Cougar Rear Shock Question/issue: Answered!


I’ll measure the heights again after another month or so to see if anything changes again. In the meantime I am going to enjoy the rest of the summer driving her! (If it ever stops raining here)

No shock (other than a spring-assisted shock) in it’s proper application should change ride height. If it does, that shock is limiting the suspension at rest because it is at the limit of it’s travel, this is a bad thing.

I saw that this topic came up in another post and then I remembered I promised to follow up on the height issue. I just re-measured and the ride height is still 1/2" to 3/4" taller with the 344052 shocks. This is even after a full summer and autumn of driving.

The 'stang length shocks must have been limiting the spring resting height. So, (for you) is the new height a good thing or a bad thing Bern?


It’s a good thing as I have P255/60R15’s and occasionally they’ll rub the wheel lip mouldings if I go over a large bump at higher speeds.


I just received and installed my new Kyb rear shocks 344052 to replace the 343219 that I had put on a couple years ago. The 344052 look more robust with a bigger cylinder at same length, and I like that, even though I do not spend much time looking at the underside of the car!
In my case, height of the rear remained the same, but what a difference on heavily patched roads as we sometimes have here in Qc. I was happy with the 343216 that provided a smooth ride on most roads but what a better stability (and no more bung bung) when asphalt is damaged, with no sacrifice on the smoothness of the ride on better roads. I am very please with them - thanks to you folks for providing the info here.

I bought new shocks based on this new info posted here for my lady’s 69 XR-7 convertible. The car had air shocks installed in the 80s to help deal with adult passengers in the back seat. When I let the air out, the car dropped significantly, and I quickly came to the realization that even the new shocks that would fit the Cougar would not be enough to compensate for the sagging rear springs. I started to look around to find some rear coil over shocks, but cannot find a suitable version for her cat. In the mean time I have replaced the front and aired up the rear air shocks, as new rear springs are not in the cards at this time.
Anyone know of an available rear coil over shock solution?

Scott, as you probably know, the upper shock mounts on the rear, were not designed to support the weight of the rear of the car.

I do know that, but she doesn’t want to do rear springs this year (maybe a winter project), so the air shocks will probably have to stay for a little while longer.

I ran air shocks on my 68 for years without breaking anything. Heck, they’re even listed as an accessory in my 68’s owners manual. Used as an assist, the air shocks don’t put the weight of the rear of the car on the shock mounts, only enough of the weight necessary to compensate for the extra load. Obviously, if your springs are shot and you pump the shocks up hard, put 500lbs of friends in the back seat, and take a fast drive down the old country roads, something’s going to break. Most of the horror stories regarding air shocks were the result of guys using them to lift the back of the car for a mean-looking rake. I agree that’s a bad idea because in that case, the springs aren’t really supporting anything, the air shocks are.

These air shocks provided just that support for some old friends of hers.
I think there was a conversation way back about the best rear springs to get, but I can’t remember the consensus of which company had the best springs that rode at the correct factory height.

I used ESPO springs on the rear of my 'vert and after roughly 3 years of running them I am still very pleased.

X2. However, the Espo’s are not exactly correct. Close, but not exactly. I understand that Eaton ($$) are and are made from the Ford blueprints.

As Robert points out the mustang shocks are too short. I had ordered KYB KG5517 from Summit expecting a replacement for original but didn’t plan on new springs at that time. I now have ESPO Competition springs that are 1" taller and with the Cougar on jackstands, the rear end sits about 1.25" lower than the shock at full extension, not good even though I’ll never be jumping the car. I could run with these but am researching new shocks. The KYB measure 17.25 full extension on the body of the shock, I measured the mounting surfaces and I record 20.75". Gotta find new shocks.

Did you check out the specs on the AMX shocks mentioned in this thread?

344052 (the AMX shock) is 19.37" at full extension (per KYB, not sure if you and they measured the same way). Either way, this is a major improvement over the shocks KYB specifies (which are wrong, mustang shocks).

I saw the picture of the two shocks in the beginning here and realized right away after I posted. This needs to be a major Notification as soon as you sign up here!!! I’ll order these today with my wheels.

In late July 2016 after having the KYB 344052 GR2 shocks on for over a year I replaced them with another shock from KYB but this time their gas assist style. The 344052 were or became just too soft for my liking. I had to go through all their shock styles and specs to find one in their much firmer gas assist version that was reasonably close to the 344052. I found their KG5429 to be very close. Extended length is 20.04", collapsed 12.48", and the stroke is 7.56" versus 19.37", 11.3", 8.07" for the 344052. Now almost a full year after being installed, my overall ride has maintained the much firmer characteristics I wanted and also kept my ride height. Too be clear I am not going to tell anyone to follow my path but am just sharing another option that I found that worked better for me and still avoided the air shock solution that others use.

Mike, I too would rather the Gas-A-Just over regular. I assume you driving a 69-70? The little bit taller with the firmness is more of what I need.

Where did you get the KG5429s Mike?

I did a little checking and AutoZone lists them for $44.99 and Amazon has them for $24.77. Amazon had a feature to “check if this fits your car” and it comes up that these don’t fit a 1968 Mercury Cougar.

Want to make sure I am ordering the correct shock as I need to replace the air shocks currently on mine.

Thanks for all the great info everyone!