# <<<< MFactory Helical LSD testing and review >>>>



## Marcus_Aurelius (Mar 1, 2012)

I just received a box from MFACTORY with a set of their front and rear helical LSD to review and test for the community. Let me preface this by saying that I am in no way affiliated with MFactory. I'm always skeptical of new companies entering a market with some big shoes to fill, therefore when I saw a company with better pricing and claims to have comparable/better products than the existing LSDs, there were some doubts. However, you have to keep an open mind and give a "new" product a chance to prove itself. One thing you gotta give to MFactory is some respect for standing behind their products and allowing an independent unbiased testing to be performed. You won't find many companies willingly putting their product out for review when they don't have any control on the outcome. 

The LSDs arrived well boxed and protected, initial look over is very promising. No forging imperfection (yes these are forged, not cast). Looks top notch and very well made. So definitely an A+ there! 

I was tempted to do both at the same time, but felt that I would be doing the community a disfavor by not installing and doing initial reviewing on them individually. At least that way we can have some gauging of what to expect from each upgrade individually, and those on a budget (we all are) can pick which one to do first to benefit what they're after in their builds/car. 

Watch this place for detailed installation pics and description, and short and long term review on the products.





























*FRONT*


















*REAR*


----------



## 20v master (May 7, 2009)

What's the plan, front first then rear? Will front be swapped for an stock trans/open diff when the rear is installed if that is the plan? Or will front be left with M Factory unit then rear installed?


----------



## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> What's the plan, front first then rear? Will front be swapped for an stock trans/open diff when the rear is installed if that is the plan? Or will front be left with M Factory unit then rear installed?


Rear is already installed! The path is to test the rear, then do the front and pull the rear to test the front alone (rear is much easier to do in a couple hours). Then, finally put the rear back in and test the car with both. Hopefully I have the discipline to stick to the plan.


----------



## ticketed2much (Feb 18, 2012)

Really curious to see how the rear alone affects handling:thumbup:


----------



## Marcus_Aurelius (Mar 1, 2012)

I took an afternoon to drop the rear factory open differential and press in the new LSD. I didn't use any press or specialty tools because I didn't plan the job that day, just got bored on Saturday and started doing things. Besides getting an outer rear cover seal and a bearing, this can be done without any specialty tools and basic stuff that you'll find in the average home garage. 



*Tools used* 

- 17mm hex bolt -- double 17mm nut. This is for drain and fill plug (I welded the final version for myself but the double nutted trick works... put some locktite or epoxy on there if you wish). 

- M8 torx for axle bolts

- 13mm socket for diff cover bolts

- Propane torch

- House freezer and oven (wait till the wife goes food shopping)

- large axle sockets to tap bearing and diff out 


Pic of the makeshift drain/fill plug tool





















*Install*

- Undo the RH axle bolts

- Drop the outer tie bars end

- Drop the axle

- Press the axle flange by using 2 long 13mm bolts at 180 deg spacing 

- Press the diff cover out using the 2 factory 13mm threaded holes

- Cut a slot in the Haldex coupling bushing bracket facing the diff cover. This makes sliding the assembly straight out possible with the casing "in frame".

- Pull the assembly out

- Remove old outer flange seal

- Remove output circlip 

- Press OEM diff out on the bench by heating the housing with a blow torch, and it will tap right out

- Same procedure for the bearing 

- New bearing and LSD in the freezer for an hour and they both dropped right in the hot housing with a light tap. 

- Pack bearing with grease

- Reinstall circlip 

- Install new outer seal

- Reinstalling is reverse of removal. Then add new fluid once the side cover is sealed (it's not a bad idea to grease the cover O-ring to allow it to swell back into proper shape while the cover is out). 

- The LH outer lateral links ends need to come come out as well to re-engage the axle flange and input after the work done on the other side. If overlooked, you risk damaging the axle and you will have a open rear. So don't skip on checking and fixing this. I simply rabbit-kicked the hub assembly (with lateral links disconnected) until the axle flange was fully seated.




Axle removal (RH)


























Axle flange and shaft out. Press out with long 13mm bolts bolted to contact the casing cover (place something flat as a cushion in between the bolt and cover to protect it). 










Press case cover using two threaded holes in the cover. The other mounting holes are hollow without threads.









Pic of interference on the bushing bracket and how to cut it. 


























Assembly out. 










Stock open vs LSD










Stock diff pressed out










LSD pressed in, new bearing and seal 


























Pics of the LH side after pressing the assembly back in. This must be addressed and not overlooked.


----------



## 20v master (May 7, 2009)

ticketed2much said:


> Really curious to see how the rear alone affects handling:thumbup:


Same. I like the plan, Max. Unfortunately, I'm wondering how your results would be affected by stock Haldex programming.


----------



## XLR8NTT (Feb 27, 2003)

Glad to see this happening!


----------



## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> Same. I like the plan, Max. Unfortunately, I'm wondering how your results would be affected by stock Haldex programming.


Adam, IMO the Haldex programming has nothing to do with how the LSDs will perform and transform the platform overall. Front slip will happen and power will be transferred to the back (stock programming or not). At my power level for example, I always have at least 50% of the TQ generated applied to the front wheels. That is 200-up WTQ applied to the front wheels, and more than enough to create plenty of rotation/slip differential to engage the Haldex at full tilt at any decent throttle application when going straight. Cornering, or any small percentage of steering angle, the front wheel are traveling at different speed... which mean "slip" detection and rear Haldex operation. Even at lower power levels, all that is needed is a small wheel speed differential to engage the haldex. Therefore the kind of programming (even the watered down stock) has no real bearing on LSD operation in the grand scheme of things. 

With that said, I don't run on stock programming... haven't done so in years.


----------



## Marcus_Aurelius (Mar 1, 2012)

ticketed2much said:


> Really curious to see how the rear alone affects handling:thumbup:


Got a chance today to give it some proper trashing (windy and cold in the low 40's F). The initial report is positive and exactly what I expected from my previous experience with AWD cars with rear LSD. You can finally lead with rear based on throttle application, and it has become totally controllable with the go pedal. Yaw angles while cornering are now totally controllable. You want the rear to step out more, give it more gas -- back off gently and it gets back in line without a fuss. The caveat is that, if you're too deliberate, you need some counter steering. I am saying this because I feel that this demands some respect from the novice driver until they learn the dynamics. Make no mistakes, at least at my power level, you can easily create too much rotation on throttle (I can spin it around in circles with the throttle now). 

Going straight, I can also apply full throttle in first gear and I have full forward momentum. Before, I needed a healthy dose of throttle modulation in first gear to prevent rear wheel spin. Now the car just takes off with full throttle application, just correct with steering to keep it straight. I believe the "drift" aficionados would love this rear-only LSD. Here is a video of me going through the gears before, at the line you can see what I'm talking about with needing to back off the throttle to get moving. Now I can give all the beans and it kind of takes it with a little tail wiggling. This should help 60' times big time. 
https://m.youtube.com/watch?v=DsLWOtxT4S0

The only non positive I can say is that the car feels noticeably tighter -- as if there is more drivetrain parasitic drag. When you lift off the throttle and let it roll while still in gear, the engine braking seems more pronounced and you can feel it being tighter. I have a feeling that some break-in period is needed before it feels less tight. New bearing was also packed in hard grease (an old habit) and I am also running a more viscous diff fluid at 75w140 vs the standard 75w90. I will report after a while if the car loosen up once broken in. 

As for the MFactory rear LSD as a product, so far so good! Everything is as it should, you wouldn't know unless told that it's not the leading Helical LSD performing in the car. :thumbup: :thumbup:


----------



## ticketed2much (Feb 18, 2012)

Sounds promising. Do you think in an autocross/HPDE setting you could get on throttle sooner out of corners to reduce lap times? Or would only having the rear LSD just make t easier to drift?


----------



## Marcus_Aurelius (Mar 1, 2012)

I can see it help time on track definitely. For starters you can rotate and point the car with the throttle which would be a big help in autocross and tight corners at the road course. As far as getting on the throttle sooner I'm not sure, maybe more forward thrust once you're pointed and get on the throttle. It's an AWD car, you never really have to wait to get on the throttle (at least not in my experience). I agree, very promising!


----------



## Gonzalo1495 (Feb 2, 2015)

Very promising. Huge props to MFactory for going through with this and standing behind their product. :beer:

With that said, I'm eagerly awaiting to see how the front LSD performs! The rear seems like a good upgrade but we all know the reason we're here is for that front LSD :laugh:


----------



## 20v master (May 7, 2009)

Sounds great so far. I know what I'll be buying of things seem positive after some proper track thrashing. :beer:


----------



## YayItsBlake (Apr 11, 2016)

Very cool Max. Thanks for doing the grunt work for those of us with more curiosity than free time and money. Lots of reputable guys will try a product and give a thumbs up or down, but you give us everything except a hot lap in the passenger seat. Definitely excited to see how the other dif performs, but honestly you answered my biggest curiosity right out of the gate. 🍺

Coming from a primarily rwd background, I really enjoy a lot of the characteristics you describe from the rear dif alone. 

Sent from my LG-H811 using Tapatalk


----------



## l88m22vette (Mar 2, 2006)

opcorn: :biggrinsanta:


----------



## Tempes_TT (Oct 24, 2010)

You know youve spent too much time on the facebook groups when youre looking for the like button on the thread... 

LSDs have been on the list for a long while, but due to the market harboring the good parts at ~$1200 a pop, that moved them quite low on the can-do/should-do list, financially. This, though...this stirs the pot a bit and makes it a much more justifiable purchase if the turn out! Good stuff as always Max. :thumbup:


----------



## TheDeckMan (Sep 26, 2004)

Great write up Max, glad to see MFactory came through on getting you some to try out. Always is interesting to see if a company is going to stand behind their product and is interested in providing samples for experienced forum members to try out. It goes a long way to establish the product rather than just saying "We make a great product", this adds the oomph behind it. Even more so if the product stands up to the solid abuse.


----------



## erabbit777 (Jan 11, 2009)

Subscribed! Really looking forward to seeing how this one goes...

Sent from my VS986 using Tapatalk


----------



## XLR8NTT (Feb 27, 2003)

Any new updates?


----------



## Marcus_Aurelius (Mar 1, 2012)

XLR8NTT said:


> Any new updates?


Yes, I found out that the backlash in my transmission is way out of spec (I have a good 15-20 degree of play rotating the front wheel). My car is a 2001 so I have the old o2m casing without the removable plastic cap, so I can shim the backlash. I am doing a full rebuild with longer TDI gears and will slap the front LSD in the process.


----------



## ticketed2much (Feb 18, 2012)

Marcus_Aurelius said:


> Yes, I found out that the backlash in my transmission is way out of spec (I have a good 15-20 degree of play rotating the front wheel). My car is a 2001 so I have the old o2m casing without the removable plastic cap, so I can shim the backlash. I am doing a full rebuild with longer TDI gears and will slap the front LSD in the process.



Curious how you end up liking the TDI gears. Did you go for the really long TDI gears or just longer than the 1.8t gearing? Are the gears a straight swap or are modifications needed? Trying to get as much info as possible as I am hoping to do this in the future also.

Thanks


----------



## MCPaudiTT (Nov 26, 2006)

I'd love to see a write up and parts list for the TDI swap as well... TTremoRS really can't use first gear at all....

Please to a write up here and if you can post a link in this thread it would be appreciated, Max!

BTW, did you get my email on the hard top? Joe said you had interest, so I expected a reply. It came from mmphill(at)gmail-dot-com, not [email protected] as I no longer have the domain/website/email... Ping me there if you are interested, or if you didn't get the message.


----------



## erabbit777 (Jan 11, 2009)

When changing the gears are you talking 1-6? Or, final gears also? I was looking to swap the gearing on mine with a set from a GLI, but was told the front and rear final ratios must match. That only 1-6 can be swapped.

Sent from my VS986 using Tapatalk


----------



## 20v master (May 7, 2009)

erabbit777 said:


> When changing the gears are you talking 1-6? Or, final gears also? I was looking to swap the gearing on mine with a set from a GLI, but was told the front and rear final ratios must match. That only 1-6 can be swapped.
> 
> Sent from my VS986 using Tapatalk


Each gear shaft's output gear must match the final drive gear. Any of these can physically be changed, but to change the final, you have to change the other two.


----------



## erabbit777 (Jan 11, 2009)

20v master said:


> Each gear shaft's output gear must match the final drive gear. Any of these can physically be changed, but to change the final, you have to change the other two.


Gotcha

Sent from my VS986 using Tapatalk


----------



## BR_337 (Sep 3, 2011)

subbed opcorn:


----------



## vdubguy97 (Sep 13, 2003)

Any updates..especially the front differential review?


----------



## Marcus_Aurelius (Mar 1, 2012)

vdubguy97 said:


> Any updates..especially the front differential review?


Hi, I feel bad as I haven't posted on this page in a while. I have a host of updates I have been posted on other forums and Facebook. I also apologize to MFactory for dropping the ball last season. I had developed some bad input shaft backlash that needed attention and I called off the rest of the racing season (it was already starting to get cold here too). So, the next few posts I will be dumping a host of info gathered. :beer:


----------



## Marcus_Aurelius (Mar 1, 2012)

MFactory LSD metal composition 










For comparison's sake, here is the metal composition of a wavetrack LSD










Bolts material composition 










Thread form on the supplied hardware









Bolts are good at 4140, threads are rolled and run at ~ 32 Rc










Machining process however is not the sharpest


















A cool feature on the front LSD flange is that they are machined with provision for pressed in studs, or to use the machined threads and bolts to attach the diff into ring gear. I like this because with bolts, there is no need for nuts which keep the unit rotational mass lower and lessens the chance of harmonic vibration. The only concern with using bolts vs pressed in studs/nuts is that you have to make sure that the bolts don't back out. Heavy duty thread lock is what most use but I'm going to tack welding mine in place. Never going anywhere! 









All in all, IMO the product is up to par with industry standards. You can't beat it a that price. The provided hardware for the front is not top quality like say some ARP bolts (which I recommend to the normal user). I am going to run the supplied hardware anyway because someone has to put it through some abuse so we know they can hold up. In all honesty though, the end user just gets a stud/nut kit from ARP if you're anal about having some peace of mind -- or you can mimic what I did on mine if you have mean to do so.

I give an A+ on the LSD casing -- and a B on the provided hardware.

PS: Thank you Noah Decker at Phenix Engineering for doing the material composition tests on his spare time for the community. :thumbup::thumbup:


----------



## Marcus_Aurelius (Mar 1, 2012)

I started the front LSD install last week with a friend of mine (really a two man job without a lift). We got the box out and apart in 2 hours flat, but I didn't like the amount of life left on the clutch, so decided to build another one while in there. So stay tuned for full review of both LSD working together and what the front feels like with the Haldex disabled and no AWD. As mentioned on the previous post I proceeded to use the supplied hardware to bolt the front LSD to the ring gear. What I did is weld the bolts head to prevent them from ever backing out, overkill but you can never be too cautious with critical components. 














Subframe dropped










box split open




























Drilled the factory rivets heads out


















Rivets driven out and ring gear freed up










LSD with ring gear bolted and left in the freezer overnight. Bearings heated in the oven and they dropped right in


















Ring gear bolts welded in so they never back out (overkill but safety is never overdone)



















Timken diff bearing is the same as a Porsche rear wheel bearing. Cheaper and much easier to source than the actual Diff bearings that somehow cost a fortune in comparison for an identical tapered roller bearing










New Clutch


























Box buttoned up


----------



## Marcus_Aurelius (Mar 1, 2012)

Today I did some proper trashing with the Haldex disabled to test the effect of front LSD by itself as a single variable, and then enabled the Haldex back to get a feel overall with front and rear LSD. With the Haldex disengaged, I can now power out of corners instead of hopelessly spinning and understeering like a pig. When I added the Haldex and AWD back in the mix the car became super tight and neutral around corners. You just point it and it follows and stays on whatever line you pick for it. Really amazing what was missing without the LSDs, they really transformed how the car feels and react ... I really would love for the people that discredit the Haldex AWD to get a feel for the car with a performance Haldex and Limited Slip Differentials. I am really upset I didn't do these before, real game changer and makes the TT on par with EVOs and STis which I previously had experience with. I have a track event this weekend, so I'll be able to add more inputs on what these do in track environment.


----------



## ticketed2much (Feb 18, 2012)

Marcus_Aurelius said:


> Today I did some proper trashing with the Haldex disabled to test the effect of front LSD by itself as a single variable, and then enabled the Haldex back to get a feel overall with front and rear LSD. With the Haldex disengaged, I can now power out of corners instead of hopelessly spinning and understeering like a pig. When I added the Haldex and AWD back in the mix the car became super tight and neutral around corners. You just point it and it follows and stays on whatever line you pick for it. Really amazing what was missing without the LSDs, they really transformed how the car feels and react ... I really would love for the people that discredit the Haldex AWD to get a feel for the car with a performance Haldex and Limited Slip Differentials. I am really upset I didn't do these before, real game changer and makes the TT on par with EVOs and STis which I previously had experience with. I have a track event this weekend, so I'll be able to add more inputs on what these do in track environment.


Car looks really good! Awesome review, are you sticking with your upgraded DMF or going SMF?


----------



## Marcus_Aurelius (Mar 1, 2012)

ticketed2much said:


> Car looks really good! Awesome review, are you sticking with your upgraded DMF or going SMF?


I am still a firm believer in the dual mass technology. Won't attempt to fix what's not broken and has been proven to work well in my application. :beer:


----------



## l88m22vette (Mar 2, 2006)

Nice work and that was damn fast, glad to hear is a legit option at the pricepoint. I'm so mad my Outback's EJ pooped itself, this thread makes me want to get my TT going! 

Great updates as always Max :thumbup:


----------



## Marcus_Aurelius (Mar 1, 2012)

After taking the car to waterfest and competing, I can say without a shadow of a doubt that this is the best the car has ever been, and most of it is attributed to the LSDs. The handling is totally transformed, from tight car with a hint of terminal understeer, to total beast with massive throttle lift rotation and power oversteer at corner exit. If you didn't know, you'd think that you were driving an tuned ACD EVO with aftermarket 2-way rear LSD. It's that easy to steer with the back instead of the front. Turn-in understeer is completely gone, so you can apex late ... way late... and stand on the throttle as soon as you have it pointed. The car is now officially a true point-and-shoot AWD monster. The LSD really was the missing puzzle piece on this TT handling saga -- if anything, I may set the alignment slightly tighter because 3 other experienced drivers that took the car out all came to a consensus that it's a bit too tail happy... although I personally love it. 

The aftermath of all this was 1) Race Prep class win and 2nd place 2) Fastest overall Audi/VW for the 5th time at waterfest 3) Top Pax time for me. Couldn't be more happy with the Mfactory Limited Slip Differentials. 








































and beating this thing by nearly 5 sec with a National SCCA champ behind the wheel


----------



## XLR8NTT (Feb 27, 2003)

What... No GoPro videos of the run?!?!


----------



## ticketed2much (Feb 18, 2012)

Congrats, that's awesome.


----------



## CorradoFuhrer (Mar 21, 2002)

great thread, lsd's ftw


----------

