Diff????????

Tlvivo · 05-24-2011, 09:32 AM

Wassup yall...

i drive 320i steptronic my diff is messed I know nothing about diffs but it started making a knocking sound one day when I was pulling off a robot... Finally got the thing out the car and this is the result:

look inside - teeth are broken - what could cause this?

when i turn this propeller i get the knocking noise

is the last few number my ratio on the diff?

aggieE46 · 05-24-2011, 11:32 AM

Yep, last numbers are your ratio.

Tlvivo · 05-24-2011, 12:45 PM

thanks aggieE46, so when looking for replacement how much does this matter i have had someone offer me 3.38?

Chris-alfonso · 05-24-2011, 01:07 PM

A 3.38 is going to make your car accelerate slower and its going to drop your revs when cursing make it a little more fuel efficient.

Rob43 · 05-24-2011, 01:09 PM

Quote:

Originally Posted by Tlvivo

......... how much does this matter i have had someone offer me 3.38?

3.91 to a 3.38 diff is a 13.5% LOSS.

You probably don't want that.

Good luck.

Tlvivo · 05-24-2011, 01:13 PM

right seems like I am getting the hang of this now - how high can I go after 3.91?

Steven747 · 05-26-2011, 08:35 PM

wow stock you have a 3.91 thats preety cool

Tlvivo · 05-27-2011, 06:57 AM

Hey Steven747 yes, is that unusual?

Steven747 · 05-27-2011, 07:05 PM

Quote:

Originally Posted by Tlvivo

Hey Steven747 yes, is that unusual?

From what I recall I've only heard off diff ratios that high on x3 and 5 autos.. Does it pull kinda hard through first?

Tlvivo · 05-30-2011, 04:13 AM

No it doesnt pull hard at all... I enjoy this car, a lot of people get shocked when they find out its a steptronic... because it drives so well...

Tlvivo · 06-27-2011, 02:50 PM

guys finding a 3.91 ratio diff is proving pretty tiresome cannot find one anywhere, if i had to get a 3.64 ratio how much loss am i looking at there and what can i gain? Your expert knowledge would be appreciated.

Steven747 · 06-27-2011, 03:31 PM

Quote:

Originally Posted by Tlvivo

guys finding a 3.91 ratio diff is proving pretty tiresome cannot find one anywhere, if i had to get a 3.64 ratio how much loss am i looking at there and what can i gain? Your expert knowledge would be appreciated.

Alot better gas mileage

Rob43 · 06-27-2011, 03:47 PM

Take a look at this.....

http://www.diffsonline.com/product/gearsets.shtml

Good luck.

Tlvivo · 06-28-2011, 08:26 AM

Rob thanks for the link its pretty affordable to get these gear sets even if i have to ship them - how hard is it to replace? Can I DIY or not?

Rob43 · 06-28-2011, 01:18 PM

Quote:

Originally Posted by Tlvivo

Rob thanks for the link its pretty affordable to get these gear sets even if i have to ship them - how hard is it to replace? Can I DIY or not?

Can't answer, I've never rebuilt a diff. I'm told you need to be Very Precise, If you DIY definitely read up on how to do it.

Good luck.

TxZHP04 · 06-28-2011, 01:59 PM

Bulding a diff is a bit of an art. I wouldn't normally recommend the average DIY'er attempt it. It is doable though and if you decide to tackle it make sure to do your homework before diving in - it's really easy to ruin a diff if it's not built right.

mrshelley · 06-28-2011, 02:24 PM

I can pretty much rebuild anything and have done a fair share of diffs in other cars. For mine, I am willing to spend the bucks to have someone else to do it.

Also, if you are looking at diffs, the Z4 and X3 take the same diff housing. This means they will bolt up into an e46. For example, my diff is from a 2007 Z4 3.0i automatic. For $400 I got a complete 3.73 diff which was better than the $1200 I was getting quoted for just a 3.73 ring and pinion.

Drewfus2101 · 06-28-2011, 03:14 PM

Quote:

Originally Posted by mrshelley

I can pretty much rebuild anything and have done a fair share of diffs in other cars. For mine, I am willing to spend the bucks to have someone else to do it.

Also, if you are looking at diffs, the Z4 and X3 take the same diff housing. This means they will bolt up into an e46. For example, my diff is from a 2007 Z4 3.0i automatic. For $400 I got a complete 3.73 diff which was better than the $1200 I was getting quoted for just a 3.73 ring and pinion.

Good info. I need to do the same thing.

Tlvivo · 07-04-2011, 09:27 AM

Guys thanks for the info I really learnt a lot here about Diffs, i did not even know much about how these worked!!! I finally fixed the car on friday - I basically spent most of my saturday looking for a diff and much later in the day I was lucky found a very good second hand 3.91 diff for $298!!!!! While repair places where offering to recondition my old one from about $670 - $1200. My car is back on the road doing what it does best...

05-24-2011, 09:32 AM	#1
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	Diff???????? Wassup yall... i drive 320i steptronic my diff is messed I know nothing about diffs but it started making a knocking sound one day when I was pulling off a robot... Finally got the thing out the car and this is the result: look inside - teeth are broken - what could cause this? when i turn this propeller i get the knocking noise is the last few number my ratio on the diff?

05-24-2011, 11:32 AM	#2
aggieE46 Keep it clean Join Date: Aug 2006 Location: Royse City Posts: 8,012 My Ride: Evo, 330Ci, Xterra View My Garage	Yep, last numbers are your ratio. __________________ ^No longer looks like this Buy my:: 3.46 Differential Coolant hard line European Head Unit

06-28-2011, 01:59 PM	#16
TxZHP04 Registered User Join Date: Feb 2006 Location: DFW Posts: 5,732 My Ride: ESS TS2+ ZHP View My Garage	Bulding a diff is a bit of an art. I wouldn't normally recommend the average DIY'er attempt it. It is doable though and if you decide to tackle it make sure to do your homework before diving in - it's really easy to ruin a diff if it's not built right. __________________ 04 IR 330i ZHP \| ESS TS2+ SC \| MagnaFlow "headers" \| KMS 3.64 LSD \| AST 4100 550/650\| APEX ARC-8 18x9 \| H&R front sway bar \| Vorshlag camber plates, RTAB limiters \| TMS subframe & swaybar reinforcements \| UUC SSK & DSSR \| UUC TM & TME \| BW motor mounts \| Dinan strut & shock tower bars \| vaio 4-bolt oil pump Last edited by TxZHP04; 06-28-2011 at 02:29 PM.

06-28-2011, 02:24 PM	#17
mrshelley Registered User Join Date: May 2004 Location: Bethlehem, PA Posts: 914 My Ride: 2004 330i View My Garage	I can pretty much rebuild anything and have done a fair share of diffs in other cars. For mine, I am willing to spend the bucks to have someone else to do it. Also, if you are looking at diffs, the Z4 and X3 take the same diff housing. This means they will bolt up into an e46. For example, my diff is from a 2007 Z4 3.0i automatic. For $400 I got a complete 3.73 diff which was better than the $1200 I was getting quoted for just a 3.73 ring and pinion. __________________

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05-24-2011, 12:45 PM	#3
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	thanks aggieE46, so when looking for replacement how much does this matter i have had someone offer me 3.38?

05-24-2011, 01:07 PM	#4
Chris-alfonso Registered User Join Date: Jan 2009 Location: Miami Florida Posts: 1,126 My Ride: 330i View My Garage	A 3.38 is going to make your car accelerate slower and its going to drop your revs when cursing make it a little more fuel efficient.

05-24-2011, 01:13 PM	#6
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	right seems like I am getting the hang of this now - how high can I go after 3.91?

05-26-2011, 08:35 PM	#7
Steven747 Registered User Join Date: Aug 2010 Location: Orange County, CA Posts: 4,182 My Ride: 05 330ci View My Garage	wow stock you have a 3.91 thats preety cool

05-27-2011, 06:57 AM	#8
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	Hey Steven747 yes, is that unusual?

05-30-2011, 04:13 AM	#10
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	No it doesnt pull hard at all... I enjoy this car, a lot of people get shocked when they find out its a steptronic... because it drives so well...

06-27-2011, 02:50 PM	#11
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	guys finding a 3.91 ratio diff is proving pretty tiresome cannot find one anywhere, if i had to get a 3.64 ratio how much loss am i looking at there and what can i gain? Your expert knowledge would be appreciated.

06-28-2011, 08:26 AM	#14
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	Rob thanks for the link its pretty affordable to get these gear sets even if i have to ship them - how hard is it to replace? Can I DIY or not?

07-04-2011, 09:27 AM	#19
Tlvivo Registered User Join Date: Apr 2009 Location: Johannesburg, South Africa Posts: 64 My Ride: 320i Individual View My Garage	Guys thanks for the info I really learnt a lot here about Diffs, i did not even know much about how these worked!!! I finally fixed the car on friday - I basically spent most of my saturday looking for a diff and much later in the day I was lucky found a very good second hand 3.91 diff for $298!!!!! While repair places where offering to recondition my old one from about $670 - $1200. My car is back on the road doing what it does best...