Complete GM F41 suspension upgrade

matt270avian wrote:

Scott, do you know if the struts and knuckles lined up just like stock? I figure it would be easier to pull them all off of one car to get the springs, strut top mounts, and knuckles to finish my front suspension. Same question for a 98-99 STS without the magnetic ride control.

You'd benefit even more if you took the cradle and lower control arms too.

I think the knuckles are the same '95-'99 aren't they? I'd have to check. It was the strut mounts, cradle, springs, and lower control arms that were different through the years.

I didn't have to change a thing on my '98. The struts, springs, mounts, sway bars and bushings were the same design all the way up to the 2005 PAU (with F41 option). All the other parts (not F41) were just "stock" Rivi parts.

Abaddon wrote:

You'd benefit even more if you took the cradle and lower control arms too.

I think the knuckles are the same '95-'99 aren't they? I'd have to check. It was the strut mounts, cradle, springs, and lower control arms that were different through the years.

I don't really want to do a cradle/LCA swap. Too much time money and effort for me. The knuckles on 95/96 are different from the 97+ because of a different caliper design. I'll pull my wheel off tonight to get a picture for you.

matt270avian wrote:

Abaddon wrote:

You'd benefit even more if you took the cradle and lower control arms too.

I think the knuckles are the same '95-'99 aren't they? I'd have to check. It was the strut mounts, cradle, springs, and lower control arms that were different through the years.

I don't really want to do a cradle/LCA swap. Too much time money and effort for me. The knuckles on 95/96 are different from the 97+ because of a different caliper design. I'll pull my wheel off tonight to get a picture for you.

For whatever its worth, swapping the cradle shouldn't really be too insanely hard to do. Just need a really long breaker bar and a cherry picker.

Don't even need an Engine Hoist. I think you can rent engine supports. They allow you to hang the engine with braces above the car. That way you can just unbolt the cradle and drop it on the floor.

What about jackstands under the engine?

Realistically this will probably never get done. I'll be lucky if I can get my front suspension done within the next month or two.

matt270avian wrote:

What about jackstands under the engine?

No. That's just asking for someone or something to get hurt. I'm talking about an engine support like this....

http://www.harborfreight.com/1000-lb-capacity-engine-support-bar-96524.html

It literally allows you to hang the engine from it so you can remove whatever you want from underneath without dropping it on your head or the floor. You may be able to rent one from Autozone too

matt270avian wrote:

What about jackstands under the engine?

Realistically this will probably never get done. I'll be lucky if I can get my front suspension done within the next month or two.

Ya dude the engine/trans is not balanced at all, and it's kind of unpredictable how it will want to tip. I would definitely not get under there if it was on jackstands.

I'm not sure I like the idea of that bar.. I think I would rather spend the extra cash for a cherry picker in case I get in way over my head on a project. Either way though, still probably not going to happen. Going to (hopefully) order strut top mounts, springs, and knuckles on Wednesday.

matt270avian wrote:

I'm not sure I like the idea of that bar..

We use something similar here every single day. It's the recommended way of removing cradles   

Abaddon wrote:

We use something similar here every single day. It's the recommended way of removing cradles   

I'm sure it works just fine, but I like the idea of something on the floor holding a loose engine vs. a bar across the fenders. That and a cherry picker would be a good excuse to start major work on the Camaro

I'm looking at Delco part # 45H0286 for springs. Thoughts?

https://www.rockauto.com/catalog/moreinfo.php?pk=1028085&cc=1303322

*sigh* Do it the hard way then   

What are those springs for? I see the P/N but there isn't an application listing.

Park Avenue, Riviera, Seville, etc.... Rock Auto lists them as compatible with all of them but does not specify if they're for F41/FE3 (if that even matters).

It does matter. Look on the first page with the P/N's. A lot of aftermarket places are listing the same spring for all the cars and years for some reason. Yet the P/N's on the factory spring tags are different. Give me the day and I'll bother one of my parts guys to see what the differences are between the Caddy and the PAU springs.

Abaddon wrote:

Give me the day and I'll bother one of my parts guys to see what the differences are between the Caddy and the PAU springs.

I've been looking for awhile now and I got nothing. Not to sound like a dick or anything but he'll probably come up with what we're seeing (they fit on everything).

I know Charlie had some issues with the Moog springs, but I don't know if that transfers over to other brands or not.

That's a possibility, but I'm looking at factory parts, not aftermarket. Delco is aftermarket, not GM. I remember somebody on here going to an aftermarket spring place with the factory F41 spring P/N. It showed no listing. All they had was the "universal" P/N for all cars.

Alright Matt. The Delco P/N you listed (45H0286) translates to GM P/N 19161295. It shows that they're for '95-'99 Aurora and Riviera, '97-05 Park Avenue, and '98-'05 Seville/Deville. It's one of those "generic" springs that we're talking about.

The standard Seville rear spring is GM P/N 25655473 (Delco P/N 45H2127), which is the same as the standard rear springs on the PA and Riviera.

The F41 rear spring is GM P/N 25655478 (listed on pg 1), and does not cross into a Delco number.

I did find an FE7 spring while looking    It was listed un Deville, heavy duty.

I was also looking around. I found that all STSs had FE3 springs, where the SLS had FE1 springs. Everyone on the Cadillac forums says that the FE3 springs are stiffer but does not say how much.I couldn't dig up a part number for them either. There may also be a difference between the 98-99 STS springs and the 00+ ones because every STS got the special ride control starting that year.

There was talk of the DeVille springs being really stiff, but nothing about whether or not they could swap into an STS (Rivi in our case).

Now, I couldn't find anything comparing the F41 springs to the FE3 springs. This is where you guys come in. I'll order one or the other because they should (99% chance) fit just fine. I'm thinking the FE3 springs just because everything else I have is FE3.

EDIT:

STS Front spring for 98-99 is 22132528

Any way to figure out which springs the PA would have if I were to find one in a junkyard?

matt270avian wrote:

Any way to figure out which springs the PA would have if I were to find one in a junkyard?

The tags on the springs themselves would tell you. I'd have to look at the tags on my springs so you could have the numbers/codes off of them. Also, the PAU with that suspension option had the larger chrome wheels on it. It was part of the whole package. Or, take a micrometer and measure the thickness of the sway bars. That should be a good indicator of which suspension is under it.

Unfortunately I don't have a micrometer. If you could get me those numbers by tomorrow night that would be awesome. Me and a few friends are going to spend all day Saturday wandering around the junkyard looking for anything and everything.

If you have a harbor freight near you go get a par of mics from there. They'll be like five bucks, and they'll be plenty close enough for anything you'll be doing.

I got a micrometer at HF and I am quite impressed with it. I recommend it for sure.

Thanks, China.

New Member here guys..... anyone ever buy from GMPARTSCENTER? I'm looking to do the F41 springs very soon and wanted to make sure if I order a particular part I will get it. Appreciate your input!

I picked up rear sway bar of a f41 pau today. The bar off the sts is about 1mm thicker according to my hf digital caliper. I'm gonna use the f41 bushings which are part number 25650389 white. They are way firmer than the sts bushings. Seems like it squeezes the bar firmer

Abaddon wrote:

It does matter. Look on the first page with the P/N's. A lot of aftermarket places are listing the same spring for all the cars and years for some reason. Yet the P/N's on the factory spring tags are different. Give me the day and I'll bother one of my parts guys to see what the differences are between the Caddy and the PAU springs.

my guess would be Caddy springs are calibrated for the extra weight of that small v8.

Albertj