I’ve used the Frantz filter on Renaults and Peugeots that I’ve owned for engine oil. When my wife wrecked the Peugeot in 1985, the insurance company got the car and filter, as I never had a chance to remove it. I became interested in bypass filters some months ago, more to see what was available. I settled on the Motor Guard, as I liked the TP filters I had previously owned and didn’t see a problem with the 3k-change cycle, which I presently do for the engine oil. I was some leery of automatic transmissions, as I have always owned standard shift vehicles. I purchased my 97 Chevy Astro van with 120k miles on it. Its condition was excellent and it appeared to have had good mechanical maintenance, at least from what I was told. The previous owner said the transmission had been “power flushed” at around 100k miles. Shortly after I took ownership, the “Service Engine Soon” light came on. I took it to AutoZone who reads the ODBII codes at no cost said I had the P1870 code, which was related to the transmission. I bought a new filter; B&M drain plug and a case of Dextron III. I found an article on AstroSafari.com explaining how to do a transmission flush, which I did. The magnet in the transmission had the typical gray heavy stuff coating. I cleaned it up, flushed the 12 quarts and all seemed well. I towed a 4x8 U-Haul trailer loaded as well as the back of the van on an 800+ mile trip over the mountains down I5 into the San Jose area. The “Service Engine Soon” light came back on for a period of time. It also was a P1870 code (Lockup torque converter pressure problem). I had put on an auxiliary before the trip to San Jose.
After becoming aware of this site, I became sold on going bypass filter again. I was concerned that the filter on the AT wouldn’t have enough flow to satisfy the AT needs. Thanks to Ralph Wood and Gary Allen, I decided to install the Motor Guard. Being a van, space was tight, but it is installed.
The Motor Guard has been used for some 150+ miles. What I notice is the smoothness of the shifting. I had replaced the oil around 5k miles ago so it shouldn’t have been that dirty. I have a B&M electronic shift kit installed, which gives me 3 levels of shift changes. With the B&M turned off, it’s hard to tell by feel when gears change. When the B&M is in the next level there is a little feel as it shifts between 1-2 the other gears are very smooth compared to before the filter. When the B&M is in the firmest position, it shifts firm but not “bang” as it did before. I now feel better about using the firmest position when I’m towing my travel trailer.
It would appear that keeping the AT temperature down and the fluid clean will be the key to long lasting transmission performance. The 4L60E GM transmission was not designed for towing from what I’ve read. It seems there are some light-duty parts that won’t take the towing punishment. The 4L60E seems to have some problems with wear on the solenoids that create the pressures needed. My belief is that the junk floating around in the oil is the problem causing the sticking of the solenoids and their leaking. If the smoothness I’ve found since adding the filter is any indication, the $98 for the filter plus hose, adapters and cooler will have been a real bargain. I will have little to no need to again change and flush ATF or replace the internal filter.
After becoming aware of this site, I became sold on going bypass filter again. I was concerned that the filter on the AT wouldn’t have enough flow to satisfy the AT needs. Thanks to Ralph Wood and Gary Allen, I decided to install the Motor Guard. Being a van, space was tight, but it is installed.
The Motor Guard has been used for some 150+ miles. What I notice is the smoothness of the shifting. I had replaced the oil around 5k miles ago so it shouldn’t have been that dirty. I have a B&M electronic shift kit installed, which gives me 3 levels of shift changes. With the B&M turned off, it’s hard to tell by feel when gears change. When the B&M is in the next level there is a little feel as it shifts between 1-2 the other gears are very smooth compared to before the filter. When the B&M is in the firmest position, it shifts firm but not “bang” as it did before. I now feel better about using the firmest position when I’m towing my travel trailer.
It would appear that keeping the AT temperature down and the fluid clean will be the key to long lasting transmission performance. The 4L60E GM transmission was not designed for towing from what I’ve read. It seems there are some light-duty parts that won’t take the towing punishment. The 4L60E seems to have some problems with wear on the solenoids that create the pressures needed. My belief is that the junk floating around in the oil is the problem causing the sticking of the solenoids and their leaking. If the smoothness I’ve found since adding the filter is any indication, the $98 for the filter plus hose, adapters and cooler will have been a real bargain. I will have little to no need to again change and flush ATF or replace the internal filter.
