GEAR VENDORS electronics offer several features unique to the industry. In this electronic age the importance of communication with the on board factory processor of any late model vehicle is a necessity for good performance. Our systems allow many specific features depending on the vehicle such as; automatic engagement and disengagement (AUTODRIVE™), auto lockout in 4wd mode, manual override, indicating lights to show auto mode and engagement, double overdrive canceling for vehicles where double overdrive would not be useful, automatic converter control during shifts for vehicles with lockup converters, accumulative shift counter to show you exactly how many times you used the overdrive over its life, troubleshooting indicating display, and digital ratio buffering to communicate with the vehicle computer.

These electronic features help you get the most benefit every time you drive and allow for substantial performance improvements even what you just drive and let the AUTODRIVE™ circuit do the work.


Installation is very simple in most applications as follows: Just remove the transmission extension housing and bolt on the GEAR VENDORS replacement housing which has an eight hole pattern to receive the overdrive. Tighten the eight nuts and take the driveshaft with the new yoke (included) to the local driveshaft shop to be shortened (as per the instructions). Plug in the electronics and fill the overdrive with the recommended lube, and you are ready to drive.

All trucks, rv’s, and vans have clearance for the overdrive but some cars and street rods can have very tight tunnel areas. Typically the overdrive fits these rides just perfectly but if they are tight if is usually just at the two upper rear case studs. These studs can be shortened easily and/or the tunnel can just get a ½ inch wide dimple in that area. In tight applications you will attach the overdrive to the transmission with the trans crossmember out and then jack the trans back up into position to determine exactly the point of contact. The most that is ever required is this dimple (usually then only if the subframe brace happens to be in that area). As you can see above the overdrive is very compact (roughly the dimensions of a standard coffee can) and looks very factory once installed.



Net Weight 32-46 lbs depending on application hardware.
Ratio – .78:1 pr 1:1 (reciprocal 1:1.28
Mechanically direct, hydraulically overdriven DeNormanville design.
Long Life Epicyclic planetary.
Solenoid control valve 6-12 volt negative ground @ 2amps.
650-700psi relief valve shift circuit.
Low parasitic loss common vertex Raybestos clutch.
Gross Combined Weight Rating 30,000lbs recreation (25K commercial)
Pressurized lubrication circuit to planet pinion bearings, roller clutch, input shaft pilot,
planet thrust surfaces, and ring gear.
Pressurized 2 stage permanent filter circuit.
High speed Dual Row caged needle planet bearings.
Efficient Single stroke/rev plunger pump with non-return valve.
Fluid capacity 28zo/flat sump or 48oz/deep sump.
Fluid type – GM#1052271 petroleum based or GM#12346190 synthetic.
18 Elements single row roller clutch rated to 4500lbs spike torque.
Horsepower limitations – 1200+ call GEAR VENDORS for applications above 1200hp.
Recommended service interval – change fluid every 5,000 miles depending on severity of duty.