KMS Differential Questions

[David Kirkham]

Guys,

Superformance installed a lot of our differentials in Shelby cars. From what I have heard (if anyone has other information please let me know) Superformance runs the breather line into the bottom of the catch can from the back of the differential cover plate. This isn't how we run them, but many people do run them that way. We have told Superformance we run them differently (we run them to the top of the pinion oiling hole) but as with most cars--and especially race cars--everyone does things differently.

We run our differential breather lines to the hole on the top of the differential, right on top of the pinion. We have found this is the area that best breathes the differential for us. We run the line to the bottom of a catch can which we mount up as high in the trunk as we can.

By running the line to the bottom of the catch can it allows for the oil to drain back into the differential. As you drive along, some blows out and some drains back etc. etc. etc. When you stop it all drains back in. You have to make sure your breather hose doesn't have a place that can catch and trap the oil from draining back.

Whatever you do, don't route the breather line to the top of the can--it won't allow for the oil to drain back down into the differential as you drive along. With the line in the top of the can oil can only pump out of the differential and into the can--which deprives the differential of oil. Eventually the can will fill up and overflow. There isn't a lot of oil in a differential anyway and if much oil leaks out then the differential may run out of oil. Differentials--especially the high performance Eaton TruTrack gear differentials--will not tolerate being low on oil.

I'm happy to answer any questions!

David