BMW Werkz banner

Just Added 3.46 Diff

16K views 44 replies 9 participants last post by  peterkulesza 
#1 ·
Well I had a few people ask me to post when I replaced my 2000 323i 5-speed 3.07 differential, with a 3.46 diff.

Well its done and I got it back, and its nice. I havent hooked my G-tech up yet but I can feel the difference in 1st and 2nd gear definetely. Now Im not talking gigantic differances, but it gives you that extra pull that it didnt have before in those low gears. Put together with the shark injector, CAI, and UUC exhaust its pretty fast. If anyone has any other experiences with a new diff, id love to hear.
 
#3 ·
hey guys..i am really interested in knowing more about this 3.56 diff. I'll be pickiing up my 330Ci with 6-speed manaul, in 10 days time, and i was wondering, if its worth swaping the stock 2.93 diff, with the 3.46 one. would if void my warranty, and also..i hear a couple rumours that the 3.46 diff, is too agressive...waht do they mean by this?? thanks boys
 
#4 ·
they probably mean that the ratio is so much closer that the gears run out too fast and your having to shift alot more, though you'll be knocking off a second or so on your 0-60.

had a friend switch to 4.10 and his first drive back home in it he snapped the clutch line because he was shifting so much. now given it was a mustang .. who knows. but he had a problem with redlining and bouncing off the rev limiter because he wasn't used to how fast he had to shift.
 
#6 ·
hey ive got a 00' 323ci and im basically new to diff swapping in general. can somebody tell me where to buy one, assuming i probably don't have a junkyard anywhere near me. thx for the help. also, who should i get to install it (dealer or mechanic) assuming i cant do it.
 
#7 ·
i drove a 92 w/ a bigger diff and then i ended up buying mine. anyways, it doesnt pull as fast as mine does (mine is chipped) with stock diff. it does however give it faster top speed, but it reduces your gas mileage by a lot, it does 70 on the highway at around 4k and 15-17mpg :(
 
#9 ·
hey tx323...I did a search on car-parts.com for a carrier (Thats what they call the diff), and found it at a junk yard in florida where I am for $450 plus shipping, about $60.
Just alittle info on my car, if it helps you at all.
I have a 2000 323i 5-Speed, I bought it while I was in germany, so I dont know if it has any differences between the US bought versions. It is a US Spec car though. Anyway, the stock Diff was a 3.07 but in the 2000 323i Automatic they put in a 3.46 diff to compensate for the loss in power. However they are interchangeable, so I just bought one from an auto 323i, and had the dealer install it for about $800. If you have an automatic....you might want to check on your gear ratio before you buy, maybe the same diff. Good luck!
 
#11 ·
thx jkloese, i jus checked carparts and i think i found one near me. Dealer install was 800? Yea i have a manual too, but im a little new to tuning so if you have any other suggestions to increase performance but not kill me on cost id really be interested. thx again
 
#12 ·
Well Guess what...Ive had the new diff in about 3 weeks now and last night the differential mounts ripped right off the frame. I was at a red light and when I hit the gas (just a normal take off) The car started shakeing violently and then smoothed out but I could still feel a shake. I pulled over to see if maybe a tire blew out or something and I didnt see anything wrong. Well I slowly creeped it home and jacked it up and found both rear differential mounts hanging about 4 inches below the frame. Im not quite sure how something like this happens but its in the shop now getting looked at. Just thought Id share that with you guys.
 
#14 ·
Well, ive gotten a call from the shop. They said that 3 of the 4 mounts on the rear subframe broke loose from the chassis. No parts need to be replaced but they are telling me that it will cost between $2000 and $3000 to repair the frame. That seems like an awful lot for some frame repair. Im doing some research with some other shops to see if thats correct. Oh and just to inform you, BMW service center will not repair frame damage. Thats why its at another shop. Ill keep you posted of the progress.
 
#15 ·
Originally posted by jkloese@Oct 29 2004, 09:14 AM
Well Guess what...Ive had the new diff in about 3 weeks now and last night the differential mounts ripped right off the frame. I was at a red light and when I hit the gas (just a normal take off) The car started shakeing violently and then smoothed out but I could still feel a shake. I pulled over to see if maybe a tire blew out or something and I didnt see anything wrong. Well I slowly creeped it home and jacked it up and found both rear differential mounts hanging about 4 inches below the frame. Im not quite sure how something like this happens but its in the shop now getting looked at. Just thought Id share that with you guys.
[snapback]220723[/snapback]​
If BMW installed your differential and then within a few weeks 3 of the 4 mounts were hanging, that should be there responsibilty to fix for free. Something doesn't sound right.
 
#16 ·
Why would BMW be responsible?? They didnt remove or replace the mounts. The just put in a new diff. Do you know where or what the mounts are?? The connect the subframe to the chassis. They are welded in above the floor pan. You cant even see them.
 
#17 ·
Originally posted by jkloese@Feb 10 2005, 06:58 AM
Why would BMW be responsible?? They didnt remove or replace the mounts. The just put in a new diff. Do you know where or what the mounts are?? The connect the subframe to the chassis. They are welded in above the floor pan. You cant even see them.
[snapback]289067[/snapback]​
:D Yep, I sure do know. Actually when they do this repair, they have to go in the trunk and cut out a large section. It works better when you replace all of the sheet metal in the trunk.
 
#18 ·
Originally posted by jkloese@Oct 29 2004, 09:14 AM
Well Guess what...Ive had the new diff in about 3 weeks now and last night the differential mounts ripped right off the frame. I was at a red light and when I hit the gas (just a normal take off) The car started shakeing violently and then smoothed out but I could still feel a shake. I pulled over to see if maybe a tire blew out or something and I didnt see anything wrong. Well I slowly creeped it home and jacked it up and found both rear differential mounts hanging about 4 inches below the frame. Im not quite sure how something like this happens but its in the shop now getting looked at. Just thought Id share that with you guys.
[snapback]220723[/snapback]​
Do you think this would have occurred if you had kept in the original 3.07?
 
#20 ·
what do u mean remove the mounts?? If you had read the posts, I said it happened while i was driveing, so when would they have removed them?? I seen the mounts that were pulled out with my own eyes. It wasnt lik ethey just noticed it when i was getting my oil changed or anything. You couldnt even see them cracking unless you remove the floor pan.
 
#21 ·
well first off, i did this mod last weekend. my buddy and i installed it ourselves.

there are three points where the diff mounts, two near the front and one large mount in the rear. The bolts are huge and heavy duty, and pretty impossible for the bolts to break. Other areas that contacts the diff are the rear two axle flanges and the front drive shaft (really doesnt matter for mounting)

the mounts could be ripped off. you should have checked when installing the diff to see if you had subframe damage. This is very common in E46 (mainly 2000 coupes 323/328 models).
 
#22 ·
Thanks for the info woobie, I dont know if your paying attention to any other posts this e46holic guy is writeing but he deosnt believe this can happen. He actually is bashing my other post like Im scamming someone who is buying my car after this happened to me. Check this link out and post you opinion on here. Thanks

http://www.bmw-forums.com/forum/index.php?showtopic=31455
 
#24 ·
Originally posted by jkloese@Feb 10 2005, 04:50 PM
Thanks for the info woobie, I dont know if your paying attention to any other posts this e46holic guy is writeing but he deosnt believe this can happen. He actually is bashing my other post like Im scamming someone who is buying my car after this happened to me. Check this link out and post you opinion on here. Thanks

http://www.bmw-forums.com/forum/index.php?showtopic=31455
[snapback]289426[/snapback]​
Again, you are misquoted me. I said I have seen it several times over the years, but NEVER from someone that doesn't race his car. It usually happerns when someone continually burns their tires from an intersection. Does that bring back memories????
 
#26 ·
well my friend isnt a bmw tech...i was the one who checked myself, he is just a handy man.

ANYTHING can wear your subframe. its just a poor design. Adding aftermarket (stiffer) suspension will wear it further. Going over bumps will wear it more. If you drive aggressive, turn sharply all the time, burning out....all will wear the subframe. The only way not to wear it is not to drive it lol.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top