Un-Matched Spring Pads?

[n/a]

Greetings...

I've just completed the replacement of all the rear suspension rubber bushings/donute/etc., and after allowing some time for "settlement", I can see that the drivers-side rear is sitting slightly higher than the pass. side.  I've used 30mm pads on both sides, but now don't remember if it was sitting like this BEFORE I replaced them.  Everything else seems fine as the rear ride height looks much better and the car drives very nice.  Have any of you come across this problem?

cheers,


Dennis

[jeffc280sl]

Hi Dennis,

Did you replace the compensating spring pad?   I wonder if these pads can make the rear look uneven.

Jeff C.
1970 280SL 4-speed

[n/a]

yes, I've replaced the compensator pads with new 6mm ones.  The ride height and camber are much "better", it's just that the original spring pads that I took out were the same thickness, but the new 30mm pads definitely give me a slightly higher ride height on the drivers side...

If anything, I'd think that the drivers side spring would sag more but this doesn't seem to be the case...I'm stumped...

[jeffc280sl]

How did you determine you needed 30mm and 6mm pads on your car?  The original 280SL springs were color coded and matched with particular height pads on all three rear springs.  The rear coil spring pads came in 18, 24 and 30mm thicknesses.  The comp spring was fitted with pads on each end.  They could be setup with 3mm x 3mm, 6mm x 6mm or 3mm x 6mm pads.  The spring pads were dependant on equipment such as sliding roof, pwr steering, auto tranny and A/C.  

If you let me know what color and quantity stripes you have on your rear springs I can advise what the factory set your car up with, assumming its a 280SL.

Jeff C.
1970 280SL 4-speed

[Vince Canepa]

Have you measured the difference side-to-side?  According the the Technical Data book the permissable difference side-to-side is 5mm.  It is actually the difference between the front wishbone positions left-to-right (which is how M-B measures ride height).  However, in practice the 5mm tolerance can be measured from the body to the road to get an approximation.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[n/a]

The P/N of the spring pads that came out are 110 325 04 85 and they are "shorter" than the 30MM pads I put in.

The logic here, after reading every post on this board, was that bedsides the old rubber, my springs are probably sagging too so larger(thicker) spring pads would compensate for the sag.  The 6mm pads on the compensator spring seem to be about the only one available any more, plus they would correct any sag in the compensator spring.

I just measured the side-to-side difference and the driver's side is sitting about 11-12mm higher than the pass side. Would it be terrible mechanical practice to put a (shorter)24mm pad in the drivers side to get about back in spec?  

Dennis

[jeffc280sl]

Hi Dennis,

Part 110 325 04 85 is an 18mm pad.  If I get some time tommorrow I'll try and get back into the BBB and see if I can make some sense of the pad height and corresponding ride height change.  Assuming the springs have sagged at different rates I don't think it would be bad to adjust this with spring pads.  Can you measure the inner fender height on the right and left side and let us know?  At the highest point in the arch.

Jeff C.
1970 280SL 4-speed

[Vince Canepa]

As I read this I am wondering if the axle is now off center.  Did you change the cross strut rubbers?  Also, is the hanger mount rubber in good shape?  All of these have an effect on axle position.  Also, with a difference of 11-12 mm the whole car should be higher on one side.  If the front is level, or close to it, and the rear is not, the chassis must be twisted.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[n/a]

To All...


I've measured the FRONT side-to-side ride height and it's off about 7mm so I'm guessing the frame/chassis is not twisted, just "lifted on the driver's rear.  I'm going to order the 24mm pads from Millers tomorrow and drop that side back down.

I've also read all the posts on "axle centering";  I've seen two different specs for this, like 36mm and 42mm?  What's  the right one?  Also, where are the "bores" that you measure from?


As usual, this board is a fantastic resource!



cheers,


Dennis

[hands_aus]

quote:Originally posted by kohked

To All...


I've measured the FRONT side-to-side ride height and it's off about 7mm so I'm guessing the frame/chassis is not twisted, just "lifted on the driver's rear.  I'm going to order the 24mm pads from Millers tomorrow and drop that side back down.

I've also read all the posts on "axle centering";  I've seen two different specs for this, like 36mm and 42mm?  What's  the right one?  Also, where are the "bores" that you measure from?


As usual, this board is a fantastic resource!



cheers,


Dennis

Hey Dennis,

Have you thought about swapping the springs over to the other side?

Or is the drivers síde spring in upside down?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[n/a]

Originally posted by hands_aus

Hey Dennis,

Have you thought about swapping the springs over to the other side?

Or is the drivers s�de spring in upside down?


Upside down?  Are you joking? Is there a "top" and "bottom" to the rear springs?  There didn't appear to be any difference while they were out. Wouldn't that be embarrasing!

cheers,

Dennis

[Vince Canepa]

I am almost certain that 36mm is the spec for the W113.  The bores are near the front of the trailing arms.  If you can set the car on four jack stands, you can drop a plumb bob from the center of the bolts for the trailing arm mount.  Somewhere in the archives is a diagram of a tool Arthur Dalton developed from the chassis dimensions in the Technical Data book.  You can use the dimensions from that drawing to plot (on the shop floor) the center line and then the offset.  Drop a plumb bob from the center of the pivot bolt and you will know if your axle is centered or not.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[Raymond]

Dennis.  The front springs definitely have a top and bottom, but the rear springs seem not to.  However, if everything else measures the same, you might just try swapping them from side to side and see what happens.

If it does follow the spring, you can use a rubber flange valve gasket for a shim on top of the low side spring.  I've got a bunch I'm not using and can send you.  

When you to the thicker pads, the overall ride height of the rear must have gone up.  What is it measured from the center of the wheel cover star to the bottom of the fender on each side?

When I tried to order the spring rubbers from Millers they said they only stocked 30mm.  They suggested cutting the height of the rubber if I wanted them shorter. [:0] It's the only stupid answer I've ever gotten from those guys.  

My dealer was able to order the various sizes and they didn't cost much more than the Miller's price.

Ray
'68 280SL 4-spd Coupe

[Bob G ✝︎]

Stock spring pads pulled from my 1968 280SL were 18 mm rear and 32.5 front Car ride height sat at 25/1/right rear and  to 26 inches with slight negative camber in the rear. the tires are Michelin Rainforce 185 TR 14.Height was ballanced and showed no signs of height difference between front and rear.

Bob Geco

[merrill]

so,  now I am confused

the part number on my rear spring  upper pads is 110 325 03 85 .  According to the bbb and the teck booklet that came with my car that part number is 14mm thick.
 
cheryl at K&K could not get this part, so we called ray at buds benz.  he said the part is a 24mm thickness and the books were wrong

so, then I e mailed gernold and he replied with
"the correct part number for the rear upper pads are as follows,"

108 325 0185   30mm
108 325 0285   24mm
108 325 0385   18mm

the Wokshop Manual tells you how to check the thickness of the pad

Ray said he had the same pad part number in stock and they are 24 mm.
I am going to check the thickness of the old and new and probably install the new pads.

I sure wish this was easier.
matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[waqas]

FYI-- there's some fine info related to spring pad thickness in these threads:

http://index.php?topic=4228,pad,height
http://index.php?topic=3903,pad,height
http://index.php?topic=3661,pad,height
http://index.php?topic=2039,pad,height

(A Dalton, where are you??   )

WAQAS in Austin, Texas