3.38 Diff Installed, 4 hours my ass.... 1 hour install

Hi all.... just put a 3.38 in tonight and I gotta say, we did a lot of work and it wasn't difficult at all. So for anyone who can put their car on a lift, go for it, this was as easy as putting an exhaust on.......



K for starters, I used this DIY

http://forum.e46fanatics.com/showthread.php?t=145570

Perfect 10/10...... no roadblocks, no surprises (surprisingly lol), very straight forward, and thats that




In a nutshell... did a couple things different...

1. I have a TSE3, so rather than letting the exhaust hang, I simply removed the last two sections... made it very easy

2. Car was on a lift, left in neutral

3. Remove the clips on the sway bar, however didn't take it out, we just pivoted it down all the way, it gave more than enough room for the diff to clear when we took it out

4. Removed the rear suspension reinforcment bar..... took 1 minute, 6 bolts

5. Removed the 6 bolts per axle, took about a minute per side with the air gun... you can rotate the tires pretty easily rather than trying to maneuver around the axle

6. Removed the 6 bolts for the driveshaft.... took a few minutes since its a little less space to work in and a little harder to rotate

7. 2 bolts in the front and 1 bolt in the back holding the diff up, removed those in within a few minutes, then had to pry the diff off the driveshaft while we lowered it out of the car...



Diff off the car

Banged out the flanges, took a minute per side if that.... swapped them. Yes the 3.38 has a different flange....

-The 3.38 flange had 6 holes equally dispersed... so a normal 6 star pattern (think of a rim...)

-The 2.93 flange (on my 6spd 330ci) had 6 holes, but it was designed more like a split 3 rim... so, 2 were next to eachother, another 2 were next to eachother, and another 2....

No big deal, bang em out with a hammer, and bang the others back in

In the meantime with the diff off the car, we removed the back of the diff, cleaned all the sh*t out of the inside, sealed it, bolted it, and filled it up with oil. I used the 75w90 Royal Purple, one bottle will do the trick

Reversed everything and thats it...... install was very straight forward. Took about 15 minutes total to put the diff on the car, bolt everything back up, and take the car off the lift.


For all of you "thinking" about doing this, don't hesitate... there really isn't any hard part if you have the right tools... however I'm fortunate that a buddy of mine is a mechanic with a lift, so I give you credit to tackling this on jack stands







First Impressions

Right of the bat, the car felt lighter putting it in reverse and backing out of the garage....

When I am WOT at low RPMs, I feel like i'm in the gear lower...... so gunning it at 30mph in 4th gear feels like what 3rd gear gave me.

I didn't really notice too big a difference with the RPMs.. still drove at 35mph in 4th gear, however the car is comfortable in 5th gear at that speed as well. Of course the big difference is when I am going faster, so we'll see how I like going 70-80mph in 6th...

1st gear is very noticable, however definitely not neck snapping

I haven't done a highway run yet so no info on that

The most impressive is the 1st to 2nd pull when you really get on it.... 2nd gear is REALLY strong, so it feels good shifting and still having those g's pulling hard

I'll do a good sprint tomorrow on the highway

Oh and please check out www.car-part.com
This mod costs me a hundred bucks Found a local place that had the diff, had 70k miles on it, and wanted $100... When we opened up the diff, the gears still looked brand new. Coming out of an automatic, it would be pretty difficult to fvck up a differential so 70k for that is still nothing.



J

I saw that you got this a few days ago I thought you were joking lol it seems too good to be true. Did you just give the place a call and picked it up?

Pretty much lol... however I called last Friday, they said they had a 3.38 in.
Went there Monday to pick it up, however it was still on the car. They took it off in an hour, which gave me time to go to the ATM and grab a coffee...

So took it home Monday, brought it by my buddies shop today so he could get an idea of what needed to be done, and said "lets just do it, it will take no time"

Never again will I post in this forum friggin crickets

Anyways, took it on the highway today on my way to work, all I gotta say is WOW. 3rd and 4th are great, while 5th and 6th surprisingly pull relatively hard. The car is definitely more ready to GO

Need to get used to driving 60mph, i feel like i'm killing my car cruising at 2700rpms

I did mine without a decent jack, took a little longer, but maybe like 15 minutes Its a very simple swap, even if you're lifting it up into the car on your chest

haha that must have been fun

I was thinking about doing this in the future. I really hate the way first gear is so short. Whats your rpm when you're at 75-80mph? Around 3500 I'm guessing?

My install took a few hours. As I recall, removing the half shaft bolts is tedious for those without air tools. You must turn the drive shaft every couple of bolts and then wedge something to prevent it from turning. This has to be done for both shafts. Of course, you wouldn't have to do this if you had an air wrench.

Originally Posted by E46Rida

I was thinking about doing this in the future. I really hate the way first gear is so short. Whats your rpm when you're at 75-80mph? Around 3500 I'm guessing?

actually its a tad over 3000........ probably 2900 at 75, 3200 at 80mph

I gotta say, I quickly noticed the higher rpms on the highway, and its helping me stay at 60-65mph

And.... after an aggressive tank of gas this weekend, i'm still averaging 22.5mpg, and i didn't go on my highways either

usually i'm at 23mpg, i'm sure that won't change

Originally Posted by lkstaack

My install took a few hours. As I recall, removing the half shaft bolts is tedious for those without air tools. You must turn the drive shaft every couple of bolts and then wedge something to prevent it from turning. This has to be done for both shafts. Of course, you wouldn't have to do this if you had an air wrench.

yep, put it in neutral and turned a little every 2 bolts....... definitely easy being under a lifted car

nice info bro. im planning on doing a 3.38 diff for my 330. got my cousins lift at his shop so i should be good. when u mean u turned the bolts a lil every 2 bolts u had to remove them evenly?

ohh yea also do you need to get fluid for the new diff?

Originally Posted by JELBMW330I

nice info bro. im planning on doing a 3.38 diff for my 330. got my cousins lift at his shop so i should be good. when u mean u turned the bolts a lil every 2 bolts u had to remove them evenly?

no, when you are removing the bolts from the drive shaft, you can't reach all 6 at one time, so when you remove one completely (or two), you'll have to turn the drive shaft to put the other bolts in the same position that way you can remove them

once you get under there you'll get it

remember, the flanges just knock right now, don't be afraid to give it a good whack

You just convinced me on my next mod. Cheers!

I want one!!!

Originally Posted by Young Gun

You just convinced me on my next mod. Cheers!

You'll be VERY happy when you get it

Originally Posted by brysterman

I want one!!!

Get one!

Originally Posted by JJR4884

haha that must have been fun

I did my trans the same way when I replaced the clutch I really need to just invest in a damned jack already

Originally Posted by JJR4884

yep, put it in neutral and turned a little every 2 bolts....... definitely easy being under a lifted car

Now that I think about it, I remember that this install was easy, but turning and then locking the drive shaft every two bolts was a total PITA. I think that I had to wedge both my rear wheels every time. Of course, I was on my back by myself in the garage. Did anyone else find a better way to keep the shafts from spinning as they loosened the half shaft bolts?

Good to hear. I'm going with a 3.15 soon. Didn't want anything too short since I still spend a lot of time on the highway.

Originally Posted by bigjae1976

Good to hear. I'm going with a 3.15 soon. Didn't want anything too short since I still spend a lot of time on the highway.

I've got a 3.15 in my 330, and I wish I had a 3.46. The highway RPM difference is not enough to even worry about that, IMO.

Originally Posted by lkstaack

Now that I think about it, I remember that this install was easy, but turning and then locking the drive shaft every two bolts was a total PITA. I think that I had to wedge both my rear wheels every time. Of course, I was on my back by myself in the garage. Did anyone else find a better way to keep the shafts from spinning as they loosened the half shaft bolts?

using an air tool, i only had to hold the driveshaft with a firm grip, it didn't spin at all

Originally Posted by bigjae1976

Good to hear. I'm going with a 3.15 soon. Didn't want anything too short since I still spend a lot of time on the highway.

meh... for the low end acceleration, the 3.38 is worth it. not to mention, i always drive by sound of the engine, not speed... so keeping it at 2500rpms will keep me at 65ish... i don't mind going a little slower, it will save me from getting an 80 in a 65 ticket

Originally Posted by AdamBath

I've got a 3.15 in my 330, and I wish I had a 3.46. The highway RPM difference is not enough to even worry about that, IMO.

do you have a 6 or 5 speed?

idk i don't enjoy cruising at 80mph.... 3000 rpms sounds a little bit too much for the engine IMO, 2700 tops for me