A new diff with 3.42's

[Docta]

I found a guy selling a 3.42 diff and a Magnaflow cat-back for a really fair price, and I think that will be in my garage soon enough. I just wanted to make sure I know what would be involved before I go ripping my rear end apart. Is it possible to do without a lift and such? What's the process?

[whitdog54]

Re: A new diff with 3.42's

what gears do you have in your car right now? you might need new carrier if you are 3.08 or lower. Or are you getting the entire rear end?

I wouldnt reinstall gears myself, it can be done, but it needs to be done right. Otherwise you will get lots of whine, and maybe get uneven wear on the teeth.

[Docta]

Re: A new diff with 3.42's

It's got 3.08's atm... And that's why I'm getting the whole diff, I don't want to mess with installing gears in it. I just want to know how hard a diff is to install.

[truekoa]

Re: A new diff with 3.42's

It's an install left for a professional but I believe there are instructions in a Haynes manual; you should pick one up.

If its the entire rear end like mentioned above, then its alot easier since you'll just swap the entire rear end.

[Docta]

Re: A new diff with 3.42's

Would it be in a Chilton? I have one of those :P If not, I can get my neighbor to print out the AllData to do it...

[whitelightning87]

Re: A new diff with 3.42's

It should be in the manual then, unless Im missing something its basically out with the old in with the new.

[Docta]

Re: A new diff with 3.42's

It's not.... The only things diff related in the manual are gear oil drain and replacement.

[kristen]

Re: A new diff with 3.42's

it is totally pointless to move up to a 3.42 on a manual

[Docta]

Re: A new diff with 3.42's

Why's that? It's step up from 3.08's..

[Blizzard242]

Re: A new diff with 3.42's

Docta, I want to clarify a few things cause I can see some confusion with you or other members. A differential/carrier sits inside the rear end/axle housing. A ring gear is installed on the differential/carrier and the pinion is install into the rear end/axle housing. You cannot replace just a differential and ring gear combo without replacing the matching pinion gear which requires a dial indicator to measure backlash. Unless you're getting a complete rear end/axle housing with a differential and gears installed, I just want you to know what you'll be getting into.

If anyone doesn't like my terms, please correct me cause I'm doin this off the top of my head.

[whitdog54]

Re: A new diff with 3.42's

3.42 gears in an m5 is a step up for sure. Also in an m5 RPMs at 65 would be higher then in an a4? I thought I heard that somewhere, because the final gear on an m5 is steaper then a4?

i think in a t56 it would be worthless, better off going 3.73s or 4.11s

[ssms5411]

Re: A new diff with 3.42's

Docta, I want to clarify a few things cause I can see some confusion with you or other members. A differential/carrier sits inside the rear end/axle housing. A ring gear is installed on the differential/carrier and the pinion is install into the rear end/axle housing. You cannot replace just a differential and ring gear combo without replacing the matching pinion gear which requires a dial indicator to measure backlash. Unless you're getting a complete rear end/axle housing with a differential and gears installed, I just want you to know what you'll be getting into.

If anyone doesn't like my terms, please correct me cause I'm doin this off the top of my head.

I don't like your terms, stop posting. LOL J/K well done , plus if not going turbo 3.73's would be great for a M5 or A4, but if your freeway/highway driving I wouldn't go 4.10's, saty with 3.73's. GM Motive gears are pretty quiet , I drove 90 mph about 180 miles and they can't be heard.

[Docta]

Re: A new diff with 3.42's

Docta, I want to clarify a few things cause I can see some confusion with you or other members. A differential/carrier sits inside the rear end/axle housing. A ring gear is installed on the differential/carrier and the pinion is install into the rear end/axle housing. You cannot replace just a differential and ring gear combo without replacing the matching pinion gear which requires a dial indicator to measure backlash. Unless you're getting a complete rear end/axle housing with a differential and gears installed, I just want you to know what you'll be getting into.

If anyone doesn't like my terms, please correct me cause I'm doin this off the top of my head.

I'm not entirely sure what I'm getting myself, yet. I'll be sure to put up the pictures that I get sent. I got the ones of the exhaust today... It's looking pretty clean. Not sure when I'll get the diff pics but I'll put them on this thread to see what you guys think..



Is it worth it to upgrade to a posi with 3.42's for an extra $100?

[ssms5411]

Re: A new diff with 3.42's

Depends how many miles on the posi and gears and what they look like? (if they have nicks in them or the posi is worn out then no. If alot then no, becuase you'll be having problems later on or have alot of noise.

[Docta]

Re: A new diff with 3.42's

That would make sense. I should be getting the open diff 3.42's pictures today...