Used Differential purchase from Ebay ends with nice surprise

[fattycharged]

Purchased a used differential off of Ebay a while back in an attempt to quick fix an issue I was having diagnosing a severe clunk I was experiencing. At the time I made the assumption my 4.1 m-variable unit was on its way out and needed replacement. I had the vehicle out at MSR Houston at the time and decided to just let them give it the once over and install that replacement diff at the same time while I was having an alignment done and a fresh set of tires put on. When I received the call she was ready, I assumed the new differential had been put in, turned out I was incorrect, I just didn't have the front bolt tq'd properly...somewhat embarrassing, but oh well, saved me some labor and I had a spare diff to now take up some of that extra space in the garage. Fast forward 5 years or so, I'm clearing out the garage and oh hey spare differential, I should get rid of you. So after listing it locally for sale, I decide to take a look at it for whatever reason and check the output ratio, some "feeling" I had about it right before handing it off for $500. So I mark the output with a zip tie and throw a bolt in the input to mark it and start turning it. Wouldn't ya know, that output spins 4 times...so I double, triple, quadruple check it, yup, 4.1. So random I ended up with another 4.1 when I was shooting for a stock 3.62. Today I decided to have another look at it and replace the currently shot cover bushings with some e36 bushings I have lying around. I'm sitting here staring at it thinking, this is not how I remember my carrier looking. So I hit up the google trying to find something that matches what I've got and after a few minutes of searching, I land on this linked below....guess they not only sent me a 4.1, but also sent me a z4M diff as well. Yay, I think. If you made it through my rambling, congrats on your patience

Anyone running one of these? Thoughts?

[fattycharged]

[sapote]

Yep, it is version V2 that being used on E46 M3 in later years, 2005 to 2006 I believe. I have one on my 2006 M3.

[sapote]

Today I decided to have another look at it and replace the currently shot cover bushings with some e36 bushings I have lying around. I'm sitting here staring at it thinking, this is not how I remember my carrier looking.

I assume the internal carrier is still in the diff and you only removed the cover. Can you check the radial plays on the left and right output flanges? For V2 diff, the left has more wobble/plays and the right flange should be solid. The reverse is for V1 diff.

[George Hill]

Yep, it is version V2 that being used on E46 M3 in later years, 2005 to 2006 I believe. I have one on my 2006 M3.

This is in line with what Dan @ Diffsonline told me too.

[fattycharged]

I assume the internal carrier is still in the diff and you only removed the cover. Can you check the radial plays on the left and right output flanges? For V2 diff, the left has more wobble/plays and the right flange should be solid. The reverse is for V1 diff.

Yes, just the cover has been removed. I notice no play on either side on this V2, absolutely none that I can demonstrate. Very very solid compared to my 01 passenger side output, which has noticeable radial play.

Ok, so it is not necessarily a Z4 unit, I didn't recall noting what year model this came from on purchase and the Ebay link has since been archived where I cannot retrieve it.

[sapote]

Yes, just the cover has been removed. I notice no play on either side on this V2, absolutely none that I can demonstrate. Very very solid compared to my 01 passenger side output, which has noticeable radial play.

Then it is in great condition original stock, or it was rebuilt. Most used V2 diff have radial plays on left side output flange.

[lemoose]

is either one considered "better" than the other?

[fattycharged]

Then it is in great condition original stock, or it was rebuilt. Most used V2 diff have radial plays on left side output flange.

was obviously worked on as it has a 4.10

[sapote]

is either one considered "better" than the other?

V2 is stronger but hard to disassemble -- needs special tool to open the carrier to get to the clutch set, and side-gears for shimming.

[old///MFanatic]

was obviously worked on as it has a 4.10

Yes, since it's stated clearly it has a 4.10 it's obvious it had to be worked on.