This Black Friday, I decided to buy something with the expectation it will probably yield zero result (which I will not know for sure until the car comes out in the spring). ZZP sells a replacement washer for the top of your struts called the "anti-pogo washer". ZZP does claim this is beneficial to people who use lowering springs, but also state people on stock ride height claim they also felt a benefit. My 2004 Monte Carlo is on stock spec suspension (the struts and strut mounts have been replaced, but still factory springs). That being said, based on ZZP's statements, I am not the best candidate to get the most from this mod from and I remain skeptic this mod does anything for stock ride height. I am not an expert on strut assemblies, but from what I understand, that top washer locks everything in. Once it is tightened, there should be no play there. So I am not sure how a washer with a shallow cap will change anything. But, I figured, $15, nothing to loose.

The real reason I started this thread was to look into a rumor I read YEARS ago. The rumor is that the ZZP anti-pogo washer is really a GM W-Body Sub-Frame Washer (GM P/N: 10203412). In addition to the ZZP anti-pogo washer, I got my hands on some sub-frame washers with that part number stamped into them. Visual inspection, they are NOT the same (perhaps it was in the early days, but what they sell today is not). The sub-frame washer is taller than the ZZP washer and has two holes in part of the "cup". Next, I grabbed my not so trusty Harbor Freight digital measuring caliper (sadly, this tool is very unreliable, not sure if I got a dud or if they are all like that). I used it to measure the cup height on both of those AND a stock washer. I noted the digital decimal reading but also checked the measurement with a tape measure (I trust the tape measure reading.

So here are the results:
ZZP anti-pogo washer - 9/16"
Sub-frame P/N 10203412 - 11/16"
Stock Washer - 13/16"

Very small differences. Curious the differences (if any) in the feel of the ride. Anycase, some fun pics from this adventure!










And now some "on the car" stuff

 

I have those on my car, the ZZP anti-pogo washers with ZZP lowering springs and the adjustable struts they sell. What my understanding of "pogo" is, is whats made WORSE by these. They seem to hold tension on the strut and the car is always ready to bounce around. They do help handling by making the ride stiffer but its just so damn bouncy and not comfortable for daily driving. Ive been wanting to swap them back to stock but I have a vg30 to put back together whenever I have time to do "car stuff".

I had them on the rear in the past and was able to swap those back to stock and it softened it back to a comfortable level.

 

Jason, I'm curious what your thoughts are on these after some use. Have you had enough drive time to find any noticeable difference and, if so, did it improve or worsen the ride/handling? As you know, my 2006 SS has been lowered for 11 years now on Bilstein HDs with Canuck Motorsports lowering springs (1.5" drop in front, 1.8" rear). I've been using the original, stock washers the whole time and have never had an issue with the ride/handling.

What's interesting is that wht02monte said these made it worse in his case. I find that interesting because certain people seem(ed) to talk so highly of these.

 

So I solved this problem. Made the struts softer, no more bounce. I think part of it was just unrealistic expectations. These cars are so long and that makes it "feel" like its more bouncy. Still kicking myself for not going with coils. Ended up paying more than coils because I got lazy and had a shop redo it.

 

Hopefully I can compare with and without soon. Once I have both Montes ready for summer driving I can say more (one will have these and one will not).

 

I wanted to circle back to this thread....

Anycase, the blue Monte got the ZZP Anti-Pogo washers. I will admit, not having done any fresh driving with the blue Monte before and after, hard to say for sure if there is a feeling difference. I tend to drive the black Monte a bit more and have some better before and after experiences with the car. I did notice while working on the car how the strut and that stock washer adjust, there is some play to be had there. I also had a set of sub-frame washers sand blasted and powder coated. I toss these on the black Monte. I believe these make a bit of a difference. I would want to lean on helping keep the wheels planted just a tiny bit. But I will also be 100% honest, it is possible it is the placebo effect (I changed something so therefore it MUST have made a difference). Not a mod worth tons of money, but considering my ZZP washers were a black Friday special of $15 and my sub-frame ones were near free, it is worth the price.

Excuse the rusty strut plate on the black Monte, but that is sadly common with these cars (and the strut can be perfectly fine).