Road-racers..autocrossers…time-attackers…corner-carvers…this is your moment! Well, it might not be your moment, exactly, but now that we've got your attention, you really need to focus on the subject of this month's Tech Inspection—a cool, simple axle reservoir from Bob's Auto Sports.
The reservoir ($129.99), patterned after the OEM canister installed exclusively on Ford's Shelby GT500 KR models, is designed to serve as a safety device for hard-driven S197 and newer 'Stangs. It collects hot axle fluid as it expands, and deposits it back in the axle housing once the fluid is cooled down.
When pressurized under extreme driving conditions, rearend lube will leak from the vent port on the axle housing, and fluid also has a tendency to exit through the wheel bearings on the newer Mustangs. This reservoir eliminates such leakage and prevents potentially dangerous conditions by keeping oil off the track or road.
There really isn't much more to say about Bob's axle reservoir, other than letting you know that it's a really cool upgrade for performance-driven '05-up Mustangs. The system is basic but effective, and it can be installed quickly using a small assortment of handtools.
Bryan Verbancic's S197 is decked out with an array of Steeda suspension pieces that keep his ride hugged down when he bombs through SoCal canyons. The crew at GTR High Performance recently upgraded the rearend housing on Bryan's ride (welded axle tubes), and we were on hand as the Bob's Auto Sports' axle reservoir joined the party.
Bryan's Pony is set up for...
Bryan's Pony is set up for handling thanks to a full battery of suspension goodies from Steeda. Notice the welded axle tubes? Locking down tubes in this fashion definitely is recommended when your driving style is, shall we say, aggressive.
Here is the super-simple collection...
Here is the super-simple collection of pieces that make up Bob's Auto Sports Mustang KR-Style axle reservoir ($129.99). The CNC-machined canister is made from 6061 aluminum, and the system includes every fitting, clamp, and hose that is necessary for clean installation on all S197 and SN-10 'Stangs.
To finish the installation,...
To finish the installation, connect the supplied hose to the axle reservoir...
....and the straight fitting...
....and the straight fitting on the housing.
The OEM axle vent cap is removed...
The OEM axle vent cap is removed and installed in a port on the top of the new reservoir. In its place, this adaptor fitting and barbed straight fitting are placed in the factory vent-cap hole on the passenger side of the axle housing.
The axle reservoir bolts in...
The axle reservoir bolts in place with the upper-control-arm bracket. Installing the unit does not require any fabrication or reengineering of any sort. It only requires snaking the reservoir into position within the tight area created by the differential housing, exhaust, upper arm, and bottom of the car.
Ricardo removes the 18mm upper-control-arm...
Ricardo removes the 18mm upper-control-arm bolts. A long extension is necessary; a pole jack (or floor jack if you're working on the ground) must be used to support the rearend during this step.
Mounting brackets for Bob's...
Mounting brackets for Bob's axle reservoir are 1/4-inch thick, and feature a notched-out section in the passenger-side arm to create necessary clearance with the upper-control-arm fasteners.
Here is the finished product...
Here is the finished product after an easy installation effort that shouldn't take more than 40 minutes. Note how the relief tube is routed over the exhaust? Failure to install the tube this way could result in it being damaged by the exhaust. Placing the hose above the pipe provides more than enough clearance and eliminates the possibility of heat damage.