Lowering + gears=Rear wheel well noise?

[cbr1100xx]

Just got my '08 GT lowered with Ford Racing springs (1.5") and 3.73 gears installed and FRPP GTA axleback.

Car runs fine (less than 500 miles) but now it seems like a hear what sounds like an air pump or something coming from rear wheel wells while driving at least 30mph.....it's kinda loud and annoying.

Don't remember hearing this when the car was stock. Is the just normal when you lower a car or do the springs need to break in?

Thanks for any replies.

 

[Towelly]

Are you sure its not the gears whining? You suspension is more likely to make clunk's and squeeks than hisses or whining. I'd take it back to whomever installed the gears and ask them. This is a unfortunate but common' issue with gear installs. The 8.8's are kind of a PITA to install gears in. Especially if you get the wrong brand (Motive) .

 

[cbr1100xx]

Posted via Mobile Deviceactually yes, it probably is the gears now that I think about it. Rowing through 1st-4th,all sounds fine. Just cruising at say 60 or faster in 4th or 5th, I hear a whistle like sound from the rear that is kinda annoying. Shop that did it has been around a long time and they specialize in mustangs...so doubt they didn't do the job right. Gears are Ford Racing. One disappointment with the mustang is how even with gears 5th is still so much taller than 4th. Its more responsive now than before but still only 2400 rpm at 80 and 4th is like 3k rpm at 60....so really no comfortable 75 mph cruising unless I'm reving high or sort of lugging it. a 6 spd would be ideal but still like the 373s vs the 331s...just hope the whine doesn't get too annoying and I get used to it...which I think I will.

 

[Towelly]

Posted via Mobile Deviceactually yes, it probably is the gears now that I think about it. Rowing through 1st-4th,all sounds fine. Just cruising at say 60 or faster in 4th or 5th, I hear a whistle like sound from the rear that is kinda annoying. Shop that did it has been around a long time and they specialize in mustangs...so doubt they didn't do the job right. Gears are Ford Racing. One disappointment with the mustang is how even with gears 5th is still so much taller than 4th. Its more responsive now than before but still only 2400 rpm at 80 and 4th is like 3k rpm at 60....so really no comfortable 75 mph cruising unless I'm reving high or sort of lugging it. a 6 spd would be ideal but still like the 373s vs the 331s...just hope the whine doesn't get too annoying and I get used to it...which I think I will.

Just crank it up!! But if it gets a lot louder in a short period of time take it back to that shop. I wonder if you got Motive gears (Used to be sold even by Ford racing). Some guys, even with a good install, have had whine from Motive gears.

 

[bigcat]

ask the shop what they used for install specs, then post the results here. backlash around .007" is good.

 

[cbr1100xx]

I'll ask the shop. The gears were Ford Racing. I have the part # on the paperwork and they told me they were beforehand.