whine from rear end when coasting?

[evil281]

so my friend just got a 2001 mustang gt and there was a whining noise coming from rear, me owning a stang for a while thought ok bad gear install(had 3.73 gears when purchased) so we had a shop take it apart and they said it was actually the LSD not gear, so my friend replaced that and used a master bearing kit too, well sure enough still whines like hell when coasting, so the shop now said to replace gears, so he did that but it still is whining like hell after he brought it home today!!! What the Heck could this be, several people have test driven it and can confirm the noise is coming from rear half of car not tranny or clutch, anyone care to take a guess????

 

[bdcardinal]

they arent setting up the gears correctly.

 

[Mustang5L5]

Bearings??

 

[Stark77]

find a new shop

 

[mustang50v8]

passengers in the back seat complaining about driving to fast?

 

[mrmustangman357]

backlash may be excessive. does it clunk between drive and reverse?

 

[evil281]

lol great answers!!! now ive figured it out thanks to you helpful people!!!! lol jk

seriously i couldnt imagine this shop is installing wrong especially twice in a row, i have other friends who had gears done thru them and they worked perfect, same installer in fact, all the bearings were changed too had a master bearing kit installed at same time

 

[evil281]

i do not beleive there is a clunk but i will have to ask, i know that sometimes it is hard to put it into reverse, not sure y that is, come to think of it it may clunk when u finally do get it to engage into reverse, so whats that mean?

 

[SaleenGT2001]

the gears are not set up correctly. my guess is the pinion depth is not right. once the gears have a bad wear pattern set in them it is hard to get them to stop making noise.

 

[evil281]

he just had new gears installed yesturday tho and its the same noise, id find ithard to beleive they installed them wrong twice, altho i cant say 100%they are awesomely good installers but from the past i know plenty of people who used that show for gears no problem

 

[Flghtmstr1]

It doesn't matter how good the shop is (or claims to be), or how many people were happy with their work before. If freshly-installed gears are whining, they were not installed correctly. Gears should never whine, and if they do, take your car back to the shop and tell them to fix it. Whining on decel is probably incorrect pinion depth, as suggested by SaleenGT2001.

 

[deftsound]

Mine made the same noise even before i had my gears installed, turns out one of the axles had a dimple in it which was causing it to wobble a bit thus causing the whine

 

[evil281]

thanks defsound i was looking for things outside the relm of a gear whine, gives us more possibilities to ensure its just one thing thats the problem