Vintage Mustang Forums banner

Strut Rod Bushing Issue (with video!)

14K views 71 replies 21 participants last post by  Ford.P51  
#1 ·
I've been hearing this strange metallic "pop" sound from the front end as I come to a stop after hard braking. I put a go-pro under the car to try to diagnose what was going on and this is what I found (fastforward to 1:00):

https://www.youtube.com/watch?v=gPhRhZYLTpI&feature=youtu.be

The moog strut rod bushings are deflecting so far they are coming unseated.
The noise I'm hearing is them popping back into place. Has anyone ever experienced this before? I removed and reinstalled them, making sure they were installed correctly (washers facing away from the rubber) and torqued to spec... but no improvement.

Whats the deal? Is the only solution to switch to some StreetOrTrack style adjustable strut rods?

Thanks in advance for any advice.
 
#2 ·
Great video, thought I was watching a NASCAR race, love the shots of the suspension working and the rotors turning bright orange.

On the Moog strut rod bushings, just installed a set this spring and do not have the issues you are experiencing. It looks like you have the washers installed correctly for the Moog bushings, the only thing I can think of is the torque setting. Did you go with the Ford Shop Manual or Moog instructions. IIRC, the Moog torque setting is higher than the stock Ford Shop Manual. In addition, were the threads clean (no rust or corrosion) on the strut rods so that get you a true torque/compression of the bushings?

Image
 
G
#5 ·
I've never had a situation like that and have owned/worked on Mustangs for 40 years now. When I saw your post, I figured you had to have poly bushings . . but not to my surprise. Funny on the washers . . . other cars have used similar setups to the Fords. However, some of them mount the washer the other way, OEM. I wonder why??? I suppose you have no wear on your strut rod that could be catching? Did you try some lube to see if it takes the problem away?
 
#7 · (Edited)
that squishing is normal for rubber bushings. on the 65-66 you run the nut down until it bottoms. at 100+ mph the front of a mustang wants to wiggle under hard breaking. spherical rod ends eliminate all that.

the noise sounds like strut rod bushings. if those are steel lined something might be wrong.

i can see its hose wiggling around
 
#36 · (Edited)
I know where the noise was coming from. It's that wire hanging down, LOL.

Seriously though. I don't know why you have so much slop. You could pull it apart again and double check. You might find something you over looked.

More to the point is to comment on what Supershifter said about adjustable struts. I have them on my 66 which is a pure street car. If I build another Mustang, they would be the first thing I'd install! Besides making it easier to add a little more caster and easily at that too, the car just drives so nice. It has a precise and predictable feel. Presently I still have drums. The car just stops dead straight no matter what. I have hit the brakes hard with no hands on the streering wheel. No muss, no fuss just a nice straight stop. I too, am using SoT struts.
 
#10 · (Edited)
We must all be on the same page because I was checking this same stuff.

The threads were clean. No visible wear on the rod and the bushings are new. I lubed everything up to be sure.

The nuts/washers are definitely shouldering out on the strut rod so additional torque wont compress the bushings any more, it will just push the nut & washer harder against the steel shoulder on the strut rod.

OpenTracker: I noticed that too. I'm pretty sure what you are hearing is the passenger side bushing popping back onto its seat. In the video you can see how the bushing gets cockeyed when it pulls off seat. I think the passenger side bushing got hung up until I turned the wheel. At 1:30 you can see the driver side bushing gets a little cockeyed, and you can also distinctly hear the passenger side bushing "pop" a second after the driver side bushing.

I wonder if I got a bad batch of bushings with softer than normal rubber? To be honest I've wanted adjustable strut rods for a while anyways, so I'll probably just use this as an excuse to get them, but I figure its worth sharing and doing a little investigating incase anyone else runs into the same issue.

Edit: good catch Fly! I'll look into that rubbing area and see if it might be the culprit.
 
#11 ·
That is a very cool video and a fine example of why these cars are know for darting around under braking. Seeing how much caster loss there is under braking is impressive and scary. The outer tie rod end moves back too, taking away your toe angle. It would be interesting to have a before and after video with a set of rod end strut rods ( adjustable struts ).

It could be one of the bushing washers is clicking on the strut rod support.
 
#14 ·
They look like the steel-lined bushings. Is that what you have there?
(Moog K8122)
I think that's where the noise you have is coming from. I like the
camera approach- we did that once with a camcorder to verify
how much the LCA pickups move around.

I just chased a front end thump in my '66 a couple of weeks back-
turned out to be polyurethane sway bar frame bushings that
had ovalized.

ex-Global West GM
1991-1995
 
#15 · (Edited)
One of the many tricks we use to get the cars around a road course a little safer and still be vintage legal is to use a poly bushing in the front and the rubber in the rear on the stock strut rods. I've done it on some street cars as well with good results. The poly won't compress as much as the rubber so you get less caster change. Having the rubber bushing in the rear lets the strut rod move up and down without flexing it so there's less chance of breakage.
 
#16 · (Edited)
Deleted

Paul
 
#17 ·
I know those bushings are by far way better than stock but when I got my car I had the stock ones with a similar but not quite the same issue. The stock bushing even though brand new was shot and the rod was pushing the whole front part of the bushing/rod out of the hole. Sometimes it would return like yours and even worse sometimes not until the next bump or stop. The whole car would list under braking hard.

After I saw that I wasn't to comfortable with any bushings and went with the Street or Track adjustable's. Stiffened things up a bit which I dont mind but so much nicer under braking. First picture you can see the brown mark in the bracket just how far the rod was pushing through and rubbing on the top. Second picture is how the SoT mounts, just eliminating everything related to a bushing and using a heim joint. It does creak a little under slow driving but I will take it for the safety.

Image


Image
 
#22 ·
Yes def something wrong with the bushing and way more severe that what is going on with his, it was brand new with less than a few hundred miles on it put in by the previous owner so I don't know what happened. I didn't wait long enough once I got it to find out how much worse it could have gotten that is for sure. I am sure it was a cheap repop but after seeing that and the damage it have done to the rod I needed both so the SoT was kind of a no brainer. Especially since I am not a stickler for 100% original and I couldn't just stick new bushings on it after it did that to the rod.

May not quite be related to his if it is just the rubbing of a washer but I am wondering if that is how mine started out at first the and the popping in and out all the time eventually lead to the bushing failing?

I will tell you it was a scary feeling the first time I got on the binders really hard and that rod went through and the car pulled dead right. It got parked until I installed the new rods that's for sure.
 
#23 ·
Very cool video.

Makes me glad I went with SorT adjustable strut rods.

Be cool to see the difference adding a poly bushing to the front would make.
 
#28 ·
Handy Man, your video is excellent - thanks for posting it up :)

It's astonishing how much it moves under there. As already posted, no wonder these cars get squirrely when braking. The wheels move a long way and also rotate enough to reverse the caster by the look of it. I am surprised there are not lots of issues with brake judder as well.
 
#45 ·
#34 · (Edited)
Adding to the issues of running full poly bushings: If the poly is restricting up/down motion enough to cause metal fatigue, it will also be binding the suspension and resisting up/down movement of the lower control arm, which would be detrimental to handling and ride comfort. (in case "risk of death" isn't enough to convince someone its a bad idea, lol)

Green: In concept the Maier bushings seem like a great idea but they are pricey! RoseHillPerformance sells full adjustable strut rods for just $45 more. I'm guessing Maier's bushings are really intended for race cars in classes that are require non-metalic bushings. Being the above-all best option for a race car justifies that kind of price tag.
 
#39 ·
I would rather know what a problem is for sure before just ditching the parts but I run the Street or Track adjustable strut rods. Something about that doesn't look right to me either but I have never put a camera under my car to watch the old stock strut rods move. I don't remember my stock bushings being as thick as the one you have and they were a very dense rubber but then there is a lot of force being applied there so maybe they deflected like that. I don't know.
 
#51 ·
Handy Man, have you had a chance to remove the washer and outer most bushing to see if the washer was catching/scraping the U frame channel?
Have you contacted Moog and talked to a tech?


Regardless if you go to install an adjustable set of strut rods or not, would like to learn why something was doing whatever it was doing and what corrected it. Can't help it, it is in my aviation mechanic blood to know "why" and "how".
 
#53 ·
Arguments and aftermarket suspension setups aside -

Ford made MILLIONS of vehicles with this suspension setup:

Automotive History: Ford’s “Falcon Platform” – From Falcon To Versailles In 18 Different Wheelbase Length/Track Width Variations.

As I understand it the purpose of the 'rubber bushing sandwich' is to allow the strut rod to pivot at the front allowing it to travel up/down with the LCA but not move axially front/rear - perhaps some tiny amount of front/rear movement is inevitable but the huge amount in the OPs video does not seem right. Either we are saying 'they all do that' (eg large movement front/rear per the OPs video) - or - there is something very wrong with his setup. Which is it?

Thanks
Paul
 
#55 ·
Arguments and aftermarket suspension setups aside -

Ford made MILLIONS of vehicles with this suspension setup:

...but the huge amount in the OPs video does not seem right. Either we are saying 'they all do that' (eg large movement front/rear per the OPs video) - or - there is something very wrong with his setup. Which is it?
I agree with this. Ford made too many vehicles with this setup for this not to be a rather isolated case. To the OP, does your car show any accident damage or rust around the strut rod mount? I can't think of anything else that would make the whole strut rod move that far. To me, it almost looks like the whole bracket is flexing under pressure.