By Brent Sanchez

I acquired an older style Frantz Filter and decided to paint it up and use it as a bypass filter on my Allison 1000 5speed Automatic Transmission. Probably major filter overkill since the transmission is a sealed unit. Mounting the filter housing was simple with homemade “L” brackets mounted to studs holding a plate to the body of the truck, 6” behind the engine oil filter.

 I had to figure out the plumbing as nobody seemed to know how to do it.

Next to the spin on Transmission Filter is a 15mm head bolt that is 7/16-20 thread with a Duro Brown Vinton O-ring.  Under that bolt is a pressure port, where I installed a banjo type fitting with an automotive brake line female fitting. I paid the Hydraulic Company to crimp me the proper male brake line fitting on a 2’ piece of ¼” 1100 psi hose. I left the other end of the hose open so I could push it on the fitting at the filter. 

In order to keep this hose clear of the front drive shaft, I ran the hose up and over the oil cooler lines on the left side of the transmission and back down to the filter with a 90 degree weather head fitting.

These Weatherhead fittings allow easy installation and removal of the oil lines. The return line was installed in an inspection/PTO plate on the left side of the transmission above the oil pan. Remove the plate, drill and install the swivel fitting provided by Frantz.  The length of the fitting sticks out inside the transmission so figure out where it will clear the housing or you can cut the fitting down (that is what I did) once it is installed in the plate.  Using a short piece of ¼” 300 psi hose, I ran the hose from the transmission to the Filter’s 90 degree Weatherhead fitting.

This installation was a breeze and cost for the special hose and fittings was $35.00…well worth it in my opinion. Road tested it and no leaks!

Brent Sanchez