NOW AVAILABLE: JHM Limited Slip Differential (LSD) for B5 A4-S4 Manual Transmission

[Jake@JHM]

INTRODUCING THE JHM HELICAL REAR LIMITED SLIP DIFFERENTIAL!!!


CLICK HERE FOR MORE INFO!

After years of research and development, we are proud to release our JHM Helical Rear Limited Slip Differential LSD for the B5 A4-S4.









In the stock Audi rear differential, the torque from the motor that's sent to the driveline is evenly divided between the two rear axles. In most driving situations this is normally fine. However, in cases where traction is lost at one wheel (i.e. under hard acceleration out of a corner or launching from a stop) power is only being sent to the spinning wheel. In these situations, a gear-based limited slip differential will take the torque from the wheel that's starting to spin and send it back to the wheel with that's not - the one with better traction. This means that both rear tires will spin together - with or without traction.

Features and Benefits of the JHM Helical LSD:
- Helical gears respond to changes in traction conditions very quickly
- Improves traction and predictability of vehicle behavior: both rear wheels will spin at the same rate. Under hard acceleration out of corners or launching from a stop the car will either "hook up" and go or both rear tires will spin. Some "track focused" drivers say that this allows you to steer the car better with the throttle.
- Prevents "one-legging" (spinning one rear tire only) and therefore eliminates losses in acceleration under load out of corners and heavy acceleration from a stop (launching).
- Maintenance free! There are no clutch packs to replace as they wear out.
- No special gear oil or additives necessary. Again, since there are no clutches, you can run the same gear oil as recommended by Audi in our LSD.
- Our JHM Helical Rear LSD comes with a Limited Lifetime Warranty against manufacturer defects.


While we recommend our LSD for anyone looking to improve the traction and predictability of their quattro Audi, the more horsepower your car has or the harder you drive, the more our JHM LSD will make a difference in your car.

CLICK HERE FOR MORE INFO!

If you have any questions or would like help placing your order, please don't hesitate to contact us!

[email protected]
209-968-0077

Jake

[Yuppie]

Is this out of Porsche 944?

[Gujuhammer]

Does it have a lifetime warranty like Wavetrac?--->Limited lifetime warranty, sorry I missed that.

How is it on the street? Is it loud?-->clicking and what not?

[LJS]

Jake- NICE!!!!!
Question-what's the torque bias ratio of this unit----I'm familiar with the clutch type units but the geared units (Quaife, Torsen) are new to me.
I found no mention of this at your web site.

[Nollywood]

Jake, will this fit into the B6/7 differential housing?

[Jake@JHM]

Is this out of Porsche 944?

Nope!

Does it have a lifetime warranty like Wavetrac?--->Limited lifetime warranty, sorry I missed that.

How is it on the street? Is it loud?-->clicking and what not?

Limited Lifetime

It's helical, so its as quiet as stock!

Jake- NICE!!!!!
Question-what's the torque bias ratio of this unit----I'm familiar with the clutch type units but the geared units (Quaife, Torsen) are new to me.
I found no mention of this at your web site.

Let me see if I can find that answer for you!

Jake, will this fit into the B6/7 differential housing?

We have B6-B7 specific differentials! https://jhmotorsports.com/catalogsearch/result/?q=LSD

[csobel]

Jake--
This looks great, and a good price point as well. Can you comment on using it with a 0A3 swapped B5; specifically a late 0A3 with the 4:1 center diff? The rear diff is a DAJ from an A4 which looks like it's on your list of approved differentials.
Chris

[wbrunner23]

Works for me


https://jhmotorsports.com/jhm-helica...nsmission.html

In stock and ready to rock. Our weekends coupon code is still active until tonight if you hurry.

Whelp, that was easy! I missed the sale.

What I'm most concerned with is my inside, rear wheel lifting during hard cornering. I think I would want a mechanical or viscous LSD to lock both rear wheels when one is in the air, no?

[FlyboyS4]

Is this out of Porsche 944?

Looks similar to the MFactory unit.

[chris86vw]

Looks similar to the MFactory unit.

Can't believe it took 24 hours for someone to point this out.

[wbrunner23]

I ordered one today

Jake/Flyboy - any install tips?

[FlyboyS4]

I ordered one today

Jake/Flyboy - any install tips?

When I contacted MFactory prior to install they advised to install the LSD the same as the factory unit, adhering to the same specifications. I had a shop install mine.

[wbrunner23]

When I contacted MFactory prior to install they advised to install the LSD the same as the factory unit, adhering to the same specifications. I had a shop install mine.

Thanks - I read the bentley and it's pretty straight forward. Anybody know the part number for the diff cover large o-ring?

[Jake@JHM]

Our's will installs same as factory as well.

[christianb5s4]

When I contacted MFactory prior to install they advised to install the LSD the same as the factory unit, adhering to the same specifications. I had a shop install mine.

I remember reading your review a while back, how do you like it now that some time has passed? Any handling benefits you've noticed in normal and spirited driving?

[chris86vw]

Thanks - I read the bentley and it's pretty straight forward. Anybody know the part number for the diff cover large o-ring?

Side cover oring N90514401
oring between front and rear halves of diff 010325381A
front (input) flange seal 857525275
(2) output flange seals 016409399B


Some of these have been superseded..


You'll also need bearings and possibly adjustment shims.

[wbrunner23]

Thanks, Chris!

[Scotty@Advanced]

Looks similar to the MFactory unit.

It's the same unit.

[Drehmoment]

It's the same unit.

Oh no, does that mean that the world ‘ s best engineering house, JHM, did not “spend years of research and development “ on this mile stone of drive train revolution?

[FlyboyS4]

Does it have a lifetime warranty like Wavetrac?--->Limited lifetime warranty, sorry I missed that.

How is it on the street? Is it loud?-->clicking and what not?

I have not noticed any sounds with the MFactory LSD.

Jake- NICE!!!!!
Question-what's the torque bias ratio of this unit----I'm familiar with the clutch type units but the geared units (Quaife, Torsen) are new to me.
I found no mention of this at your web site.

When I was researching the MFactory LSD the information I found from them was that it can transfer up to 75% torque.

I remember reading your review a while back, how do you like it now that some time has passed? Any handling benefits you've noticed in normal and spirited driving?

In normal driving I haven't noticed any difference, and that's about the only type of driving I have been doing so I don't have any feedback under other conditions.

MFactory seems to offer direct inquires a lower price than what they advertise on the website, and they have some decent sales. I purchased mine for $550 shipped during an overstock sale.

[AudiTechS4]

It's the same unit.

they look very different to me

- - - Updated - - -

mfactory

\
jhm

[chris86vw]

they look very different to me

How about If you compare the actual current MF factory unit not a few year old overstock blow out diff?


mf-trs-05aa4


How do they look then?

[AudiTechS4]

good call lol , i followed flyboys link .

[MacDaddy]

they look very different to me

- - - Updated - - -

mfactory

\
jhm

Looks like different camera lighting.

Who cares anyway, helical LSD’s suck, there will only be a lock up condition when torque is applied (accelerating) and instantly turn into an open diff if traction is lost on one axle, which is why flyboy doesnt notice a difference when notmal driving because it does nothing unless driving agressivley. A clutch type LSD will give you a tigher turning radius even under normal driving because of the torque applied to the outside wheel.

Also, seeing as how ZF made the drivetrain for the 944 and the S4 and ZF only makes 3 differential sizes (afaik) its a relativley safe bet that the s4 diff will accept a 188mm LSD (clutch type) from a BMW. I sourced a BMW LSD already but im trying to find a s4 diff that isnt over priced (near impossible) to test my theory, ill post up when i find a doner s4 diff.

[armageddon-]

Looks like different camera lighting.

Who cares anyway, helical LSD’s suck, there will only be a lock up condition when torque is applied (accelerating) and instantly turn into an open diff if traction is lost on one axle, which is why flyboy doesnt notice a difference when notmal driving because it does nothing unless driving agressivley. A clutch type LSD will give you a tigher turning radius even under normal driving because of the torque applied to the outside wheel.

Also, seeing as how ZF made the drivetrain for the 944 and the S4 and ZF only makes 3 differential sizes (afaik) its a relativley safe bet that the s4 diff will accept a 188mm LSD (clutch type) from a BMW. I sourced a BMW LSD already but im trying to find a s4 diff that isnt over priced (near impossible) to test my theory, ill post up when i find a doner s4 diff.

Do you need any measurement in particular? I have a spare diff on the garage

[Nollywood]

It's the same unit.

Ouch, Scotty!

No more cookies for you, lol.

[Nollywood]

The rear LSD from a Audi V8 4.2 Quattro D11 differential is a direct transfer to the stock B5/6/7 housing.

[Perth_RS4]

The rear LSD from a Audi V8 4.2 Quattro D11 differential is a direct transfer to the stock B5/6/7 housing.

B5 rear diff is different to the B6/7 rear diff.

[Nollywood]

B5 rear diff is different to the B6/7 rear diff.

Yes, I’m aware of this.

The housings are different - but the actual differential are 01R-based, and interchangeable. Dates back to the B2 Ur-quattro, Coupé quattro and C3 100/200 quattro.

[replica_rs4]

Yes, I’m aware of this.

The housings are different - but the actual differential are 01R-based, and interchangeable. Dates back to the B2 Ur-quattro, Coupé quattro and C3 100/200 quattro.

+1 . A very late b7 s4 and rs4 is slightly different . i think it was 2008 only at least for NA market


Sent from my SM-N960F using Audizine mobile app

[Nollywood]

+1 . A very late b7 s4 and rs4 is slightly different . i think it was 2008 only at least for NA market

True. 01R up to August 2008, September 2008 onwards 0AR or 08V.

[armageddon-]

The rear LSD from a Audi V8 4.2 Quattro D11 differential is a direct transfer to the stock B5/6/7 housing.

its not a direct fit, one of the bearings is larger, so either you modify the housing or the diff, I chose to machine the diff to accommodate stock bearing

[FlyboyS4]

How about If you compare the actual current MF factory unit not a few year old overstock blow out diff?


mf-trs-05aa4


How do they look then?

That's the part number of the product I purchased.

Looks like different camera lighting.

Who cares anyway, helical LSD’s suck, there will only be a lock up condition when torque is applied (accelerating) and instantly turn into an open diff if traction is lost on one axle, which is why flyboy doesnt notice a difference when notmal driving because it does nothing unless driving agressivley. A clutch type LSD will give you a tigher turning radius even under normal driving because of the torque applied to the outside wheel.

Also, seeing as how ZF made the drivetrain for the 944 and the S4 and ZF only makes 3 differential sizes (afaik) its a relativley safe bet that the s4 diff will accept a 188mm LSD (clutch type) from a BMW. I sourced a BMW LSD already but im trying to find a s4 diff that isnt over priced (near impossible) to test my theory, ill post up when i find a doner s4 diff.

Of course a helical LSD sucks, and luckily you were able to point that out early in the thread, thank you! Everyone reading the thread will benefit from your wisdom.

[Nollywood]

its not a direct fit, one of the bearings is larger, so either you modify the housing or the diff, I chose to machine the diff to accommodate stock bearing

Thanks for correcting, and reminding me.

It’s been a long time since I took these differential apart, and made comparisons. No doubt I’ll be referring to this thread once I begin the transfer of the V8 LSD into the B6 housing.

Thanks again!

[Scotty@Advanced]

Gear based helical diffs aren't limited slips they are torque biasing differentials and have benefits over a clutch type lsd. The V8 torsen diff works well if you can prevent it from shedding spider gears. There have been many failures of this diff.

[Nollywood]

Gear based helical diffs aren't limited slips they are torque biasing differentials and have benefits over a clutch type lsd. The V8 torsen diff works well if you can prevent it from shedding spider gears. There have been many failures of this diff.

Thanks for letting me know this, Scotty. I certainly don’t want to have to pull the differential from the car once it’s all done.

Do you have any other cost-effective solutions? Please feel free to send me a PM.

[MacDaddy]

Do you need any measurement in particular? I have a spare diff on the garage

Thanks for the offer, ive kept the BMW med case together, but i may open it up this summer after i finish my X5 project.

The rear LSD from a Audi V8 4.2 Quattro D11 differential is a direct transfer to the stock B5/6/7 housing.

What years did they make that, was it late 80’s early 90’s? Ill keep my eye open, machining shouldnt be much of an issue.

[MacDaddy]

Of course a helical LSD sucks, and luckily you were able to point that out early in the thread, thank you! Everyone reading the thread will benefit from your wisdom.

No problemo, although i know its going to buzz a cognative bias (not intentionally on my part as my post wasnt directed at you) because im criticizing a product you've spent your money on so your going to feel the need to defend said purchase.

Helical is better than nothing, but if im going through the effort im getting a clutch type 2 way.

[Mikse]

Who cares anyway, helical LSD’s suck, there will only be a lock up condition when torque is applied (accelerating) and instantly turn into an open diff if traction is lost on one axle, which is why flyboy doesnt notice a difference when notmal driving because it does nothing unless driving agressivley. A clutch type LSD will give you a tigher turning radius even under normal driving because of the torque applied to the outside wheel.

Also, seeing as how ZF made the drivetrain for the 944 and the S4 and ZF only makes 3 differential sizes (afaik) its a relativley safe bet that the s4 diff will acce

Based your comment you have never ever driven a street car with clutch type LSD. It is absolutely horrible and definitely not needed in a street car, btdt. Sure it wins hands down helical type on the track. Helical type is much better for a street car for a reason you mentioned, you won´t notice it when driving normally, only when you "need it" when driving hard. On a clutch type you definitely notice it when normal driving...

[okkim]

A clutch type LSD will give you a tigher turning radius even under normal driving because of the torque applied to the outside wheel.

No it doesn't. It just locks the axle, and the inner wheel starts to hop and slip because it would like to turn faster than it should. I had Stasis rear diff, it was horrible in the street when making tight turns.