Everyone knows what a transmission is, but when it comes down to the internals and how they work, the curve of knowledge drops off. We recently had the chance to check out Bowtie Overdrives and Maximum Offroad Transmissions in Hesperia, California, while we were getting some work done to our 4L70E.

Our 4L70E in for a 4WD to 2WD conversion. Stay tuned for more on this in a future article.

Both transmission shops are under one roof and cover all of your needs. “Bowtie Overdrives is for street performance to high performance,” Chris Gardner explained. “Maximum Offroad Transmissions is for the off-road enthusiasts with anything from a prerunner to an Ultra4 rig.”

All under one roof, from classics to modern pickups.

Bowtie and Maximum deal with only GM-based transmissions, sorry Ford fans. They can look at doing anything from a rebuild to making the proper transmission for your project.

Transmissions come in needing help, but leave the shop looking better than they did off the assembly line.

“Bowtie Overdrives specializes in GM 700R4, 2004R, 4L60E, 4L80E, 6L80, 6L90, and Allison transmissions from stock to high performance,” Gardner said. “We have been in business 23 years, and were the first company to provide bolt-in conversion kits for ’55 and up vehicles including Camaro, Chevelle, Nova, El Camino, Corvette, GTO, and Firebird.”

From being able to CNC parts in-house to over 20 years of spare parts it is all here. The HAAS CNC lathe makes all their transmission components and resurfaces the pump assemblies. The transmission cases are also blasted and tumbled to have a raw aluminum look with no paint.

If you are into playing in the dirt, Maximum Offroad Transmission is where to head. They have played a big part in the Ultra4 community, and usually have between 80 to 100 transmissions out during King of the Hammers, in all the different classes.

Walking around the shop we got to check out all sorts of transmissions. Maximum Offroad Transmissions has built Randy Slawson's Bomber Fabrication 4L80E transmission when he won King of the Hammers in 2013 and 2015.

“Maximum Offroad Transmissions started as a hobby for some of the off-road community in 2009, before we took it full bore in 2010,” Gardner continued. “Maximum specializes in strictly off-road applications from competition rock crawlers to Trophy Trucks. We build Powerglide, TH400, 4L80E, 700R4, TH350 to survive the harsh elements of off-roading.”

Each style of transmission has its own bay where all the required parts are housed. This enables one person to work on the transmission with everything they need or within arms reach.

We had the chance to check out the new shop and everything that was inside. They have service bays for transmission service and repair as well as CNC machines to make all the parts they need in-house.

The shop truck, every transmission that comes through the shop gets bolted in and run on the street to check pressures. The shop test truck Ram Jet 350 motor with 350 horsepower and 400 lb-ft of torque.

Every transmission that is put together in the shop gets real-world testing before it is shipped to the customer. Gardner and his team put the transmission in the shop truck and take it for a spin. The shop truck has had over 11,000 transmissions run through it.

Another part of the shop is the fabrication area where they make transmission crossmembers for a variety of vehicles to allow for specific transmission to bolt directly in.

For more information on Bowtie Overdrives and Maximum Offroad Transmissions be sure to check out their respective websites.