Clunk on front end

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Dec 10, 2017
Messages
714
Reaction score
282
Location
Georgia
My Car
1973 Mach 1 "Q Code"
I have rebuilt my front end, new upper control arms, lower control arms, both upper and lower control arms included ball joints, inner and outer tie rods, new conversion from drum brakes to disk brakes kit ( Willwood kit), front strut rod bushings, stabilizer bar bushings. The only original parts that I used were were the idler arms, center drag link between the inner tie rods, and the pitman arm that I was unable to remove from the gear box. The gearbox came from a parts car that I had the registration and was on the road in 2017. I have checked torque specs and all fall within the specs but I have a clunk on the front drivers side. It mainly happens when I go from concrete to a grassy area or from a grassy area to a concrete (especially if straightening up when backing up into my driveway). It is kind of intermittent because it doesn't happen all the time. I have not had a wheel alignment yet since I have not driven it a lot since getting it running. I will say that I have Grant Classic steering wheel that sqeaks constantly when being turned and is not on straight ( I pulled it tonight to put it to the 10 and 2 position but have not fully installed it yet). I was thinking that the pitman arm was just hitting something because the wheel was not on the correct orientation, but the clunk feels like something is loose or falling into position. Looking under the car tonight, the tires are straight ahead and the pitman arm from the gearbox is from 12:00 (Gearbox) to about 5:00 (toward the passenger side) at the center drag link (looking from the rear to the front if that makes sense).
Any advice is appreciated to find this clunk. Thanks in advance.

Tom
 
Check for other parts of the car in that general area like sheet metal and components under the hood. I had a similar issue with an intermittent clunking from the front passenger side. Eventually tracked it down to a loose battery tray knocking around.

I would start by jacking up the front of the car and grabbing the tire and trying to yank it hard in all directions. Look for any unexpected movement and listen for noises. Then while you're there, grab all the other parts of the car, like the battery tray and radiator, and give them a shake to make sure they aren't loose.

If you have a buddy, you can put them in the drivers seat and have them go back and forth to make it clunk while you stand outside the car, or lay down to get a better view, and try to spot some parts moving.

There's a bunch of parts down there that you touched. Too many to list them all. Some that pop into my head are the brake caliper flopping around, lower control arms shifting at their proximal mounting points, strut rods shifting at either end where they mount.
 
Great points, thank you giantpune. Hopefully the rain holds off tonight as I will be under a carport but, getting wet will be worth it if I find the issue. I will report back when I know something. Thanks.

Tom
 
I haven’t driven it yet but did find that the pitman arm castle nut and inner tie rod nut had loosened and were not torqued properly. I remember now that I ran out of cotter pins during the install. I have torqued everything back down and will be picking up cotter pins in the AM to install before the next drive. I really appreciate Cleveland Crush and Giantpune for their advice on going forward. If all works well, it will be going in for an alignment and paint in the next week or so. Thanks everyone.

Tom
 
Thanks for the info and advice 73 Mach 1 4 me, when I rebuilt my front end, I installed new ones. I checked their torque last night as well and they were good. I plan to take a test drive today or tomorrow and see how it goes. More to follow.

Tom
 
You might check the torque on the strut rods at the crossmember too.

kcmash
 
I am in a similar spot, all new front end except for the same parts you mentioned…stock brakes…I also have a clunk, slow speed turning wheel…it’s more of a pop or bind and I can feel it in the floorboard….haven’t figured it out yet….car runs straight, is aligned….
 
My shock clunk may have been exacerbated by worn rubber on the bottom shock mounts. When I changed them I was surprised at how bad they were, and also the fact that until I removed them I couldn’t tell they were compromised until I had them out.
 
Thanks Kcmash, Ribs and Billw69, I forgot to check the torque on the front of the strut rod but will check today (before if I get a chance to test drive, wife has got me busy). Anyone have the specs for the strut rod? Ribs and Billw69, I hope you figure your issues out and will report back soon.

Tom
 
If identifying thed cause of the klunking proves to be elusive after following the ideas provided in this thread, you may be able to hep narrow your problem down using a listening device tool kit from Steelman (https://steelmantools.com/). This kit has multiple listening devices that can bew attached magnetically and/or using tie wraps to secure said listening devices in various, locations inside the car, under the can, in the trunk, pointing at different possible sound sources. Then, with some else driving, you can begin to listen to the various listening devices individually until you find the one picking up the klunk. If you need to move the other listening devices closer to the source of the sound to further narrow don the device causing the klunk, you can do so and go for another drive. The kit itself is fairly costly, but I would guess if you had known of it, and gotten it, in the beginning of your effort to stop the klunking, you would have saved a lot of time and money. Here is the one I selected:

1679241375830.png
 
Thanks Kcmash, Ribs and Billw69, I forgot to check the torque on the front of the strut rod but will check today (before if I get a chance to test drive, wife has got me busy). Anyone have the specs for the strut rod? Ribs and Billw69, I hope you figure your issues out and will report back soon.

Tom
Looks Like 60 to 80 ft lbs for strut rod torque
 
Thanks Gil, that is great idea. Hopefully, I am good now but will keep this in mind.

Tom
I know the equipment is costly. I got it on a whim, after another person in a different forum ran into a vibration issue he could not locate. He decided to rebuild his engine after a compression and leakdown test indicated he had a problem (more than 10% compression variance two adjacent cylinders, and leaking air out the exhaust for one cylinder. Two of the valve guides in one of the heads needed to be replaced. I am not convinced that is where his vibration is coming from. I am going to offer to ship the kit to him to use in the event the vibration persists. But it may be a few weeks before he is ready to use it. Meanwhile, if it turns out you still have a klunk after retightening the pitman nut and inner tire rod nut, email me at [email protected] and let's work something out where you can use the kit. I hate to see a fellow enthusiast suffer like this.
 
I haven’t driven it yet but did find that the pitman arm castle nut and inner tie rod nut had loosened and were not torqued properly. I remember now that I ran out of cotter pins during the install. I have torqued everything back down and will be picking up cotter pins in the AM to install before the next drive. I really appreciate Cleveland Crush and Giantpune for their advice on going forward. If all works well, it will be going in for an alignment and paint in the next week or so. Thanks everyone.

Tom
I just ran through mine. The pitman was fine, however, the upper ball joint holes were too low and didn't lock the cotter pins in the castellations. I had to add washers for spacers or they were going to keep coming loose. Geeze my clunking was from the shafts themselves, they were worn to where I was wondering why one of them didn't break. Did you use the 1" drop springs? I noticed my tow and caster were fine, but my camber is now positive. Also time for alignment for mine as well.
 
Back
Top