Rear leaf spring replacement, what else do I need?

Hi fellow Cougar boffins,

I need to replace the rear leaf springs, having just bought 4 new shock absorbers what else should I replace while its all torn down?? Been looking on WCCC website but I’ve gone blind looking at suspension parts. First car on leaf springs hence limited knowledge on these things.

Found U bolts, anti squeak pads( how many do I need??) ,leaf spring center mount insulator pad & leaf spring front eyelet bolt kit. Did I miss anything??

Thanks, Zakk

Beer. Lots of it. Seriously, you’ll need some way to cut out front eye bolts- I used carbide blades with a sawzall but other folks prefer a grinder.

:beerchug: Got the beer covered bud, and my 4" grinder primed for destruction. Anything else you guys replace while its all torn down??

Rear shackles & bushings.

You might not need to cut the front eye bolt. Give it a good soaking with penetrating oil the day before you start the job.

As long as you have the beer your covered :beerchug: I’ll 2nd the overnight soaking, I replaced mine and didn’t have to cut anything out. Did use a steel pipe for better leverage on the sockets tho :smoke:

Oh, and the link another member provided me when I started mine :smoke:

Bookmarked for future use, thanks for posting this!

Thanks all, beers on me :beerchug:

I’m interested in the details on this as mine is in dire need of rear suspension work too :-/
The rubber is all pretty much toast, it makes a clankity noise from the back when I go over bumps, and the wife keeps asking me why my car looks “tilted” in the back too.

I figure worse comes to worse, I’ll pull it all apart and send the leafs out to be re-arched. While that’s being done I can order up new rubber and other bits and go from there.

I replaced my springs and shocks this winter. All the nuts and bolts came off just fine. However after I installed the new spring insulator pads I could not get the original U-bolts back on. The pads were too thick no matter how I tried to compress them. The bolts were about 1/4" short.
I ordered the 1" longer U-bolts and everything was a snap after that. Now that they are on and everything has been tightened up I could probably now remove them one at a time and reinstall the originals.

Thanks for sharing your experience, so you recon they have to bed in for a few weeks? Did the bolts loosen before you noticed? Thanks

I ran into something similar to that but it was because the bottom plates had bent upwards over time and when I pressed them flat, the u bolts were too short. BTW, don’t bother trying to hammer the plates flat unless you happen to have Mjolnir handy.

suprahuman - I have not had the opportunity to drive her enough after installing everything to she how everything settles. Winter! I was able to tighten the U-bolt nuts a little more after just sitting for several weeks. I’ll check them again in about a month after I’ve been able to put some miles on the springs.

Spring rates, something to consider. Don’t buy just any thing offered. For 69/70 I’ve had good luck w/ 66-252 or 33-283. These tend to keep the “factory” ride height, not lifting them up like air shock. Please don’t waste you $ on re-arching old springs. (Mike you may have a leaf broken on the side thats “tilted”. Your car also should have (? c6 or 4 speed?)staggerd shock mounts, check the trunk mounts too.)

New U-bolts - never use old ones! AMk or a local shop will have what you need
New spring pads all 4. Peel out old ones and sand blast bottom plates (w/ shock holes), U- shaped top brackets, the 2 wedges (staggered shock plates for Mike:-)
New front eye bolt -Put lots of greese on it!
New shackles- Not Mustang, wrong size bushings.
Use silicone to get rear shackles in. Hang spring from frt bolt(s), lift up to shackles and spray again and your new springs should be in & ready for final assembly!

Hope this helps!


Thanks Bill, much appreciated.

Which springs will give it a raised look?? My saggy bottom end leaves nothing to be desired (both man and car :laughing: ). I want an aggressive “get out of my way” look, I.E high(er) rear, low front.
I’m in the UK so leaf springs for american cars is not something too many shops keeps in stock.( if any) :boohoo:


Ninja edit: are the 66-252 & 33-283 part numbers??

Thanks much for the tips / info and details Bill! Mine does have the staggered shocks, and the PO installed Lakewood traction bars. I thought it was the traction bars making my clankity noise, but it seems to only come from one side. I’m hoping to get some time to put my car up on jack stands in the next week or two so I can get under it and take a good close look.

Personally, I’m looking for a stock ride height. Were all the '69 / '70 Cougar leaf springs the same, or do I need something specific for a 428/4-spd/competition suspension car?

Zakk, you’ll have to post up some pics when you get a chance. If I get under mine any time soon I’ll post some too.

The springs will not raise the car like you want. They will only bring it up to approx factory height. Don’t run air shocks, as they will cause damage to the body/upper mounts. Maybe try longer shackles for the look you want. Maybe lower front end?

Get rid of those bars. I suggest getting the traction masters (must be for Cougar only) bars. Looks better, period correct,and they don’t move.
You should have rear sway bar too. Plate between shock plates and leaf springs.

The N.S.I.(Nat’l Spring Inst.) books show LOTS of springs for these Cats!The info I have shows thicker material and 4 leafs . Can’t find info now… But I recall 428 4 speed and auto’s being different. The best bet is to use M.U. and decode their #'s. I think you would be fine w/ the 428 springs. Around $300 for pair…

Again hope this helps!


Best place for springs is either Eaton Detroit or ESPO. The former being twice as much but they are always spot on. Springs need to be matched pairs or your car may lean. Most of Mustangs Unlimited springs have the squared off ends which is not correct.

Thanks Fellahs!

Mine does have the rear sway bar. I’d love to get rid of the traction bars and go back to stock staggered shock plates (eh, it’s only money, right?). My goal is to stay / return to as close to stock as possible.

Here is my current config;

[quote="]Which springs will give it a raised look?? My saggy bottom end leaves nothing to be desired (both man and car :laughing: ). I want an aggressive “get out of my way” look, I.E high(er) rear, low front.
I’m in the UK so leaf springs for american cars is not something too many shops keeps in stock.( if any) :boohoo:


Ninja edit: are the 66-252 & 33-283 part numbers??[/quote]

Air Ride for the rear.

Local Hero can give you info on it.
Looks great on his.