Identify 901 LSD Diff?

[Jim2]

This LSD diff is in my 914 transaxle. It is an HA transaxle not an HB, so the diff would have been added at some point. I wouldn't know a ZF etc diff if it bit me, but can any of you reading this tell me what brand it appears to be? There are about eight or so 1/2" holes around it's periphery, and it's coarse spline.

Jim

[Matt Monson]

Wavetrac tbd.

[Jim2]

Thanks Matt, I just searched that unit on the web and found identical pictures. Too bad it's TBD, I thought it was clutch type based on the friction/effort needed to rotated the stubs, though I'm sure it's all this 914 will ever need

[Matt Monson]

Here’s a video explaining how they function. It’s a unique design. They claim it’s a break through design. I’m not convinced, and that not just because I’m the competition, sort of. The complaint I get from owners who track them heavily is they snap “open” when you get off the brakes in the corner. The stability their system provides as you enter disappears once the brakes are no longer applied, unsettling the car. This really only applies if you trail brake and are midturn. It’s less predictable than either an open diff or traditional tbd. The counter argument I have heard is that it’s tolerable if you catch it with throttle input. Not having actually driven one myself I don’t claim to speak from personal experience and am just sharing what customers and pelican and rennlist members have said. Ymmv.

If it’s a street car it will make a nice difference in the street. I doubt you will ever be braking and entering a corner hard enough to exhibit the behavior I describe. It’s just nice to know it’s there if you ever approach the limit. I mean, the reality is that even if you lost the rear end like that in an LSD car, the solution is the same, throttle on and counter steer as required.

https://m.youtube.com/watch?time_continue=5&v=ElaMcoO_drg&feature=emb_logo