OS Giken Differential Realtime Install

[admranger]

Originally Posted by ///Mobbin

In case anyones curious what the factory vLSD looks like. Bunch of 16mm bolts securing the rear diff cover then pried it open with a large screwdriver.

Once everything is cleaned up, please post close up pics of pinion and ring gears so we can see wear on teeth. Mileage would be helpful as well.

[///Mobbin]

Finding it difficult to get a consistent backlash measurement, basically the amount of play between the ring and pinion gear. The amount of grease is not helping the situation, this is the basic setup though for reference. (Perhaps it will be easier to get a measurement on the new clean setup.)

[///Mobbin]

To pull stub axles / flanges just use a long screw driver and lever against the side cover bolts. Flanges came out pretty easy after you get past the initial tension holding them in place.

[///Mobbin]

13mm bolts on side covers, torque wrench seemed needed.

[///Mobbin]

Side cover pries off with two screwdrivers, some light hammering on one of the screwdrivers helped get things started here, side cover came out pretty easy. Don't forget to label your shims driver/passenger as they are likely different widths on each side. You can also see the o-ring that will be replaced inset in the inner portion of the side cover.

[///Mobbin]

After the side covers are off, the diff falls out. Thinking these must be the same bearings used on the e46 m3, may order a set to compare them with.

[///Mobbin]

@admranger some wear on the ring and pinion, 90k miles, I think they still look good to run, what do you think?

[admranger]

Originally Posted by ///Mobbin

@admranger some wear on the ring and pinion, 90k miles, I think they still look good to run, what do you think?

Full send. No need for a float test. I'm looking for pitting, chipped, cracked, and severely uneven wear on the gears. I don't see anything like that.

[///Mobbin]

Ended up ordering all of the following from BMW Parts Now (best price on the e39 m5 flanges):
2 x E39 M5 Output flanges - part no. 33131214068
2 x E92 M3 Shaft Seal w/ lock ring - part no. 33107510289
2 x E92 M3 O-rings - part no. 33111214144
2 x E92 M3 Differential drain/fill plugs - part no. 33117525064

Ordered from Amazon:
1 x VIVOHOME 1100 Lbs Steel Lift Jack with Dolly
1 x Permatex 85080 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker, 9.5 oz. PowerBead Can
2 x E46 M3 Differential Carrier Bearings - JLM104948 - went with Timken Brand

Ordered from Rockauto since shipping delayed with Amazon:
2 x E46 M3 Differential Carrier Bearing Races - JLM104910 - went with Timken Brand

Decided to try the E46 M3 bearings/races, if they don't look right back to the drawing board.

In case anyone is interested in the total spend here, the diff was $1975 shipped and I spent ~$615 on all the misc. stuff, though the lift jack with dolly will be re-usable on other jobs.

I do still need to order the Giken gear oil also.

[///Mobbin]

Another YouTube video showing an e46 m3 diff rebuild for a 2005-2006 e46 m3. Same vLSD as the E92 M3 and the bearings look the same also.

[dogbone]

Really great info you’re sharing here.

As for the small parts, to ensure getting the right ones on the first try, I would encourage you to reach out to Dan at Diffs Online. He knows the correct parts needed. He sold me the small parts for my diff.

[///Mobbin]

Originally Posted by dogbone

Really great info you’re sharing here.

As for the small parts, to ensure getting the right ones on the first try, I would encourage you to reach out to Dan at Diffs Online. He knows the correct parts needed. He sold me the small parts for my diff.

Appreciate it Gabe, thank you!

I had considered grabbing the smaller parts from one of the diff builders but they all mark these parts up quite a bit (3x-8x depending on the part). I get that they've done the research and need to make a profit, just would rather source myself if I can.

Fwiw, I just found out there is a 3-5 week wait on the E39 M5 flanges, I'm fine to wait that out but means no updates for awhile. On the same topic, if you are in a pinch it is nice that the diff builders keep these parts in their inventories!

[///Mobbin]

Pretty sure these e46 m3 bearings are the correct ones.

[///Mobbin]

So a hammer and screwdriver not enough for me to get the bearing races out, will take them to a shop and have them pressed/out new/in when I have the bearings pressed on the new diff. I did find a visible part number on one of the races and it matches the e46 m3 race part number!

[cchen9_]

Hey great thread here I have the OSG on my k-series honda and love it, plan to get it for the e92 as well. Jealous!

When I was reading OSG website tech info about this LSD they wanted you to buy a longer e9x output flange (P/N 33132229972) then shorten both by a bit. Which seems like kind of a headache if you want it done right, need to be machined...
See link: https://cdn.shopify.com/s/files/1/01...es/d37.pdf?826

Are the E39 M5 flanges a direct "pnp" swap alternative instead of shortening the e9x parts? This alternative makes much more sense and would probably cost less in the long run.

[///Mobbin]

Originally Posted by cchen9_

Hey great thread here I have the OSG on my k-series honda and love it, plan to get it for the e92 as well. Jealous!

When I was reading OSG website tech info about this LSD they wanted you to buy a longer e9x output flange (P/N 33132229972) then shorten both by a bit. Which seems like kind of a headache if you want it done right, need to be machined...
See link: https://cdn.shopify.com/s/files/1/01...es/d37.pdf?826

Are the E39 M5 flanges a direct "pnp" swap alternative instead of shortening the e9x parts? This alternative makes much more sense and would probably cost less in the long run.

I saw the OS Giken instructions as well, thank you for sharing them here. It's my understanding that the equal length E39 M5 flanges (they were also used on other vehicles besides the E39 M5) work great with the Giken diff and I confirmed with fsmtnbiker that it is what he used when installing his OS Giken diff, so at least one success story there. Others have used these on their Drexler or other clutch-type diffs as well and in fact I believe this is the same part diffsonline sells for this purpose also - LINK

[DrFerry]

Sub'd.

[cchen9_]

Originally Posted by ///Mobbin

I saw the OS Giken instructions as well, thank you for sharing them here. It's my understanding that the equal length E39 M5 flanges (they were also used on other vehicles besides the E39 M5) work great with the Giken diff and I confirmed with fsmtnbiker that it is what he used when installing his OS Giken diff, so at least one success story there. Others have used these on their Drexler or other clutch-type diffs as well and in fact I believe this is the same part diffsonline sells for this purpose also - LINK

OK, good to know, this makes life easier then. Sub'd to see your results!

[///Mobbin]

Parts are in! Also grabbed some yellow gear marking compound from Amazon.

The install continues.

[///Mobbin]

New and old flanges for reference.

[///Mobbin]

19mm for ring bolts.

[///Mobbin]

Out with the old and in with the new, nice having a buddy with a shop!