awbreyjd

I just installed the complete Ford Racing SVT Rear Axle Assembly as we broke the axle tubes in my stock one. It came with the 3.73's. Unit comes assembled and full of oil already. After about 200 miles of driving and multiple warm up/cool down cycles I noticed it developed a pretty loud whine between 70-80mph. The first day I drove it 30 miles on 2 seperage occasions over a highway at 75mph and there was no whine. the second day I cruised a little before lunch then mid day decided to make the 30 mile trip again and at 75 when under acceleration or maintaining throttle it whines. under Decel it is much quieter.

jpplaw

I have the SVT rear in mine also. I just noticed a very slight whine at about 70 mph after about 15,000 miles. It is very quiet though and not too bad at all. I did put RP 75/140 + modifier in before I put the rear in though.

What LCA's are you running? Some aftermarket LCA's will really amplify any whine.

Before the install, lots of people told me 3.73's were noisy but this isn't really bad at all. I had 4 sets of 3.31's (including the originals) take a dump on me - those whined unbearably LOUD. The repeated failure of the 3.31's is the primary reason I went with the whole SVT housing set-up, in case my OEM housing was a problem.

awbreyjd

well I have upr uppers and lowers with a new upper mount. The are solid bearing style lowers so there is absolutely no dampining. You may be right about the sound being amplified. However when I say new rear I mean we put it in on Saturday and that evening I drove it with it haveing no whine at 70+. day 2 it started whining pretty loud. Might try changing the fluid it came with from the factory with the Royal Purple and friction modifier.

jpplaw

I used Red Line when I was having trouble with the last set of 3.31's (all dealer installed btw - Tasca) and it quieted them down quite a bit. I used almost 2 qts of the regular red line gear oil and 1 of the Shockproof with some modifier.

awbreyjd

anyone else have this problem.