Diff issues

[smokyJ]

Hi all,

I tried having a search around the forum and older threads as I know this comes up a lot, without much luck however. Apologies in advance for any questions or assumptions I make/have that are completely off track (or just plain wrong.) I'm trying to use this forum to learn about my car and it's workings as I go and will be more than grateful for info and advice you learned fellows can offer.

Over the past fortnight there has been an increasing whine in the drive which I thought was the wheel bearings. I took it to my mechanic who immediately said it was the diff and recommended completely rebuilding it as opposed to buying second hand - more costly but more safe? I don't want to buy a dud? My bearings are shot as well which I already knew about so those will be replaced at the same time.

Main question surrounding it all is if I do have the diff rebuilt, is it as easy as having it built with the different size(3.9's?) What is the general consensus on different diff gear ratio's?
Is this going to exponentially increase the cost of the work?
Will it provide much of a difference?

I do plan on doing a fair amount of work to the car, but have only had it for a while and have been going through the process of replacing a lot of components in it. It has a 2.5" catback and CAI in the garage to be fitted this weeked.

Driving is split 65:35 apprx city to highway kms.

Apologies in advance if this doesn't make sense. It is 4.43am however at the end of a dogwatch shift :P
Cheers

[shanhsv]

Sounds like the bearings are shot mate, you can buy a second hard diff but yeah, could be on its way out too. if you choose to rebuild would be a good idea to add a limited slip and/or new ratio would be a great idea if you can afford to do it.
The thing with changing your diff ratio is the higher the numbers (3:08, 3:46, 3:70, 3:91, 4:11) the faster ur car accelerate, drive up hills easier and tow better,but also highway fuel usage will increase due to a higher RPM. Not sure how the 5speed will go but a 6speed with diff ratio of 3:46 will sit about 1500 rpm at 100-110kmp/h, with a 3:9 ratio, it'll sit on about 1850 rpm so not really a big deal with fuel but great take off

[smokyJ]

Thanks Shan! exactly what I was after.

[Kurtp]

Hey smokyJ i had the exact same problem, i just got a second hand diff from a mechanics from a newer VS. You shouldn't pay your mechanic to do it, they're really easy to change just nuts and bolts, the only difficult thing is bleeding the brakes, and reattaching the drum brakes which are in a bitch of a position. Havn't had any problems with the diff as of yet. You will save a lot of money, cost me 225.

Though if you're set on getting a new ratio, have fun!

[smokyJ]

Hey smokyJ i had the exact same problem, i just got a second hand diff from a mechanics from a newer VS. You shouldn't pay your mechanic to do it, they're really easy to change just nuts and bolts, the only difficult thing is bleeding the brakes, and reattaching the drum brakes which are in a bitch of a position. Havn't had any problems with the diff as of yet. You will save a lot of money, cost me 225.

Though if you're set on getting a new ratio, have fun!

I don't think i'm quite competent enough to bleed them. not too mechanically minded - trying to learn as I go though.

Regarding the new ratio, have fun? doesn't sound good....

[hako]

Regarding the new ratio, have fun? doesn't sound good....

Pretty sure he means basically to enjoy it....in a positive way.

[shanhsv]

Forgot to say also,speedo correcter will be needed with a diff ratio change

[smokyJ]

Thanks Shannon - getting some prices this week will keep it updated

[a.j]

does any1 know what it will cost to get a live diff centre re-built for a vr?

ive got the whine, and the LSD doesent work very well anymore

cheers