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| | | Forums66 Topics128,120 Posts1,056,649 Members48,450 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jul 2006 Posts: 584 'Bolter | | 'Bolter Joined: Jul 2006 Posts: 584 | First of all, sorry to be here only when I need something...Life is so busy that I seem to just post a question about every 6 mos. Hopefully life will slow and I can socialize with you guys on this forum more often. So anyway, without discussion of the fabrication and physics of this task, will a PS gearbox work mounted upside down, just strictly from a hydraulic standpoint of view? I want to mount a Isuzu NPR ps box in a COE and it seems it will work if upside will distribute the fluid properly. When fabricated in place, the PS lines would screw UP into the BOTTOM of the unit when mounted as I need it to. As always, thank you guys for information. All my best. Tom | | | | | Joined: Dec 2002 Posts: 2,549 'Bolter | | 'Bolter Joined: Dec 2002 Posts: 2,549 | | | | | | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | Yes, strictly from a hydraulic point of view. I see no reason why it would not work. From a fluid power standpoint it is working as a hydraulic motor and position makes no difference. However there may be other mitigating factors you haven't shared with us.
Though you say it may not be worth the discussion I can see some serious installation problems IF you intend to use it to steer the truck. Maybe you have some other use in mind for it such as a rotation device for some mounted equipment, etc. Doubtful.
Just for clarity's sake why not tell us why? | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Dave, I don't know much about steering boxes, but what kinds of issues could you have with installation? Also, if this were mounted upside down, would the power steering lines be open to snagging things and likely to break? And Tom, you should be ashamed of yourself to just ask for help.  Isn't that what we all do! Jeff | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Sounds good to me, only issue I can possibly see is burping the air out of it but that shouldn't be hard.
Make sure after you flip it that when you turn the steering wheel right the truck steers right... | | | | | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | Absolutely Grigg. It would require some kind of bellcrank and at that point it all becomes very, very iffy.
Toncoe: can you say unsafe? | | | | | Joined: Aug 2009 Posts: 184 Wrench Fetcher | | Wrench Fetcher Joined: Aug 2009 Posts: 184 | As far as I have seen gravity does not play a role in anything in a PS gearbox, so it's orientation should not matter. I would think that there should be enough pressure and flow from the pump the get the air our regardless of it's orientation. Just don't mount the PS pump upside down.....I don't think that would work out very well.  As others have said....please do let us know what you are looking to do. If you ignore the people who say don't do anything different ever or we'll all die you might just get a couple good suggestions..... or give someone else an idea or two Tad
1946 Chevy OS 1.5ton, 1955 GMC 3100, along with other various IH,Ford,Nash,MGB,.....
| | | | | Joined: Apr 2001 Posts: 199 Shop Shark | | Shop Shark Joined: Apr 2001 Posts: 199 | I looked at this thread a couple times and I am wondering what "upside down" is. The NPR box is verticle with the lines coming in from the back of the box. I had to lay my box back and my lines come from the under side now. I have not seen any issues with it so far. I have yard driven my truck and the steering works fine. It did take a few times working the srteering back and forth to get the air out. I think this may be what he is refering to as "upside down" | | | | | Joined: Jul 2006 Posts: 584 'Bolter | | 'Bolter Joined: Jul 2006 Posts: 584 | Hey everyone, thanks for all the chat so far....see? this is what I mean...I've been dying to get back to see what was said and I'm just now able to get back to SB! So for discussion sakes...I did a google search and honestly couldn't find a good 'original' mounting of the box in an NPR, but it looks like if I were to mount it the original way, lines up, that places the steering arm on the motor side of the frame. In my 41 COE, I need the steering arm to be on the wheel side of the frame, which would result in lines down. There will be no clearance problems, no snagged lines,and the steering coupler will be in the same place so I don't see any danger to speak of. And unless I held my tongue wrong, it appears that the steering will be correct.... right turn = right. So maybe I'm mounting it the way it was intended...or it was a right hand drive box..I don't know. I just know that lines up, steering arm on the motor side of the frame won't work. My fab skills are fine, so if the hydraulics part will work, I will probably give it a try. I'll double check that the steering will be correct, but I did think of that and the first time I looked it seemed to be right. That part is worth checking 4 times  . Thanks again everyone! PS, the reason I believe what I'm doing is 'upside' down is because the lettering in the casting....maybe when mounted in the NPR's the lettering is upside down... SO that is all i'm basing it on.
Last edited by Tomcoe; 05/02/2012 5:38 AM. Reason: added info
| | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | | | | | | Joined: Apr 2001 Posts: 199 Shop Shark | | Shop Shark Joined: Apr 2001 Posts: 199 | Grigg, Looks like yours will be layed back about the same as I did. | | | | | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | Griggs example is not truly upside down. It appears be the a stock Izuzu in it's standard position. That is noy what I envisioned a "upside down" or truly inverted. If this is all you mean then why ask as you can look at any small COE and see them in action. | | | | | Joined: Jul 2006 Posts: 584 'Bolter | | 'Bolter Joined: Jul 2006 Posts: 584 | Thanks, especially for the pictures...well good to know. I've always seen them with lines out the top, and casting numbers right reading when installed....but so be it, and great!
As always, thank you for all of the help and in this case, peace of mind.
Best, Tom | | |
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