Hello All,

I am the proud owner of a 2005 MCS that I have owned since 2007. Back in 2010 I installed a Torsen T2 from a Ford dealer. This was pretty unique at the time and I got ten years of service. A few months ago I finally managed to blow it up. I scanned the options out there and decided on a Wavetrac which I purchased through CarID. The diff arrived in perfect shape and I started working to install it.

I pulled the old diff, pressed on bearings and bolted on the ring gear. So far so good, and the Wavetrac appeared to be very well made.



I went head and replaced the races in the trans which had been damaged when the diff blew up. I did a dry test fit of the diff and shimmed the races to ~0.005in of preload. The shimming turned out to be very import as without them the diff would have ended up floating between the races once they fully seated.




Fast forward about two weeks and I have the diff back on the engine and I am about to start installing the axles prior to putting the subframe on. All of a sudden I find that my brand new GKN passenger side axle I had purchased from FCP Euro would not seat in the diff. "Weird", I though to myself. "No matter, I have an OE intermediate shaft left over and a Sneed axle I can also try, lets see if those fit". Well it turned out that neither of those did. I had suspected that it was the bore that the axle ride on (not the splines) and did some testing to try and validate that. Proved it was not the issue. Here are a pair of Youtube videos I uploaded explaining what I encountered.



This is where it starts to get really frustrating.

 

I called Wavetrac to inquire about the issue. Imagine my surprise when Wavetrac was rather insistent on me using Genuine Mini axles. They repeatedly stated how they designed around OE axles and implied that it was my parts at fault. This was even after I explained how I test fitted the axles against my original open diff I still had on hand after all the years and my blown up Torsen which still had spines that were perfectly intact. I finally confronted him with the thought experiment of what somebody would actually do if they were putting a $1000 diff in there car and they had to purchase new axles. "An owner is not likely to buy Genuine Mini axles, they are likely to purchase a quality aftermarket part such as a GKN or an uprated aftermarket like an RMW. Are you telling me this is not OK?". They somewhat relented and they agreed to look at my diff. I pulled it out of my car and test fitted all five axles against the 3 diffs I had. Essentially all 5 of the axles I had in my possession fit both of my old diffs. Here is a video of me doing the test fits after I pulled the Wavetrac back out.

The two passenger side axles I have fit fine. The driver side were all varying degrees of tight fit. To be clear, the GKN axle I intend to use will not going in even if perfectly lined up with the diff out of the car and several very strong hits from a mallet. To the point where you have to pound it back out. Not acceptable.


I pay to ship the diff back to Wavetrac and they inspect it. The axle was sent on January 23rd. Generally it takes about 5 business days for parts to ship from CT to California via UPS ground and Wavetrac 2-3 days to do anything and email with the parts once they arrived. Once the diff arrived they did not find any issues. They also gave a theory that they believed the axle was not bottoming out and the snap ring was not engaging. This was completely unrelated to the issue I described on the phone and as anyone familiar with our cars would know the pax axle does not have a snap ring. They also suggested that to get the snap ring to engage i grind material off the end of my axle to get it to seat fully. They did not give any detail on what inspection they performed, they just stated everything appeared ok.

I made one last call to Wavetrac after the no issues diagnosis where they continued to insist on Genuine Mini axles. I dropped making phone calls to them at this point in the interest of record keeping.

I then had the following email exchange:

ME:

(Note Wavetrac lost track of this youtube link, I had to resend it to them today)

Wavetrac:

It's worth noting how they give themselves an out here with regards to the axle sizing. I went to school for mechanical engineering and have designed my own chain drive differential based on an E36 BMW Salisbury differential. To me this seems like they may have gone and measured one or two axles and designed to a line on line fit without leaving any room for manufacturing variation. I even went so far as to call FCP Euro to see if they had ever heard of someone bring an axle back because of this and while they have not the rep on the phone came to the same conclusion as me unprompted, bad tolerancing/failure to account for manufacturing variation.

I ended up sending them my GKN axle to for them to figure anything else out. Wavetrac paid up for this and my axle arrived on February 12th. Here is the reply I got back from Wavetrac. Again I think I need to point out Wavetrac doesn't seem to know exactly what is going on as the only way to split the axle apart is to undo the CV boot. Not something somebody would want to do on a brand new axle. I am wondering if they though the intermediate shaft was bolt on to the CV shaft like some cars.

Here is what I got back from them after they received my axle. The response came at 4pm CA time on Friday after the axle arrived at 1035am CA time on Wednesday.

Wavetrac:
Which brings me to where I am now. I don't posses an OE driver side axle and have made no mention of it to them in the past to my recollection. I have lost about a month to this and there does not seem to be a resolution in sight. Wavetrac claims to have an OEM Mini diff on hand (I also offered to send them mine) to which I have twice asked if they have test fitted my axle to it. The first ask was ignored and the second I am awaiting a response on. I currently have not been given a timeline or offered any solution.

I have been posting around and Mod Mini actually encountered a similar issue to this with a drive side axle. This was also a big problem in the Acura community at one point. Note at least 9mo went between the OP in that thread bringing the issue to Wavetrac and other forum members having the same issue.

https://www.clubrsx.com/threads/wave...oblems.759079/

As it is I feel Wavetrac wants to blame everything but the differential. Has anyone else been through something like this with them?

 

Can`t provide input since I have no experience with stuff like this but following.

 

Thanks for keeping us in the loop.... WaveTrack IS the ATB-Diff I want to go with (over the Quaif and Gicken)....

I'll also probably be upgrading the axles in the car.. which are at 120K miles.... when I do this and the stage 2 tune in my R56-MCS (same diff) with Akro Cat/ARP setup.


I'll be following this thread closely.

Thanks !!









.

 

My Quaife had the opposite problem. The passenger axle went too far in to line the carrier bracket bolts up. I had to pull the axle out about 1/4" and it caused the diff to begin weeping fluid from that side.

 

I cant speak for quaife, but on both of my cars with factory axles, the passenger side is easy on/off. The drivers side takes hitting with a rubber mallet to remove and to install.

I've had both off of both cars repeatedly for work, axle boots, clutch, lsd install, more axle boots

 

I had a Quaife installed in 2005 - its now being moved into the third transmission about to go into the car.

 

Well, might not be much more to follow at this point. Wavetrac has no timeline available and the OEM diff they claimed to have doesnt have the side gears for them to measure for axle fitment anyway. I'll update with there latest email exchange.

I am now going to do everything I can to get a refund.

I am looking at either a Quaife or one of these as a replacement: https://gripperlsd.com/product/bmw-mini-r53r56/

I am personally a big fan of that diff as it is basically the same design as the one I made back in college for the Formula SAE car. Those are basically bulletproof, pretty easy for an end user to service (no timing) and just simpler overall.

 

Isn't that why you would want something like a Torsen? The Quaife ATB is similar; it's fully gear driven. Should not need servicing.

 

I was in a very different place back in 2010 when I fitted it. The Torsen was the cheapest option after the OBX. I didn't want to risk the OBX but I didn't have the money for the Quaife (college student). It was 400-500 cheaper which was a big deal to me then. The car was also a daily driver at that point. I've also learned a lot more about differentials (designed my own) and the car is no longer a daily. I'll probably put less then 10k on it per year. The Torsen is arguably a step down from the Quaife since it doesnt have any preload washers like that one. It goes fully open when you lift a wheel.

After seeing the abuse that our Salisbury took in a formula car I would not hesitate to use one. We ran ours with just whatever oil was left over from a rebuild for a whole summer of testing between semesters. Clutches were a bit more worn then normal but everything else was fine.

This is a little bit of the FEA I did on the magnesium housing I designed




Here is the 4340 stub axle I designed. Reverse engineered from the original BMW parts and the Taylor Race Engineering tripod housing.





Earlier stub design that didn't have the stress relief grooves for the splines and smaller diameter inner bore. By adding a groove where the splines go to the major diameter you actually reduce overall stress. That let us pull more weight out of the middle. These were manufactured by Perry Technologies in CT. They are a major manufacturer of gear and spline components in CT.


Here are the guts of our diff

Here is an exploded view of KAAZ. You can see how other then a whole bunch of clucthes these are very simple

Cut away of the designed. We eventually tuned it down to 2 clutches

Render of an earlier design.

Another render.



Test fitting

 

Why did I post all of that? I really want to stress that I know my way around drivelines. Wavetrac seems to not trust it's customers at all regardless of their background.

Here is the latest exchange. Prior to sending my Axle off I offered to also send the my OEM open diff to give them another thing to measure,They politely declined stating they had one on hand. Here is what I send them a few days ago

Here is Wavetrac's response back

Again, I can't help but get the feeling they haven't heard of or dealt with this because people generally can't have their car down for a month while Wavetrac seems to try and come up with excuses for how this isn't the fault of their design.

Here was a draft note I was working on too them to help explain where I was coming from. I see no sense in sending it now given their attitude. Maybe I am being too harsh? I have lost a month due to the debacle.

 

I don't think that's too harsh at all. Not sure if they would agree that 5 incindents makes it a non-isolated issue tho... depends on the amount of units they sell I guess. I'm certainly convinced, and seriously re-thinking my plans to move from Quaife to Wavetrac on my car (I'd prefer some pre-load). Maybe the Gripper is the way forward.

 

I remember this from one of the Mini FB groups, and considering how this has evolved, I won't purchase, or suggest anyone else purchases, a Wavetrac product in the future. Similar to Ireland Engineering stating they can't understand how a roll-pin can slacken and develop tolerance. /sigh

This is disappointing, but I've had great luck with Quaife in previous cars, so might as well stick with what works... That Gripper LSD looks pretty interesting though. Some Guy - do you have any commentary about their plate and preload options? You obviously know what you're talking about, would you mind explaining what their options in the second drop-down box are referring to? (45/45 60Nm). Thanks!

 

Same question. Also, do you know if there's a US distributor? I poked around the site a bit and didn't find anything.

 

Hi,

I emailed Gripper and they gave a suggestion based on what I told them I wanted to do with the car.

Basically the number represents the angle between a pin that transmits torque from the housing into a thrust plate that pushes again the clutches. Think of it like an incline plane. The shallower the angle the less force you need to push something up the hill. In this case the shallower number the less torque you need to get a the same amount of force on the clutch packs.

The first number is going to be the accel side and the second is the decel side. The formula car was 45/45 so same on accel and decel. The new one we have is now 40/60 so a little more locking an accel and a good deal less on decel.

The preload is how much clamping is on the clutches when you are not applying any drive torque. This would be what would cause the opposite wheel to rotate in the same direction if you put the car in the air and rotate the near one. More clamping is going to make the diff behave more like a spool (welded) so it depends on the application. For the formula car we found a pretty light preload worked well for the inexperienced students on a tight autocross course.

These articles are all worth looking at

https://www.google.com/url?sa=t&sour...sqUX2HwST46SXi

I really like this link

http://www.intothered.dk/simracing/differential.html

Some formula student stuff

https://murmotorsports.eng.unimelb.e...rence-part-two

As you read around you'll see that diff tuning is easily just as important as suspension tuning. In some ways that makes things like the Quaife more appealing since you just put it in and go. But even those the locking is adjustable just in a different way.

This is actually a pretty good explanation


Wavetrac is now offering to modify the diff to fit the axle. They are saying a roughly a two week turn around. Which I think is reasonable since they probably need to send it to the manufacturer do the work and then presumably inspect it. Going to call and try and get the details today.

I'm still thinking of selling it on. After looking at the Gripper more I'm getting a bit excited about that. They also seemed like pretty stand up people. I specifically asked about axles and they seemed a lot more reasonable.

I'll update after I hear back from Wavetrac. And probably also for spelling later since I am typing super fast

 

someday I will upgrade to one like the gripper, picking your own ramp angles is critical, one size does not fit all use/applications. On my track car I could use damn near a spool as long as it unlocks in braking zones and initial turn in.

I get quite a bit of inside tire wear with the OEM lsd, too much wheel spin on the inside tire

 

Thanks for the explanation Some Guy. Ramp angles and preloads were remotely familiar from the brilliant late 90's game/simulator Grand Prix Legends.

Would be interesting to hear experiences with the Gripper LSD, especially in street use vs. torsen/Quaife. I do a lot of track days, but I also daily the car during the no-ice season that we call summer.

 

Thanks for those links. I have some questions.

1. It makes sense that an open diff would create the most oversteer in a corner under power. I'm confused because my Quaife has reversed that. My car now oversteers in corners under power with the Quaife.
2. Do ATB diffs like the Quaife function in deceleration or is that reserved for ramp style diffs with clutch packs?
3. What would cause an axle to go farther than intended inside the diff? Aren't the only contacting points on the splines?

 

Sevin they behave a bit different on the street where you are not at 100 % grip level in a corner. On the track or autocross they cause understeer if you are not careful with the throttle or are already at maximum grip available and you push into the pedal. I like to imagine my hands and feet connected, no throttle until I start to unwind the wheel or it'll understeer bad because the outside wheel is already doing all it can. Sometimes this is good if the rear end starts to spin or if you are on a course where you need to move deeper, add gas it'll power understeer! All that said the point in time where I'm not on the brake and not on the gas (vmin) is pretty small, when I started out it was terrible.

on the street you never or rarely get to drive on the tire grip limit, so they feel like they add oversteer

 

Some guy, thanks for sharing your experience. I was seriously considering a Wavetrac for a project, but now will probably just go with a Quaife.

 

I don't get much throttle understeer at the track with Quaife. It's actually more likely to spin the inside wheel as it gets unloaded while cornering, which is a bit disappointing. This is why I'd like some pre-load on the diff.

On the back roads it does tend to pull the front end in with throttle, which is nice.

 

Hey All,

Wanted to give another update. Been very busy with work so haven't had time to post.

First Wavetrac is active on social media. After posting this on Reddit and here I got an email saying that they were either offering a refund or to repair the diff within two weeks of me telling them to do so. It is very disappointing that it took them nearly a month to reach the same conclusion I achieved within a few days and what seems like only under the pressure of social media. The gears are just designed too tight. I had a pretty long phone call with a manager their and he gave me a couple of tiddbits that lead me to thinking this theory is correct.

1: Rather then just reworking the one gear for my diff they are sending a whole bunch to the manufacturer for rework
2: It wasn't 100% clear over the phone but it sounds like take measurements off of the differentials but then play with the final sizing until the get a "good fit" on the axle they have in front of them
3: They had a batch of diffs for a VW product that randomly stopped fitting stub axles. According to them VW changed suppliers for the stub axles and the axles then stopped fitting the Wavetrac. It would take a lot to convince me that in the process of changing suppliers VW also updated the part numbers and hence the manufacturing of the diff to match the axles from the new supplier (which likely have the same PN).

I made what is perhaps a poor decision and opted to go with the repair option. They said they could open up the splines a little bit at their manufacturing facility which is in a different state from their distribution center is in CA. I had already shimmed the diff and had the bearing all set ready to go. This was supposed to be the easier of the options and was also going to save me about ~$300-400

They had to send the axle and a batch of gear to the manufacturer for rework. As said they were stating a less then two week turn around. The manufacturer is going to "lap" the splines until they fit my axle.

As is It's been almost two weeks. I asked for an update on Friday the 28th and they said they would have one for Monday. Email them on Monday and was told the manufacturer was closed and would receive update on Tuesday. I've emailed them almost everyday so far this week and still no status update. Emailed them again today and didn't even get a response. Maybe I live in a different world but when my customers ask for status updated on their parts/jet engines I have to give them status or I am in a world of hurt.

We will see if by some miracle I get the diff back within two weeks or if this is a classic case of over promise and under deliver. I wasn't expecting them to beat 2 weeks, but it's incredibly pathetic that they can't even keep their customer informed on what is happening. This would be awful if I was trying to run a business or race team and was relying on them for support. I would have no ability to plan or otherwise do scheduling. I wonder if other AutoTech customers also have to deal with this?

I suppose I can always press again for a refund.

If this debacle somehow makes it to March 20th my diff will have been at Wavetrac for two months and not have been fixed.

Another option may be a 3J diff. Gotta keep that in my back pocket too.

 

hi,
where did you find your shim?
thanks

 

I ordered the Shim from AutoTec, it was for a VW trans, I want to say maybe the DSG gearbox?

I wanted to follow up with how this concluded. 2020 ended up being quite the year and I ended up getting the diff back just a few days before all the quarantines started to happen. I don't remember if they hit their two weeks exactly but they came close. The diff is in the car now and works just fine.

I just want to highlight again how incredibly pathetic a company has to be to only respond to customer complaints when they start getting called out on social media. Would I get a Wavetrac again? Tough call, I would need some sort of agreement or assurance that a situation such as this could not occur again.

Compared to my Torsen T2 (which has no pre-load like a Quaife or fancy auto clutch like the Wavetrac) the performance is better but not mind blowing. In the dry if the Torsen was a 6/10 the Wavetrac is maybe an 8 (let's assume an OS is 10/10 for argument sake and open is 0). It behaves itself better then the torsen if you hit a patch of sand or something but on dry pavement where you are just dealing with normal weight transfer they are fairly comparable. So in that regard a Quaife would probably be a 7. In the wet I do feel the Wavetrac is much better then the Torsen. The Torsen was maybe a 4 and the Wavetrac is maybe a 6, but don't compare these numbers to the dry numbers please, it's apple to oranges. Based on my experience I probably would have been pretty satisfied with a Quaife for what has turned into a daily/track car vs the rallycross machine I was planning.. For a dedicated rallycross car I'd probably go clutch type, maybe Gripper since they offer so many custom options. For a hardcore track build I can see why there may be some debate but an OS would serve well assuming you don't mind performance shift over time due to clutch wear.

 

Thanks for the update. Good to hear about the experiences Torsen vs. Wavetrac. Probably not worth the trouble to upgrade from Quaife to Wavetrac then, even if there were no issues with their customer service...