128 front suspension issues

P

pdxgeo

True Classic
Im having an issue with the front right suspension. When i hit a bump (especially when the wheels are turned) I hear and feel a loud banging sound. I jacked up the car and it looks like the strut(shock?) might be broken. There is a rubber boot floating there that is clearly broken but the strut itself looks odd. The car was lowered when i bought it presumably by using x struts as i doubt John Lickley would have cut springs...

If this is the issue are the struts pretty easy to get? Is there a brand that is better?

Thanks
 
Check the steering rack inner bush... this is quite often the source of banging on the passenger side.

Grab the inner end of the steering arm and try to move it up and down... if the rack bush is U/S it will be quite obvious... there should be no movement at the inside end of the steering arm.

SteveC
 
I was going to suggest removing the strut and testing it by hand, if the strut is very worn it will be easy to compress, too easy. It also sounds like your bump stop is worn out. I'd replace them as well.
 
Thanks Greg. Ill call MWB tomorrow. Is there anything else I should think about while im in there?

George
 
Check the stru towers

For metal fatigue, they are know to develop stress cracks. My 128 had the cracks.
 
Inspect strut "bearings", I think the 128 uses thrust plates, there are also upgrades in the form of actual bearings for this. And of course top strut mount. Not sure if it's unique or same as X1/9.
 
Same as the X, but slightly different bolt pattern for the mount

Sadly we can't use the upgraded Plaia mounts unless you want to drill extra holes in your strut tower. Probably worth it though to be honest.

I have a set of stock springs from my sedan if you want them George. I'll be up your way next week.

-Dean
 
They use the same strut hardware as early X's, except the strut top mounts have studs spaced evenly (120 degrees) around. I've been running prototype Plaia bearings on my Rally for 15 years!
 
Waiting for parts...

the right shock was shot. So was the upper perch/tube. The rubber bump stop would not "seat" in its lip so I ordered a used set from MWB which should arrive today.

Also noticed tie rod ball joints rubber looking shot so have them arriving as well. Hopefully all back together this weekend. There is a Plaia bearing mount up there, installed by Mr. Lickley.

Thanks Dean for the offer but I like the ride height so don't want to make any changes just yet. If the combination of stuff in there causes another shock failure I may take you up on it in the future.
 
If the springs have been cut and your still using the stock 128 sedan bump stop/upper spring perch assembly then that is going to be an issue as this cuts the available suspension movement... the bump stop steel tube section needs to be shortened if using shorter springs (just like a euro 128 coupe has shorter springs and it's bump stop steel tube is shorter)

This is quite possibly why the bump stop rubber and the steel lip of the top spring perch / bump stop steel tube where the rubber fits into was damaged.

SteveC
 
Pics of (USA) 128 sedan & X1/9 bump tubes

This should be 128 sedan and X1/9 bump tubes. About a 30mm difference! I'm pretty sure wagon tubes would be the same as sedan.

128%20Sedan%20Front%20vs%20X19%20Rear%20Bump%20Stops%202016-05-11%20001s.jpg


128%20Sedan%20Front%20vs%20X19%20Rear%20Bump%20Stops%202016-05-11%20002s.jpg


128%20Sedan%20Front%20vs%20X19%20Rear%20Bump%20Stops%202016-05-11%20003s.jpg


I didn't have any coupe tubes since my coupe came with X struts already.
 
128 coupe is about the same length shorter than sedan/wagon type... looks like 128 coupe and early x19 could be the same part..

if shorter springs and long bump stops are used it just bottoms out all the time and damages other parts

SteveC
 
So I'm still having issues. The 3 studs on the upper strut mount are "splayed" (likely due to the reason Steve mentioned above) so when I get the assembly put back together I have to twist from below and pry on it from above to get all 3 studs through. All this twisting causes the spring to fall out of the lower perch (every time!)

If I use the shorter X19 bump stops will that help prevent other/future damage? I just ordered new upper strut mounts so hopefully with straight studs I won't struggle to get them through the friggin holes.
 
That's from the strut bottoming out and transferring all the load to the strut top mounts... it also bows the bodywork and causes cracks in severe cases... so you should order different bump stop assemblies,or cut your existing ones down.

Cut springs leave an 'open' wind at the cut end... stock springs have a 'closed' wind so the spring will sit on the perch correctly... you need to close the wind on the coil, or replace the springs... leaving an open wind and the spring that short is very poor practice.

SteveC
 
It's also possible that he's got X springs on 128 struts, so there's no preload when the strut is not compressed under the car. George, do you have any pics of the setup out of the car? Or just of the spring? I have done the cut spring without closing the coil too (many moons ago on my X19) and it sucks. My solution for keeping the spring in place was to use bailing wire to strap the spring to the seat. Makes me cringe just thinking about it!

George, new top mounts would help with your splayed stud situation, but if the strut tower is bowed you'll need to flatten it back out somehow (or the new mounts will just get tweaked). You may be able to straighten your mounts in a shop press. I have never tried though, as they are just easier to replace.
 
I have to pull it back out so I'll get a pic when I do. The threads on the top mount studs are also getting pretty flat and need to be re chased so I figures new ones would be better at this point.

What started this mess was I hit a big pothole (at low speed) with both wheels simultaneously. It bottomed out so hard there are some torn welds on the inner fender on the driver side. The passenger side is the one with the dead shock. Hopefully there was not too much additional damage but I'm dubious...

Thank you for the help, I hope the pics will shed further light on the situation and what to do about it.
 
Oh, and John Lickley confirmed that these are cut 128 springs, not X springs.

What a drag this is becoming. I asked MWB if I could exchange the 128 shock tubes I bought for the shorter X19 version. That is what you're recommending correct?

Thanks again, more to come.
 
You can also modify the 128 sedan bump stops... if you look closely you'll see the tube is spot welded to the upper perch plate and the lower bump stop groove...if you carefully drill out the spot welds, the sections come apart. You can then simply cut off the desired amount (to be determined by loosely mounting the bump stop assembly to the strut and ensuring that the bump rubber bottoms BEFORE the strut shaft does...) and then re weld the spot welds with a puddle of mig...

You also need to find some more appropriate front springs.

Yep it's become bigger than Ben Hur... that's why it pays to do the job right the first time around.

Sachs struts are pretty good, BOGE are my preferred go to brand for a 128. What you really want is some euro 128 coupe front springs, from memory they are 6.5 (or maybe 7) winds and slightly thicker wire than the 128 sedan coils...

My 128 sedan runs coupe springs and bump stop assemblies... after the weekend I'll have time to measure and maybe take a picture for you.

SteveC
 
Was the passenger side strut the one with the bump stop rubber not sitting in it's groove?

If it was that could be the reason the strut is dead... the strut shaft has likely bottomed out inside the casing, and broken the valving assembly when it did so...that rubber stopper performs a vital function and if it wasn't in place it allowed the strut shaft to travel that last inch or so and bottom out.

SteveC
 
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