2 months ago
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How a $5 part cost us $10k, and rendered WTF86 useless the past 9 months.

People have been asking "WTF happened to WTF86", you know that huge project we spent 3 years building, only to have it hit the track once and not be seen again for nearly a year?

Well, we finally found the culprit.

When we purchased a rear diff setup for the vehicle, it came preassembled as a kit. It was installed into the car and everything *seemed* ok. That is, until the first time it hit the track.

After a few laps, a driveshaft blew out a CV joint.

We figured it was a faulty driveshaft, as although they are only rated to 1000hp (and our car makes around 1300hp), the car was detuned for track use and only ever ran full boost on the dyno, with no "real world" load like the track.

Driveshaft shop happily replaced the driveshafts with an upgraded outer CV (big shout out to the guys there!) which we fitted shortly thereafter.

With the car all back together, we took her out on the street again, and wouldn't you know it, within hours the car was broken again. This time it was an inner CV, attached to the stub axle. At this point we were only running 98 octane fuel and around 650whp, so we knew it was not from abuse.

With our heads banging against the desk for the next couple of weeks, we were trying to work out wtf had gone wrong, as all the parts were overkill, over engineered and rather expensive.

Liaising with the supplier of the driveshafts (DSS) and the diff (FBM), we managed to narrow down the possibility of the problem being caused by the stub axles not being held in place properly.

After stripping the diff down we found that it was MISSING a vital part that makes this diff compatible with an IRS vehicle. You see, this diff is a common part from Ford, which in some applications goes on a live rear axle, meaning that there is no lateral movement on the axles into the diff housing, as the hubs are FIXED.

In an IRS car, however, the axles push and pull as you go around corners, meaning that they move around in the diff.

To prevent this movement, there is a snap ring (to stop the stub axle pulling OUT) and a spacer (to stop the stub axle pushing IN).

Unfortunately our diff was supplied without the spacer.

The supplier of the diff has merely stopped speaking to us when we pointed out what the problem was. We even offered to buy a new replacement diff, and ship this one back so they could assess the problem and refund us.

As yet, the diff supplier has continued to ignore our pleas for help, which is quite upsetting.

While I understand that everyone makes mistakes, it is how a company treats a customer following those mistakes to make amends that is what counts, and what is remembered.

DSS came to the party and shipped us drive shafts THREE TIMES, and replacement CV's multiple times, at their own cost to try help us out of this mess, only to find out that all along the fault was the diff centre.

Huge props to them for being proactive and for all their help, no doubt making a loss along the way.

As for where we got the $10k figure from, well every time the diff came out there were parts and labour, missed event entry fees, tow trucks, and countless months of the car being off the road and off the track, wasting away while we tried to figure out what the problem is.

We are finally glad to have uncovered the problem and look forward to getting this baby back on the track :D

Once again - THANK YOU Drive Shaft Shop!