5660 Springs 9/1/2021

mikester

Royal Smart Person
Mar 10, 2010
2,121
113
Small town NY
I read through a portion of the posts regarding the Moog 5660 springs. To save a ton of time, what is the exact advantage over a set of stock springs ? Seems like a lot of people wind up cutting some off the 5660s anyway.
I have the OEM spindles all painted and ready to go in my wagon. I was going to get the car back on the ground tomorrow. Figured I would take some measurements with it on the ground before I pop the dropped spindles out. At this point I dont want to have to do this multiple times. I also dont know what the front springs are that are in the car now. Are they usually marked ? I did the front end work back in 2015 but to be honest I dont remember seeing any numbers stamped in them.
 
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81cutlass

Comic Book Super Hero
Feb 16, 2009
3,524
113
Western MN
Stock G body springs regardless of application are long and have a low spring rate
5660's are a 91/92 Z28 non AC front spring (and some S10 stuff) and are shorter and higher spring rate. 5662 are the same 91/92 ws6/z28 spring but a little higher spring rate since they are for AC

The stock G body spring rates have a low rate gain per inch so when you hit a bump the car dives a lot and when you go over a dip in the road the car boats. There is not much energy gain when you hit a bump so it causes the car to either dive hard or hit the bump stops, and when you go over a dip there is a lot of energy still at the bottom of the suspension travel so it causes the car to want to keep rising.

Stock springs are OK for pure comfort on long flat roads with some moderate dips/bumps but honestly they seem to bottom out easy and I'd take a little more jostling from time to time than slamming the bump stops when you hit a pot hole.



They really aren't intended to be lowering springs, they are more 'get rid of the boat' springs. Sometimes they raise the front of a car depending on how saggy the stock springs are and how much the car has settled over the years. Saying they are a drop spring is a shot in the dark guess.

Many people put 1/2" taller lower ball joints in because
A) the lower ball joints are almost always toast if the car has over 40-50k miles on the OE ones and unless you did it with decent quality the parts store ones seem to die quickly
B) they 1/2 longer ones lower the car without any spring cutting or negative travel and improve the camber gain curve.
 
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81cutlass

Comic Book Super Hero
Feb 16, 2009
3,524
113
Western MN
I have looked into it (but never done it) Using a 02ish ZQ8 Blazer/s10 front spring. They have the same 590lb/in rating that the 5660 has but they are 0.375" shorter free height. (13.25 vs 12.875)

If you are concerned the 5660's will not drop the car and you don't want to cut them or have a light car or don't want to run tall lower ball joints it might be a good option. It's just they are $140 vs. $50 for the moogs.

From the good old rock.
SC20364

 
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motorheadmike

Geezer
Nov 18, 2009
7,517
113
Ottawa, Ontario Canada
5664s, 1/2" taller lower BJs, and 2" drop spindles are the cat's posterior. Plus, the ZQ8 bump stops. The 1/2" taller upper BJs are a nice addition too.
 
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mikester

Royal Smart Person
Thread starter
Mar 10, 2010
2,121
113
Small town NY
5664s, 1/2" taller lower BJs, and 2" drop spindles are the cat's posterior. Plus, the ZQ8 bump stops. The 1/2" taller upper BJs are a nice addition too.
Mike, I decided to remove the drop spindles that are in the car already. Hopefully I'll have one side apart by the end of tomorrow so I might be able to figure out what front springs in there. This whole front end thing is a thorn in my side. Jim suggested the 5660s over the stock springs. I just want it finished. Two cars in the garage and I cant drive either one of them and Im getting tired of it.
 

motorheadmike

Geezer
Nov 18, 2009
7,517
113
Ottawa, Ontario Canada
Mike, I decided to remove the drop spindles that are in the car already. Hopefully I'll have one side apart by the end of tomorrow so I might be able to figure out what front springs in there. This whole front end thing is a thorn in my side. Jim suggested the 5660s over the stock springs. I just want it finished. Two cars in the garage and I cant drive either one of them and Im getting tired of it.

I hear you. I am just offering my experience with my wagon - which was a total treat to drive to little league soccer tonight.
 
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pontiac guy

G-Body Guru
Oct 28, 2016
551
93
Royse City, TX
I have the 5660s in the front of my GP with the factory height lower ball joints. I love the ride but they are too tall. I've become accustomed to it but it should be about an inch lower. Get the 5660s and cut them
 
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mikester

Royal Smart Person
Thread starter
Mar 10, 2010
2,121
113
Small town NY
I have the 5660s in the front of my GP with the factory height lower ball joints. I love the ride but they are too tall. I've become accustomed to it but it should be about an inch lower. Get the 5669s and cut them
Whats the difference between the 5660 and a 5669 ? And if the 5669 needs to be cut why not just cut the 5660 ?
 

liquidh8

Comic Book Super Hero
Mich, Moog 5658, I dug up some old threads on montesS and turbobuick, these seemed to drop the car1-1.75 inches in most cases. I recall running the 5660's, on my elcamino, but it had a big block. It was low to, nowhere near stock height. The 5658's are like 579 lb/in springs, so a higher rate than the OE or even the F41 (420lb/in) springs. This my be an option.
 
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pontiac guy

G-Body Guru
Oct 28, 2016
551
93
Royse City, TX
Whats the difference between the 5660 and a 5669 ? And if the 5669 needs to be cut why not just cut the 5660 ?
Sorry that was a typo. I meant 5660. I didn't proofread. I also went back and corrected my original post to prevent confusion for anyone reading through the thread
 
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