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Oil filter: Vert or Hor?

X

XJade

NAXJA Forum User
Location
87XJ_4L-Automatic, Arizona
Does it affect oil filtration whether the oil filter is mounted vertical or horizontal? Mine originally was vertical but when I had a friend put in a new engine a few years ago I noticed he had bolted the elbow horizontal. I haven't gotten around to changing it back. Or maybe I shouldn't bother?
 
I don't think it matters. Chrysler changed from vertical to horizontal when they introduced the HO version of the engine in 1991.
 
The horizontal mount moves it out of the way of any intrusions like sticks and branches and tucks it above the starter. I've seen some vertical mounted ones sheared off on GM engines, one Olds/Buick V6 had the darn thing horizontally in the front of the engine to the left of the mechanical fan kinda hanging in mid air pointing at in the direction of the passenger side headlight. Vertical mount makes life a bit cleaner though if it is straight up and down when changing oil, no spillage that way....
A true vertical mount also allows you to pre-fill the filter for a faster pressure build up after an oil change and NONE of it drains back after shutting the motor down.
 
In terms of the quality of the filtering job it does, doesn't matter one little bit. The oil gets pumped through the filter either way, and filters aren't made specifically for mounting one way or the other.
 
my 91 xj with and 4.0 HO has the filter horizontal, i agree with dmillion that it doesn't matter which way its mounted.
 
it doesn't matter which way its mounted as long as it filter's your oil.
 
Thanks for chiming in, everyone. Appreciate the advice.

Having the filter mounted vertically sure made it easy to change. Nowadays I gotta crawl underneath the beast to pull it outta there. Which would be okay had I skinny hands.
 
XJade said:
Thanks for chiming in, everyone. Appreciate the advice.

Having the filter mounted vertically sure made it easy to change. Nowadays I gotta crawl underneath the beast to pull it outta there.
Click to expand...
Unplug your oil pressure sender and you should be able to reach right in from the top to get the filter out. I usually have to back mine up a bit and stand it upright but hten it narrowly fits out through the top. That's with a larger-than-stock PH8A-sized filter as well.
 
hey yucca-man what year is your jeep?
i use the ph-16 filter but i've been looking for an bigger filter so if an ph-8 will fit i'll try it out.
i have a 1991 xj with 4.0 HO.
 
Right under my name - 96XJ. If you fit a PH16 now the PH8 will as well. I don't know of a larger version that I would trust for the earlier PH3985 in the Renix.
 
cool thanks yucca-man so it should fit, i'll have to try that next time.
i thought that the filter might be a little small my dad has a 99 dakota(4 banger) and he runs the same filter, my fliter having to clean two quarts extra. not that my oil is ever very dirty.
thanks again yucca- man.
 
I understood the filter adapter change was with the HO engine and that Renix engines had the vertical adapter. Renix used the PH3985 and HO use the PH16...
 
sjx40250 said:
So did the oil filter threads change when the orientation changed or is it unrelated?
Click to expand...
Yes, the threads did change. The older AMC non-HO filter is a metric thread, and the vehicles came from the factory with a yellow sticker under the hood that started out with a big "VORSICHT!" -- which I assume means "Hey, Stupid, listen up!" or something like that. The newer ones with the horizontal mount take a standard American SAE thread.
 
Mine uses a roll of toilet paper, but that is a story for a different day :woohoo:
 
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