Do these differentials look OK?

[Swap_File]

I am currently swapping in an M50 and a manual transmission into my 318ti. Since I know the stock 4.45 ratio will not work very well, I went to the junkyard and picked up a few E30 and E28 differentials.

I know I will be replacing the input and output seals of whichever one I end up using, but it would be nice if someone could look at the gears and tell me if they look OK before I spend time on swapping it in.

3.73 LSD #1:



Is that surface rust starting to form? Or something else? It does not look nearly as bad in person, the camera's flash seems to make it really stand out.

3.73 LSD #2:

[Swap_File]

(Splitting post due to too many images)



I cleaned the dust off after I took the picture. Otherwise this one looked good, but it did seem much darker than the others.

2.93:




Very clean, but not an LSD. And even with the extra power of the M50 engine this ratio would probably be a lot less fun.

[tiFreak]

I'm not sure if that's surface rust or what on the first one, other than that it's not bad, and if it is just surface rust, I believe it would come off with use, is that dust on the second one? looks pretty good too, the third's the best looking out of all of all of them, but as you stated, wouldn't be the most fun with the added power

[dave45056]

with gears look for obvious problems with wear. Hypoid gears slide and push so you will see the same type of wear on all the gears, but different amounts. The color doesn't matter much unless it looks burnt as in run without oil... or too little of it. All of these look pretty goood. Unfortunately you can't tell the condition of the gears with pictures alone. You need to feel how they mesh and how much backlash it in the gears.

[spidertri]

Man, I wish there was junkyard around here with e30/28 diffs all over the place. If you don't mind my asking, how much did those 3.73s run you?

[trickiekid]

Spider, have you ever checked in bowie. I have seen a few e30's and e36's out at some.

[Swap_File]

I got them all from the local pick and pull. They charge a flat rate $46 for differentials, but unfortunately they do not get many BMWs in. I have been watching since last December (almost a year), and they have only gotten in 2 E30s and a E28 (I pulled all the differentials).

I paid full price for the 2.93 and the first s3.73. I got the second s3.73 on half price day, so it was only $23.

And yes, there was some dust on the second differential. It fell in when I took the cover off. I carefully cleaned it before closing it back up for storage.

[Will'sBimmer]

Awesome prices for Diffs. I wish I could have find some for that price.

[spidertri]

Originally Posted by Swap_File

I got them all from the local pick and pull. They charge a flat rate $46 for differentials, but unfortunately they do not get many BMWs in. I have been watching since last December (almost a year), and they have only gotten in 2 E30s and a E28 (I pulled all the differentials).

I paid full price for the 2.93 and the first s3.73. I got the second s3.73 on half price day, so it was only $23.

Ridiculous. If you want to sell one of the 3.73s let me know.