View Full Version : Anyone know of any problems with ....

12-04-2002, 02:58 AM
putting a 3.73 diff from a 89 325i into a 91 318i? i know the 318i has the 4.10 small case and ive heard about people putting 3.73 in place of the 4.10. any info would be cool.

Bimmer Heaven
12-04-2002, 03:16 AM
Dont see a problem... the only question is why??? Do you want to make your car beat high speed recards!!?? A lower ratio diff like this will make your car slower off the line, but somewhat faster at top speed...:huh?:

12-04-2002, 07:51 PM
no im doing this cuz my differential went out and i picked a full rear end for 100 bucks. people were telling me that the 3.73 was stronger and that my gears wouldnt rev out as much as they do now. so i dunno i thought i would try this differential for alil bit while its winter and see if i like it. this is also going to cost me close to 300 instead of some place chargin me 750 for the differential and to install it.

ps. ive never had my car over 100 so im not going for any top speed records.

Bimmer Heaven
12-05-2002, 02:20 AM
I think you should do it because of the good price, but I'm almost sure you wont like the way the car feels with it! Another option is to get one from an older (84-85) 318i, it will be a 3.91 so its closer to what you had. I know that diff is very strong; years ago when my 2.78 went on my 325e I got a 318i diff for $75 thinking it wont take the power of the 325, but I was wrong! 4 years of hard driving (with modified engine) and that diff was still good to the last day I stripped the car!