bdc65654.jpg
Right side
https://cimg9.ibsrv.net/gimg/www.rx7...e3fa0748ca.jpg
Diff/subframe

billyboy 02-02-24 11:29 PM

The car has had a subframe change at some stage at least.

Maybe a straightforward upgrade, rather than accident damage. I'd go through that link j9fd3s has kindly provided and check datum points if there's no conspicuous anomalies.

Edit: That last pic of the lower LHS suspension pick-up looks weird - camera angles possibly though.

Valkyrie 02-03-24 06:19 AM

The camber bolts are pointing in slightly different directions, but I'm sure that's a non-issue.

Maybe use a plumb line to mark spots on the floor to see how far the hubs and fenders are from centerline of the car?

The car needs to be perfectly level, though.

Lex89 02-03-24 06:26 AM


Originally Posted by billyboy (Post 12591838)
The car has had a subframe change at some stage at least.

Maybe a straightforward upgrade, rather than accident damage. I'd go through that link j9fd3s has kindly provided and check datum points if there's no conspicuous anomalies.

Edit: That last pic of the lower LHS suspension pick-up looks weird - camera angles possibly though.

The car has had the subframe changed, to the later model subframe with bracing etc.
it is possible that it wasn't straight when I bought it? I bought it from a wreckers but it looked straight and there's no visual damage.

in regards to measuring the car perfectly, it's very hard to find the exact centre line of the car and to get it on exactly level ground.

I'm still leaning towards the subframe bieng the issue, but i need to pull it out and compare it side by side with another one.

I have read the body manual that was posted here, thank you very much. It gives me a few other ideas on measuring etc.

Molotovman 02-03-24 07:29 AM

Pictures with everything blown apart don’t help. Take the wheels off and take fresh pictures.

to me, the quarter panel still doesn’t look correct. It’s almost like you’ve got a molded widebody on one side or a cut was put on top of damage underneath. Talk a picture of the inside of the fuel fill area too.

DaleClark 02-03-24 09:25 AM


Originally Posted by Lex89 (Post 12591834)

That upper Y-shaped aluminum arm that the bottom of the coilover is bolted to is upside down. There is a Mazda logo cast into it, it should be readable when it's installed.

That may not be the whole problem but that's a lot of it for sure. That will really jack up the rear end alignment.

Dale

j9fd3s 02-03-24 09:26 AM


Originally Posted by Valkyrie (Post 12591848)
The camber bolts are pointing in slightly different directions, but I'm sure that's a non-issue..

i notice that too. the alignment will affect (effect?) where the wheel sits, and the bigger the wheel the more you'd notice

Spalato 02-04-24 02:33 PM


Originally Posted by DaleClark (Post 12591865)
That upper Y-shaped aluminum arm that the bottom of the coilover is bolted to is upside down. There is a Mazda logo cast into it, it should be readable when it's installed.

That may not be the whole problem but that's a lot of it for sure. That will really jack up the rear end alignment.

Dale

Dale is correct. Look at the diagram below. It clearly shows the correct positioning of the upper arm. The end of the arm where the pillow ball sits should be pointing upwards, not down.


https://cimg2.ibsrv.net/gimg/www.rx7...14a345c62.jpeg


Valkyrie 02-04-24 07:22 PM


Originally Posted by DaleClark (Post 12591865)
That upper Y-shaped aluminum arm that the bottom of the coilover is bolted to is upside down. There is a Mazda logo cast into it, it should be readable when it's installed.

That may not be the whole problem but that's a lot of it for sure. That will really jack up the rear end alignment.

Dale

lmfao, this whole time I was thinking "are the upper arms upside down?" but I was too lazy to check if I was right and didn't want to say anything in case I was wrong.


Originally Posted by j9fd3s (Post 12591866)
i notice that too. the alignment will affect (effect?) where the wheel sits, and the bigger the wheel the more you'd notice

I thought it might be an indicator that something was off, but I don't actually know off the top of my head how much a full swing of the bolt changes the camber.
I don't/can't do alignments on my own car.

Lex89 02-05-24 04:51 AM

UPDATE
thank you Dale and others for the resources and your thoughts.

the upper control arms are installed correctly now, and unfortunately it didn't resolve my offset issue.

I pulled all the rear arms off, unbolted the PPF, subframe etc.
I tried to adjust the PPF and the subframe however it only gave me a couple of mm adjustment at most due to the subframe locator pins.

I haven't finished putting the wheels on and dropping the car on the floor etc, but I can still see that the hubs STILL don't sit equal inside the wheel arch.
So I imagine once the wheels are on and car is on the ground, it will be the same.

I am lost again and don't know where to go from here. I have tried to measure using the body manual attached above and everything seems normal.

I can only put it down to a bent subframe which is forcing the right side arms outwards and the left hand side arms inwards.

thoughts please..

gracer7-rx7 02-05-24 11:44 AM

Subframe sounds like the most likely culprit right now. I've bent many Miata subframes in my racing career. :)
Try getting a measurement between the alignment bolts. Maybe someone here can do the same measurements on their car to compare.

Molotovman 02-05-24 12:58 PM

Now that I'm looking at this on a PC you can see as clear as day that this car has been wrecked before. Your whole driver's side quarter panel is body filler from the front of the arch and over around to the fuel filler door. It's all wavy and none of the spot welds are visible because the detents have all been filled with body filler.

boostin13b 02-05-24 01:30 PM


Originally Posted by Molotovman (Post 12592076)
Now that I'm looking at this on a PC you can see as clear as day that this car has been wrecked before. Your whole driver's side quarter panel is body filler from the front of the arch and over around to the fuel filler door. It's all wavy and none of the spot welds are visible because the detents have all been filled with body filler.

Agreed, looks like from that picture that the fuel filler door doesn't even line up. I'm guessing they may have pulled out that whole side too far with whatever happened causing the overage.

ptrhahn 02-05-24 02:10 PM

That entire quarter panel (to half way up the roof pillar) is still available from Mazda.One way to fix that is get a new one and have it cut/welded and smoothed in.

Lex89 02-05-24 03:49 PM


Originally Posted by Molotovman (Post 12592076)
Now that I'm looking at this on a PC you can see as clear as day that this car has been wrecked before. Your whole driver's side quarter panel is body filler from the front of the arch and over around to the fuel filler door. It's all wavy and none of the spot welds are visible because the detents have all been filled with body filler.


I did mention before that the car has been resprayed about 15 years ago. The rear guard was NOT smashed, only had a minor ding.
the fuel door does line up however my latch and spring are broken so it looks like it doesnt.
I dont see how the rear guard is the problem because it doesn't explain why the right hand side has shifted outwards.

Lex89 02-05-24 03:50 PM

Does anybody have measurements for the subframe that they would like to share?

billyboy 02-05-24 05:41 PM

Did you see the car the subframe came out of originally - or was it just something that came off the wrecker's dexion? Unfortunate that there appears to be no measurements in the manual, there is a subframe here, but not sure if I'm likely to be over where it is any time soon.....and its modified for camber on the lower pick- ups.

If you can find fixed points on say the upper subframe, and shim your jack stands or whatever you're using level with plumb bobs (or use diagonals) you should be able to derive the centreline to scribe and measure the lower pick-ups at least. Of course the other least favourable way is just to buy another - all come out of rollers, so should be good......

Edit: appears the facebook link is no good, FDRX7 parts, James in Newcastle. He indicates he has a few.

Lex89 02-05-24 06:45 PM

Thanks Billyboy.
I did not see the car that the subframe came out of but it was from a wreckers so im assuming it was out of a smashed car.
it's hard to measure the subframe without something to compare to.
I think I might have to either replace the subframe and hope that it fixes the issue, or take it to a body alignment shop and have them laser measure the chassis/suspension etc. I just can't justify selling a kidney to pay for it
James Pearson does have lots of parts, he seems like a decent guy.

Molotovman 02-05-24 10:11 PM

I believe that you're in denial OP, it appears that when it was repaired it was pulled out too far along the arch. If the subframe was bent you'd have alignment issues and the car would be walking all over the road. All of the suspension components line up and your struts bolt up correctly, if the suspension was too far in it would be angled going up into the pocket where it bolts in.

You're chasing an easy problem the hard way, have the car inspected and measured by an auto body shop.

Valkyrie 02-05-24 11:30 PM


Originally Posted by Molotovman (Post 12592140)
I believe that you're in denial OP, it appears that when it was repaired it was pulled out too far along the arch. If the subframe was bent you'd have alignment issues and the car would be walking all over the road. All of the suspension components line up and your struts bolt up correctly, if the suspension was too far in it would be angled going up into the pocket where it bolts in.

You're chasing an easy problem the hard way, have the car inspected and measured by an auto body shop.

This.

He needs to take a large framing square and measure the distance between a flat part of the unibody (e.g. the spot on either side of the shock) and the widest part of the fender lip.

That, or just have the other fender pulled out a bit more and call it a day.

Lex89 02-06-24 01:23 AM


Originally Posted by Molotovman (Post 12592140)
I believe that you're in denial OP, it appears that when it was repaired it was pulled out too far along the arch. If the subframe was bent you'd have alignment issues and the car would be walking all over the road. All of the suspension components line up and your struts bolt up correctly, if the suspension was too far in it would be angled going up into the pocket where it bolts in.

You're chasing an easy problem the hard way, have the car inspected and measured by an auto body shop.

Thanks Molotovman but you are wrong about the guard. I can confirm this because I measured the other guard and made a cardboard template following the curve from the hatch edge to the guard lip.
I then compared it to my other guard ( problem side ) and it matched. It was max 1-2mm difference which could just be because the template was made by hand.
I then compared this to my friends low kms, stock s8 fd and his guards match my template.
I have also measured my guards inside the wheel well and both are the same measurement.

That rules out the guards bieng the issue.
It might be the angle or lighting in the photos that make it look like they arent straight.

The hubs are out at least 10mm out from each other which I think has to be either the subframe or a part of the rear suspension.

Is it possible for the trailing arm adjustment ( castor ) or camber adjustment or coilover adjustment to cause my issue?

Lex89 02-06-24 01:59 AM


Originally Posted by Molotovman (Post 12592140)
I believe that you're in denial OP, it appears that when it was repaired it was pulled out too far along the arch. If the subframe was bent you'd have alignment issues and the car would be walking all over the road. All of the suspension components line up and your struts bolt up correctly, if the suspension was too far in it would be angled going up into the pocket where it bolts in.

You're chasing an easy problem the hard way, have the car inspected and measured by an auto body shop.

Thanks Molotovman but you are wrong about the guard. I can confirm this because I measured the other guard and made a cardboard template following the curve from the hatch edge to the guard lip.
I then compared it to my other guard ( problem side ) and it matched. It was max 1-2mm difference which could just be because the template was made by hand.
I then compared this to my friends low kms, stock s8 fd and his guards match my template.
I have also measured my guards inside the wheel well and both are the same measurement.

That rules out the guards bieng the issue.
It might be the angle or lighting in the photos that make it look like they arent straight.

The hubs are out at least 10mm out from each other which I think has to be either the subframe or a part of the rear suspension.

Is it possible for the trailing arm adjustment ( castor ) or camber adjustment or coilover adjustment to cause my issue?

j9fd3s 02-06-24 08:50 AM


Originally Posted by Lex89 (Post 12592146)
Is it possible for the trailing arm adjustment ( castor ) or camber adjustment or coilover adjustment to cause my issue?

sort of, if you change the angle of the wheel, it changes where the lip will sit. the effect will be bigger the bigger wheel too.
for example if you have more negative camber the top of the tire will move inwards, which people use to tuck under the fender lip

Billyboy suggested finding the center of the car, and then you can measure the distance to the suspension pivot points on the subframe and see if they are symmetrical, if not then subframe is bent
https://cimg7.ibsrv.net/gimg/www.rx7...866eee1b97.jpg

gracer7-rx7 02-06-24 09:16 AM

^That pic is what you want to measure

billyboy 02-06-24 03:12 PM

On the diagonals may be easier, if you can clear the chassis mounts and any protrusions, without having to worry about going back and forth levelling - may need to drop the ARB and the fuel tank gravel shield to get best access. Basically following this X in the subframe brace, RH rear top to LH bottom mount and vice-versa - hopefully discover if there's any discrepancy.

Can't remember if the bolts are 12mm now? Threaded rod with a couple of nuts to adjust height and either sharpened to a point on the lathe, or spun up in a drill against a bench grinder would be best for an accurate measurement. You can probably eyeball it sufficiently without going to that extra trouble though. I seem to recall the two upper mounts are planar, but that's definitely not the case in the front.......you should be able to work something out to compare sides using some Greek guys ancient theorem if they aren't though. :D


Originally Posted by Lex89
or take it to a body alignment shop and have them laser measure the chassis/suspension etc. I just can't justify selling a kidney to pay for it

I'd imagine putting it on a car-o-liner or similar nowadays would cost way more than the $350 for the subframe, then again, you want to be sure you're not pissing money away replacing parts and still be in the same boat.

https://i.imgur.com/BtI4Wm6.jpeg


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