@ElmerKTM Thanks for sharing your first impressions.
I also found a improved rear grip after installing my Quaife ATB , moving up from an OEM Open Diff (base model V6).
Usually the V6S model F-Types with OEM LSD perform better than the Open diff cars, and act in a similar manner as the Quaife ATB.
I am wondering if your OEM LSD with failing clutch discs provided any LSD benefit, or if it was defaulting back to an Open Diff.
Either way, it is great to hear that the rear diff upgrade kit + special tools worked smoothly with a 1 day shop turn around.

I recently participated in a JCNA autocross and was able to drop my times by about 5%, some of which was due to the Quaife ATB.
(other contributors were the ideal weather, accumulation of experience on this course, and new Pilot S4S tires).

Onca Engineering will consider making a new batch of Quaife ATB units if there is interest.
The applicability chart is still under development...

Application Table Quaife ATB for Jaguars with DANA AdvanTEK gears.

 

I've been running a quaife in my daily driver for at least 10 years. There are amazingly stout and don't seem to require adjustment nor service. Sounds like a great option if the LSD in our V6S bites the dust.

 

Hi All,
Just wanted to give my experience with Quaife ATB since installing it about 2 and a half months ago.
Some background; my car is a 2016 V6- base, 6spd manual which I purchased used in 2019 with 4k miles. I have since put on and additional 34k miles.
It has a VAP crank pulley and tune as well as Mina gallery upper and lower intake. I absolutely love this car and with the modifications it has really come alive.
The ATB has been one of the best modifications that I've made. Along with the pulley and tune, it has transformed the car into a true sports car.
The difference in traction is noticeable immediately coming off the line and it feels like the car can finally put the power down into the pavement.
Handling through turns is also markedly improved and the car handles in a much more linear, predictable fashion.
Installation was not terribly difficult, but does require the removal of several components to access the differential. Herman's detailed instructions and support were invaluable during the process.
I did have a slight issue with the unit being dropped during shipping which resulted in a slightly dented pinion yoke, which I was able to hammer back into shape with the help of a CV bearing cup which Herman sent me.
Otherwise the install went smoothly and I decided to replace the cats and downpipes with the VAP 200 cell units while I had the stock units off.
These are much louder than stock and I have experienced some resonance/vibration noise with them, especially with the muffler valves open. I was concerned this noise could be coming from the diff, but I am quite certain that it is due to the vibration of the exhaust transmitting into the cockpit.
I did change the diff oil twice to inspect it and initially noticed what seemed to be a lot of metal paste on the drain plug and some "shimmering" of the oil, but in discussion with Herman, he noticed the same thing and Quaife did say that some wearing in of the gears is normal initially. On my second oil change the paste was much less and the oil cleaner.
So, in short if you are considering going from an open diff to an LSD like I was, the ATB is a huge improvement and will really make driving the car as it was intended that much more fun.
I am looking forward to many more miles of driving enjoyment from my F-type.
Thanks for reading and happy to answer any questions anyone might have.
Jordan

 

I'm not surprised by the metal paste. There are a lot of gears in there that need to get properly acquainted. I'll make sure to do a break-in oil change on mine when I do finally install it.

 

Hello everyone.. I'm interested in a helical LSD for mine
x260 XF 30d 2.19 diff (GX-63-4A213-FA) can anyone confirm if it is possible? Greetings

 

@Luka Bilic @RPGx260

I saw your interest in the Quaife ATB for your Jaguars.
This upgrade makes the rear end of the rear wheel drive Jaguars much more "planted" and helps with increased cornering speeds... or better traction on slippery surfaces.
Onca Engineering has applied the ATB design to a few gear ratios, and has also found that some gear ratios would require a new design with altered ring gear mounting face.
See chart above for details.
First, the commissioned Quaife ATB was designed for the "modern" Jaguars with rear wheel drive (and perhaps some AWD models that have the same rear diff design).
In order to confirm compatibility with a new gear ratios, I would need to take some measurements on the differential carrier. Note: used rear diffs may be available for less than $400 which would support the engineering necessary, and could also become a replacement unit for your Jaguar cars.
Note: the 2.19 gear ratio sounds like it may be "out of range" .. just as the 2.56 ratio on the V-8 models was out of range for the ATB carrier that I designed.

Best,
Herman Wiegman
Onca Engineering

 

@RPGx260
I extended my Gear Ratio chart to cover the 2.19 gear ratio for Diesel cars.
The gear set is probably 16:35 which is far away from the V8's 2.54 gear ratio (gear set = 9:23)
This gives me hope that the Quaife ATB that I commissioned will fit this gear set, with a taller spacer ring.
This would be an easy adaptation, which is what I expected for some of the different gear ratios.
Are you willing to help me (Onca Engineering) purchase a used 2.19 gear ratio rear end and see if it is compatible with the Quaife ATB?

 

It has been a few weeks since I successfully installed a Quaife ATB in my '16 F-Type, and I wanted to publicly thank Herman/Onca Engineering for his invaluable assistance. If it were not for his efforts to work with Quaife to design and order the units, create and publish installation instructions and videos, and provide the necessary shims, bearings, seals, and tools, my base trim F-Type would still be handicapped with its OEM open differential.

A wonky supercharger coupler has limited my post installation assessment of the Quaife, but so far, it seems that everything is working with no strange noises or vibrations. I performed the installation in my garage, with the car on jack-stands. This is the second time I've removed a differential from a rear subframe, but it was the first time I've removed and replaced the inner working of a differential. Following Onca Engineering's instructions and videos made the process fairly straightforward.

I have a few observations from the swap:

- The ~$100 Harbor Freight transmission jack shown in the Onca Engineering removal and installation videos was money well spent. Using it made removing and installing the muffler and differential much easier.

- I did not remove the downpipes and catalytic converters. I just removed the exhaust mid-pipe, muffler, and associated heat shields. Removing and installing the mid-pipe required some gentle persuasion with a hammer and some scrap wood. I can't say that leaving the downpipes and cats in place was necessarily easier or faster, but it is an option that allows you to remove fewer parts from the car.

- I did not disconnect the driveshaft from the transmission. I only disconnected the driveshaft from the differential (as I was lowering the differential from the rear subframe). I used a spare jack stand to keep the aft portion of the driveshaft elevated and out of the way.

- I was expecting the driveshaft to separate easily from the differential. This was not the case. It also required some gentle persuasion with a hammer and precision tool. Onca Engineering's video titled "Sport Touring Clutch" addresses removing the driveshaft from the differential.

- I lowered the subframe to access the front differential mounting bolts as per Onca Engineering's instruction. It was a relatively easy process with the transmission jack.

- Removing and reinstalling the large, heavy "K" brace becomes a bit of a puzzle with jack-stands supporting the car and/or rear subframe. I had to reposition the jack-stands a few times in order to get it clear of the car.

- Seating the axles with the new spring clips into the differential took a bit more effort than I expected. A "very healthy" shove was required.

My base-trim F-Type has a manual transmission, a VAP crank pulley and tune, and just under 30,000 miles on the odometer. Once I get the supercharger coupler sorted, I'll post some additional driving impressions. I plan to change the differential fluid in a few hundred miles and will post an update after I complete that.

Thanks again, Herman.

 

@waldo
Great to hear you were able to extract and rebuild your V6 rear differential with the kit and instructions provided.
Thanks for sharing the tip on removing just the rear portion of the exhaust system when extracting just the rear diff.
Isn't the "K" brace under the rear subframe a total pain in the posterior side?
Good of you to change the diff oil after the first few hundred miles. The helical gears will shed some metal paste.
I am looking forward to your driving impressions. The rear of your car should feel so much connected to the road.
Top Tip: use TracDSC (if equipped) to experience less intervention from the traction control.

To other interested Jaguar enthusiasts...
I can commission a new batch of Quaife ATB to meet demand. Please PM me with your application.

Drive Well,
Herman
Onca Engineering

 

Hi. I am interested in a kit but has there been any conclusion as to whether or not this can be made with the gear ratios to match my 2018 XE S (380)?

 

Recently, a 2.73 gear ratio from a Jaguar was successfully equipped with a Quaife helical ATB.
So the range of acceptable gear ratios span from 3.31 to 2.73
It is noted that the Quaife ATB is not applicable to the 2.56 eDIffs from the V8 models.

I am working out a supply agreement with a Jaguar specialist in the UK, so share you details and we can get you on the list.

Drive Well,
Herman Wiegman
OncaEngineering@gmail.com

 

so looking forward to this so I replace two rear tires at the same time instead of just one

 

The unit that's been sitting in my garage is likely to find a new home in my F-Type very soon. I'd been noticing some whine I thought was the diff and so did the technician doing the annual service and coolant pipes noticed on the road test. Sigh. At least I've got on on hand, since they seem to be unavailable at the moment through JLR.

 

St/Liz
I am sorry to hear your OEM LSD rear diff is starting to whine in your V6S.
These OEM LSD units with bonded carbon fiber friction disks can fall apart, and the oil can degrade.
You could try to change the oil and see if that maintenance item improves the whine. (Castrol BOT 750B, 0.75 liters)
Otherwise it may be time to swap in your Quaife ATB equipped rear diff.

I may be interested in retrieving your old diff as a core for upgrades so other enthusiasts can benefit form future Quaife ATB builds.

Best, Herman
BTW, my Quaife rear diff is still going strong with 4 track events, 5 AutoX events, and 20 kmiles.

 

Thanks, Herman. The unit I've had sitting in the garage for "when I need it" has been called up to meet the need. I was starting to hear a little whine over a year ago. I changed the oil less than 10K miles ago and put in Red Line synthetic. It looked pretty murky then. The technician noted significant silvery flakes, so in goes the AA code unit with torsen. I'll get the old one in return (BA code). I wouldn't be surprised if it needs bearings, but hope there's no issue with the ring & pinion. Those can be a source of noise as well.

Did you ever dig into the BA code one I sent you? I think it was relatively low mileage, but it seems the service life of the clutch pack is not great. I was originally going to have you upgrade that one so I'd still have a matching code, but ditched that when you had #007 sitting there already to exchange.

I'm trying to remember where I saw a listing for replacement clutch discs. It was a couple of months ago when I was looking for something else, so chances of me remembering are only so-so.

 

Steve,
The -AA rear diff that you sent back to me had worn axle bearings due to an over torqued cover and bearing pre-load.

I made an error in my previous e-mail to you suggesting a diff oil change... I spec'd BOT 750B, which is in error..
I should have spec'd BOT 720 for the LSD and eDiff (with friction modifiers).

The replacement friction discs for the Jag OEM LSD and eDiff are now supported by RacingDiffs (I commissioned these solutions from them).

Best,
Herman

 

The unit I sent you was definitely a -BA. I'd got it specifically for that reason, and paid a premium for it. The -AA must have been from someone else.

That's probably where I saw them, when I was looking at LSD options for a '91 Miata.

 

I've got my car back. I was thankful the dealer was willing to install a part they did not provide, although with the expected disclaimer that they can't vouch for it. The labor for the coolant pipes was more than the labor for the diff :/

On the drive home I did not really test anything out, since I had a core differential unit in the cargo area. It was secured, but could potentially do some serious damage while "maneuvering." I'll have driving impressions in the next couple of days. I don't expect the night/day difference going from open diff to ATB LSD, but perhaps I'll notice something compared to a friction-style LSD.

 

Any updates @HermanWiegman

 

What update are you looking for? The units he's set up are in service, probably with the most miles on his own.