VAC Motorsports - 335i, 135i Performance Built Differential

Brian_VACsales · 02-13-2012, 10:02 PM

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Hey guys,

A number of folks were wondering what our banner ad means when it says 'precision work done in house on our CNC machines.' I am proud to say that we in fact do everything in house - nothing is outsourced.

As many know, most 335i and 135i models have a challenging stock differential. Unlike most cars, most 335i and 135i models have a differential where the ring gear is WELDED to the unit. Note: Just about every car on the road has a ring gear that is BOLTED to the unit.

In order to add a Quaife, Wavetrac, OS Giken unit to your 335i or 135i, you need to re-use the ring gear and pinion in your differential. Not so easy since the ring gear is WELDED to the stock unit!!

So, in order for us to upgrade to a Quaife, Wavetrac, OS Giken etc. we put our machines to work and created this incredibly accurate process to to separate the ring gear from the carrier and prepare said ring gear it to be bolted to the new aftermarket unit.

This is a quick tutorial. We wanted to do the best job possible, so we configured our CNC lathes and mills to handle this challenging task. The end result is beautiful =)

VAC Performance Built Differentials are built to last with the highest quality components, procedures, and technical expertise in the industry. We have been building BMW differentials since the 1980s - 2002, E46, E92, street, race - we have done it.

How is a VAC Performance Built Differential made (this is not a complete list, but most major operations are covered)

1. Photograph and inspect every differential for damage/missing parts etc.

2. Drain and inspect fluid looking for shavings or anything odd with the fluid.

3. Remove cover, inspect ring gear, confirm gear ratio. Pictured: The infamous welded ring gear. Note how it is actually welded to the carrier.

4. Test backlash before dissassembly.

5. Remove axle shafts, old side cover seals, snap rings.

6. Carefully remove the carrier.

7. Remove inner races from carrier.

8. Clean up the carrier, and prep for CNC operation.

9. Set up the carrier in our ultra rigid and precise CNC lathe. Pictured: Stock welded ring gear/carrier on one of our lathes.

10. Machine away weld that secures the ring gear to the carrier. This is an extremely robust weld.

11. Remove the resultant step (weld) so it is flat enough to machine. Pictured: stock ring gear separated from carrier.

12. Machine the ring gear flat (to ensure a precise mating surface for the new unit) Pictured: Separated ring gear | fully machined ring gear | drilled/tapped ring gear

13. Set up the newly finished ring gear on our CNC mill. Pictured: Machined ring gear on our HAAS 5 axis machine.

14. Machine the ring gear to make it compatible with the limited slip unit.

Pictured: Completed ring gear still in the HAAS mill.

Before:

After: Note how we machine the entire face, not just the area where the LSD bolts. Our machining method ensures ideal accuracy and reliability. Not sure that anyone takes it this far.

15. Assemble the limited slip unit.

16. Pressure wash and paint the housing.

17. Soda blast and clean the differential.

18. Install bearings/snap rings.

19. Check pattern, install seals, gasket material and differential cover. Pictured: Checking the pattern on the newly assembled differential.

20. Tag and prepare for install/shipment. Pictured: VAC Performance Build Differential with optional Billet Differential Cover.

Brian_VACsales · 02-13-2012, 10:03 PM

reserved

M3_WC · 02-13-2012, 10:11 PM

WOW!

CJ421 · 02-13-2012, 10:13 PM

Excellent write-up Mike. I was wondering myself, even though VAC already built my diff into a Quaife.

Write-up of my differential build experience at VAC:
http://www.e90post.com/forums/showthread.php?t=631500

A performance diff is worth every last cent!! At VAC.

P.S. make sure you get the M3 subframe brushings to go with it.

ichi_ban · 02-13-2012, 10:30 PM

Newb question, but what's the benefit from removing that weld?

blisstik · 02-13-2012, 10:34 PM

I got mine built there as well, then I ended up getting the M3 suspension with it.

Brian_VACsales · 02-13-2012, 10:35 PM

Quote:

Originally Posted by TeamSoloE93

Newb question, but what's the benefit from removing that weld?

Since the ring gear is welded to the carrier, it is impossible to upgrade to a Quaife, Wavetrac, OS Giken etc. You are not able to buy a new ring gear, so the stock unit must be re-used.

turugara · 02-13-2012, 10:39 PM

I also had my differential built at VAC. Excellent place to go.

here's my review of it:
http://www.e90post.com/forums/showthread.php?t=566942

amclint · 02-13-2012, 10:48 PM

Wow that's very impressive!

ichi_ban · 02-13-2012, 10:50 PM

Quote:

Originally Posted by Mike@VAC

Since the ring gear is welded to the carrier, it is impossible to upgrade to a Quaife, Wavetrac, OS Giken etc. You are not able to buy a new ring gear, so the stock unit must be re-used.

PM with a Quaife LSD please.

BQTuning · 02-13-2012, 11:07 PM

Do you need the car or can I send you the 335is Final Drive for it to be worked on and then shipped back ?

ichi_ban · 02-13-2012, 11:10 PM

^^I'm pretty sure you can ship it to them.

skim7x · 02-13-2012, 11:21 PM

I see what you did there

Nice write-up Mike!!! Hopefully I'll be getting one of those beauties in my e92 this spring!!!! YOU tell ME

99three · 02-13-2012, 11:41 PM

Nice details!

Alpina_B3_Lux · 02-14-2012, 03:22 AM

Very interesting documentary. I already have a Quaife, but still quite enlightening to see how it's done.

BTW I'm getting my VAC differential cover (anodized black street version) installed right now. A real quality piece!

Alpina_B3_Lux

tres · 02-14-2012, 07:26 AM

Nice I plan on installing the solid diff bushings in a few

Brian_VACsales · 02-14-2012, 10:42 AM

Quote:

Originally Posted by TeamSoloE93

PM with a Quaife LSD please.

Will do!

Quote:

Originally Posted by BuraQ

Do you need the car or can I send you the 335is Final Drive for it to be worked on and then shipped back ?

Send us the final drive and we handle the rest. I will PM with more info

Quote:

Originally Posted by mykal335xi

Wow that's very impressive!

Quote:

Originally Posted by turugara

I also had my differential built at VAC. Excellent place to go. here's my review of it:
http://www.e90post.com/forums/showthread.php?t=566942

Quote:

Originally Posted by blisstik

I got mine built there as well, then I ended up getting the M3 suspension with it.

Quote:

Originally Posted by CJ421

Excellent write-up Mike. I was wondering myself, even though VAC already built my diff into a Quaife.

Write-up of my differential build experience at VAC:
http://www.e90post.com/forums/showthread.php?t=631500

A performance diff is worth every last cent!! At VAC.

Quote:

Originally Posted by M3_WC

WOW!

Quote:

Originally Posted by 99three

Nice details!

Thanks guys. This is in my opinion the #2 mod for a N54/N55 powered vehicle. #1 being boost/power stuff.

Quote:

Originally Posted by Alpina_B3_Lux

Very interesting documentary. I already have a Quaife, but still quite enlightening to see how it's done.

BTW I'm getting my VAC differential cover (anodized black street version) installed right now. A real quality piece!

Quote:

Originally Posted by skim7x

Nice write-up Mike!!! Hopefully I'll be getting one of those beauties in my e92 this spring!!!! YOU tell ME

Spring already started

Our machine shop:

Slops · 02-14-2012, 10:50 AM

I'm so happy and proud that you guys are semi local to me

GTiceman · 02-14-2012, 11:35 AM

awesome write-up Mike

trialskid · 02-14-2012, 11:39 AM

Can you pm me with pricing for shipping you my unit?

vasillalov · 02-14-2012, 12:03 PM

Droool! My next big purchase will be an LSD from you guys!

Fundahl · 02-14-2012, 12:43 PM

Awesome documentation!

It would pair well WITH THAT ported/enlarged intake-valve N54 HEAD! (hint hint)

02-13-2012, 10:02 PM	#1
Brian_VACsales Captain 193 Rep 933 Posts Drives: E92 M3 VF Supercharged, 135i Join Date: Feb 2011 Location: Philadelphia, PA iTrader: (0)	VAC Motorsports - 335i, 135i Performance Built Differential - How we do it! Follow us on Facebook Hey guys, A number of folks were wondering what our banner ad means when it says 'precision work done in house on our CNC machines.' I am proud to say that we in fact do everything in house - nothing is outsourced. As many know, most 335i and 135i models have a challenging stock differential. Unlike most cars, most 335i and 135i models have a differential where the ring gear is WELDED to the unit. Note: Just about every car on the road has a ring gear that is BOLTED to the unit. In order to add a Quaife, Wavetrac, OS Giken unit to your 335i or 135i, you need to re-use the ring gear and pinion in your differential. Not so easy since the ring gear is WELDED to the stock unit!! So, in order for us to upgrade to a Quaife, Wavetrac, OS Giken etc. we put our machines to work and created this incredibly accurate process to to separate the ring gear from the carrier and prepare said ring gear it to be bolted to the new aftermarket unit. This is a quick tutorial. We wanted to do the best job possible, so we configured our CNC lathes and mills to handle this challenging task. The end result is beautiful =) VAC Performance Built Differentials are built to last with the highest quality components, procedures, and technical expertise in the industry. We have been building BMW differentials since the 1980s - 2002, E46, E92, street, race - we have done it. How is a VAC Performance Built Differential made (this is not a complete list, but most major operations are covered) 1. Photograph and inspect every differential for damage/missing parts etc. 2. Drain and inspect fluid looking for shavings or anything odd with the fluid. 3. Remove cover, inspect ring gear, confirm gear ratio. Pictured: The infamous welded ring gear. Note how it is actually welded to the carrier. 4. Test backlash before dissassembly. 5. Remove axle shafts, old side cover seals, snap rings. 6. Carefully remove the carrier. 7. Remove inner races from carrier. 8. Clean up the carrier, and prep for CNC operation. 9. Set up the carrier in our ultra rigid and precise CNC lathe. Pictured: Stock welded ring gear/carrier on one of our lathes. 10. Machine away weld that secures the ring gear to the carrier. This is an extremely robust weld. 11. Remove the resultant step (weld) so it is flat enough to machine. Pictured: stock ring gear separated from carrier. 12. Machine the ring gear flat (to ensure a precise mating surface for the new unit) Pictured: Separated ring gear \| fully machined ring gear \| drilled/tapped ring gear 13. Set up the newly finished ring gear on our CNC mill. Pictured: Machined ring gear on our HAAS 5 axis machine. 14. Machine the ring gear to make it compatible with the limited slip unit. Pictured: Completed ring gear still in the HAAS mill. Before: After: Note how we machine the entire face, not just the area where the LSD bolts. Our machining method ensures ideal accuracy and reliability. Not sure that anyone takes it this far. 15. Assemble the limited slip unit. 16. Pressure wash and paint the housing. 17. Soda blast and clean the differential. 18. Install bearings/snap rings. 19. Check pattern, install seals, gasket material and differential cover. Pictured: Checking the pattern on the newly assembled differential. 20. Tag and prepare for install/shipment. Pictured: VAC Performance Build Differential with optional Billet Differential Cover. __________________ Brian Casella Sales Representative, VAC Motorsports Office: 215.462.4666 \| Fax: 215.462.4667 EXT 13 \| Email: brian@vacmotorsports.com Last edited by Brian_VACsales; 02-15-2012 at 02:40 PM..
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02-13-2012, 10:11 PM	#3
M3_WC Brigadier General 1040 Rep 3,622 Posts Drives: M3 Join Date: Jun 2009 Location: CA iTrader: (0)	WOW!
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02-13-2012, 10:13 PM	#4
CJ421 Brigadier General 1520 Rep 4,101 Posts Drives: BMW M3 Join Date: Feb 2011 Location: Blue Bell, PA iTrader: (1) Garage List 2024 BMW M3 Sedan [9.50]	Excellent write-up Mike. I was wondering myself, even though VAC already built my diff into a Quaife. Write-up of my differential build experience at VAC: http://www.e90post.com/forums/showthread.php?t=631500 A performance diff is worth every last cent!! At VAC. P.S. make sure you get the M3 subframe brushings to go with it. __________________ 2024 BMW M3 Sedan Frozen Pure Grey II/Fjord Blue, 6MT Past: 2021 Z4 M40i Frozen Grey II/Black Alcantara \| 2017 F30 340i Mineral Gray/Coral Red, 6MT \| 2011 E92 335i Le Mans Blue/Black, 6MT
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02-13-2012, 10:30 PM	#5
ichi_ban Major 36 Rep 1,019 Posts Drives: X6 50i Join Date: Nov 2011 Location: FL iTrader: (24)	Newb question, but what's the benefit from removing that weld? __________________ @ichi_ban
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02-13-2012, 10:34 PM	#6
blisstik Lieutenant Colonel 151 Rep 1,677 Posts Drives: E92 Join Date: Jul 2009 Location: California iTrader: (14)	I got mine built there as well, then I ended up getting the M3 suspension with it.
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02-13-2012, 10:03 PM	#2
Brian_VACsales Captain 193 Rep 933 Posts Drives: E92 M3 VF Supercharged, 135i Join Date: Feb 2011 Location: Philadelphia, PA iTrader: (0)	reserved
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02-13-2012, 10:39 PM	#8
turugara Major 91 Rep 1,324 Posts Drives: 335i Coupe, 6 Speed Join Date: May 2011 Location: NYC iTrader: (5) Garage List 2011 BMW 335i [9.44]	I also had my differential built at VAC. Excellent place to go. here's my review of it: http://www.e90post.com/forums/showthread.php?t=566942
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02-13-2012, 10:48 PM	#9
amclint boom 12 Rep 598 Posts Drives: 335xi Join Date: Apr 2011 Location: Varies iTrader: (6)	Wow that's very impressive!
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02-13-2012, 11:07 PM	#11
BQTuning Banned 469 Rep 4,392 Posts Drives: 2012 Z4 sDrive35i M Sport 6MT Join Date: Nov 2010 Location: bq@bqtuning.com iTrader: (0)	@VAC Do you need the car or can I send you the 335is Final Drive for it to be worked on and then shipped back ?
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02-13-2012, 11:10 PM	#12
ichi_ban Major 36 Rep 1,019 Posts Drives: X6 50i Join Date: Nov 2011 Location: FL iTrader: (24)	^^I'm pretty sure you can ship it to them. __________________ @ichi_ban
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02-13-2012, 11:21 PM	#13
skim7x Colonel 208 Rep 2,558 Posts Drives: 335i, C63 AMG Join Date: Sep 2006 Location: USA iTrader: (4) Garage List 2007 335i [10.00]	I see what you did there Nice write-up Mike!!! Hopefully I'll be getting one of those beauties in my e92 this spring!!!! YOU tell ME __________________ '07 Space Gray 335i coupe - R.I.P. COBB ProTuned \| AMS \| CP-e \| BMS \| Quaife
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02-13-2012, 11:41 PM	#14
99three Banned 25 Rep 838 Posts Drives: 993, e92, e36, F355, Z32, Jag Join Date: Sep 2010 Location: in the 416 iTrader: (3)	Nice details!
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02-14-2012, 03:22 AM	#15
Alpina_B3_Lux Colonel 263 Rep 2,564 Posts Drives: Audi R8 LMX, BMW M550i xDrive Join Date: Feb 2008 Location: Germany iTrader: (0) Garage List 2009 335i [8.90]	Very interesting documentary. I already have a Quaife, but still quite enlightening to see how it's done. BTW I'm getting my VAC differential cover (anodized black street version) installed right now. A real quality piece! Alpina_B3_Lux __________________ Audi R8 LMX, BMW M550i xDrive (G30 LCI); gone: Alpina B3 3,3 (E46), BMW 335i, Audi R8 V10 manual, Audi R8 V10, BMW M235i, BMW 550i F10
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02-14-2012, 07:26 AM	#16
tres Major 34 Rep 1,381 Posts Drives: 2011 bmw 335is 6MT Join Date: Apr 2009 Location: maryland iTrader: (6)	Nice I plan on installing the solid diff bushings in a few
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02-14-2012, 10:50 AM	#18
Slops Major General 188 Rep 5,417 Posts Drives: 2005 C55 AMG Join Date: Jan 2011 Location: Oxford iTrader: (2)	I'm so happy and proud that you guys are semi local to me
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02-14-2012, 11:35 AM	#19
GTiceman Parrothead 137 Rep 1,232 Posts Drives: E90 M3 Join Date: Jul 2010 Location: Tampa iTrader: (5) Garage List 2020 BMW X3 M40i [0.00] 2009 BMW M3 [0.00]	awesome write-up Mike __________________ \|e46 M3 Stahlgrau/Red\| - Sold \|E92 335i BSM/Saddle\| - Sold \|e90 M3 Space Gray/Fox Red/6MT\| See Garage for Mods
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02-14-2012, 11:39 AM	#20
trialskid Private First Class 8 Rep 147 Posts Drives: 08 335i Join Date: Dec 2011 Location: Ontario iTrader: (0)	Can you pm me with pricing for shipping you my unit?
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02-14-2012, 12:03 PM	#21
vasillalov Mad Linux Guru On The Loose 1121 Rep 5,396 Posts Drives: 2008 335i Sedan, 2023 M3 Join Date: Aug 2009 Location: Chicago, IL iTrader: (5) Garage List 2023 BMW M3 [0.00] 2008 335i E90 [8.00]	Droool! My next big purchase will be an LSD from you guys! __________________ 6MT \| COBB \| AR \| AE \| Forge DV \| HPF \| P3 Gauge \| Hybrid Intake \| O.S.Giken TCD \| All M3 bits \| TCKLine \| StopTech \| UUC \| ER \| SPEC
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02-14-2012, 12:43 PM	#22
Fundahl Captain 8 Rep 704 Posts Drives: VO 1M, 300zx TT Join Date: Mar 2011 Location: Corpus Christi, Texas iTrader: (0)	Awesome documentation! It would pair well WITH THAT ported/enlarged intake-valve N54 HEAD! (hint hint)
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