Lucas Oil Rules???

[chop6259]

Can someone explain this from section 12.14?E.) No “live-axle” rear-ends are permitted.Wouldn't this pretty much disqualify everyone in a dirt late model?

[MasterSbilt_Racer]

They incorrectly mean exposed axles.

[RCJ]

I've always took it to mean no sprint car rear ends.Were what looks to be the axle tubes are really the axles.

[dirtcrazy4u]

I thought they did away with live axles years ago. Unless something has changed, a live axle rear is what you find in sprint cars. SLM are running birdcages but as far as I understand are they not welded to the axle tubes ??? Due to the 4 bar rear suspension and the timing of the birdcage maybe they are on a bearing ???

[chop6259]

Every vehicle dynamics book I have ever read defines a live axle as one that has the left and right wheels linked together through a solid member. This means that any input on one wheel also induces an input on the opposite wheel making the system non-independent. For example, the rear end of an F-250 pick-up truck is a live axle rear end.

[tb1545]

Thats the issue when writing rules. Depending on who you talk to and where you are living, terms can mean multiple things in different regions. Thats why they always put something to the effect of officials interpretation of the rules are final.
Ive always heard live axle= exposed axle like sprints, and midgets.

Im also not sure that an f250 would be considered live axle in the vehicle dynamics book definition due to the differential that actually makes both wheels turn at different rates.

[chop6259]

I'm talking from a suspension input via bump or droop, not power input into the axle.

[Josh Bayko]

That rule has been on the books for years. All it means is no sprint car rears. It's just poorly worded. Should say no exposed axle rears or something.

[fastford]

joush is right, they should have just said no sprint car type rear ends, and if that f250 has a spool or the spider gears welded, then it would be a live axle. also a lot of 4wheeler atv,s are live axle.

[Josh Bayko]

joush is right, they should have just said no sprint car type rear ends, and if that f250 has a spool or the spider gears welded, then it would be a live axle. also a lot of 4wheeler atv,s are live axle.

It's not like a sprint car rear would even prudent in a late model. Just wouldn't work all that well with current chassis designs, and the fact that a late model weighs a thousand pounds more than a sprint car would bring up some durability issues for sure.

[chop6259]

Yeah, it wold be nice if they would incorporate a glossary of terms or something to give some clear definition on things. Especially when you are racing across different regions of the country where terminology may differ some. A live axle is just a solid beam axle that drives the wheel(s). It really has nothing to do with whether or not each wheel is driving via a spool center section or just one wheel doing the driving. Another example of poor word usage in text books. Many authors misuse the phrase solid axle to mean solid axle housing. If neither of the wheels are receiving power, it is considered a dead axle.

[fastford]

i always took it to mean each rear wheel was connected to each other by a non slip device, whether it be a spool, solid strait axle or welded, no PT units or spider gears welded , but i guess the correct terminology as far as text book goes, it probably does mean a one piece solid axle that goes from one hub to the other, like most 4wheelers.