I am installing (attempting) the STi "rear" rear diff bushing. I thought I had it figured out but ran into a hurdle. The bushing is held in w/ four bolts, the two outer ones hold the bushing to the cross member, the two inside ones go through the bushing strap and hold the rear diff to the cross member. The two inner "bolts" are actually studs and I think I can back them out of the diff by putting a couple of nuts (12X1.25) on the end (long bolts)- that would free the rear diff (supported by jack stand). I thought I could simply unbolt the two outer ones, pull out the bushing and replace. Here is where I ran into the snag. I unbolted the two outer ones and went to pull the bolts out- they come out a couple of inches then bump right into the rear axles (near the top). No way to get them out. My question is can I lower the diff safely- probably 2" (thus lower the axles w/ it) and then I would be able to pull the bolts out and reinstall them w/ the new bushing. Can the rear diff be lowered a couple of inches safely? I don't want to ruin any seals or such. Does anything forward of the rear diff need to be removed to allow it to lower?

Pic of four bolts from rear



http://www.clubwrx.net/forums/showthread.php?s=&postid=151491#post151491


A pic of the bushing- arrow where I'm running into problem w/ axle

http://www.clubwrx.net/forums/attachment.php?s=&postid=151491

Thanks

Big Sky

dam red X

try again

http://www.clubwrx.net/forums/attachment.php?s=&postid=151490

Lookup the whiteline rear diff bushings and where those go you could loosen/remove that to perhaps lower the rear diff a bit. Although getting 2" I couldn't answer that.


Whiteline rear diff support (KSB751)

It may be possible to saw the heads off and remove the bolts from the back, then install new bolts with the head on the outside and the nut inside, unless there are engineering reasons against reversing the bolts.

I thought about that, I'd probably have to go w/ a slightly shorter new boltas I would want to ensure there was no rubbing w/ the axle-I don't think there is any engineering advantages w/ the bolt one way or another. Cutting the bolts would be a pain however as there is not tons of room

tevai-boy- I got to thinking about your idea some more and unfortuantely it won't work as lowering the member also lowers the bushing as it is in the member housing. In other words I would be in fact lowering the differential, but also lowering the bushing at the same time, thus not gaining anything.

I'm thinking that if I remove the lower differential bracket (sits just infront of the rear diff) and pull the two center studs- the rear diff would be "free" just sitting on the jack. I'm thinking I could then lower the rear diff slightly a inc? or two and then the bolts should clear. The only thing I'm concerned about is if the lowering of the diff (1-2") would have any adverse effects?

Thanks for everyones suggestions thus far.

Big Sky

Ok, I wish I had taken pictures when I did this, but I didn't. Maybe should redo it and take pics.

Anyways, here is the trick to this. You do have to take out the two studs. The two middle bolts on the pic below. Take off one of the nuts on either side and turn it around and put it on the other stud and tighten it down so you have two nuts on one stud up against each other tightly. Then just turn the one closer to the diff and it will start unscrewing the whole stud.

Once you have that stud out put the two nuts on the other stud and do the same. It's just a matter of having those two nuts tight enough together to loosen the stud. It's kind of tricky but once you get it, the job gets really easy. Once you have those two out, you can drop the diff about 1-2 ". Not really necessary to drop the diff at this point, but it can provide you with more room to get to the outside bolts. Since If I remember correctly the drivers side one is a pain since the exhaust is right there and you have to work around the shaft to get to it. Best to have a jack or something holding it up. Don't worry it won't drop, but I am just paranoid and just like to have things like my drivetrain supported. ;)

Anyways once you have those two studs out of the way and the other two bolts out, you can just slide the diff mount easily out and the new pretty sti one in. And just redo the studs the same way just using the nut on the outside to tighten it down. If this doesn't make any sense, let me know and I will see if i can get some pics to clarify.


also, it's best to just use two open end wrenchs on the studs in the diff since you can't get a socket over the first nut to the second.

Oh, and standard disclaimer. I take no responsibility for what you may do to your car while doing this. But after I got mine in, unfortunately the knock was still there, but the diff doens't like to float around like it used to, which is a vast improvement in cornering.

Originally posted by BIGSKYWRX
dam red X

try again

http://www.clubwrx.net/forums/attachment.php?s=&postid=151490

Thanks. That was my original idea, but was told not to go that route for fear of stripping bolts- sounds like that won't be a problem.

How do you know if the stud is seated deeply enough when re-installing? Does it "bottom" out?

Thanks. I can't believe how much work I did previously and still didn't get it in

mad:. I shoudl have gone w/ my first "instincts".

Mike

bigsky - please take some detail step by step pics when you do it successfully this time. Me (and probably a lot of other people) will thank you for it :)

Originally posted by bemani
bigsky - please take some detail step by step pics when you do it successfully this time. Me (and probably a lot of other people) will thank you for it :)

Will do. Hopefully this weekend.

Big Sky

Let me know if it all goes well, if not I will pull mine apart and take pictures as I put it back together this weekend. Probably after racing on sunday.

Originally posted by wrxwgn03
Let me know if it all goes well, if not I will pull mine apart and take pictures as I put it back together this weekend. Probably after racing on sunday.

Thanks, I appreciate it.

Done! Third times a charm. Thanks wrxwgn03 for the help.

Tutorial w/ pics here:

http://www.clubwrx.net/forums/showthread.php?s=&threadid=24484

Will get it up on scoobymods as well.

Big Sky

what is the part number of this bushing?

Originally posted by bemani
what is the part number of this bushing?

ST413104S000- try Wayne at AVSport, they usually have them in.

Thanks. Just received the part from AV sports today. I'll probably have more 'fun' installing than you, seeing how I have to take the oem differential cover off also ;)

Is there an upgrade like this for GC?

What do you think about the difference now that you have replaced the diff mount with the STi version?

I didn't not expect much, however the rear end seemed tighter right way.

Originally posted by RokketRide
Is there an upgrade like this for GC?

I'm 99% sure same part #, check w/ Wayne @ AVSport.

I didn't notice a huge difference, but it was perceptable. Also didn't notice any increase in NVH. I think it is much like the tranny/engine mounts- not a real noticable difference in day to day driving, but when pushing 9 or10/10ths, it's noticeable:D .

Big Sky

Pretty sure the rear diff in my car bolts up differently than on WRX.

One thing for sure, it is now the sloppy point in the drivetrain.

Originally posted by RokketRide
Pretty sure the rear diff in my car bolts up differently than on WRX.

One thing for sure, it is now the sloppy point in the drivetrain.

There is a good pic above that you should be able to compare.

Finished! Very easy thanks to the tutorial. :D The hardest part was the stud, and it was actually easier to do when the 2 flat parts of the nuts are next to each other (nuts' directions are reversed compare to the picture). Just squeeze them real tight and start turning :disco:

I spent more time putting that dang diff protector back on :lol:

Originally posted by bemani
Finished! Very easy thanks to the tutorial. :D The hardest part was the stud, and it was actually easier to do when the 2 flat parts of the nuts are next to each other (nuts' directions are reversed compare to the picture). Just squeeze them real tight and start turning :disco:

I spent more time putting that dang diff protector back on :lol:

Glad it helped! Noe if someone would get up a trailing link bushing tutorial- I'd be set;) .

Big Sky

Too bad I can't help - I took the easy way out and got the whole STi trailing arm instead :D

Originally posted by bemani
Too bad I can't help - I took the easy way out and got the whole STi trailing arm instead :D

Cheater;) .