* Need Help Soon *

[Project_E30]

Have a 325e swapping out Diff from 2.93 < 3.25 Anyone done this with some advice?? Gear oil + Gaskets <~~ what type of gear oil plus was wondering for the cover what gaskets i need ??

Newbie with this. Doing the swap on SAT.
Have all the tools and been working on cars for a little while but no Diff swaps, little bit of knowledge would help, what else should i do while i'm in the area of the car?

THX!!

[Starmavin]

Not to rain in on your paraide, but, you do NOT want to do that. Swapping diffs for a lower raito will not increase your power with an eta powered car. ETA motors make their power at lower rpms, all you are doing is dropping the usefull power band in each gear (You'll be in 4 gear by about 40 mph), killing your milage (you'll be running about 3000rpm at 60mph) and in the long run it'll only hurt your eta.

[Project_E30]

Soon to swap m50. Will the swap on the diff work for a month or two??
The 2.93 is shot. What would you sugest??

Very open to advice.

THX

[Starmavin]

That'll be fine untill you do the swap.

[Project_E30]

Swap was a lot easier than i thought.
Had to change the cover and flanges, (Note: Slide hammer works great for a removal tool on the flanges)

And i can tell the difference a lot. Good times when the engine swap comes along, until then going to have to take it easy.

However, i have a new issue, noise is gone from the Diff, yet i'm getting a pretty bad vibration. This came before the swap, shortly before the swap but nonetheless before.
Drive shaft U-joints?? Can't tell really where it's coming from, only active when in gear. Regardless of what speed once you push in the clutch it's gone. Higher RPM faster the vibration. Doesn't feel like it's coming from the back, i wana say almost from the clutch itself, but thats what makes me beleive it's maybe u-joints. Difficulty changing u-joints???? Advice????

Once again, in need of some knowledge.

(My many (?)'s are making me feel like a leech. )

[Starmavin]

Good chance its the center bearing, or guibo.

[gotKRAUT]

Originally Posted by Starmavin

Not to rain in on your paraide, but, you do NOT want to do that. Swapping diffs for a lower raito will not increase your power with an eta powered car. ETA motors make their power at lower rpms, all you are doing is dropping the usefull power band in each gear (You'll be in 4 gear by about 40 mph), killing your milage (you'll be running about 3000rpm at 60mph) and in the long run it'll only hurt your eta.

odd it takes almost a full second off the 0-60 on a chipped Eta when you swap in a 3.25...anything shorter than a 3.25 then it will really hurt you. I could see it being a problem on a non chipped Eta though being that the motor makes no top end power pre chip...

[Starmavin]

Originally Posted by gotKRAUT

odd it takes almost a full second off the 0-60 on a chipped Eta when you swap in a 3.25...anything shorter than a 3.25 then it will really hurt you. I could see it being a problem on a non chipped Eta though being that the motor makes no top end power pre chip...

It also takes a full 20 mph off your top speed, and drops your mileage by about 3-5 mpg or more, and the chips do nearly nothing for anything over 4000 rpm, and even with the rev limiter gone you don't want to stay in the red for too long with an eta.

Why? Been there done that. I did the 3.25 swap and went back, with stock gears I can wind out each gear longer making the most of the eta's power band, with the 3.25 you are shifting into 5th at 45 mph. It sucks.

[Project_E30]

Originally Posted by Starmavin

Good chance its the center bearing, or guibo.

Center bearing i know about. Possible you could enlighten me on what a guibo is?

THX!!

[gotKRAUT]

Originally Posted by Starmavin

It also takes a full 20 mph off your top speed, and drops your mileage by about 3-5 mpg or more, and the chips do nearly nothing for anything over 4000 rpm, and even with the rev limiter gone you don't want to stay in the red for too long with an eta.

Why? Been there done that. I did the 3.25 swap and went back, with stock gears I can wind out each gear longer making the most of the eta's power band, with the 3.25 you are shifting into 5th at 45 mph. It sucks.

lol er theres a little math error there, are you sure you arent thinking of the 3.73? cause that sounds like joemadoos car in the video with a 3.73 installed...we're talking about the 3.25

[Starmavin]

Originally Posted by Project_E30

Center bearing i know about. Possible you could enlighten me on what a guibo is?

THX!!

It's the rubber flex disk off the back of the transmission.

[Starmavin]

Originally Posted by gotKRAUT

lol er theres a little math error there, are you sure you arent thinking of the 3.73? cause that sounds like joemadoos car in the video with a 3.73 installed...we're talking about the 3.25

Perhapps, but, none the less it is still making more shifts too soon and lowers the amount of usefull torque in each gear.

[gotKRAUT]

either way, its been shown time and time again that with the 3.25 installed the cars 0-60 time drops considerably, thus making it a worthwhile install,

you can not reach 60mph in second gear with a 2.93 and even raised redline of dinan chip anyway, you will reach about 56mph, i have tried so its not like you are losing anymore time to shifting...still have to get into 3rd gear to hit 60mph

[ldsbeaker]

^^ I hate that about our cars.
However, if you have an S52, and a 2.93....

[gotKRAUT]

no, S52 and 3.73 would be tits haha

alexs M50 with the 3.73 installed is insaaaaaaaaaaaaaaaaaane, super close ratio, always in the power band, so nice

but he daily drives on the 3.25 for gas mileage