Blackline helical LSD - any good?

[1536Z4]

Just pondering as I have a lovely quaife diff for a 18i/20i/30i manual

On the Mattlewisracing site it says the blackline LSD that fits the E86 which has the 188k diff also fits the E89 2.3i s drive and the 3.0i s drive

https://www.mattlewisracing.co.uk/produ ... 1_3_series

[B21]

Just pondering as I have a lovely quaife diff for a 18i/20i/30i manual

On the Mattlewisracing site it says the blackline LSD that fits the E86 which has the 188k diff also fits the E89 2.3i s drive and the 3.0i s drive

https://www.mattlewisracing.co.uk/produ ... 1_3_series

[Joycey]

Right chaps. I’ve just fitted my Blackline LSD and so far so good. Crown wheel swapped over no issues and alignment was spot on. You’ll need new bearings and seals doing this conversion, seals get damaged on removal and bearings good practice to change when removed. Also took an hour to remove and hour to refit. The Blackline unit has a real tight lock which is nice, you can really feel it turning in. Will know better on track next month. Local transmission guy to us charged £180 to build the diff.

[GuidoK]

You’ll need new bearings...

Why do you need new bearings for this fitting?

[Joycey]

You’ll need new bearings...

Why do you need new bearings for this fitting?

You have to remove them. Just good practice while it’s all apart. My diff had 150k miles on it.

[SDJ]

You’ll need new bearings...

Why do you need new bearings for this fitting?

You have to remove them. Just good practice while it’s all apart. My diff had 150k miles on it.

Do you know where they were purchased from, as they I was told they are no longer available?
I was told by a specialist bearing supplier that normal deep groove bearings could be fitted instead of the taper originals, but they were £150 each!

[SDJ]

Actually, they are different bearings to the ones in my 2003 e85 3.0z4

[1536Z4]

on track next month

Thanks for the update and look forward to see your thoughts after taking it on track .

[Joycey]

Why do you need new bearings for this fitting?

You have to remove them. Just good practice while it’s all apart. My diff had 150k miles on it.

Do you know where they were purchased from, as they I was told they are no longer available?
I was told by a specialist bearing supplier that normal deep groove bearings could be fitted instead of the taper originals, but they were £150 each!

I don’t mate. I could always ask him. We use this guy to build our diffs so we get a warranty.

[GuidoK]

You have to remove them. Just good practice while it’s all apart. My diff had 150k miles on it.

I know you have to remove them, I've had my quaife apart more than once. But if they're fine they're fine. Easy to inspect.
So imho this is more on a decision basis.
What also is a problem with replacing bearings, is that there is a chance you have to reshim your diff.
That is done with the 2 large C clips on the end. These are specific thicknesses (laser etched on them), but these shims are not something you can just buy. Different thicknesses have to be sources from scrap diffs afaik, so there is definately a downside to replacing bearings.
So playing with different thicknesses you can both align the gears to set backlash, and if necessairy remove lateral bearing play.
These different thicknesses of C clips are also necessairy if the width of the diff is out of spec, so measuring the width (at the bearing mating contact points) with a micrometer is good practice.
Here you can see some C clips with the different thickness I'm talking about:


One here is 3,80mm and the other one 3,74mm (so 0,06mm difference) so these tolerances are all pretty tight. So these different thickness rings are of course also used to compensate for tolerances in the casing (so tolerances in casing, bearings, diff width and alignment of crown/pinion)

So taken all of this into account, my opinion is that if your bearings are OK and you don't have ridiculous mileage on your car, it's maybe best not to swap them. Especially if you don't have a scala of micrometers and indicator dials and of course some ink.

[B21]

You have to remove them. Just good practice while it’s all apart. My diff had 150k miles on it.

I know you have to remove them, I've had my quaife apart more than once. But if they're fine they're fine. Easy to inspect.
So imho this is more on a decision basis.
What also is a problem with replacing bearings, is that there is a chance you have to reshim your diff.
That is done with the 2 large C clips on the end. These are specific thicknesses (laser etched on them), but these shims are not something you can just buy. Different thicknesses have to be sources from scrap diffs afaik, so there is definately a downside to replacing bearings.
So playing with different thicknesses you can both align the gears to set backlash, and if necessairy remove lateral bearing play.
These different thicknesses of C clips are also necessairy if the width of the diff is out of spec, so measuring the width (at the bearing mating contact points) with a micrometer is good practice.
Here you can see some C clips with the different thickness I'm talking about:


One here is 3,80mm and the other one 3,74mm (so 0,06mm difference) so these tolerances are all pretty tight. So these different thickness rings are of course also used to compensate for tolerances in the casing (so tolerances in casing, bearings, diff width and alignment of crown/pinion)

So taken all of this into account, my opinion is that if your bearings are OK and you don't have ridiculous mileage on your car, it's maybe best not to swap them. Especially if you don't have a scala of micrometers and indicator dials and of course some ink.

Interesting write up..thnx

[GuidoK]

Apparently there is a kit now on the market with different thickness circlips.
Not cheap though
https://www.ebay.co.uk/itm/263582689780

The installment guide from Bird's auto states: "The friction torque of the pinion
bearings, the backlash and tooth contact pattern will not
have to be adjusted again provided the circlips and
bearing races are reinstalled in their original positions,"
With changing bearings the bold section is not happening, so that's why if you don't have to change bearings, it's better not to. Especially taper rollerbearings vary in width.

When fitting new bearings or other parts that can effect the preload, it has to be assembled without crownwheel (so the pinion doesnt rotate) and preload has to be adjusted and measured with a rotational torque measuring device (don't know what it's proper name is) at 50revs/min.
So this is pretty specialized stuff. This is not listed in TIS anymore for the e85/e46 as those diffs are deemed by BMW not servideable anymore, but you can find such settings and procedures with older models that also used the 188 diff. Obviously those don't have the circlip system (but used proper bolt flanges and shims) but if you look through that you can find the info and understand the procedure.
Just like the pinion bearing, the axle bearings have to be under a preload, otherwise wear is extremely accelerated on bearings and gears (they are obviously under a great forces when the car drives). The preload and thus the rotational torque even has to be set differently according to what brand bearings (FAG/SKF/Timken/Koyo) you use..
So that preload you don't measure with a normal torque wrench (that clicks) but it has to be measured as drag torque. Those tooles are pretty much made from unobtanium but I measure it with a spring scale set at a certain distance and recalculate torque that way.

[Joycey]

Apparently there is a kit now on the market with different thickness circlips.
Not cheap though
https://www.ebay.co.uk/itm/263582689780

The installment guide from Bird's auto states: "The friction torque of the pinion
bearings, the backlash and tooth contact pattern will not
have to be adjusted again provided the circlips and
bearing races are reinstalled in their original positions,"
With changing bearings the bold section is not happening, so that's why if you don't have to change bearings, it's better not to. Especially taper rollerbearings vary in width.

When fitting new bearings or other parts that can effect the preload, it has to be assembled without crownwheel (so the pinion doesnt rotate) and preload has to be adjusted and measured with a rotational torque measuring device (don't know what it's proper name is) at 50revs/min.
So this is pretty specialized stuff. This is not listed in TIS anymore for the e85/e46 as those diffs are deemed by BMW not servideable anymore, but you can find such settings and procedures with older models that also used the 188 diff. Obviously those don't have the circlip system (but used proper bolt flanges and shims) but if you look through that you can find the info and understand the procedure.
Just like the pinion bearing, the axle bearings have to be under a preload, otherwise wear is extremely accelerated on bearings and gears (they are obviously under a great forces when the car drives). The preload and thus the rotational torque even has to be set differently according to what brand bearings (FAG/SKF/Timken/Koyo) you use..
So that preload you don't measure with a normal torque wrench (that clicks) but it has to be measured as drag torque. Those tooles are pretty much made from unobtanium but I measure it with a spring scale set at a certain distance and recalculate torque that way.

It's for this reason we use a local diff builder who then gives us warranty. He's also not precious with the knowledge so invited us down to show use how to build the 188 Diffs. We have a few more Z4 diff conversions coming up so this will be very helpful for everyone.

[SDJ]

I've noticed mine makes a bit of noise when it's hot now. It's a very faint whine type noise, although not as high pitched as that. My backlash came out right at the bottom of spec which may be why.

[Joycey]

Little update chaps, yesterday I was at Brands Hatch. I was also at Brands ealier this year with the open diff, I can confirm the LSD unit makes a huge difference on track more noticable in and exiting the corners along with the high speed cornering. I've covered around 500+ miles with 100 of them on track, So far so good with this Blackline unit this seems very good value for money.

Costs: £545 for the Diff

Install/Built: £180 with warrenty (Diff removed by myself)