Rear spring question...

[FiberFast]

So I saw recently someone mention their car was higher on one side in the rear and had used shims to fix the problem. I may go this route if I cannot determine a better way to solve the issue.
My question is, is there a left and right rear spring? Is it possible I have placed the springs on the wrong side of the car?! For the front its pretty obvious, the springs are wound directional so they one fit on the perch one way. For the rears I figured they were the same. Anyone can verify this?

[magnetron]

Identical, i've swapped to a coilover set and lowering springs in the back, and it is identical.


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[bluptgm3]

Use spring pads to correct ride height issue, there are at least four different thickness. Plus cut the center out and stack two thin ones.


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[FiberFast]

Use spring pads to correct ride height issue, there are at least four different thickness. Plus cut the center out and stack two thin ones.


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As bad as it is... I think I am going to go with 5mm top and bottom on one side and 15mm on the other side. I might even get a 21mm. I need to get it on a level surface and measure the difference... Its quite significant.

[pbonsalb]

Make sure your upper shock mount under the carpet on the low side has not broken through the tower sheet metal.

[FiberFast]

Make sure your upper shock mount under the carpet on the low side has not broken through the tower sheet metal.

Can you show me with a picture? If it is, I would sure like to weld it!

[pbonsalb]

Just pull the side carpet back to look at the upper mount. You will see right away if the tower has broken. You can search for pictures. I don’t have any. This is just a possible explanation. A broken spring is another. A missing upper or lower pad is a possibility. Maybe broken chassis subframe mount is a 3rd. There are not many reasons why there would be a substantial side to side ride height difference.

[66 6]

Shocks should have nothing to do with the height the car sits. This is completely a frame / spring / UCA / tire issue.
First make sure the top and bottom spring pads are in good condition, measure the height of each tire off the car, correct pressure, outer bushings on the trailing arm and UCA condition and Frame condition where the spring/pad make contact with the car.

[FiberFast]

Shocks should have nothing to do with the height the car sits. This is completely a frame / spring / UCA / tire issue.
First make sure the top and bottom spring pads are in good condition, measure the height of each tire off the car, correct pressure, outer bushings on the trailing arm and UCA condition and Frame condition where the spring/pad make contact with the car.

Its not the rims or tires, I replaced all the bushings EXCEPT the sub frame and diff bushings. I put in a custom torsion bar and I am trying to see if this could somehow be the problem but I doubt it. Has megan racing adjustable rear control arms and TCKline delrin Rtabs, Koni Orange struts and Bavarian auto lowering springs with UUC bars. I love how it feels, I just want to make it look proper... Maybe lift the rear a little, the spring pads were toast and were one of the few things I did not replace. Well... Seems like everything I did not replace on the car needs to be fucking replaced lol...

[FiberFast]

Its not the rims or tires, I replaced all the bushings EXCEPT the sub frame and diff bushings. I put in a custom torsion bar and I am trying to see if this could somehow be the problem but I doubt it. Has megan racing adjustable rear control arms and TCKline delrin Rtabs, Koni Orange struts and Bavarian auto lowering springs with UUC bars. I love how it feels, I just want to make it look proper... Maybe lift the rear a little, the spring pads were toast and were one of the few things I did not replace. Well... Seems like everything I did not replace on the car needs to be fucking replaced lol...

Well... I though about it, added up the cost of a set of spacers, then ordered a pair of solo-werks rear adjustable spring perches. So, to put this into perspective (I am slightly amused) in order to get my non adjustable konis and bavarian sport springs to fit and function correctly (Its not a knock on them I have m3 spindles ect) I have had to install adjustable rear sway bar end links, adjustable trailing arms, adjustable rear spring perches, camber/castor plates, wheel studs and spacers for wheel to strut clearance/preventing rub on full turn. Its like I built an adjustable car around my non adjustable suspension lol... works fuckin good though, I would be pissed if it sucked.

[bluptgm3]

With adjustable rear perches I believe the ride height will be too high


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[pbonsalb]

Could be time to look for a used set of shorter rear springs from a coil-over kit if ones with a rating compatible with the existing fronts can be found.

[FiberFast]

I had not even thought about that, honestly it was too low in the back, or as most people report, too high in the front. The M-sport suspension used these super thin pads so mine is probably sitting extra low so the addition of 1/4" of material is fine. I may pull the lower pad completely, and just go with some thin delrin plastic or rubber sheet cut to fit the spring perch. I should probably replace the tops with 5mm new rubber as well. Only issue I have is its sitting too high on one side and to low on the other... I am also wondering if maybe this is a bushing thing and its just settling. Cause it has evened out a bit. Regardless I was going to try to lift the rear a little. I like how the front sits now, its just right for me, I want to be able to use my suspension for real, now I can make the rear ride correctly and look like the front. Could probably pull more camber out if I wanted. Go to -1.5 degrees...

[FiberFast]

Nvm, it already has a rubber gasket on the bottom so no need to make one.
https://www.ecstuning.com/b-solo_werks-parts/e36-rear-adjustable-spring-perch-price-each/s1bw001-23~sow/
Looks like it would be equal to about a 10mm pad? Am I trippin? I think I just need some 5mm uppers.

[bluptgm3]

Use spring pads to correct ride height issue, there are at least four different thickness. Plus cut the center out and stack two thin pads to raise slightly

Rear Spring Pads
SPRING PAD LOWER 33531135420
UPR SPRING PAD 5MM 33531136385
UPR SPRING PAD 7,5MM 33531136386
UPR SPRING PAD 10MM 33531136387
UPR SPRING PAD 15MM 33531094754
UPR SPRING PAD 21,5MM 33531091599


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[FiberFast]

Rear Spring Pads
SPRING PAD LOWER 33531135420
UPR SPRING PAD 5MM 33531136385
UPR SPRING PAD 7,5MM 33531136386
UPR SPRING PAD 10MM 33531136387
UPR SPRING PAD 15MM 33531094754
UPR SPRING PAD 21,5MM 33531091599


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That is exactly what the adjustable perch does. it sits there and acts as a 10mm spacer at full lock, as you adjust the knob it extends the height exactly like a thicker shim would. Why fiddle fuck with the spacers, when you can use an adjustable shim? Did you look at the part I linked? I dont need new springs (Although I thought about it) after rolling the bavarian springs on konis I wont swap them. They are super comfortable and predictable. The fact they are a little softer makes them allot of fun, feels like my tires are digging harder then they would with stiffer suspension and I feel like I am getting less deflection than with the M-sport springs. I was also riding toasted Monroe shocks though.
658964

[FiberFast]

Ok so it looks like I need the shims and these install in the upper position. I am going to use the thinnest ones all the way around.

[pbonsalb]

That is exactly what the adjustable perch does. it sits there and acts as a 10mm spacer at full lock, as you adjust the knob it extends the height exactly like a thicker shim would. Why fiddle fuck with the spacers, when you can use an adjustable shim? Did you look at the part I linked? I dont need new springs (Although I thought about it) after rolling the bavarian springs on konis I wont swap them. They are super comfortable and predictable. The fact they are a little softer makes them allot of fun, feels like my tires are digging harder then they would with stiffer suspension and I feel like I am getting less deflection than with the M-sport springs. I was also riding toasted Monroe shocks though.
658964

You could always run one of those on the low side and nothing on the high side. Or run both but end up higher than now after adjusting one side to level out the car.

You can install those adjustable perches on the top or bottom but they can be harder to adjust if on the bottom so you might have to set them while off the car and then install them if on the bottom. I have run them in both locations.

[FiberFast]

You could always run one of those on the low side and nothing on the high side. Or run both but end up higher than now after adjusting one side to level out the car.

You can install those adjustable perches on the top or bottom but they can be harder to adjust if on the bottom so you might have to set them while off the car and then install them if on the bottom. I have run them in both locations.

Yea these look titts for corner balancing adjustments as well. I was kinda thinking to run them in the lower location raw (No pad) but yea, the adjustment thing. Would probably wear better tucked int he upper control arm as well. I wonder what difference in effect on the spring having it up vs down is. You notice any difference pbonsalb?

[MINIz guy]

I don't know what your ID of your springs are, but there is a chance the adjustable perch doesn't match up.

[pbonsalb]

I don’t think it matters whether the adjustable perch is on top or the bottom, but it is easier to get to on top to adjust. I did not notice any difference and have run them in both positions.

[FiberFast]

I don’t think it matters whether the adjustable perch is on top or the bottom, but it is easier to get to on top to adjust. I did not notice any difference and have run them in both positions.

Thanks, guess I will run them in the upper position. The Uro (Oh noh) spacers are cheap so I will order a set. Some parts I am ok with Uro, like a hunk of rubber I mean... A hose? Ooof, don't know bout that.
MINIz guy, the perch is for a 60mm spring top. If you look at the Solo-werks adjustable suspension set you can see the rear springs are stock style like the Bavarian springs I have. At one point I had considered putting the M-sport spring back in the rear so the car is raked forward a bit. These perches should allow me to achieve that goal.
Bonus! The car is not leaking oil! Well maybe a little but what I have been seeing is... Powers steering fluid! The ps fluid resivor appears to be cracked at the hose. I will order a new resivor and hose, considering making one from metal.
Also need to figure out what is clack clacking in the back... My suspicion is an axle/cv joint or the diff... I think its the diff... Sounds like a box of rocks under acceleration :(

[MINIz guy]

Thanks, guess I will run them in the upper position. The Uro (Oh noh) spacers are cheap so I will order a set. Some parts I am ok with Uro, like a hunk of rubber I mean... A hose? Ooof, don't know bout that.
MINIz guy, the perch is for a 60mm spring top. If you look at the Solo-werks adjustable suspension set you can see the rear springs are stock style like the Bavarian springs I have. At one point I had considered putting the M-sport spring back in the rear so the car is raked forward a bit. These perches should allow me to achieve that goal.
Bonus! The car is not leaking oil! Well maybe a little but what I have been seeing is... Powers steering fluid! The ps fluid resivor appears to be cracked at the hose. I will order a new resivor and hose, considering making one from metal.
Also need to figure out what is clack clacking in the back... My suspicion is an axle/cv joint or the diff... I think its the diff... Sounds like a box of rocks under acceleration :(

Solo-werks rear spring perches are for a 62mm ID spring. Just because Solo-werks uses a beehive spring does not mean the ID is the same as the Bavarian springs you have.

[FiberFast]

Solo-werks rear spring perches are for a 62mm ID spring. Just because Solo-werks uses a beehive spring does not mean the ID is the same as the Bavarian springs you have.

I'm hosed... Piece of rubber hose? I am fairly certain I can make it work.

[FiberFast]

So I got to thinking about this and you made me slightly concerned for a moment. Not the spring ID part but more the coil ends. The stock spring ID is 60mm so if the solo works rears are 62mm that's 0.078" I am pretty sure I can flex/bend/get the spring on the seat no problem. The coil ends though have me worried, It looks like the solo-werks has a flat ground end on the coil. I may have to grind the bottom of the coil flat but we shall see, I am a fairly handy guy so it will be made to function well with the components I have. I'll let you know how much of a bitch it is...

[bluptgm3]

You really want to adjust with spring pads.


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[pbonsalb]

I want to know why the car is crooked.

[FiberFast]

I want to know why the car is crooked.

That is a good question, and one I have spent some time considering as this was not a problem when I had the M-sport springs and swaybars and worn bushings. I have to conclude that I have installed something incorrectly. Possibly I have installed a spring upside down? I bought these springs used, so it is possible they have worn this way as well. My current plan of action is to pull the prototype torsion bar and use it as a template for the revision. That will remove the torsion bar as a possible culprit and allow me to dial in the suspension before putting the production version on and also allowing me to get a butt feel for what it is doing. Two steps forward one step back, I agree shims are probably the best way to do this, probably cut and stack them to get the right height. Again there is the question though... why? Could it be that the torsion bar is set to preload the chassis to one side? This is exactly why I wanted to use threaded nuts on the swaybar box tabs instead of the lich pins fml... Its either that or the springs. Unless you guys have some other possible idea what could cause this.
What I did was:
New oe rubber bushings in the trailing arms (for the lower control arms, upper arms ect, I made extra sure to put them in the right way)
TC-kline delrin rtabs
Koni orange struts
Bavarian sport springs
uuc swaybars and adjustable endlinks
Custom made torsion bar <--- Possible culprit but others are having this issue, and its not just on Bavarian springs so wtf?...
M3 brakes, wheel studs and spacers (Probably has nothing to do with it)

The Bavarian springs looked symmetrical to me. So I will remove the torsion bar, install new 5mm spring pads, swap the left and right springs with the adjustable perches installed and set to zero. This will also give me a moment to inspect everything carefully once more and see if I can determine the issue. Once the car is lowered again I can inspect it, if the problem is swapped to the other side I will know its the springs.

[FiberFast]

Feck... Minizguy was right, no way in hell these are going to work. These will only fit solo-werks springs Going to send them back and I guess order a variety of spring pads. Feck...

Double what the feck, just went out and measured the car on a level surface... Problem has solved itself? I guess shit was just settling but its still too low in the rear so I am going to just use thicker spring pads... Wierd... Ill get some pics.

[FiberFast]

Took it out and went for a drive and checked it again. The height difference between the rear wheels is completely gone, I guess it just needed to settle? I guess I will leave the bar on for now as well but I do plan on doing some updates to that. The front is about two fingers 1.25" on either side, while the rear is one finger about 0.75" I like how it looks/rides in front so I am going to return these perches and put thicker pads in. This has been fun...

Side thought, what if the diff is sliding on the torsion bar bushing and preloading one side intermittently... So when I get on it, the diff twists and puts leverage on the bar and pinches the diff to subframe on one side. This would cause the problem to reoccur on the same side because the diff twists in the same direction. So the right thing to do is honestly first, see if the problem repeats itself with the prototype bar. If not, I will assume it was a settling issue, if so, we know its the bar. That is ok as well, I am going to use a much larger bushing on the production bar and this is part of the learning process.

If this turns out to be the case, its actually a very good thing I recon. It means the torsion bar is doing allot of work (Not correctly obviously) but a larger bushing/better grip on the bar should solve that and prevent the sliding/pinching in the first place if you get my drift.

[pbonsalb]

I’d have to look at a picture of the torsion bar installed. You are spending a lot of time pondering and working on solutions for problems that may not exist.

[FiberFast]

- - - Updated - - -

659110
This is the best shot I have atm. I have since had the alighnment. This problem seems intermittent, that is why I am suspecting the bar. You can see in the pic the torsion bar bolts to the bottom of the diff, and ties in at the sway-bar tabs/reinforcements. I had intended to put threads on the bar ends and a pair of nuts/washers on either side to apply a pinch or splay preload to the subframe. I used the litch pins shown in a hurry as I had to move the car at the time.

For the ride height difference front/rear I am going to use two sets of 15mm uppers I think, one on top, and one upper on the bottom. Unless anyone thinks that is a bad idea. I have searched around and from what I can tell, no ill will come of it. Looks like it has 5-7.5mm spacers now. So increase in height would be roughly 15-20mm pending. That should give me the difference between the 1.25" front gap, and the 0.75" rear gap. I really like the ride quality of these springs, but Bavarian auto either needs to make the rear coil taller, add a shim kit or make an adjustable seat to go with these. I am not the only person who has experienced this particular problem "Too high in the front". Alternately you could reduce the front spring height by 1/2", which is what most people would prefer, I think there are plenty of kits like that out there for people who want to slam their cars, and the ass needs to come up. Not trying to be overly critical, I like the ride quality of these enough to go through the hassle of adjusting around them.

[pbonsalb]

So it’s like a swaybar for the diff? I think the front of the diff wants to rotate up and to the right when looking at the input. It seems like a brace should be on the front of the diff rather than the rear. The rear has 2 parallel bolts holding it but the front has only 1. Mike Radowski made a very simple weld-on brace for the front that was effective. So effective that those of us with big power and traction would snap diff output flanges, twist driveshafts in two, and break transmissions but the front diff bolt would remain intact.

https://www.bimmerforums.com/forum/showthread.php?698916-Radowski-DSB-Installed/page3&highlight=mike+radowski+diff+brace

[FiberFast]

So yea, kudos to everyone for trying to steer me in the right direction while watching me do something stupid. 1. The perches didn't fit. 2. This should be adjusted with pads 3. I need to install a line lock kit on my e-brake handle but that a different fuckup lol.

[FiberFast]

So it’s like a swaybar for the diff? I think the front of the diff wants to rotate up and to the right when looking at the input. It seems like a brace should be on the front of the diff rather than the rear. The rear has 2 parallel bolts holding it but the front has only 1. Mike Radowski made a very simple weld-on brace for the front that was effective. So effective that those of us with big power and traction would snap diff output flanges, twist driveshafts in two, and break transmissions but the front diff bolt would remain intact.

https://www.bimmerforums.com/forum/showthread.php?698916-Radowski-DSB-Installed/page3&highlight=mike+radowski+diff+brace

That's about right. I know about the front mount reinforcement. If you think about it, bracing the diff from the bottom allows the upper mounts to work better as well, effectively pinning the differential between the upper existing and lower torsion bar bushing(s). The new lower mount will be a box instead of L bracket with a properly desighned urethane bushing. Threads on the end of the bar, with nuts, and new sway bar reinforcements.

[MINIz guy]

:rofl

Are you measuring ride height on a level pad? Confirmed with a water level?

[FiberFast]

:rofl

Are you measuring ride height on a level pad? Confirmed with a water level?

:rolleyes Yes... I have it parked on an uneven surface. I will fix that, where I measured earlier I used a 12ft lvl to check the surface and it was dead nuts in the bubble. So the left right problem is fixed, the front rear problem will be fixed with thicker shims.
I check it twice, before and after a drive. Looks even.

"For the ride height difference front/rear I am going to use two sets of 15mm uppers I think, one on top, and one upper on the bottom. Unless anyone thinks that is a bad idea."
https://www.ecstuning.com/b-genuine-bmw-parts/rear-spring-pad-pair/33531094754kt/ Two sets of these am I right? Costs exactly the same as the perches lol... Whoops.

[MINIz guy]

Using a 12ft spirit level doesn't mean that the level is accurate. I mentioned water level because the only way to get it wrong is user error.

[FiberFast]

659179
Miniz guy over here like...

[MINIz guy]

While you're short circuiting your brain looking like...

https://imgflip.com/i/vg7fd
https://i.imgflip.com/vg7fd.jpg

[FiberFast]

They were common symptoms, not a common cause. It didn't look good, which is why I was asking in the first place. The ground I measured it on was level enough, its suspension, it moves around. I shook the car back and forth to let the suspension work and settle, then took the measurements. 0.75" on either side in the rear. 1.25" in the front. This would probably look ok on 18" rims? I liked the raked forward look, now the car seems perfectly level (Rocker panels look parallel to the ground)

[FiberFast]

So it’s like a swaybar for the diff? I think the front of the diff wants to rotate up and to the right when looking at the input. It seems like a brace should be on the front of the diff rather than the rear. The rear has 2 parallel bolts holding it but the front has only 1. Mike Radowski made a very simple weld-on brace for the front that was effective. So effective that those of us with big power and traction would snap diff output flanges, twist driveshafts in two, and break transmissions but the front diff bolt would remain intact.

https://www.bimmerforums.com/forum/showthread.php?698916-Radowski-DSB-Installed/page3&highlight=mike+radowski+diff+brace

After some further reviews I would shy from this mod. Mainly because the diff case is cast iron, so as others have reported, getting a good weld is difficult.
If it were me and I wanted a solid diff support, I would make a 1/2" plate that extended from the dog ear I bolted to, to the rear jack point on the car. I am going to remove the "custom" nut I had to make to get it bolted up, and thread the holes. I had a difficult time threading the holes before and it ate my tap, so I am thinking I need a different tap material. I haven't done threads in cast iron before so its again, a learning process.
In my case, I have used a bushing to allow for some flex.

[pbonsalb]

It actually works great. I did it on 2 diffs. But yes, you must do the welding properly or have someone do it who knows how to weld. Well proven among drag racers and trackers over the past decade.

[FiberFast]

It actually works great. I did it on 2 diffs. But yes, you must do the welding properly or have someone do it who knows how to weld. Well proven among drag racers and trackers over the past decade.

Yea, but why not just thread the dog ears and bolt a solid mount to it? Then you have better torsional control. Make a plate over to the rear sub-frame jack point. I just feel like there are better ways of doing it personally.

[pbonsalb]

Have you run a solid mounted diff? I now run an E32 210mm 3.15 LSD that uses 75D poly in the diff cover ears and is solid mounted with 2 bolts in the front on the passenger side, and it sings loudly due to the stiffer rear and solid front mount. The singing is really obnoxious at some rpm and speeds and pretty much imperceptible at others, but overall it makes driving less enjoyable. The Maximum Psi brace for the 188mm diff is the simplest and best solution to breaking the front diff bolt, with no singing (audible diff whine). It will still allow the diff to rotate up and to the drivers side since there is a one bolt one side front mount, and that is not ideal, but the diff output stubs, driveshaft and trans will break before the front diff bolt breaks.

[FiberFast]

Possibly, but i dont think those would break either from torsional stress. I put the bushing in to ensure that of course. I was more concerned with snapping them off by hitting the bracket on a speed bump or something. I set the shim height so the angle sits flush to the bottom of the case, i have scrubbed it a few times and so far so good. You can see why this will be boxed in, in the future. It sits about flush with the rear subframe jack point so its pretty tucked up, but it the event of an impact on something i dont want it to catch/pull and rip the dog ears out and/or bend the subframe at the sway bar tabs.