GOOD AXLE OR TOMATO STAKE - Derby Tech - March, 1984

by Marv Wolfgang

There have been many excellent articles published over the years and most recently in the Gravity Drags News, on the need for good axle alignment and many of the tools used to achieve that end. I will not be discussing specifically that topic, instead I would like to share some of my ideas on what I consider a prerequisite to good axle alignment. The area I am speaking about is the selection of a good axle.

I know what everyone is thinking, that the only way to get a good axle is to manufacture it, not true. Both championship races we won, in 1982 and 1983 were run on stock All American axles. I have also checked the quality of some of the 1984 All American axles and found them to be very good. This does not mean that every axle the All-American manufactures is good, but what I've seen of the 1984 axles is encouraging to say the 'Least.

Another alternative if you are racing in the N.D.R. Gravity Drags is to manufacture your own, however it must meet the N.D.R.'s dimensions specified in their 1984 rule book. This alternative can be expensive and you may end up with nothing more than a good tomato stake. So much for that.

This is a check list that I follow when picking an axle:

1. Is the axle straight without any twist? I hope the answer is obvious.

2. What is the length of the square stock? Look for the maximum length within the legal dimension.

3. What is the length of the round stock? Chock the machined area between the square stock and the wheel retaining hole.This should be the maximum length within legal dimension. This will allow your wheel to float more freely.

4. What is the finish like on the machined area of the axle? I'm not going to give you a lot of technical jargon on a
micro finish because I do not understand that myself. Just remember you want your wheel to float across this area as
freely as possible so the smoother the better.

5. Check the machined area of the axle with a micrometer caliper. Is the axle round? How much taper is there between the inside and the outside? My rule of thumb is anything within .0005 on the taper is acceptable. I also like to start with a round axle.

6. Are the machined ends of the axle in the center of the square stock? It is better if it is but they usually are not. So you must be very careful when you place your alignment marks on the axle especially if you use the square stock for this manner.

7. Are the dimensions we just discussed the same on both ends of the axle? They should be, if they are not give the axle to your competition. Who knows he may need tomato stakes.

8. Make sure you drill your kingpin hole in the center of your alignment marks in both directions, length and width on your axle. Remember your machined area in most cases will not be in the. center of your square stock.

In conclusion, I would like to add that we do have a hardness preference we look for in an axle, but that is predicated on the type of suspension we are running. I would also like to say that I have not run any tests to prove what I am recommending in selecting an axle. Most of my information is strictly logic and experience.


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