My second factory unit has given up the ghost, I have all the parts to diy a PSC ram on to another factory u it and I’m comfortable with drilling and tapping the factory box. As of yesterday a friend of mine offered my his 3 month old psc big bore box for a fraction of the price and I couldn’t help but think that it’s definitely worth the money if another factory unit. Has anyone ever tapped their own psc for hydro? The process itself would be the same but I wonder if the locations and depth change with the larger box. I’ve looked at pictures of the big bore unit and it seems pretty straight forward but I’m looking for some real world knowledge. Thanks for any help.

 

Jayers, I have tapped and drilled a STOCK gear box for diy hydro assist and it was truly worthwhile. I believe PSC makes a big bore box that is drilled and tapped already. Was thinking that you could visit the PSC site and pull up an image of the tapped box to chaeck out the locations. This won't tell you the depth of the taps but should give you a better idea of where to drill. I have to ask if this set up may be overkill as the hydro assist with a stock box is giant improvement as it is. I did not look to see what tires you are running 37's? how much rock krawling do you do? this might factor into weather this modification is worth it. Those boxes are over a $1000 bucks so even a good deal from a buddy sounds expensive. Please let us know how it works out , pics please of the drilling process.

 

I know @Sv_dude has a big bore box and almost positive it is tapped. He's not been around in a while but maybe gets a notification with the tag and chimes in.

 

@XJRefugee thanks for jumping in on this for me. I did a lot of searching and PSC actually uses a completely different cap on the unit where it goes out to the intermediate shaft and it’s beefed up to accommodate the fittings. I do mostly rock crawling and my end goal is to add the ram I already have to the set up as I creep towards 40s. After a lot of digging it would seem the box is exactly the same as a stock box except much more heavy duty minus the special section psc adds. So I went ahead and drilled the box as if it were a stock unit. I’ll be installing it today so we will see if I just wasted $500.

The rear fitting isn’t dead straight but it has plenty of engagement and the hoses clear so I’m not to concerned. I’ll be back on here later to either celebrate or to post pics of a tapped stock box. 😅

 

As for the drilling the box is pretty thick so I’m happy about how deep I could cut threads in the unit. Talk about stress though.


you can see the case is beefy in the pics. I know it’s overkill but this is the third box for me and I don’t want to pull it to drill it later. I used a magnet and grease to trap the shavings and cleaned out the holes repeatedly after tapping. Since the unit was used it was full of fluid and I got lucky that it pushed out of the housing as I was working. I shot several videos of the process and if it works out in the end I will share them. My current box is under warranty so I’m going to exchange it and drill and tap it as well, I’ll keep it for a backup or sell it to someone in my group of wheelers.

 

Hey Russ! I’m online most days but just don’t post often.

I do have a tapped big bore but it’s factory tapped, I didn’t drill anything. With a ram, I can turn the 37” wheels under any condition with a pinky finger. I will say that the psc high flow pump kinda sucks though. It flows at a high enough pressure but the volume of fluid flow kinda sucks so there is the common steering lag at low engine rpm’s.

If you get a high flow steering pump, be sure to order the psc upgraded pressure line that goes from the pump to the gear box. I had a tapped stock box that I drilled, but the higher flow from the pump caused the Teflon liner to slip from the factory pressure line and it jammed up the steering box.

 

@Sv_dude thanks for the info on the line, I’ll make sure to swap it. I’m running the 3.8 in mine so I’m going to add the redneck rams underdriver pulley for now and see if I need to step up the pump from there. Did you add the psc large reservoir to your set up or a cooler? I have a cooler that will work just not sure if I’m gonna need it other than to add extra volume.

 

I wouldn’t suggest using a larger pulley on the stock pump. I’ve talked to the guys at Howe performance (they really know their hydro steering stuff) and they said that you run a high risk of cavitation in the pump by running it higher than what it was designed for.

I do use a larger psc reservoir, and an in-line fin style cooper mounted on my core support in front of my radiator. So far I haven’t had any issues with my setup aside from when I try to turn the wheel fast at low speeds, the psc pump isn’t able to produce the higher volume of fluid necessary.

As for the necessity of the cooler, I would say absolutely. If you’re in cooler temperature areas you may never have a need for it. But if you’re in the desert at higher temps, you may have an expensive regret by not having one. Besides, they’re cheap to buy. The only downside to them is it’s just another thing to have to hassle with during the install. But that’s a one time thing.

 

Jayers, SVDude makes so many good points in his posts! steering at low engine RPM is stiff. An inline fin style cooler is needed for cooling and fluid volume. Buy the PSC pressure line . its easy install and not bad price. The price you paid for the PSC big bore box was a bargain as you suggested. Only thing to add, I had an issue with the ram rolling the rod end on the tie rod when turning driver. I tried all kinds of things to get it to stay centered . Synergy makes a low misalignment washer for rod ends and fit perfectly over my 1 ton rod ends. These washers fixed that issue pronto. Have had on the synergy tie rod washers on now for couple of months with no issues and no rolling rod ends.Highly recommend adding these.

 

I appreciate all the feedback, the box works amazingly well on its own I got it installed this morning. I have the cooler in my parts pile, I ordered it at the same time as the ram so i will definitely be putting it in. I’m going to check on those washers as well. I think the larger res is definitely in order as well and I’ll grab one for when I install the ram. Only issue I had with the install is that I seem to have busted my clock spring so that’s going to have to get taken care of now as well.