Inner Axle Tube Seal
We recommend using inner axle tube seals on all 9” Ford housings and all Quick Changes with differentials. (Solid Spools do not allow rear end lube around the axles and therefore do not need inner tube seals) My preference is the Seals-it brand axle tube seal because it seals well on any diameter axle. You want to keep the differential lube in the housing where it belongs. Differential lube is not the same as wheel bearing grease and does not do as good of job. It also creates more drag for the hub as the bearing is forced to push through the thick lube. Properly packed bearings will roll more freely than hubs filled with lube.
Low Drag Hub Set-Up Service
Race installation is optional and normally costs about $15 per hub. Races make the least difference of all the low drag options, but are available. We normally turn the hubs around in 48 hours or so. If you would like for us to set up your hubs, simply ship your hubs with a note including what you would like done and all of your contact information. We will call you when they’re ready to ship back. Feel free to contact us anytime with any questions.
2 7/8” Inverted Drive Flange Style Hubs
Lighter Weight Axle Tubes
Lighter Weight Axles (Shorter Length)
Requires Axle Tube/Spindle Change
Shorter Axle Increases Axle Rate/Reduces Twist and Decreases Forward Drive
Bearings are questionable in quality. No high quality option available.
Large Seal ID (3”) creates significant drag.
Minimal Reduction in axle weight will not be noticed on the stopwatch (Small OD of the Axle = Low MOI)
In summary, I believe the con’s more than outweigh the pro’s. A large percentage of the Northeast Dirt Modified Market (where the 2 7/8” hubs began) have switched their fronts back to the smaller 6 pin style spindles and hubs. I believe this will be a fad in the Wide Five Market (kind of like angular contact bearings and oil filled hubs). It may have some staying power in the IMCA style market for the rear 5x5 hubs though.
In our testing, races made the least difference of all the hub components. Here’s the order of importance: Bearing Spacer, Seal, Grease, Bearings, Races. I do not think you will see a difference on the stopwatch if you don’t change the races.
. The K&C rig at Morse Measurements is a great machine. K&C rigs are one of the only fixtures that apply lateral loads to the chassis, which is the only way to somewhat accurately measure lateral and longitudinal jacking forces. They really downplay the use of pull down fixtures (naturally) in their article and ignore the fact that we measure kinematics on all four wheels, although not with the same level of precision they do. That’s what you miss out on for the $9,985,000 you save. J
They are correct that lateral (jacking loads) have an impact on vertical loads. Part of our training process covers this area. If you notice in their example, the difference does not become especially pronounced until the vehicle is in a high roll and high wheel load state. Your car will not typically get to 1800 RF load and should not have anywhere close to 4deg roll. The rear loads can be more pronounced depending on the track bar angle.
We relieve scrub through our slip plates for consistency. Your emphasis should always be on consistency in your measurements and whatever equipment you have should be able to give you repeatable numbers. We will make sure your equipment does just that, while being as accurate as possible.