Rattly front end

[Justin71]

All,

I'm looking for some thoughts here for potential causes. We have a 71 302 2V with a C4 trans. When I got the car, i had front bearings replaced, front shocks & spring perches, new struts both sides and both new lower control arms. Also had a good alignment done all at a reputable shop.

These days (it's been over a year since that work) everything drives well, holds the road fine, low levels of slack in the steering.

On bumpy roads (small sharp bumps) though, I hear a "rattling" noise from the front. Just sounds like something is loose.

upper ball joints are probably not in great shape but a year ago the shop judged them to be "ok" (it's been driven less than 5Kmi since)

What can cause kind of a "twangy rattle" up front on bumpy roads? don't really notice it on smooth surfaces, and there are no other "ill symptons". The noise as perceived during driving seems "up front" only, and not specific to one side or the other.

Is this a "feature" of this older suspension? Could the sway brace be loose? what else?

Any help?

THanks-

Jay

 

[luxstang]

I have no answer to this but I have had the exact same problem for the last few weeks. It's not typical because mine worked without rattling for years until a few weeks ago.

I have not yet had the time to look into it, so I will monitor your replies.

 

[clevelandcoupe]

I had a similar issue, take a look at the lower shock mounting bolts for bad bushings / loose bolts.

Thanks, Jay

 

[Bill73Ragtop]

I had a similar issue, take a look at the lower shock mounting bolts for bad bushings / loose bolts.

Thanks, Jay

I would also recommend checking the upper shock bushings. I had a real problem with the upper bushings disintegrating in the last couple years. Whatever they were made of, it was not rubber. They would crumble into dust within 200 miles. Ended up going with urethane.

 

[TommyK]

If it is an automatic car check the trans cooler lines. If a clip has fallen off they can rattle going over bumps.

 

[Mikes73]

My money is on loose or worn sway bar end link bushings.

 

[Justin71]

Great ideas. I will check these things are report back. I've had a thought of throwing a GoPro video camera in there in various places and driving around some, but I haven't done that. It's gotta be fixable.

I did do a repair on one of the trans cooling lines near the radiator. I had to replace a section of the steel line with copper (somehow got bent when i removed radiator... can't image how, I'm so careful - lol). In my head I'm thinking the noise has a "deeper" sound than that.... but you never know til you know.

All ideas could be it.

I'll let you know what I find.

Jay

 

[72HCODE]

could be some more items.

The sway bar links are a good one.

when was the last time the zerk fittings were greased?

check noise isolator on the springs. there is a shaped piece of rubber that goes on top of the spring to prevent rattles.

check the strut bars the rubber bushings that go into the cross member if they are falling apart the strut bars can rattle.

I had my spring perch disintegrate on me and i switched from the made in china repop perch to a roller bearing perch.

the lower suspension arm has a bushing by the cam adjusters that can go also.

 

[Justin71]

when was the last time the zerk fittings were greased?

check noise isolator on the springs. there is a shaped piece of rubber that goes on top of the spring to prevent rattles.

check the strut bars the rubber bushings that go into the cross member if they are falling apart the strut bars can rattle.

I had my spring perch disintegrate on me and i switched from the made in china repop perch to a roller bearing perch.

the lower suspension arm has a bushing by the cam adjusters that can go also.

hit all the zerks after all the front end work.

The noise isolator is a good thought.. Will check that.

strut bushings were new ones I had put in with the alignment.

I also had new spring perches - they were cheapies, so I'll check but should be ok.

You've lost me on the last item... both sides have new LCA's.. are you talking about the nuts that hold the end of the bar that is bolted to the shock tower? I'm not familiar with the term "cam adjusters" for this area. Could you mean eccentric bolts?

 

[72HCODE]

yes eccentric bolts, inspect the bushing just in case.

if you changed the bushings and then some time later the noise started then double check them.

I've had new bushings fail after one drive.



you should of heard the noise that failure made. also the steering was scary and i had to limp home.

check the sway first i've had the endlinks loosen up for no reason, i've double nutted them and used self locking nuts.

my New made in china spring perches failed in less then 2000 miles as well, and i replaced with rollers.

if you replaced anything with poly bushings seriously think about going back to oem rubber.

 

[mach1000]

Id agree regarding sway bar end links. They may not look loose but when the suspension is in action the bushings compress and rattle.

 

[Justin71]

A small update on this task guys. I got into the car a little this weekend. I ran by Johns Mustang in Houston and picked up a 1 1/8th performance sway bar. They had them for $110, and I think it could make a significant safety upgrade for this cars' suspension. The primary driver is 16 and in the case of unexpected higher speed swerves, I am hoping less body roll will help maintain control in case the situation arises.

I got under the car, and removed the old (significantly smaller!) sway brace. I didn't find any smoking guns there, the LCA linkage bolts had nuts that were pretty well rusted in place, but after removal (thank you PB blaster) I would say that the rubber bushings were obviously old (probably original) and permanently deformed, but none broken or missing. Unfortunately, Johns Mustang gave me the wrong part, and so I couldn't replace it. They are out of stock on the 71-73 sway bars, and so is Don at Ohio mustang. CJ pony wants at least $25 more. Anybody got a line or where I can get one of these kinda quickly?

One thing I did identify is that the transmission cooling lines are hitting the oil pan side. It is possible that this could be the source, but I can't be sure til I fix it. Can anyone summarize where the cooling line mounts are? Its seemed like there weren't many places underneath to secure them. In any case I'd like to locate the mounts and replace them for these lines to prevent them from touching the side of the oil pan.

I didn't get a lot more checked on my brief efforts thus far. Really hard to eyeball the coil spring insulators up in the top of the shock tower.

Thanks in advance!

Jay Estes

 

[TommyK]

A small update on this task guys. I got into the car a little this weekend. I ran by Johns Mustang in Houston and picked up a 1 1/8th performance sway bar. They had them for $110, and I think it could make a significant safety upgrade for this cars' suspension. The primary driver is 16 and in the case of unexpected higher speed swerves, I am hoping less body roll will help maintain control in case the situation arises.

I got under the car, and removed the old (significantly smaller!) sway brace. I didn't find any smoking guns there, the LCA linkage bolts had nuts that were pretty well rusted in place, but after removal (thank you PB blaster) I would say that the rubber bushings were obviously old (probably original) and permanently deformed, but none broken or missing. Unfortunately, Johns Mustang gave me the wrong part, and so I couldn't replace it. They are out of stock on the 71-73 sway bars, and so is Don at Ohio mustang. CJ pony wants at least $25 more. Anybody got a line or where I can get one of these kinda quickly?

One thing I did identify is that the transmission cooling lines are hitting the oil pan side. It is possible that this could be the source, but I can't be sure til I fix it. Can anyone summarize where the cooling line mounts are? Its seemed like there weren't many places underneath to secure them. In any case I'd like to locate the mounts and replace them for these lines to prevent them from touching the side of the oil pan.

I didn't get a lot more checked on my brief efforts thus far. Really hard to eyeball the coil spring insulators up in the top of the shock tower.

Thanks in advance!

Jay Estes

I got mine from John at ORP.

http://www.opentrackerracingproducts.com/frontswaybar/

 

[Justin71]

Awesome price ($100), and only $25 to ship. If it's going to take my guy very long to order, I'll probably get it from ORP. Thank you.

DO any of you have any advice on 1.0in vs 1.25in? I think the original is maybe 0.75in. How big is too big? remember I am not going for a racing suspension as much as I am safety in the hands of an inexperienced driver… Thoughts?

Jay

 

[Justin71]

That new sway bar finally gets here tonight. Will post my findings after I've driven it a bit.

 

[72HCODE]

as far as sway bars the bigger the better the largest is the 1 1/4 bar for the front.

for the rear the non-competition suspension cars are stuck with 3/4" , if you had factory rear sway then you could get the 7/8" bar.

now i will HIGHLY recommend getting the rear sway bar. The front bar is a good upgrade if you don't have one and going thicker is better on these cars, but you will see a massive improvement from installing a rear sway bar.

my fastback had lots of rear body roll when braking and it made handling uneasy as the rear of the car would roll around, the rear sway stopped all that and made the car much easier to control. i wish i had installed one sooner.

 

[Justin71]

Thats really fascinating about the rear sway while braking. NOT something I would have expected!

As for my case, I obtained the new front sway bar (1in from opentracker as recommended above) and WOW! a MAJOR improvement! As for the main thrust of this thread - rattle - I have to say that replacing the front sway bar has greatly reduced the rattle. I would say the rattle only comes back on sharp bumps now. I think it could well be the xmission cooling lines, as they have NO support anywhere, and actually rest against the oil pan. Can someone provide me the proper restraints for these lines? Clearly, they can't just be hanging there….

As for my size choice, I originally tried to get a 1 1/8 diam bar, but was given the wrong part. When they didn't have the 71 version for 1 1/8 in stock, I bought at open tracker as recommended above. Just before I bought, I got advice that if you don't have rear sway bars, don't go to full 1 1/8 bar in front. The rationale is this… if you stiffen the front as much as possible, but don't have any anti-sway in back, you can get into a situation where rear sway can be too much for the major stiffness up front. In other words, "keep it balanced". So I bought a 1in sway bar, and installed it. But my oh my, what a major difference! The front end seems much "tighter" and more responsive. SIGNIFICANT change in body roll when cornering. Especially at 20+ mph speeds. The car behaves MUCH better, and I do believe it will be much safer to handle in the event of a high speed swerve. I couldn't be happier with the upgrade.

In any case, I wanted to share a positive experience with opentracker. Their stuff came in about a week, and the quality was fantastic. I've attached some pics of the parts in the kit:









The bar from open tracker had some incredible paint or powder coating on it. Very hard and durable. I hope that is showing well in the pic - very high quality. The bushings where the bar mount to vehicle came with some lube to put between the bar and bushing - keeps things moving easily - very nice touch. My only issue was that with this bigger bar, the metal brackets that hold it to the frame are almost too broad for the 71 standard coupe hole pattern on the frame. It did not come with new bolts to hold these brackets, so using the originals, I had to flatten one edge of the washers on the originals in order than the washers wouldn't interfere with the new bracket.

That issue, then I found that while installing the bar, the new bolts that hold it to the LCA where about 2 or 3 threads too small, I couldn't get all the brand new uncompressed bushings, and washers on there and get the nut on. I had to take one off, crush things a little, then add the last one. A little more time consuming than I would have liked, but that's what it took.

I'm really happy with this upgrade. It has solved the majority of the rattle issue, and more importantly, the car I believe is MUCH safer. the suspension feels more responsive, and the turns are a joy now. Thanks for everyone's help! I'm very thankful for this forum and all the help I get!

Jay