FOURSPEEDVETTE

I just replaced all the verified original 34 year old factory shocks on my 1985 4+3. The car has 51,000 miles on it and has always been garaged and correctly maintained. The mounting bolts had absolutely no corrosion on them and were very easily removed. The non-Billstein original standard factory shocks looked like new, No oil leaking, no rust and they still had very good pressure left in them. Amazing! I replaced them just as a "feel good" type maintenance item because of their 34 year old age. Is it normal to have shocks this old last so long and still look and operate so well?

VikingTrad3r

where did the car live? id say no.

James C4

@FOURSPEEDVETTE I don't know if it's normal but I replaced my original shocks on my '84 this past summer with 60k miles and they were shot. They wouldn't even press back out on their own and they were covered in oil. Unless you have owned the car for a long time I'd guess they aren't the originals.

vader86

Usually the factory ones are done by 75K, if the car has been babied I'm not surprised yours lasted this many years, but its uncommon.

95LT1ZF

How did the car feel with the new shocks? Same? Better?

CorvetteRules

The shocks on the 91 I recently bought with 106,000 on it looks to have the original Billstein shocks which I plan to change out in the spring.

DGXR

If it is low miles and garage kept, I am not surprised they are still working. But I would also replace them just because. Good job

zachaeous

I purchased a 84 with 58000 miles on it and it came from the Chicago area. Shocks appeared to be original and were in terrible shape. The lower bodies were rusted to the point of having holes clear through them. Just about useless as shocks anymore.

I do not think that it is normal for shocks to last that long.

Patsgarage

FWIW I just ordered new shocks for my 79 DeVille (I know, not a C4, but the topic is relevant) with 21k on it. The car was always garaged and obviously rarely driven, but while only one has leaking seals they all are shot.

USAsOnlyWay

If the existing shocks were non-Bilstein I think you upgraded to factory then as I believe all C4s came with Bilstein stock.

FOURSPEEDVETTE

No, Mine wasn't one built with original Bilsteins. I don't know what the build code was for that set up, but some had the yellow Bilsteins, and some had AC Delco(?) or the plain standard black shocks. I think only the Z51 suspensions all had Bilsteins. I've known about my 85 since the day it was ordered and delivered new to the original owner. I bought it from him with 20,000 miles on it and every service receipt and parts receipt since new. I have quite a folder for this car. The shocks I replaced were definitely the ones that the car was originally delivered with. The car has never seen road salt or winter weather of any kind. I do drive it some, but only from May to October here in Pennsylvania.

DGXR

Most of the factory Bilsteins also had the AC Delco name on them. This was from an agreement / manufacturing contract between the two at the time these cars were built. New Bilsteins just say Bilstein, even if they are exactly correct units for your car. But you can have the original Bilstein / AC Delco units rebuilt if you want, with different valving.

jefnvk

Yep, mine are factory (albeit 1992), they're marked with both Bilstein, and directly below that just Delco (no AC, GM, Chevy, etc)

At 170k, mine are soft (read: nonfunctional), and got some rust and definitely are getting tossed in a junk box this spring. I don't doubt at 51k they could still look great and feel OK, but I'd be shocked if you put them on a dyno and it didn't show considerable loss from new. Sadly, Bilstein won't rebuild these anymore, that was the first option I tried.

aklim

I agree partly with you based on my call to Bilstein. From what I gathered, GM contracted Bilstein to build them shocks. That is where the agreement ends. Buy it with Delco coloring and box and it is a GM warranty. Buy it from Bilstein and it is a limited lifetime warranty. Same factory DOES NOT mean same product just as siblings from the same parents might not be the same person. We actually do private labeling. So say you wanted X25, it has 25% of the active ingredient and the rest fillers. X50 gives you less fillers but more active ingredient. We ask the factory to adjust the mix based on what you want to pay.

Why would you rebuild the original units? You have a 90 day warranty from what they tell me. The yellow Bilstein ones have lifetime.

Edit: If you had an NCRS thing and wanted to keep it original, I suppose you have to rebuild.

aklim

OK. That is new. Last time they said they would rebuild it but you would not get a lifetime warranty. Just 90 days.

I had a leak on one of them a couple years back. At that time they were 10 years old. I was asked to send the leaking one back to be tested on the "shock dyno". Called them and asked if they could also check my other one. They said to send it along. According to Fedex, within less than 2 hours of receipt of the old shocks, they created a label for shipping. NFW would I believe they tested them so quickly after receipt. Regardless, I got 2 new shocks back. Guess I will be happy since they are $200 FX3 shocks.

Another time, I had a hose that was venting crankcase fumes to the exhaust. It came out and blew oil fumes on the rear shock of the truck. By the time I discovered it, it was too late. I wiped the shock up and a couple days later, it was still oily. Checked the shock off the truck and it wouldn't bounce back. Wiped it and sent it back for a new one.

FOURSPEEDVETTE

Yeah......you're probably right. If I did put them on a dyno, it most likely would show loss from new. But for general driving purposes, they still seemed fairly good.