Help. New KYB front shocks shorter than old KYB front shocks (picture added)

[will e]

EDIT: I originally typo'd the part number. I had written kg4505 and should have written kg4504. I have corrected it in this original post.

I purchased a set of kyb front shocks. Part number kg4504. I noticed they were shorter than my existing kyb shocks part number 343156.

With the tires sitting on the ground there is only about 1/2" of 'down' travel available. The old shocks provided about 2" of 'down' travel.

To be clear. When I put the shock mount on the new shocks there is about 1/2 inches between the shock mount and the shock tower before I tighten it down. . The shock will only be allow to extend about 1/2".

Has anyone run into this? I didn't purchase them from summitracing but both part numbers show as 'compatible' with my car. One shows up as 'mono-tube' the other as 'twin-tube'.

It seems that 1/2" of extenstion is not right. This will cause some weird handling for sure.

I appreciate any thoughts and input.

I did find a chart on the web: http://www.kyb.com/knowledge-center/shock-tech-for-pros/dimensions/

343516 extends to 13.9 and compresses to 8.9

KG4505 extends to 13.5 and compresses to 9.09 << I looked up the wrong shock!

This doesn't match what I have. I even tried installing it and using a pry bar to extend the shock and it would not budge. I wonder if I got a bad set. I will contact the vendor but any input is appreciated.

 

[73pony]

Weird. The KYB's ordered were KYB4504 (gas-a-just) with extended length of 12.32 and compressed of 8.5 for a 3.82 stroke and they fit perfect.

 

[red351]

Weird. The KYB's ordered were KYB4504 (gas-a-just) with extended length of 12.32 and compressed of 8.5 for a 3.82 stroke and they fit perfect.

I said it before and say it again. Today replacement shocks are shorter when fully extended than what was OEM. That is why our rubber shock bushing are crushed when lifted.......... To much downward spring load left over......

 

[Stanglover]

This was discussed in length not too long ago. A member was crushing rubber bushings. The problem in my case was not enough crush with KYB KG4504 shocks. Briefly, I needed to ADD a thick 3/8" washer top and bottom inside the steel caps to take up the extra length of the piston shaft. Once done, my rubbers no longer move around and have not cracked or deteriorated in any way. Pictures were posted before. KG4504 are the correct KYB shock for the Mach1 with a 351 C engine.

So why the difference?

 

[red351]

This was discussed in length not too long ago. A member was crushing rubber bushings. The problem in my case was not enough crush with KYB KG4504 shocks. Briefly, I needed to ADD a thick 3/8" washer top and bottom inside the steel caps to take up the extra length of the piston shaft. Once done, my rubbers no longer move around and have not cracked or deteriorated in any way. Pictures were posted before. KG4504 are the correct KYB shock for the Mach1 with a 351 C engine.

So why the difference?

Glad that worked you. I tried using washers hoping so the top bushing wasn't pulled down thru the top mounting hole. They would just split instead of being pulled thru. I even tried larger diameter bushings . Made some homemade shock extensions for KYB's whatever number they were.... after measuring OEM's I had from my parts cars. Problem was solved. Shocks would bottom out just as upper control started making contact with bump stop

 

[Stanglover]

This was discussed in length not too long ago. A member was crushing rubber bushings. The problem in my case was not enough crush with KYB KG4504 shocks. Briefly, I needed to ADD a thick 3/8" washer top and bottom inside the steel caps to take up the extra length of the piston shaft. Once done, my rubbers no longer move around and have not cracked or deteriorated in any way. Pictures were posted before. KG4504 are the correct KYB shock for the Mach1 with a 351 C engine.

So why the difference?

Glad that worked you. I tried using washers hoping so the top bushing wasn't pulled down thru the top mounting hole. They would just split instead of being pulled thru. I even tried larger diameter bushings . Made some homemade shock extensions for KYB's whatever number they were.... after measuring OEM's I had from my parts cars. Problem was solved. Shocks would bottom out just as upper control started making contact with bump stop

We may as usual, be getting off the original posters question.

I have not researched the shock number he quotes, but I had none of these problems with KG4504 shocks other than as I described above. I think he has a, the wrong shocks, or b, the wrong height springs. Again from my own experience, when I replaced my front suspension , the "kit" from Scott Drake came with front springs that were way too tall and when installed, sat the ride height nearly 2" up and it was all but impossible to get the shocks in. Realizing this fact, I researched the correct spring height for my car with Eaton Detroit Springs (OEM supplier) and ended up reinstalling my original and still good springs. Problem solved, well almost, I needed to add compression to the rubber bushings by installing washers as described earlier. That was in June and so far absolutely no problems.

Job done!

EDIT: What I forgot to say and what I remembered at 3 am this morning, was that while the shock rods themselves were not too long, requiring the washers, it was that the threaded length was too short. This meant that the nuts bottomed out before the required compression on the rubbers was met. The washers effectively overcame this problem, allowing proper compression.

Also, our poster put this in the wrong category, but not to worry.

 

[will e]

Here is a picture:



The old KYB shock (343516) is on the left and the new shock (KG4505) is on the right. The new shock has the number 553314 stamped on it. The extension of the new shock (KG4505/55314) is 12”. I did try to extend the new shocks but was unable to get them to go past 12”. The new shocks otherwise seem fine. They extend automatically when off the car and do not appear to have any other issues.

 

[Stanglover]

Here is a picture:



The old KYB shock (343516) is on the left and the new shock (KG4505) is on the right. The new shock has the number 553314 stamped on it. The extension of the new shock (KG4505/55314) is 12”. I did try to extend the new shocks but was unable to get them to go past 12”. The new shocks otherwise seem fine. They extend automatically when off the car and do not appear to have any other issues.

Mike, the shocks I and 73pony are referring to are KYB KG4504, not 4505. I have not yet checked that number out, but you may have the wrong shocks. The ONLY issue I had fitting the shocks was for the need to use a jack under the lower ball joint to raise the shock rod through the tower. Other than what I describe above, I had no problems at all. I will look at the number you give as I'm curious as hell as to what the difference is.

Geoff.

Wait a minute!! I just enlarged your picture and the number on the box is 4504, NOT 4505. 4504's work so what's the problem?

OKaaay, 4505 does not come up for the 71-73 Mustang, only 4504. By the numbers, a 4505 looks to be a longer shock if I'm understanding the numbers at 13.5 X 9,09 X 4.41, from KYB's website. Hmmm!

 

[will e]

Well at least I was consistent in my typo!

So yes, they are 4504 not 4505. I will correct my original post too. So they do extend the 'correct' amount:

KG4504 12.32"

But that is too short for my car. I wonder if the removal of the AC and aluminum intake caused the ride height to go up? They are not the original springs, I bought them years ago from Ford. I may have bougt 428 springs trying to get a stiffer ride at the time.

I will go measure at the fender and the distance from the top of the upper A arm to the shock mount. Perhaps my car is a bit to high in the front?

Here is a picture. I have just recently replaced the back spring which lifted the rear about an inch.

 

[Stanglover]

Well at least I was consistent in my typo!

So yes, they are 4504 not 4505. I will correct my original post too. So they do extend the 'correct' amount:

KG4504 12.32"

But that is too short for my car. I wonder if the removal of the AC and aluminum intake caused the ride height to go up? They are not the original springs, I bought them years ago from Ford. I may have bougt 428 springs trying to get a stiffer ride at the time.

I will go measure at the fender and the distance from the top of the upper A arm to the shock mount. Perhaps my car is a bit to high in the front?

Here is a picture. I have just recently replaced the back spring which lifted the rear about an inch.

Yep, that explains it, lol!

Perhaps either go on Eaton Springs website or look in the NPD catalog for the correct spring info for your car and its equipment. Springs I bought in a kit were totally wrong, so I called Eaton and was given the correct dimensions required for MY car which was 15" tall, free standing. There is a chart on their website. (This has been posted before in Suspension section.) I reinstalled my original springs as they still met the criteria and as I said, no problem with shock install other than the thread length.

Looking at your picture, the front does look a bit on the high side, but a picture can be deceiving. Hope all this helps solve the issue. Let us know what you come up with.

Geoff.

 

[Stanglover]

Just found this picture of the KYB KG4504 installed. You will notice where the rubber was moving around, making a mark on the cap. This was when I realized that there was not enough compression and the washers were installed.

The second picture is after the correction.

 

[will e]

So I measured from the top of the spring perch to the opening at the top of the shock tower.



Just under 13 1/2 inches.

Front fender came in at just under 26 inches:



Rear came in at about 25 3/4"



I started a separate thread for comparing the level of our cars. Here I have a level at the 'ford' on the rocker. This is the passenger side so the rear is to the left.

 

[Stanglover]

Mike, I don't know what to say. I just measured my fender heights at 26 1/2" F&B with 235-60-R14 front and 245-60-R14 back, so your height is not the problem. I can't measure the perch to cap obviously without taking a shock out. So what else? Are you sure you got the correct shocks in the boxes? Could they be wrong shock, right box number?

KG4504's should work. I can't, with my very limited knowledge, add to what I have already offered.

Geoff.

 

[will e]

The KG4504's would 'work' in the sense they can be installed but the 'up' or 'extended' travel would be very very limited. Do you recall how much your shocks pushed your shock town past the inner fender well? I would end up with just about 1" or less of up travel. This can't be adequate.

 

[Stanglover]

I have a pair of NOS D1ZZ-1812-4E Mustang shocks. Fully extended they measure about the same as the 4504's if I'm doing it right. Here's pictures.

I guess the only way I can check the 'UP' stroke, is to jack the car up, then measure the wheel arch to the bottom of a wheel. Would that do it? The suspension can only drop as much as the shock travel, yes?

However, if the shocks are the same total length as the NOS ones, I see no problems. All I can say is the 4504's on my car don't seem to be any problem when I hard corner it.

 

[will e]

Hey! Thanks for all of your help and taking pictures too. Yeah, those stock shocks would require maximum extention to be installed in my car.

Yes, for most of us, if you jack up the frame of the car the shock becomes the limiting factor for the front suspension travel. This is not recommended.

I would be curious, if you have some time, at how much the shock 'lifts' the shock mount when it is not bolted down. This would require removing the brace that goes over the shock mount along with the third nut. Your gas charged shocks should push it up. Knowing the travel limit of your shock we can then calculate the distance between your spring perch and the shock mount. I am going to guess it is less than my 13 1/2 inches.

The KG4504 only has 3.82 inches of stroke. The OEM shock looks like it has about the same. So there isn't much to begin with and I would imagine we would want the majority to be compression, not extention. But I think the 1/2" or so that I have is not enough. Or perhaps I am overthinking this...

edit: I watched a couple of youtube video's. This one desribes why I am concerned about too little extention in the first minute of the video:

 

[Stanglover]

Hey! Thanks for all of your help and taking pictures too. Yeah, those stock shocks would require maximum extention to be installed in my car.

Yes, for most of us, if you jack up the frame of the car the shock becomes the limiting factor for the front suspension travel. This is not recommended.

I would be curious, if you have some time, at how much the shock 'lifts' the shock mount when it is not bolted down. This would require removing the brace that goes over the shock mount along with the third nut. Your gas charged shocks should push it up. Knowing the travel limit of your shock we can then calculate the distance between your spring perch and the shock mount. I am going to guess it is less than my 13 1/2 inches.

The KG4504 only has 3.82 inches of stroke. The OEM shock looks like it has about the same. So there isn't much to begin with and I would imagine we would want the majority to be compression, not extention. But I think the 1/2" or so that I have is not enough. Or perhaps I am overthinking this...

Mike, I can do what you're asking. Right now, I have the drivers side brace off as I have the power steering box and pump off for rebuilding, so it's half way there. Personally, I don't think you have any problems with the 4504 shocks. If you do, then I and everyone else using this shock has the same problem. Spring height is the variable as far as I can see. Most of the aftermarket springs seem to be a one-size-fits-all deal, i.e. the SD kit I bought and had to return the springs that were 2" taller and not enough weight in the front end to squish them down. I believe it is ESSINCIAL that ONLY the correct spring be put in. Cutting springs alters their rating, so why go through that hassle?

I'll get back to you on this after Christmas.

Have a good one my friend,

Geoff.

Edit back! I'll look at that, thanks.

 

[will e]

Thanks Geoff! I suspect I have the wrong springs as well as reduced weight from the AC removal and aluminum intake. It will be interesting to see how much different yours is.

 

[Stanglover]

Thanks Geoff! I suspect I have the wrong springs as well as reduced weight from the AC removal and aluminum intake. It will be interesting to see how much different yours is.

That's good info on that video. I get why you're concerned and something I didn't think about. I (and others) just buy the parts listed for our application. A fully custom suspension would obliviously be a different ball game. I'll get back to you asap.

Question, can this thread be moved to Suspension section? Just sayin'

Geoff.