ld63

attempting a diy rear spring removal to try different spring pads, but the inner bolt of the lower control arm bolt is blocked by the exhaust seems to be a common issue in the DIY spring threads

I have the car on jack stands and have the jack supporting the lower control arm, but cant fit a tool in to remove this bolt. I even removed the nut connected to the back of the bolt, but the bolt still wont budge.

I tried loosening the exhaust clamps by the resonator with the intention of sliding the whole rear of the exhaust back and out of the way, but certainly not a slam dunk working alone on jack stands.. does it really "slide" back if you yank hard enough? is there a better way?

just need to get the spring out to replace the pad.. any tips?

crazy1eye

Buy 2 new bolts first...

Rear inner table bolt part # 003-990-26-05 ~$16

The exhaust doesn't move enough to remove the 14mm x 110mm bolt so I got the bolt out to the point where it buts up against the exhaust by using a hammer & punch then I cut the bolt leaving enough of it to get vice grips on to remove the rest. Then inserted new bolt from the front.

Ingenieur

I'm thinking about doing the same: going to the shortest pad, should lower rear of the car 5 mm or so
but have hesitated because it sounds like a pita, lol

I'm thinking of making a simple tool:
1 each 1' x 3/4" threaded rod
2 each 8" x 2" x 3/8" steel bar stock, drilled with a 3/4"+ hole in the middle
5 each 3/4" nuts
3 each 3/4" x 2" washers

put 2 nuts on the rod ~ 1.5" from top, 'jam' them
slide rod (nut end up) up through bottom of perch, there is a hole, I checked
place washer and put 1 bar on top, as close to the top of the spring as possible
put washer and 2 nuts on top 'jammed' and securing the bar
place a bar on the bottom
place the washer and nut on the bottom and tighten
compress spring until you can remove/replace other pad
slowly release making sure every thing is aligned/seated properly

ld63

Interesting ideas! Brute force the bolt or a DIY spring compressor.

Crazy1eye, have you successfully done this? Are there any thread grooves in the hole that get damaged by hammering the bolt out?

I may also try to rent a spring compressor, not sure i would trust my DIY engineering skills for this

Ingenieur

here's the available pads
A 210 325 01 84 - 5mm Spring Pad
A 210 325 02 84 - 9mm Spring Pad
A 210 325 03 84 - 13mm Spring Pad (this is what's on mine, 3 little '****')
A 210 325 04 84 - 17mm Spring pad

so if I get the 5 mm pad that is a 8 mm drop
which is perfect
now if the front can be shaved down 4 or 5 mm

Larry, what size are you installing?
my rear seems to sit a bit higher than the front, measure floor to fender lipo:
F 26"
R 26.3"

so this 8 mm drop would help even it up a bit

the front tire OD is also bigger (by about 0.4" or 10 mm), so the gap is smaller than the rear
basically gap = floor to lip ht - tire OD
F 26 - 25.4 ~ 0.6
R 26.3 - 25 ~ 1.3, if I lower the rear 0.3 (8 mm) that will take it down to 1"

ld63

Ingenieur, I am actually planning to try 17mm pads as I am on H&R springs and this is a common suggestion by the community. On stock pads w/ H&R, the rear appears to 'sag' lower than the front, so many folks find the 17mm pad to be visually appealing.

still, it seems sacrilegious to be lifting it.. ugh :-/

Are you on stock springs?

Very interested in trying crazy1eye idea if it doesn't compromise thread grooves to hammer that bolt out. Totally makes sense to put the bolt in backwards for future maintenance too.

Ingenieur

yep, a lot of people use the thicker pads with the H&R

I'm on stock springs and would like a little lowering and to maintain stock ride comfort

you can probably tell if the bushing sleeve is threaded by looking at the new bolt
if no threads on the shank you are probably good to go
I'm guessing not, so the arm can swing freely

Ingenieur

do our cars have items 8 and 9?
PN's anyone?
thanks

Valvestud

In EPC the number 8 part in the illustration are the parts you put in your last post. The lower shim is A-204-324-01-84.

Ingenieur

I thought the numbers I posted were for the top rear?
The top front & rear are the same?

if so why couldn't they both be changed to lower the car a bit?

for the lower, is there different thicknesses or only one?
the rear has a lower one also, but no different thicknesses

thanks

abcut973

I only know 2 types of upper spring pads 13mm and 17mm (item #6) with the part numbers mentioned in previous posts.
The 5mm and 9mm pads (item #7) are the lower ones which go where your springs sits. So there is no way to install them in place of the upper pads since they are for different purposes.




As for OP question. You can remove the inner bolt by unscrewing it manually. You will reach a point where it will butt against the exhaust. If you keep going by applying little pressure upward on the exhaust you'll be able to free up the bolt. A PITA but if you are alone with no lift to remove the exhaust that is your only option without cutting. Then when finished with your spring job just insert the bolt from the other side so it would make your life easier for future rear suspension work

Valvestud

Sorry, thought you were looking at rear. If anyone wants part numbers, let me know what you're looking for and the model year.


Regards,


Joe

ld63

Thanks, but I cant even fit a socket wrench between the bolt and the exhaust.. I dont see how I could manually unscrew it like this unless I use my hands - but even with the nut off, the bolt would not budge.

What tool did you use to manually unscrew it?

And do you use the jack at all to put pressure on the control arm (just under the inner bolt) and allow the bolt to come off easier?

abcut973

I used a torx wrench (T55 if I'm not wrong) like this one... a real pain... lol

Ingenieur

so the 4 part numbers I previously posted are for the rear upper mount (4 different heights), correct?
5, 9, 13 and 17 mm

what are the numbers for the front upper and lower pads/shims?

crazy1eye

Yes... No there's no threads to damage inside the arm.

Yes a jack under the arm helps to remove & install the bolt.

I lowered mine 2 years ago with H&R springs & kept the stock 13mm pads in, loved the look but with new tires, same size 275/30/19 different brand, I was rubbing a lot so I swapped in the 17mm pads in about an hour alone. Would be easier with a friend to help align the arm to insert the bolt

Valvestud

Correct.

Autosport7

So to do a flat stance you would need to replace the oem pad with 17mm?
How big of a drop does that make from oem?

kfriedenberger

H&R springs = - 3/4" (19mm) - 13mm + 17mm = -15mm

Autosport7

Thanks for the response.
I love a low car, but for the Benz I am more or less looking for better handling as I plan to track this car a bit.

Ingenieur

Thanks
Are there different thicknesses for the front or only one?

And there is a top and bottom for the front?

So 9 mm in the rear = 8 mm drop

Sand top and bottom in the front 3 mm each = 6 mm drop

ld63

What tool did you use to cut the bolt? Would a dremel work? It's a bit tight back there on jack stands. Thanks!

crazy1eye

I used a small angle grinder with a cutting disc, 5" disc.

ld63

Spent a good part of the night and got one bolt about 1/2 way out. Removing these inner arm bolts have to be the biggest PITA I've dealt with on this car. Incredibly frustrating and completely not worth the DIY investment.

Anyway, a few of you mentioned the inside of the arm is NOT threaded, however I just hammer the sh* out of the nut end of the bolt and it didn't move a mm. But when I manage to manually unscrew from the head of the bolt, it slowly comes out. So far, it really feels like I am unscrewing the entire length of the bolt it's awkward and requires full force grip for every turn.

Also, the replacement screws I picked up from the dealer (the exact part number above from crazyeye) are threaded along the entire shank.

Are you sure it's not threaded bushing in the arm??

Well rant over.. Tomorrow I'll try to finish the job. Thanks for your answers.

Autosport7

My 17mm pads and springs have arrived. I planned on a diy, probably still will as I had the same issues on my BMW when I lowered it, exhaust in the way.
If I still decide to diy, I will stop back in and let you guys know if I am able to magically make this any easier, although I am doubtful as some pretty inclined guys have posted up with the same issues...
May just buy the bolts ahead of time incase cutting them off is the best route.