Umi antihop kit installed and new noise...

[Jukens]

With installing new lca's and relocation brackets I expected more nvh but is this normal. It sounds like mud tires on highway except only on deceleration. I swear I am getting a new noise with each part I install...

http://www.youtube.com/watch?v=xzoSNZaQo4E&sns=tw

Not my video but same noise.

 

[Nuar]

Well if you read the comments, the vid owner had to rebuild the rear end :/
Good luck figuring this out man.

 

[Napoleon85]

LCAs wouldn't cause this, but I assume that since you had to use relocation brackets you're lowered substantially. Did you put in an adjustable UCA and correct the pinion angle? If not, I would put my money on that causing the issues with your rear end.

 

[Jukens]

Lowered with eibach pro in the rear 1.5inch.

 

[5lho]

LCAs can and will transmit rear end noises to the cabin. 8.8s are notorious for being noisy, especially with steep ratios in them. This is something Ford has chosen to ignore for decades now. Foundationally, the issue is setup error. Unlike a rear end setup you pay for, where a pattern is run and checked, etc., the 8.8 is set up on the line by torquing a crush sleeve to a specified torque value. This is supposed to get it in the right range for pinion depth. Problem is, it often doesn't.

This is less crucial with a 2.73 rear end but, the steeper the ratio, the more likely these setup errors will manifest as noise. Hence, big rubber bushings connecting the axle to the cab. Tighten stuff up and you reveal what's really going on back there. There's no danger of breakage, it's just an irritation.

Mine's a tetch too deep on PD, from the factory. I ran the pattern, for the hell of it, when I changed out the rear gear fluid. Hence, there's a tiny moan between 120-140 kph with UMI LCAs on. Not enough for me to rip it apart though.

 

[Jukens]

LCAs can and will transmit rear end noises to the cabin. 8.8s are notorious for being noisy, especially with steep ratios in them. This is something Ford has chosen to ignore for decades now. Foundationally, the issue is setup error. Unlike a rear end setup you pay for, where a pattern is run and checked, etc., the 8.8 is set up on the line by torquing a crush sleeve to a specified torque value. This is supposed to get it in the right range for pinion depth. Problem is, it often doesn't.

This is less crucial with a 2.73 rear end but, the steeper the ratio, the more likely these setup errors will manifest as noise. Hence, big rubber bushings connecting the axle to the cab. Tighten stuff up and you reveal what's really going on back there. There's no danger of breakage, it's just an irritation.

Mine's a tetch too deep on PD, from the factory. I ran the pattern, for the hell of it, when I changed out the rear gear fluid. Hence, there's a tiny moan between 120-140 kph with UMI LCAs on. Not enough for me to rip it apart though.

I have no drivability issues or vibrations and figured it was there before the umi lca's but I just couldn't hear it. And I am running factory 3.73s. I just want to make sure this isn't something I shouldn't be driving on.