Hey all, I've rebuilt the front end in my Barracuda. I've added SFCs and torque boxes, done an FF reinforcement of the K-frame, boxed the LCAs, adj strut rods, installed offset UCA bushings, C-barge tie rod ends, AL tie rod sleeves, fast ratio pitman, stock idler (c body idler wouldn't clear the headers), Moog "problem solver" upper and lower ball joints, 1.12" torsion bars, 7/8" sway bar with Firm Feel tabs and bushings, Bilstein RCA shocks, stock brakes.

Alignment is dialed in exactly as I want it (2005 Mustang spec with an extra .5* -camber), all the air out of the brakes, no steering linkage clearance issues, everything tight.

I'm getting some odd clunks from the front end, mostly after hard braking, during low speed maneuvers and when going fwd after backing up. Everything looks great when up on stands, but I have no lift so can't get a look with the suspension loaded.

Can anyone point me at anything to check?

A couple of thoughts I've had on possible sources :

I torqued the LCA pins with the suspension loaded, but the engine out.

The bolt in FF sway bar tabs. Tabs are located up against the upper lip of the LCA, so they can't rotate and they are torqued to the max spec of the bolt.

Again, everything is tight to spec with a good torque wrench.

Any help appreciated.

Thanks

Tbars come to mind, did you grease the hexes when you installed em? You might grab your strongest buddy & have him bounce/jounce the front end up & down & you as close underneath as you can get & see if he can make it clunk.

In my opinion that is caused by worn lower control arm sockets where the torsion bars go in, only thing with play when everything is new. Some are tighter than others, bigblock cars had better reinforcment lower around where tbe socket entered the arm, and are usually noise free or quieter. Sorry for the bad news, I wish we could buy new lower arms, just one idea.

Thanks Rapid and 6bbl,

Negative on greasing the bars. That has been on my list, but you know how that goes.

On the arm sockets, I had not pondered that net effect. I did, however, check the play and that they were acceptably strait in them before I decided to box the set. I recall them being the same (in and out & up and down, all the way around). My subjective tolerance may have been too much.

I should get a couple of wrenching hours this weekend and will get her up and grease the bars. Glad I bought that T bar tool at a swap meet years ago.

Yes grease the bars & see if that is it. those clamp on t bar pullers, I always wondered if they were kind to the bar surface.

For giggles, I'd check the front calipers and pads too. What kind of brakes are you using? Are the rotors adjusted correctly? The rotors shouldn't make noise (if they do, you've got bigger problems) but I have seen where a rotor too loose will move the pad/caliper around more so.

One other thing I have seen is lower front shock bushing inner sleeves with smooth ends will make noise at stock bolt torque, some shocks have a serrated sleeve that digs into the control arm so it does not slip and clunk on the bolt.

Well, greased the bars. That definitely made other noises more identifiable.

Rapid, on the bar clamp tool, it is kind to the bar if sufficiently torqued. If it is too lose, it will scratch the surface. Learned that the hard way on my old bars. I had to get longer bolts for the big bars.

6bbl, I've got some boots to install on the shocks, so will check the lower bolts. They were torqued to spec and have smooth ends on the sleeves. That make sense, given where I *think* the noise I have been able to identify is coming from, since the bars shut up. Unfortunately, I cant get any noise bouncing the thing.

I'll check the rotor end play while I'm in there too.

Thanks guys, Tuesday is my early off, pick up the kid day and as the wife has some work training, the boy and I can wrench until bed time. Hopefully have something to report Wed.

Are you absolutely sure it's comming from the front? I had a similar situiation, I thought the noise was coming from my front wheel area, after taking the front wheel bearings apart/checking/regreasing, discovered a spring had broke in my rear drums causing the noise and a shoe to drag.

Shocks are the noise my Cuda had, just torqued a grade 8 bolt with head bolt washers to 60 ft lbs and has been fine. It will not make noise bouncing by hand, only driving. Also check the strut washers that they are not contacting inside the k-frame, the rear where it is boxed. These k-frames vary a lot.

I'd look at the adjustable strut rods.

I'll get a look at the rods too, while I'm in there. I checked bolt torque but didn't look closely enough to see if the washers were contacting the k-frame. I adjusted them to the stock length when I assembled, but my alignment guy said adjusted them to even out the load on the bushing as it was a bit distorted once he got the caster/camber where I wanted it with the offset UCA bushings. The thought that something might be up with them had crossed my mind.

Shocks seem most likely to me now as the piece of paper that came with them said 45 ft.lbs. for the lower bolt and FSM says 50.

Highly confident the noise is from the front. Only thing coming from the rear now is some sure-grip noise (mostly went away when I changed the oil and friction modifier). The clamp on the rear of the rt spring was rattling a bit, but I was able to clamp it tight with big ol' vice grips and pull the lock tab over enough to keep it tight. The main noise I had from the rear in all this went away with new drums (vibration went away too).

Appreciate all the input guys.

I am not a fan of the adjustable rods. I believe the stock ones had a steel insert that would prevent the bushing from being over compressed but I have no idea what yours came with. When I did my 73 I bought the Mopar bushings (not poly) and reused the insert.

I used Moog problem solver line bushings, and they came with an insert. From what I understood from my alignment guy, the alignment (UBJ relocation) allowed by offset UCA bushings slightly loaded the strut bushing to one side or the other at rest and either lengthening or shortening the strut rods a bit brought the load back to the bushing center line at rest. I think that adequately explains my understanding, anyway. That was the reason I went with the adjustable rods, on the recommendation of a circle track racer with a lot of experience with these setups.

I went with all rubber bushings. I run out of talent before a poly bushing would help my cause. I was told (FWIW) that the bushings in the Moog problem solver line are higher durometer rubber than stock bushings.

I'll give it all a good inspection, hopefully tomorrow after work, and let you guys know what I see.

Adjustable strut rods should have been stock issue.

Shocks seem most likely to me now as the piece of paper that came with them said 45 ft.lbs. for the lower bolt and FSM says 50.

with the lower shock bolt it will rattle more than a clunk, also that bolt is unique as it has a taper to it at least the aussie version did so check that it's just not just a normal bolt.
when you beefed up the k/frame were both lower arm pin holes front and back nice and tight and not elongated, maybe the nut end has some slight movement.
just trying to give you some other things to look for but most likely as others have mentioned its usually the strut bar end in the frame.

Thanks dodgy, appreciate any input.

The arm pin holes "looked" good, not that I measured them with anything more sophisticated than the Mk1 eyeball and fit the pins. Once I finished removing paint from the ID of the holes, the pins went in as they should. That said, I'll get a good look when I'm under there.

On the rattle v. clunk, I should have been a little more clear in my update. After I greased the bars properly, I would describe the current sound as maybe more of a rattle (higher pitch), except that it doesn't repeat more than once, when it does happen. Hits one side, then the other, then done until the next maneuver, if that makes sense. It seems like the bar clunk was covering this current noise.

I'll also add, that it is noise free until things are good and warmed up.

Also, using the cleaned up/inspected factory shock bolts and running stock disk brakes (for now).

On the brakes, looking at the FSM, it shows/says nothing about the anti-rattle clips but it does describe bending tabs over on the outboard pads then using the old pads and a c clamp to interference fit the pad to the caliper. I don't recall my pads even having the tabs shown in the FSM, and I didn't install the anti rattle clips, I just used the disk brake quiet glue stuff, and the pads have some sort of anti-noise pad on the back. More stuff to check, but it doesn't sound like the pad rattle the disk brake quiet fixed when I replaced the pads on this thing at some point in the distant past.

Well, R&R'ed the shocks to install boots and torqued the lower bolts to 70ftlbs. Checked the hubs and found a bit of slop on both sides. I reset the brg pre-load and gave it a 1/4 turn with a tool instead of finger tight. I inspected the struts rods and ran the suspension through the full range with a floor jack on both sides and the washers aren't touching anything. LCA pivot nuts are properly seated.

So, the rattle noise is gone, I'm going to chock that up to the improper wheel brg preload and shock bolts. BUT, now I get noise(s) whenever I'm on the brakes. Go over a speed bump with foot off the pedal, nothing. Foot on the brake, or just applying the brake, I get noise from both sides, sounds like coming from the wheel area. I inspected the caliper assemblies and cracked/retorqued the slider bolts when I was in there as well.

I think I'm going to go through and re-torque everything to FSM spec as I went with the torque numbers that came on the slips with the new parts, but looking at the FSM, for example the LBJ to knuckle nut calls for 85 ftlbs, the slip with the LBJ said 55. I now recall noticing the discrepancies and going with the part mgf torque number. I used FSM numbers for everything else.

Should have checked with the brain trust on the torque number discrepancies. I hate doing $h!t twice...

Anyone have any other thoughts/considerations?

Annnnd,

Had a half hour last evening and decided to see if I would be able to re-torque the BJ's without removing the rotors. Never got the question answered though as I noticed the fat adjuster nuts on the strut rods have been cleareancing themselves on the splash shields way up front, not far from the bushings. I'll get those properly clearanced and see if that does it. Had to do so with the starter splash shield to clear the C body rods and fast ratio pitman.

While I was at it, I did retorque the strut-LCA attachment nut, the front attachment nuts and put some extra ugh on all the the adjuster jam nuts.

OK, so got it up in the air, wheels off and started checking things. It would appear alignment guy didn't adequately torque the jam nuts on my steering tie rods or the strut rods. Called the shop, they said bring it over (mid-afternoon Sat.). Got it on the rack and the toe was out a bit, but that was all. Next, we checked the ball joints and all was well, the guy wasn't worried about the torque spec discrepancy between the FSM and the parts slips on the tie rods or ball joints. The guy actually got a bit of a chuckle from the conversation and said he only goes half a turn after it gets tight, then to the cotter pin hole (my inner A&P keeps me type A on such things). I had him double check the control arm pins then, properly tighten the jam nuts with a bit of blue locktite and we went for a ride. That did it for the most part.

After a decent diagnostic drive, what is left only happens on or off medium-hard braking, or after it is really heated up. Alignment guy asked about the brake hardware. I have only changed the pads and all four of the pins were buggered a bit where the inside pad rides. I picked up a hardware kit that has the rubber bushing/isolators and clips and ordered pins from Rock Auto.

Anyway, mission almost accomplished and I got a ton of advice and benefited from the experience of a 40+ year taxi and bus mechanic from Guadalajara (he did the initial alignment and fell on his sword over the jam nuts). I guess C bodies were popular as upscale car service rides into the late 90s down there.

It'll probably be a couple of weeks, but I'll report after the brake hardware job.