F1 shock relo- rough ride

[400mphpc]

Hey guys, based on all the positive feedback about remounting the upper shock mounts, I decided to give a shot. Bought the F1mounts from Speedway and Monroe 59017 shocks. The mounting process was pretty basic and I feel I did an ok job. I drove the car to work today and although the handling is more stable, the ride was not what I expected. Every hole I hit felt like something was bottoming out. Very solid hits you can feel throughout the car. The front end bounces more than I would have expected as well.

So, what did I do wrong? The 59017 shock has the same travel as the Monroe 555004, the Napa 94038 and the Gabriel 81676. 11.250 collapsed, 17.875 Extended and 6.625 travel. I'm stumped. Any suggestions on what to do?

[ptwothree]

What condition are the springs and the rest of the suspension?  How did it behave before the shock relocation?

[BobT-47P15]

Sounds just like my situation.  I used some nice long, yellow shocks -- which promptly hit bottom.   

So I went back to my original length (shorter) shocks....they work fine.

 

 

 

TOO LONG.....

 

Edited September 15, 2015 by BobT-47P15

[400mphpc]

What condition are the springs and the rest of the suspension?  How did it behave before the shock relocation?

The rest of the suspension seems ok.  Springs have plenty of strength and all new tie rods.  Just had the front end aligned before the change over and there is only a hint of travel from the kingpin wear.   Before the change, if I hit a dip or hole in the road, the car would tend to thump, but nothing like now.  It would also dip and pull on the right side, but that is now gone with the change.  So, I feel the ride is much more controllable / safe but just need to sort out the hard thud when I do hit a hole.  I'm thinking of mounting my Go-Pro under the car to film what is going on.  

[400mphpc]

Sounds just like my situation.  I used some nice long, yellow shocks -- which promptly hit bottom.   

So I went back to my original length (shorter) shocks....they work fine.

 

 

 

TOO LONG.....

 

Hey Bob, did you already have the Monroe 555004's (like your second pic) and that is the shock you went back too?   My old shocks are almost 3 inches shorter but I guess I can give that a try. 

[lahti35]

400mphpc: did you use the 5 1/2" or 6 1/2" shock mounts... I see speedway offers two different lengths?

[MarkAubuchon]

I had the same experience on my 49 Coupe.  Finally went back to stock.

[jhm1mc13]

I fought that battle and never liked the stiff ride and went back to stock.

[Don Coatney]

This thread is the only negative feedback I have read/heard about this modification. Must be a reason. Hopefully those who have done this successfully will chime in with information on how they did this successfully.

[Plymouthy Adams]

Don..each man does things in his own way...as to where and how positioned...simple geometry makes that call...the selection of the shock is dependent on height of mount...allowing for travel and centering the piston of the shock static laden position..that is a individual measurement and selection without a given template..

[BobT-47P15]

No. The 555004 was the longer one i went to based on information from some one on here, but i dont recall who. Then i tried some other suggested number that was similar in length....also hit bottom. Returned to auto store. Then---somewhere in my information i keep, i found thr number of the shorter original size shock... Which i purchased....and it works fine.

The only thing that strikes me is the original is stretched just a little past it's middle position. Am thinking a shock about one inch longer might sit at a more normal sort of position. I have not gone to the trouble yet of determining the model number of a slightly longer shock.

Hopefully these comments make sense.

[BobT-47P15]

In my two pictures posted above---the first one is the original length shock now in use. The second picture is showing the stock number of the shock that was too long. They were yellow when new---i painted them black.

 

Moderator Edit: Use PM or classifieds for buy/sell offers.

[mopar_earl]

I had the same experience on my 49 Coupe. Finally went back to stock.

Stock shocks with frame mount or completely back to stock?

Earl

[Don Coatney]

I am searching my files, Found this note Hugh Forrest sent me a while back.

 

Posted By: Hugh Forrest <Huforco@pacbell.net>
Date: 2/8/05/ 08:46pst

In Response To: Thanks Marty; (Don Coatney)

A friend of mine has an uninstalled Fatman kit. I'll see if I can make a tracing of the bracket that I could compare to my tracing of the Mr SR bracket if you like.

BTW the shock that came with the Mr. SR kit is a Napa #RR94005 which cross-references to a Gabriel #733698. Both are basic bottom-of-the-line shocks, but will get you to the right spot in the book.

The gal at NAPA tells me the original application is the front of about any standard sized Chevy truck 1963-1991. Extended length 14.62" collapsed length 10.12" according to her book

Here are a couple photos I have in my files.

 

 

 

I see what appears to be a big difference and that is the length of the brackets compared to the truck bracket. I just measured my truck brackets and as pictured they are roughly 12 inches overall.

 

 

[61farnham]

I went thru this same thing just after buying my coupe, the previous owner had installed  F1 shock mounts and had used the shorter 5 1/2" ones and couldn't get the recommended monroe shocks to work but as the car had cut front springs installed he reused the original shocks but it still bottomed out in large pothole. When I came to install the nos standard length front springs that came with the car the measurements I got for suspension travel didn't work for the recommended shocks either and that's when I found out he had used the shorter mounts. I believe the original F1 mounts were 6 1/2" measured from the centre of the upper mounting hole to the centre of the shock mount stud and places like speedway offer the shorter 5 1/2" ones to suit the hotrod boys.

 

400mphpc I would check which length shock mounts you have, as asked above by lahti35, and then remove your front spring and measure your min/max suspension travel from the top shock mount, this will give you the info to find the correct shock for your car. Without these measurements your just guessing as to what length shock you need. I ended up using KYB 344068 shocks which have a compressed length of 9.76" and an extended length of 15.28" however when these turned up I found the lower mounting hole was slightly smaller than the top and had to modify my lower shock mount to suit so they may not be what you need to use.

 

Hope this helps

 

Regards ............. Simon.

Edited September 15, 2015 by 61farnham

[Ulu]

When I switched my P-15 from Monroe to KYB Gas-A-Just shocks, the ride improved a lot.

 

But the KYBs cost me 3x as much & they were worth it.

 

If your shock is too long, and you keep hitting bumps, you will eventually break a shock bolt off.

 

This also happens to people who lower cars and don't relocate the shocks.

 

The suspension must bottom out & top out on the snubbers, not the shocks.

[400mphpc]

Wow!  Thanks for all the support.  All of you offered sound advice and that's exactly what I needed, as I have heard too many positive things about this change.  

• Lahti35, I put the 5.5 inch mounts on.
• Plymouthy, I agree, each of us have a personal preference and will do things our own way. We are men, that's what we do ! :0) 
• Don- I came to far to let this go, so I knew you guys would come back with the positive side! 
• Simon, I have no idea If i have the original springs, so I am in a guessing game (trial and error). Where did you find the KYB shocks?
• Ulu- Did you use the same KYB as Simon?  344068 ?   

Got back under the car tonight and could tell the new shocks were bottomed out and it was something I should have done right after the install.  Decided to take BobT's advice and pull the new shocks off and put the old shorter ones on, just to give it a try. "What a difference" !   The car rides smooth and steady.  Doesn't corner like my Mini Cooper, but you can tell the difference. The current shock (that I reinstalled) is a Gabriel 737658-This number crosses over to the 69727 for a Pontiac Fiero. These were on the car when I got it and I'm not sure why...  

Product Line: Ultra Shock Shock Extended Length: 13.13 in. 333.5 mm. Shock Collapsed Length: 9.12 in. 231.65 mm. Length of Stroke: 4.01 in 101.85 mm.

From my test drive tonight, I still feel I need a few more inches of travel but overall, this will do until I get time to deal with it more and find a permanent solution. You can also tell the springs are working and the taller shocks really blocked the springs from doing their job.  

 

Thanks again - everyone ! 

[Ulu]

I'm not sure what part number I have. I'll see if it's still visible on the tubes. I did not modify anything. They fit the stock bolts OK.

Edited September 17, 2015 by Ulu

[falconvan]

I had this same issue; I just took the shock off and measured from center to center on the shock studs with the car sitting on the ground. I took that measurement and looked up Pete & Jakes Street rod shocks and found some where that measurement was right in the middle of the travel range; they sell them in various lengths. Never had another issue with it. I think they are around $60-$70 a pair.

[61farnham]

Wow!  Thanks for all the support.  All of you offered sound advice and that's exactly what I needed, as I have heard too many positive things about this change.  

 

• Simon, I have no idea If i have the original springs, so I am in a guessing game (trial and error). Where did you find the KYB shocks?

 

I got the KYB shocks from Rockauto the're listed as fronts on a 6 cyl RWD Chivvy Blazer 1969-74 but a google search would probably turn up a few more suppliers.

 

Good to hear your going in right direction. 

Edited September 17, 2015 by 61farnham

[littlemo]

When I was dealing with this issue, I remember two Monroe #'s ; 555004 was the recommended relocation shock ( for the F-1 Bracket ) or 555003 if a "shorter" shock was needed ?? This shorter shock may be the correct shock if your top mounting hole to shock bolt measurement is 5 1/2 " instead of 6 1/2 " ???  

[littlemo]

The travel measurements on the shocks I used ( NAPA # 94038 ) was supposed to be comensurate with the Monroe 555004 and Gabriel 81676 ; compressed = 11.250 / extended = 17.875  ???  Hope this info is helpful, since my "Ride" is still in the "Build" stage, I haven't been able to as yet, test this relocation combo on the street ???

[Plymouthy Adams]

F1 bracket yielded a 555003 shock for the 50 Plymouth...

[400mphpc]

Thanks again gents.  I'll have a look at the spec's on the 555003.     Drove it again this week for about 60 miles and the only issue I found is when I encountered a step up from the street into my drive.  I could feel the A-arm hit the rubber bump stop.  

[dodgeguy]

I have experience with altering suspension geometry although on another brand. From your pictures you have moved the lower shock mount inboard closer to the pivot point of the lower a arm. This greatly affects the mechanical (leverage} advantage. Making it ride rougher. You need as much travel as possible with longer shock. I was going to go this route on my 47 d24 but now have rethink it.