Jacks911

Some advice on front suspension work please? I have some increasing (in my mind maybe) Cowl shake over rough highway surfaces at about 60 mph. Cab is a Tip with 80,000 miles on the OEM front struts. I replaced the rears Shocks with new Bilstein's and that improved ride comfort and control - but did not change the shaking.
It is road speed and surface dependent - not engine speed as a downshift will not change the "shutter", which will go away on smooth surfaces. There is no steering wheel shimmy when this happens, it is all felt seat of the pants.
The wheels and tires were speed balanced On the car, and all suspension parts looked over by a suspension expert. Over time we have replaced lots of rubber bits - control arm bushings and sway bar bushings. Is it posible that the old gas shocks have gone stiff as they aged? What are my options.
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968gene

Did your symptoms increase when you upgraded to 17" wheels/tires? (I realize this is an assumption). Also, is the shake worse with the top down vs. up? If so, this may just be the inherent cab cowl shake.

Stephenwz968

The struts do wear over time, and it's a good idea to replace or upgrade those. I have the strut bar and the Brey Krause Underbody brace on my cab, and it did help a lot with the cowl shake.

Jacks911

The car has always had 17" wheels. These are from a 996 and only 7" wide fronts with 205's. They actually improve the tram-line issues common with the slightly wider tire. The rear wheels & tires are the same width & offset as the originals. I do have a Strut Brace, but with or with out these changes I have the same shake. I think I just need to do the struts... maybe a winter project? How big a job is re doing the struts with Bilsteins inserts?

Damian in NJ

Ditto to what Steve recommended, I have the same set up.

mbardeen

If my understanding is correct, with the bilsteins you have to do a couple tack welds to hold them in place. And the inserts are only for the 944 series, not the 968 series.

However, I'm no expert so I'm most probably wrong.

RajDatta

Bilsteins are direct fit, nothing needed, as long as they are 87+ offset. BTW, our shocks are not inserts, but complete assembly.

Bilsteins would be a BAD idea in a cabriolet. They are very stiff and would turn every nut/bolt lose in the cab.

I would say, stick with stock struts and get highter rate springs. Get a lower chassis brace. It makes a big difference.

18's will also adversely affect ride quality compared to 17's.

mbardeen

I must be reading it wrong then, I thought he said he already had Bilstein shocks on the rear. I also wasn't aware Bilstein made struts for the front? Where can I find those?

I was planning on going all Koni sports when I finally got around to the shocks & struts, but it's nice to know there's another option out there.

Edit: Jacks911, I was just looking at your picture. Maybe it's just an illusion, but the rear of your car seems high.

tamathumper

+1, I thought it was just me.

RajDatta

http://www.paragon-products.com/Pors...tein_s/257.htm

Yuup, the rear needs to be dropped and reindexed probably.

mbardeen

I looked there, I see the Bilstein strut insert (http://http://www.paragon-products.c...30-0104-do.htm), but the product info lists it for rebuildable struts only, all pre-87.

I'm assuming that you could make that strut insert work if you modify the original strut, as you have to do with the Konis. I have a vauge recollection of reading that unlike the konis, you have to weld the insert in...

I see no drop-in Bilstein replacement other than the full coilover setup. Oh well. The Bilstein rear shocks are quite a bit cheaper than the Konis, but I'm not sure I want to weld the strut inserts, and I really don't want to mix & match brands. And, as you noted earlier, they might be too stiff for my Cab. I guess my top choice remains the Konis.

RajDatta

That is what it is, full coilover. There is no other Bilstein strut setup. Sorry if I wasn't clear.

Jacks911

Yes the rear is a bit high. That is a result of the new Bilsteins rear shocks. Raised the rear over an inch! I do plan in getting it reset but wanted to fix the front end at the same time. I do not think the Bilsteins are stiff. The rear is better controlled that before they where added - but the "Ride Analyses Tool" - aka the Wife - says the ride has "Improved and is much nicer".

RajDatta

Jacks, I should be more precise with you. You probably have the Bilstein Escorts in the rear and not the coilover. Bilsteins are quite stiff when going with coilovers.
Raj

tamathumper

Shocks don't have any significant spring value to them, so how did they raise the rear over an inch?