05/26/2026
We now offer rear end straightening! Let us help you knock off your next tenth.
One of the most often overlooked parts of your race car is the rear end alignment. Racers spend hours, and in some forms of racing days going over the front end to make the alignment perfect based on setup sheets and notes. But how deep do we look into the rear end?
The standard procedure for most racers is to measure the rear toe just like they would measure the toe in the front from wheel to wheel. Measuring from wheel to wheel gives you a good idea of how the wheels measure relative to each other, but if you measure relative to the centerline of the center section, most of the time it tells a completely different story. Sometimes this is caused by crash damage, but it is also very common for new mass-produced brands of rear ends to not be assembled straight, which is especially common in Ford 9-inch rear ends. Sure, they may measure perfectly from wheel to wheel, but that doesn’t mean the centerline of the center section is straight in the car.
It is common to straighten a rear end using a bottle jack, a chain, and something heavy to strap it to. This will successfully get the wheels aligned relative to each other, but the wheels will not be aligned relative to the center section of the rear end.
Why is this so important?
Squaring the rear end in the chassis is one of the most important parts of the setup in any form of racing. Most chassis builders provide a measurement from the front of the axle tube to a dedicated spot on the chassis to square the rear end in the car. At this point, assuming the center section was assembled correctly and isn’t bent, the centerline of the rear end is square in the car. This leads you to believe that your overall wheel alignment is good too, which isn’t true if the wheels aren’t aligned with the center section of the housing.
We have seen rear ends that measure straight from wheel to wheel, but when measured relative to the center section, they have been off by as much as 3/4 inch. Imagine trying to tune a car at the track that you believe is square, when in reality it has 3/4" inch of skew to the left or right. Skew can be used to your benefit, but if you don't know its there it will be impossible to duplicate for the next time.
Another reason it is so important for the center section to be aligned with the wheels is to keep the axle tube seals centered on the axles. Have you ever had a rear end that wouldn’t seal, even with five axle tube seals stuffed down the axle tube? This is most often because the axle isn’t square in the axle tube, which is an indication that the rear end either wasn’t assembled properly or is bent.
Every rear end that leaves Speedway Engineering whether it is a new rear end that just came out of the assembly jig or came by for a tune up is straightened to the nearest 0.010". We guarantee perfection every time.
When chasing tenths, it is important to know absolutely everything there is to know. Stop the guessing.
Call or email us to schedule a drop off!
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818-362-5865
