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Tips on refreshing my suspension?


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I'm approaching 20 years and 147k miles on my '98. About 18 years and 110k miles, many track days and autocrosses (SMILES!) on H+R springs and 030 shocks. I haven't tracked the car in 8+ years and have been thinking about returning to OEM springs and shocks to reduce bottoming out on speed bumps, scraping the bumper on everything, and, well, sorry, but improving comfort. This should also allow me to restore some normalcy to my alignment and get me a few extra miles out of a set of tires. I also have at least one torn CV boot on original axles/boots.

With a "time to refresh because I'm keeping her forever" and "as long as i'm down there I might as well..." mentality, my initial thoughts are to:
1) restore to oem springs/shocks using original springs and new shocks
2) replace both rear axle assemblies (both make sense?)
3) replace other wear items (what are they?)

I'll have a trusted local shop do the suspension work, then I plan on some regular maint (plugs) and rebuilding the brakes. By the time all of that is complete, I'll probably have another crack in my plastic window and will think on a glass top replacement. smiling smiley

I'd appreciate your thoughts on #1, #2, #3 and anything else I should consider? Recommended place to source parts?

Thanks much! Doug
Quote
SMILIN
I'm approaching 20 years and 147k miles on my '98. About 18 years and 110k miles, many track days and autocrosses (SMILES!) on H+R springs and 030 shocks. I haven't tracked the car in 8+ years and have been thinking about returning to OEM springs and shocks to reduce bottoming out on speed bumps, scraping the bumper on everything, and, well, sorry, but improving comfort. This should also allow me to restore some normalcy to my alignment and get me a few extra miles out of a set of tires. I also have at least one torn CV boot on original axles/boots.

With a "time to refresh because I'm keeping her forever" and "as long as i'm down there I might as well..." mentality, my initial thoughts are to:
1) restore to oem springs/shocks using original springs and new shocks
2) replace both rear axle assemblies (both make sense?)
3) replace other wear items (what are they?)

I'll have a trusted local shop do the suspension work, then I plan on some regular maint (plugs) and rebuilding the brakes. By the time all of that is complete, I'll probably have another crack in my plastic window and will think on a glass top replacement. smiling smiley

I'd appreciate your thoughts on #1, #2, #3 and anything else I should consider? Recommended place to source parts?

Thanks much! Doug

Were I faced with something similar and with over 320K miles on my Boxster I could be faced with a suspension refresh at some point if I want to keep the car on the road I'd probably just refresh the car with stock springs/shocks, well, maybe just shocks unless the tech believed the springs bad. Because of the cost I would probably *not* replace the rear axle assemblies unless they were in such poor condition and were not salvageable by judicious replacement of various parts.

The other wear items are the various bushings where arms and such connect/attach. IIRC Porsche doesn't sell the bushings/etc separately. You have to buy new hardware to get factory fresh bushings. But you need to confirm this. If it proves to be the case there are aftermarket companies offering replacement bushings which are made of firmer stuff. The old bushing is pushed out the new bushing is pushed in. Trouble is these might have the car's ride harsher than it would with factory rubber bushings. But again check. Since I have not yet had to worry about this I haven't bothered to check what's available.

For the torn CV boot what the tech advised me when he found the boots on my car showing splits/cracks and leaking some slight amount of grease was to not replace the half shafts. He said Porsche half shafts have proved to be quite robust over the years with other Porsches and he was seeing the same from the Boxster half shafts. Instead he recommended they be removed, taken apart, cleaned and inspected. If inspection turned up a problem then I could replace them with new. But if not they could be repacked and installed. This was less expensive than outright replacement. New half shafts -- at least factory shafts -- were expensive then and can only have gotten more expensive since.

The clean, inspect, repack and reinstall route is what I selected and 50K+ miles later they are still just fine.
I appreciate your thoughtful and complete replies.
The choice of springs and shocks is somewhat personal, but i have learned over many years and many replacements that buying parts intended to work together ( e.g.: OEM sets, coilover) is always preferable to mixing and matching. So OEM springs and B4 Bilsteins is a good choice. My experience with springs - they often change their rate and/or crack with age. Might be worth replacing "while in there".

Now, the ROW 030 is low but ht regular M030 is NOT. I personally like the M030 very much, and it may be no more costly. You can get OEM alignment specs with either by the way. BTDT.

Pay close attention to all the rubber mounting bits; they are likely in far worse shape than your dampers. Mounts, bump stops, and the rubber disks with pressed in bearings for the tops of the struts wear all the time. Replace them.

Check the bushings on the control arms. They last very well, but some may be degrading.

As to the half-shafts: they cost $900/ea and, as Marc said, if they are clean and greased last FOREVER. I pull mine out of my tack car every two years, disassemble, clean, grease, new boots and replace. Messiest job on earth. Probably 4 hours labor with the suspension apart. Do all 4 boots - the failure mechanism on any CV is simple boot cracks, grease out, dirt in, c'est mort. Use lots of grease. Do not clamp inside boot (venting), or clamp loosely or clamp a straw in there.

Aftermarket half shafts are cheap, crap and dangerous. I'll save you the long version, but DONT get them.
I have seen the steel stretch and result in a catastrophic failure.

G

Grant gee-lenahan-at-vee-eff-email-dot-net
Thank you Grant and Marc. Revised plan to research and discuss with the shop:

1) dump the original springs that have been sitting in the attic for 18 years
2) new M030 springs and shocks and rubber mounting bits (M030 avail with '98? standard if not)
3) inspect, clean, grease, new boots for half-shafts
4) inspect all rubber and replace liberally

What are a couple of the current leading sources for OEM parts? I may just have the shop take care of everything, but I want to at least familiarize myself with the online prices.

Thanks again, Doug
OEMs
grant - 4 months ago
For control arms and bushings, TRW and Lemforder (plus some others for mounting rungs that I dont know off hand).
Amazingly, once you have the part numbers, sometimes Amazon.

If you mean the retailers, I am not all that familiar. Pelican is always a good source, although their pricing varies (one some things great, on others awful).

If your shop will work with you its hard to beat the prices they can get.

G

Grant gee-lenahan-at-vee-eff-email-dot-net
Car springs...
MarcW - 4 months ago
Quote
SMILIN
Thank you Grant and Marc. Revised plan to research and discuss with the shop:

1) dump the original springs that have been sitting in the attic for 18 years
2) new M030 springs and shocks and rubber mounting bits (M030 avail with '98? standard if not)
3) inspect, clean, grease, new boots for half-shafts
4) inspect all rubber and replace liberally

What are a couple of the current leading sources for OEM parts? I may just have the shop take care of everything, but I want to at least familiarize myself with the online prices.

Thanks again, Doug

Car springs sitting 18 years is not a problem unless the springs have rusted. If any have collected rust, that's a problem, and they need to be tossed.

If the springs were new when you removed them if you reinstall you face the small but real chance one of the springs has a manufacturing defect (an inclusion) and will break. Rare but that's what a new car warranty covers.

I didn't specifically mention this but it was implied and Grant did specifically mention it whatever springs and shocks you use they must be matched. While stock shocks can work (after a fashion) with aftermarket and lowered springs, stiffer springs, stiffer springs really subjects the shocks to dampening demands for which they were not intended and premature wear or even failure will be the result. In the meantime dampening may not be all that great.

For OEM parts Pelican Parts comes to mind.

For aftermarket suspension hardware Tarret is a pretty favorite brand.

To give you a taste of what Tarret offers, here's a link.

[www.tarett.com]
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