Opinions on racingdiffs.com

[maupineda]

my V2 kit came with the incorrect large pinion bearing, which was the ball bearing type used on the E9x M3/ E6x M5&M6. The Z4M uses the same bearing set as the E46 (either V1 or V2). So I had to buy this Koyo bearing separate, not a biggy.

What is now making me wonder I have the right parts are the seals, sound like the seals may be different too?

Edit: the V2 should be more stout for the reasons above, and they have 8 clutches, this is logical as the diff needs to handle the torque of the V10, which though not much, it is more than the S54's.
Edit2: For my rebuild I have decided not to open the diff, just change bearings and the crown and pinion for the 4.1 ratio. not worth the hassle in my eyes, plus my diff is fine. it clunks but it also locks up perfectly fine.
Edit3: I have checked real OEM and the seals are shared with the E9x M3 and E6x M5

So the issue is just the large pinion bearing, all other bearings are the same.

[mrgizmo04]

great information, thank you.
If everything is the same but the LSD carriers themselves, then can I assume the output flanges are the same, but V1 has the short one on right side and V2 with short flange on the left?

Short answer - output flanges are the same, just short vs long is swapped side to side. Because...long answer below.

Design is interesting between v1 vs v2.

If you were to split the diff in half from front to back vertically and look at it from the back, the left half of the diff would have the ring gear. V1 lsd unit itself comes apart (how you get to the clutches and spider gears) from that left side, there is a plate that you remove right after you remove the ring gear. From there, once that plate is open, still moving from left to right inside the v1 lsd unit, there are shims and clutch pack and steel plates. Now if we say we now moved to the right half of the diff and at the very end on the very right of the v1 lsd unit are the 4 spider gears. The splines on the left output flange can go through the clutch pack (clutch pack has hole in the middle big enough for the flange to go through, and clutch pack has teeth to engage the flange). So clutch pack (there are about 6 clutch discs) has the teeth on the inside and those teeth engage the spline. They alternate with steel plates which have teeth on the outside of the discs and engage with the lsd unit case. Stacking those clutch packs vs steel plates creates the slippage/friction, since clutches rotate with output flanges while steel plates rotate with lsd unit case. The output flanges can not go through the 4 spider gears. So hopefully you see why on v1 lsd units the play is in the right flanges it is shorter because the right half of the lsd unit stacks spider gear, while the left flange on v1 unit is longer because it can go through the clutch/steel plate pack and is more secure.

On the v2 lsd unit, the ring gear is still on the left half of the diff, nothing changes there, but you open the v2 lsd unit from the right side via the top unscrew plate. Behind there (going from right to left) you will find the clutch pack/steel plates, and then on the very left of the v2 lsd unit (side that is closest to ring gear) you will find the 4 spider gears. So the design flips access side to insides of lsd unit and sides on which clutch/steel played are vs spider gears. So in v2 lsd unit, since it has the spider gears on then left half of the diff, and the output flange can not go though the spider gears, left side flange is short, while right side flange is long since it can go though clutch pack. Thus play is on left side for v2 lsd unit.

Hopefully that makes sense.

I'll try to do a video. I know I used a lot of words to describe, but picture is worth 1000 words.

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[mrgizmo04]

Edit: the V2 should be more stout for the reasons above, and they have 8 clutches, this is logical as the diff needs to handle the torque of the V10, which though not much, it is more than the S54's.

So from your response in post 51 (and based on previous response sounds like you decided against actually replacing the clutches and opening the lsd unit, I dont blame you), and in talking to Luka, v2 clutch pack has the same number of clutches, which I believe is 5, as the v1 kit. So the website description is wrong in saying v2 has 8 clutches. I also watched about 6 of Luka's videos and where he rebuilds e92 v2 unit, and counted the clutches, it's also 5. There is also a comment on one of the racingdiffs videos that someone received a kit with 5 clutch plates and were confused because they expected 8, racingdiffs confirmed 5 is correct. That might actually be your comment . Agree if v2 came with more clutches I'd be more inclined to go through the trouble of rebuilding a v2 lsd unit. But if it's the same as v1 and has so many more hops and procedures to take apart and put together and reset backlash, I think it's a no brainer to just use v1 lsd units.

Agree just 1 bearing is no biggie, my problem is - people might not know that incorrect bearing is provided and also that the v2 bearing/seal kit you buy from racingdiffs is over $100 more than the v1 kit that we actually need for e46 diffs, since yes, bearings, seals, etc on e46 are same. So you are paying up over $100 more for a kit that has incorrect part + you have to shell out more $ (and waiting time) to buy the correct bearing (because returns/shipping back to Serbia is a bit more complicated).

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[sapote]

So from your response in post 51 (and based on previous response sounds like you decided against actually replacing the clutches and opening the lsd unit, I dont blame you), and in talking to Luka, v2 clutch pack has the same number of clutches, which I believe is 5, as the v1 kit. So the website description is wrong in saying v2 has 8 clutches. I also watched about 6 of Luka's videos and where he rebuilds e92 v2 unit, and counted the clutches, it's also 5. There is also a comment on one of the racingdiffs videos that someone received a kit with 5 clutch plates and were confused because they expected 8, racingdiffs confirmed 5 is correct. That might actually be your comment . Agree if v2 came with more clutches I'd be more inclined to go through the trouble of rebuilding a v2 lsd unit. But if it's the same as v1 and has so many more hops and procedures to take apart and put together and reset backlash, I think it's a no brainer to just use v1 lsd units.

So why they went through the trouble making V2 LSD? I don't think just get the 4 spiders on the locked pins to the carrier instead of stacking the pins in the square grooves. In fact it makes no difference of spiders/side-gears backlash using locked through-hole pins or stacked pins.

[maupineda]

…Agree if v2 came with more clutches I'd be more inclined to go through the trouble of rebuilding a v2 lsd unit. But if it's the same as v1 and has so many more hops and procedures to take apart and put together and reset backlash, I think it's a no brainer to just use v1 lsd units.

Agree just 1 bearing is no biggie, my problem is - people might not know that incorrect bearing is provided and also that the v2 bearing/seal kit you buy from racingdiffs is over $100 more than the v1 kit that we actually need for e46 diffs, since yes, bearings, seals, etc on e46 are same. So you are paying up over $100 more for a kit that has incorrect part + you have to shell out more $ (and waiting time) to buy the correct bearing (because returns/shipping back to Serbia is a bit more complicated).

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my comment about the no. of clutches is not based on their website info, but counting the clutches in their own video as they disassembled it as well as other people’s who have posted videos too. Also on ZPost forum another user posted photos of his opened showing there are 9 dog plates and 8 clutches. Racing diffs used more clutches in the first version of the kit too, and moved to less as they added the big bevel preload spring and there is also a thicker dog plate. I am not saying that is good or not, but a change none the less.

now your comment about clutches lasting 20k as opposed to 100k of the OE makes me wonder how much better their aftermarket clutches are, so opening the diff just for the free play shim as the only tested item is a stretch.

i agree. At this point I wish I had a V1 unit 😂

and like you said, the pricing is off as that big mama ball bearing cannot be that much more than the roller item on the E46 and Z4M

[mrgizmo04]

So why they went through the trouble making V2 LSD? I don't think just get the 4 spiders on the locked pins to the carrier instead of stacking the pins in the square grooves. In fact it makes no difference of spiders/side-gears backlash using locked through-hole pins or stacked pins.

It does somewhat, when you apply the free play shim at the end of the spider gears and the pins in v2 unit for spider gears dont line up with the holes on the case, so you have to use a press compress the freeplay shim to get the pins in, creating this static preload. In v1 sliding/stacking, i would assume creates some play once the clutched wear and doesnt provide the same static force/preload. Maybe the thinking of getting v2 units out was freeplay in v1 units, since you can also adjust the final breakaway torque of the v2 unit by tightening the final cap tighter vs looser. Maybe there was some other consideration that GKN was planning but didn't materialize. Naturally the thinking was toward more powerful cars post e46, I don't know. Maybe someone else can chime in.

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[mrgizmo04]

my comment about the no. of clutches is not based on their website info, but counting the clutches in their own video as they disassembled it as well as other people’s who have posted videos too. Also on ZPost forum another user posted photos of his opened showing there are 9 dog plates and 8 clutches. Racing diffs used more clutches in the first version of the kit too, and moved to less as they added the big bevel preload spring and there is also a thicker dog plate. I am not saying that is good or not, but a change none the less.

now your comment about clutches lasting 20k as opposed to 100k of the OE makes me wonder how much better their aftermarket clutches are, so opening the diff just for the free play shim as the only tested item is a stretch.

i agree. At this point I wish I had a V1 unit 😂

and like you said, the pricing is off as that big mama ball bearing cannot be that much more than the roller item on the E46 and Z4M

Yeah maybe they are updating designs as they test in street/racing/drifting and gather feedback. If v2 unit actually starts with more clutches (I havent opened mine up because I dont have the tool or the vice at this point) and their rebuild kit has fewer clutches and then they take up the extra room with a bigger preload shim...well, their big sales point is taking out freeplay and lsd unit noises by preloading everything until no noise is heard . That is also why Dan is not a huge fan of all the preloading Luka and team sell, as that wears out spider gears and internals faster.

On clutches lasting 20k miles, all clutch packs sold these days (non oe) dont last that long. My diff that Dan rebuilt barely lasted about 20k miles (that included a lot of track and drifting fun). He says he cant find any that last longer that are still made these days. Luka says his clutches should last a bit more than 20k miles, but I remember seeing on his site somewhere a disclaimer that clutches are expected to last about 50k kilometers (about 30k miles) with street driving and mild track. 🤷♂️

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[sapote]

Yeah, I'm not sure preloading the spiders and side-gears using the spring shims is a good solution. Just think why a brand new M3 out of the lot already had output flanges backlash (jack up and manually rock the wheel back/forth). The factory engineer purposely had some backlash built in the gears, and using spring washers or shims was just a piece of cake for them. But of course too much gear backlash is not good as clutches worn down.

[CrookedCommie]

Just wanted to update on the ZF 4-clutch LSD I got from racingdiffs (I don't think they offer it anymore). It's done after 6 track weekends and has completely locked up, not even drivable in the paddock. I'm going to send it over to diffsonline to see if they can rebuild and setup the ZF LSD, if not, have them throw in something proper.

As always, you save some money, you pay more for it in the end. Good luck fellas.

[BBRTuning]

I too have their ZF adjustable 4-clutch LSD in 1.5way configuration in mine, while it did work better than my tired factory LSD, and works decently on track (I'm logging individual wheel speeds so it's quite easy to see), the lockup is weak and 1st/2nd gear stuff it will just unload and do a one wheel burnout. I slightly improved the lockup by using straight 75w140NS (non friction modifier fluid) so now it makes noise but locks slightly better. Either way, pretty trash for the money involved. While there is a more aggressive ramp I can set it to, at this point I'm ready to just buy something better. Taking the diff out so many times to change settings is getting really old. As CrookedCommie said, you'll pay more in the end. Go with something from DiffsOnline, Drexler, OSGiken (with custom settings), etc.

[EthanolTurbo]

I too have their ZF adjustable 4-clutch LSD in 1.5way configuration in mine, while it did work better than my tired factory LSD, and works decently on track (I'm logging individual wheel speeds so it's quite easy to see), the lockup is weak and 1st/2nd gear stuff it will just unload and do a one wheel burnout. I slightly improved the lockup by using straight 75w140NS (non friction modifier fluid) so now it makes noise but locks slightly better. Either way, pretty trash for the money involved. While there is a more aggressive ramp I can set it to, at this point I'm ready to just buy something better. Taking the diff out so many times to change settings is getting really old. As CrookedCommie said, you'll pay more in the end. Go with something from DiffsOnline, Drexler, OSGiken (with custom settings), etc.

This is why I'm going with a Drexler setup from Limitedslip.de... buy once cry once.

[BBRTuning]

This is why I'm going with a Drexler setup from Limitedslip.de... buy once cry once.

Ah yes, he's the other one I was forgetting! Another great option.

[bigjae46]

Just wanted to update on the ZF 4-clutch LSD I got from racingdiffs (I don't think they offer it anymore). It's done after 6 track weekends and has completely locked up, not even drivable in the paddock. I'm going to send it over to diffsonline to see if they can rebuild and setup the ZF LSD, if not, have them throw in something proper.

As always, you save some money, you pay more for it in the end. Good luck fellas.

Did you use their upgraded preload shim/spring? I reused what came with the ZF unit and it was already pretty tight. I'm just using the 45/45 ramp angles. Not 100% sure about their adjustable ramp pressure plates.

The OE M-GKN V1 and V2 kits work. I've installed quite a few of those.

I've kind of been wondering how great 4 clutch setup is. It works, haven't had an issue with 11 events on. It is much better than my worn-out stock unit which took too long to lockup and then not unlock quick enough. I remember the metric mechanic 3 clutch diff in my 330 being more responsive than this 4 clutch conversion.

I've wanted to try their thicker preload spring.

[CrookedCommie]

Did you use their upgraded preload shim/spring? I reused what came with the ZF unit and it was already pretty tight. I'm just using the 45/45 ramp angles. Not 100% sure about their adjustable ramp pressure plates.

The OE M-GKN V1 and V2 kits work. I've installed quite a few of those.

I've kind of been wondering how great 4 clutch setup is. It works, haven't had an issue with 11 events on. It is much better than my worn-out stock unit which took too long to lockup and then not unlock quick enough. I remember the metric mechanic 3 clutch diff in my 330 being more responsive than this 4 clutch conversion.

I've wanted to try their thicker preload spring.

I received a built unit so not sure how they set it up. They told me it was 30/60 ramp angles and 150-180Nm of preload.

[Lee_Enfield]

So how are people rating the rebuild kits with the clutch packs? Where are the bearing sourced from? Would I be better off ordering seperate koyo bearings and just ordering there clutch packs?

Are there any alternatives to racing diffs clutch packs? Diffs online offer bearings and seals but not clutch packs from what I can find.