F1 shocks with a new noise...

[nonstop]

Hey guys!

I just did the f1 shock relocation on my 54 Royal (also tried the Moog cc850 at the same time - sat too low and back with the stock springs). Anyway, replaced front wheel bearings while I was in there. I love how it rides now! It did bring me to the next question though:

When I hit a bump on the right or left side, I am getting a clunk from the respective side. Does anyone else get the clunk with their set up? The wheel bearings are new and adjusted right. I made my set up using forged f1 arms, bolted to the frame with a plate on the inside and nuts welded to it. Bolts are 7/16 and torqued to 50 foot pounds with lock washers and red lock tite. The arms were bent cold in a press to keep them away from the frame. Everything is still tight and there does not appear to be any interference. I have 13.7 and 14.5 inches between shock eyes at ride height and am using Gabriel 81676 shock absorbers. The only thing I can think off of the top of my head is the noises are now being transmitted through the frame.

Has anyone else had this problem? If so, how did you fix it?

Thanks,

Nick

[Don Coatney]

Your shock travel (fully compressed to fully expended) should be greater than your suspension travel. If not that may be the problem.

[nonstop]

Thanks Don, I tried to take that into account, and these shocks are a number I came across on the board. It gives me about 3 to 3 1/2 inches of uptravel, which I thought was going to be okay (I may be wrong in thinking it's enough). I forgot to mention that it normally happens at speeds below 25 mph, if that helps.

Thanks!

[martybose]

+1 on Don's comment.  Sounds like you have front shocks that are too long, and bottom out when you hit a bump.  I used a Fatman front shock kit, and had the same problem; Since the mount was made from sheet steel, we just cut them and added 2 inches to the top shock location, and it worked fine.

 

Marty

[Plymouthy Adams]

while many defualt to the search on here for data, this is good, but even when reading a how did..there are usually no exact measurement or diagrams shown or stated.  An error in mounting location based on one subject shock by number could be defeated in application by the selected location and altering by the second party.  Principles are the same, end results can vary greatly.  One should always confirm application prior to purchase for fit and fitness..Monroe site has all necessary data on their shocks and internet searches can show how to measure for custom application

[wayfarer]

It is easier to determine the max travel than the compressed shock length so some guessing is required...along with more shock purchases...

As mentioned, your shocks might be too long so measure the compressed length and find another that is at least 1" shorter.

Be sure to also verify the extended length.  Unbolt the top of the shocks and move the shock to the side, then put a jack under the cross member and lift the front end off of the ground. Now, with the wheel hanging, will the shock reach the top mount?

[nonstop]

Thanks guys! Looks like I'll be back to the drawing board and flipping through a boat load more shock numbers!

[ptwothree]

Why not remove the spring from the offending wheel and reassemble. Now you can manually work the control arms through there travel, with the shock connected, and see whats going on.

[nonstop]

I was just out measuring and thinking the same thing! Problem right now is I am in the middle of staining a fence and juggling work today and tomorrow, so I can't commit to it for a week or so. A couple of observations - my measurement from the top shock eye to the bump stop is 12 inches as the stop is now. Now adding an extra inch would bring it to 11 inches. While I was measuring, I noticed my bump stops are rock hard and chewed up. I measured them and they are less than 2 inches tall. Should I replace those first? Even if not, does anybody know how tall they should be? I have come across different numbers for different years, but not a 1954.

Thanks.

[61farnham]

What f1 shock mounts did you use, original or aftermarket?

 

The original ferd ones measure 6 1/2" between top mounting hole and the shock mount

Places like Speedway offer two lengths 6 1/2" and 5 1/2" as the hot rod boys prefer the shorter mount, if you've used the shorter one this could be your problem.

I found this out the hard way when I fitted stock length springs back in my car, previous owner had done the f1 shock mount conversion with short mounts....

 

As said above you need to remove the spring, reassembly and measure your min/max travel between the upper and lower shock mounts and find a shock that will work.

You can be a bit shorter fully extended unless your planning on getting airborne but you need a little bit extra fully compressed than your measurment to stop the shock bottoming out.

 

Hope this helps.

[BobT-47P15]

I tried using a couple longer than original length shocks as some here said they used.

Both hit bottom on the slightest bump in the road.

 

So, I simply put back my original short shocks and they work just fine.  

I don't know the extended and compressed measurements......but it looks like I 

could use a shock about one inch longer than original.  Have not pursued that avenue

as yet since things are basically working OK.  

[nonstop]

So just a little update - I was checking under the car last night for anything loose, when I think I discovered my problem - I reused the mounting washers that were on the lower mounts (the new shock absorbers didn't include new hardware. When I looked closely, they were too large diameter and were hitting the shock body. I took off the outer washers and saw witness marks where they were rubbing. They were polished and bent in the area that was touching the shock body. I'm going to replace them today and I'll report back.

I appreciate everyone pitching in to help with ideas!

[nonstop]

Well - I was wrong. Still clunks! I removed the spring and got a measurement of 9 1/4 inches compressed and 13 inches at ride height. That was from the top eye to the flat where the bumpstop hits, then add an inch as mentioned above. So, the shock in there is about 2 inches too long! I have been searching - will keep at it, but anybody know a shock that might work off the top of their head?

Thanks!

[Young Ed]

Well - I was wrong. Still clunks! I removed the spring and got a measurement of 9 1/4 inches compressed and 13 inches at ride height. That was from the top eye to the flat where the bumpstop hits, then add an inch as mentioned above. So, the shock in there is about 2 inches too long! I have been searching - will keep at it, but anybody know a shock that might work off the top of their head?

Thanks!

Find a good parts guy and he should be able to look it up by the 2 lengths. I think you might also be able to do that on the monroe website

[61farnham]

I used KYB 344068 after much searching, they measure 9.76" compressed 15.28" extended with a 5.5" stroke, but had to change the lower shock mount on my car as these shocks have a smaller hole in the bottom mount. This is also using the shorter F1 bracket I mentioned in my previous post.

 

By your description it sounds like you've measured wrongly, you should be measuring the distance between the centre lines of upper and lower shock mounts on your car, with the spring out and control arms reassembled lift the front hub fully up to give your compressed measurement and hanging right down for your extended measurement.

Edited April 21, 2016 by 61farnham

[nonstop]

Hey guys, just an update. I found the closest thing I could to fit in Gabriel shocks. They measure 9.6x compressed and 14.73 extended. Bolted them in and the noises are gone! They were a hair short, so I spaced the upper bump stop up about 1/4 inch. The upper arm kisses the bump stop at full droop. A little longer would still be nice for peace of mind, but I am not planning on doing anything crazy or jumping the car! If anyone wants the part number, it is 81039.

Thanks for all the help!

Nick

Edited April 27, 2016 by nonstop

[ptwothree]

Hey guys, just an update. I found the closest thing I could to fit in Gabriel shocks. They measure 9.6x compressed and 14.73 extended. Bolted them in and the noises are gone! They were a hair short, so I spaced the upper bump stop up about 1/4 inch. The upper arm kisses the bump stop at full droop. A little longer would still be nice for peace of mind, but I am not planning on doing anything crazy or jumping the car! If anyone wants the part number, it is 81039.

Thanks for all the help!

Nick

So are you using the 6 1/2" or shorter 5 1/2" upper support?  Makes a difference...

[nonstop]

I THINK it's the 6 1/2 inch one... I put a bend into it with the press to clear the frame, so it's shorter.