Opinions on racingdiffs.com

[Gt4]

How did you like the 4.1 on the Z4M. I am about to buy one but the gear set is on back order at the moment. I cam do a 3.91 but don’t want to jump the gun as some say is not enough of a change over the 3.62

I had the 4.10 and ESS vt1-445 SC kit in the Z4M Coupe. It was a blast to drive!

I also had a 3.91 with Carbonetics 2-way LSD for the Z4M Coupe. The 3.91 fits my local track better than the 4.10 but I had more fun on the street with the 4.10.

[0-60motorsports]

I think it is very few E46 M3 who got the Gen2 GKN. the core is different and is the same used on E9x M3, E6x M5 and Z4M.

The Gen2 cracks open from the opposite side, and needs a special tool. Gen1 opens from the ring side

Good to know. I have been planning to overhaul my diff and as my M3 is an 04 would just using a low miles E92 M3 lsd core be better?

[maupineda]

Good to know. I have been planning to overhaul my diff and as my M3 is an 04 would just using a low miles E92 M3 lsd core be better?

as I understand, the Gen2 has a higher torque threshold, it has one more clutch as it needs handle the V10’s torque too.

[Ianb]

Maupineda - can you tell whether a Gen 1 or Gen 2 diff from the cutouts/openings in the sides of the lsd? I have seen pictures of two types. Some have circular and others have oblong cutout, picture in this link

https://z4-forum.com/forum/viewtopic.php?t=50881

I have an 05 and oblong cutouts(looks same as your picture), would this be Gen 1 or 2?

Do you have any info in the special tool required and is it something that could be made? Is that the tool in the photo, does it just fit over the lsd with the 4 lugs and you unscrew the end?

Thanks

[maupineda]

Maupineda - can you tell whether a Gen 1 or Gen 2 diff from the cutouts/openings in the sides of the lsd? I have seen pictures of two types. Some have circular and others have oblong cutout, picture in this link

https://z4-forum.com/forum/viewtopic.php?t=50881

I have an 05 and oblong cutouts(looks same as your picture), would this be Gen 1 or 2?

Do you have any info in the special tool required and is it something that could be made? Is that the tool in the photo, does it just fit over the lsd with the 4 lugs and you unscrew the end?

Thanks

the carrier with oblong openings are Gen2. Racingdiffs are very helpful and said they would provide detailed information on how to open the diff if needed.

i was told the tool is very simple, it is a circular steel plate with 6 or so tabs that engage to the carrier top cap, however, I was also let know that the carrier has a dowel that locks the cap and that needs to be drilled out. To close it back you can tap screw and use red loctite.

[maupineda]

I found some more pics...

You can see the pattern the tool needs to have



This is the dowel that needs to be drilled out

[Ianb]

That is very helpful thankyou, although sounds like I have the more difficult diff to open, at least it seems do able as after reading on another forum about a special tool being needed I was worried.

For those who have fitted the shim to remove play in the diff/spider gears has it worked and removed the play/noise? Mine really clanks in 1st and going 2nd to 1st.

[Arith2]

Well nuts. My car is an 06 but its manufacturing date is Sept of 2005. I'm hoping it has a Gen 1.

[Ianb]

Sure my car was manufactured a few months before yours, so reckon you will have a Gen 2 also.

[SandeepM3]

Just got a set of the racingdiffs advanced pack installed. Damn this thing locks up on every turn! Let's see how I feel about this.

There is a super slight wine on decel. Is that normal? Seems weird if only the clutches were changed.

[jet_dogg]

I got all the bearings, races, etc needed for a diff rebuild to supply to my builder from diffsonline. They were the right parts, assembly went off without a hitch, diff's great 👍 This place is actually one of the only places I know of where you can source the bearings for a 210mm M diff rebuild, so I would think they're pretty legit. Almost every diff builder around SoCal that I called when I was looking for someone to do my rebuild laughed at me and said "sure I'll do it if you can source the parts, but good luck". Didn't take long to find diffsonline, though, it's almost as if all these diff experts have never heard of the internet. Sure enough, once I got the parts most of them backed off and said they wouldn't be comfortable doing it

Who ended up doing the work on yours?

[sapote]

Well nuts. My car is an 06 but its manufacturing date is Sept of 2005. I'm hoping it has a Gen 1.

So have you found out if yours is V2 or V1, and did you replace the clutch kit?

[F360C]

I think it is very few E46 M3 who got the Gen2 GKN. the core is different and is the same used on E9x M3, E6x M5 and Z4M.

The Gen2 cracks open from the opposite side, and needs a special tool. Gen1 opens from the ring side

Did you end up buying the tool to crack it open? if so where did you get it from?

[maupineda]

Did you end up buying the tool to crack it open? if so where did you get it from?

No, i am about to… will buy the rebuild set, but if I am honest I am debating myself if I shall get the full rebuild kit as my diff has only 80k kms, but has the m clunk 😝

if I do get the full kit will get the tool also. I have the 4.10 gear set waiting me getting off my ass and swap it :0

[sapote]

No, i am about to… will buy the rebuild set, but if I am honest I am debating myself if I shall get the full rebuild kit as my diff has only 80k kms, but has the m clunk 😝

if I do get the full kit will get the tool also. I have the 4.10 gear set waiting me getting off my ass and swap it :0

I am pretty sure the clunk is caused by the worn clutch set. As for the tool, where do you buy one?

I plan to make the tool this way: get a 2" long steel cylinder with OD about 5mm larger than the carrier's threaded ring ID, and cylinder ID is 10mm smaller than the threaded ring ID or smaller for thicker wall. Drill 4 holes S at equal space on the cylinder end on a circle of diameter = threaded ring ID. Hole S has the same size and depth as the threaded ring half-moon 4 holes. Then turning the cylinder to cut its OD down to fit into the threaded ring within 0.001" clearance. Then machine a rod to have 4 short rods that fit snuggly into those formed by the half-moon of the cylinder and threaded ring. Cylinder length is around 2" with a 1" hole drilled through the top section for inserting a steel rod as the handle to turn the cylinder.
To use the tool, insert the cylinder into the threaded ring, align the 4 half-moon and drop the 4 short rods into the holes (formed by the half-moon) to lock them, use 1" steel rod to turn it. No welding needed for making the tool.