Syracuse315

I just had the following items installed at a reputable shop, and now I'm trying to isolate a noise I'm hearing from the rear of my 2000 GT. For some background: the car has 100k miles on it, did not have the noise before the install, and the shop is 4 hours away (so taking back in is not a desirable option).

Installed Items:

- FRPP 3.73 Gears
- FRPP 31 Spline T-lok w/ carbon disks
- Moser 31 Spline Axles
- Rear end install kit + new axle seal (http://www.americanmuscle.com/rearendrebuild.html)
- MM FLSFCs
- UPR LCAs (http://www.uprproducts.com/mustang-9...trol-arms.html)


I first assumed it was the gears, but after being able to replicate the same knocking/creaking sound by pressing down hard over each rear shock, I am certain it's a suspension component. The noise can be heard when slowing down from approx 10mph to a stop as well (even on smooth roads).

I know the spherical bearing can be noisy, but I don't know what the noise could sound like. I'm also thinking when the springs were reinstalled, there is a possibility the spring isolators were worn down (as they had 100k miles on them) and how they newly sit on the LCA could cause the noise as well.

Has anyone had something similar happen? The noise is livable if this is coming from the LCAs, but unnerving when I don't 100% know what it is.

Also, the new parts are awesome.

BoomTown96

I had some creaking after installing UPR LCAs on my 96 GT. I don't believe I had anything that you could call knocking though. The noise eventually went away after the bushings broke in. Not sure how long it took maybe 4-6 weeks or so. I don't know exactly whats recommended as far as lubrication but I used grease for the mounting points.

Syracuse315

That makes me feel better. I'll try to get a video of the rear while driving/stopping (my go-pro like camera I can stick underneath the car).

Syracuse315

Just got a response from the shop, and they are sure it's the spherical bearings on the LCAs. I'm thinking of trying some grease, but the only kind I have is the white lithium used for electronics. Think it'll work/not harm anything?

UPRSharad

Sphericals don't make noise unless they're completely worn out and loose. (then it's kind of a popping sound) They do, however, TRANSMIT more noise than rubber or poly bushings. In other words, you may not have noticed gear whine in your ring and pinion or clunking in your driveshaft before installing the LCAs, and those sounds may be more noticeable now with the LCAs. But the LCAs themselves shouldn't make ANY noise if they are installed properly. Do you know if the shop lubricated the poly bushings on the LCAs with synthetic grease before they were installed? This is standard procedure, and if they're a reputable shop, they would do this without being told to do so.

BTW, spray lube will not harm the sphericals.

Syracuse315

Sounds similair to what I found in a different thread (Although it was regarding a Panhard Bar vs Watts):

My only remaining question is why can I hear the noise while out of the car and pressing down on the rear suspension? I'm assuming the gears and aluminum drive shaft are stationary at that point.

Also, checking the bushings before install, I noticed grease already in the poly bushings. I'm not sure if they added any more, but should they have?

Syracuse315

Here is the video from underneath the car. The camera was mounted on the rear stabilizer facing the LCAs, but swung 180 degrees while driving. The noise can still be heard briefly at 0:38 and more clearly at 1:00.

At 1:14 I jumped up and down once in the seat and you can hear the noise again.

http://www.youtube.com/watch?v=Q-Jex3N9mwM

Syracuse315

Looking over Jazzer's suspension thread:

"*I prefer that if an LCA have a non-spherical bearing, it be on the axle end. This will create more NVH than the reverse, but I happen to like the relationship between an OEM type rear sway-bar and plate in which it mounts."

That is how my LCAs are now set up as well. Could be another reason for the noise (See pictures below). I've also taken some pictures of the spring isolators and they look in decent shape:

Jazzer The Cat

I'm with Sharad on this one..... I mean, I'm not with Sharad, as we are both married, but not to each other ...not that there is anything wrong with that

I don't hear anything unusual, but that pair of sphericals is going to transmit noises you may not have ever heard and maybe there all along, as Sharad said. Run around in my car for a while and will hear plenty of stuff like that. Hell, you have 2 sphericals, where I have 13 of them babies and several more that are metal on metal, just not a "spherical" bearing.

Seriously, I don't hear anything unusual, so as long as the bolts are tight and suspension is sound, I don't know that I would worry about it.

Jazzer

UPRSharad

Okay first of all, that video sounded awesome through my headphones!

Now, about the noise... hmmm... I don't know man. That popping noise at the end of the video, say from around 1:02-1:18 does kinda sound like worn out sphericals, but if those LCAs are new, they would NOT be worn out. They might do that after several YEARS, but not after several hours.

Regardless, those LCAs are guaranteed for life, so if you bought them new and they need new sphericals, we would just send them to you. That said, I just don't think this is the case. You could reach under there with the car parked and push/pull side to side and to see if you can replicate the sound?


HAHAHAHAHA!!!! There's hardly a day that goes by where I don't laugh OUT LOUD over your posts. You're not right dude!