randerson0248

Just received a pair of rear shocks ordered from Amazon for $44 each. Installed on my 1998 C5.

AC Delco part number is 540-203. The new shocks came in a AC Delco box, but the shocks have no AC Delco name or number on them. Actual part number on the shocks are 25819268. Do you think AC Delco supplied shocks from a different manufacturer?

Attached is a photo of one of the shocks.

lionelhutz

It looks correct and the number seems to be the current GM rear shock for a 06-13 Z06.

INANE

I've been looking at these C6 Z06 shocks on Amazon myself. They are priced way below other places on the net. Which has made me curious if they are the real deal or not. Does anyone know for sure if those part numbers are only used for the Z06 shock vs standard?

Front:
540-202 / 10313647
http://smile.amazon.com/gp/product/B...=ATVPDKIKX0DER

Rear:
540-203 / 25819268
http://smile.amazon.com/gp/product/B...=ATVPDKIKX0DER

IH8FORD

thats the real deal. just installed them on my car earlier this summer.

INANE

Awesome, thanks. Happy with em? Really seems like ones of the cheapest performance upgrades you can do. Plus the shocks on my car are pretty much shot. I just have to get some resistors since it has the F45.

Bryan144

Those are the correct shocks, I just did this install today actually! You will not regret it!

Good luck!

IH8FORD

one of the best things ive done to the car. I need to do the sway bars next.

jonrobinson84

I have never replaced shocks before but very apt. Is the process pretty cut in dry. A jack, jack stands, hand tools do it for things needed?

ZZ06

Changed mine a few years ago to the C6Z. Yep nothing fancy, but make sure you have a hefty torque wrench for the job as they need to be torqued to 162ft lbs.

lionelhutz

No, the rear lower bolt is torqued to 107 ft-lbs. The early shop manuals were wrong.

73Corvette

WHAT??? a GM shop manual wrong

There has been more than a few of the bolts SNAPPED off trying to obtain 162 ft lbs

jonrobinson84

Extremely glad I posted here. So 107 rear and 160 front

lionelhutz

No shock bolts are tightened to 162 ft-lbs. I don't know the numbers for the other bolts but they will be quite low.

ZZ06

Really? I searched more than one place, and have 2 different torquw value tables both have that bolt at 162ft lbs. I too thought this was high but at the time i couldn't find a post or info that said otherwise.

ZZ06

I see now! Well mine were torqued to 150ft lb when the new ones went in. Torque wrench i had didnt go that high. 162ft lbs is alot for shocks. Makes since it was an error. Havent had issues and my bolts fot reused. Next time shocks go bad, ill correct it.

73Corvette

Front lower mounting nuts are 21 lb/ft; upper are 19 lb/ft.

Rear lower is 107 lb/ft; uppers are 22 lb/ft.

https://www.corvetteforum.com/forums...107-ft-lb.html

https://www.corvetteforum.com/forums...-bulletin.html

If it's good enough for Bill Curlee it's good enough for me!

jonrobinson84

Thanks for those links!

INANE

So I've been on these new shocks for a couple months now. All I can compare them to were the F45's I took off. Those were definitely shot. Push them in and they don't pop back out on their own.

Anyway leading up to the swap I had left the dial on performance to get used to a rougher ride. These new shocks generally feel about the same as the F45's on that perf setting. Pretty sure they are better over all but it's just not as huge of a change as I thought it might be. It just has me wondering if they really are the C6 Z06 shocks or if my expectations are just off.

I know I want to do sway bars and bushing next but perhaps I need to look at springs too?

Bill Curlee

When I had approx. 35,000 miles on my 02 ZO6, I pushed it hard around a highway entrance ramp sweeping turn. Half way around the turn the rear suspension unsettled and the car almost slid off the road!

I had read about the C6 ZO6 shocks and decided to try them.

They install 100% OEM with no FUSS! When the install was completed, I took the car for a ride.

I traveled down a rural road that I have driven on a million times. HMMMMM,, I really didn't feel much of a change. I was kind of disappointed with the new shock. LOL!

WELL,,,,,,,,, I took that highway sweeper again and HOLY CRAP! NO MORE car sliding side ways!!! It went around that curve like it was glued to the road! NO MORE unsettled suspension!

You will find that the car is MUCH MORE responsive in emergent maneuvering and handles the curves a lot better! Everyday driving will yield little or no noticeable difference.

NOTE. C5s that have F45 Real Time Dampening have FE-1 (BASE) suspension!

I didn't realize how soft and compliant that F-45 suspension was in my 98 Coupe until I drove a new ZO6!! If you want a nice purpose designed performance suspension, find some used Z-51 or ZO6 take off suspension parts. That would be SPRINGS & Swaybars

There are better suspension systems in the aftermarket but, you can get a nice Z51 or ZO6 used set for cheep and they will make your car FUN to drive!

You will be VERY HAPPY!

RECOMMENDATION! Find someone with a GM Tech2 and have that F-45 Crap programmed out of the BCM. That way, its gone for good and you wont have to baby the rest of the electronics that supports F-45.

The Wrench

One thing you might look at is the rear top mount brackets. The original C5 mounts on my 2000 were canted a bit differently than the ones that came with the C6 Z06 new shocks. Compare and you will see what i mean. After fiddling around awhile, I concluded that the new top mount brackets did not align as well with the shock shaft as the original - they put the rubber bushings at a slightly cocked angle no matter which way they were oriented. So, I used the old mounts with the new rubber and they aligned perfectly. Probably not a big deal, the rubber bushings will absorb the angle difference, but I sure like the perfect 90 degrees of the old mounts to the shock shaft when the car is sitting at normal height.

As to travel, you will see the same up (compression) travel, but the down travel (rebound) lets the wheel drop almost 1/2 inch lower - no problem observed.


Also, if you see a little oil on the shocks, not to worry, just there to protect the shafts, zero leakage after they are installed.

I've had them on a couple years now, not too harsh at all and a real improvement in handling over the old shot originals.

DG