J20 Steering Box?

Just returned from another weekend out on the trails. Unfortunately my stock saginaw manual steering box is on the verge of destruction. The output shaft has lots of play, and putting my steering in a hard bind resulted in my pitman arm being bent and twisted at about a 20 degree angle. Needless to say, I have been eyeing a power steering upgrade for a while now and this appears to be the perfect opportunity to upgrade.

I currently have 35" mud terrains on my CJ and don't plan on downsizing. I already have the MORE heavy duty steering bracket and lots of beef to support it. My NT Dana 30 has D44 knuckles and high steer and as a result is already using the larger GM 1 ton tie rod ends. My understanding is the Wagoneer/J-trucks used the same tie rod end tapers. I also have acquired the factory power steering brackets for my 304.

Would a J20 steering box provide the best power for turning my large tires? I want to do this right the first time and don't want to break another steering box. Also want to make sure I can run a beefier pitman arm than the CJ one. I have seen there are variable and non variable steering boxes available, and a variety of ratios. I would imagine the variable would provide better street characteristics, which is a thought because I drive my CJ on the highways to get to the trail. Would it be overkill to run the power steering through a cooler? Here's a photo of my current steering setup (pre-damage) for reference.

 

There are actually a ton of options for gears. I've had my struggles, mostly from going cheap and having a local shop build me a variable ratio gear instead of buying a redhead, pcs or agr. I ended up buying from redhead out of auburn wa. I wanted the variable ratio, mostly for off road actually while maintaining road manners. And big bore which could also be found in fsj. Alternatively, the gear I ended up with was a stock application from a 70s cadillac, big bore, variable, bolt on. The pitman arm came from R&p years ago.

To take advantage of the big bore, redhead recommends a higher performance pump. And I don't think a cooler would be a bad idea, but maybe not necessary.

 

The J20 gear definitely has a larger bore than the gear used in CJs or Wagoneers or J10s. Supposedly GM used this same large bore gear for commercial applications like limousines and hearses. I hear that the number of 4-tab cores is limited, and reman plants are known to offer the 3-tab gear as a replacement for the original 4-tab J20 gear. You may not be able to buy a proper J20 gear (ie with 4 tabs) off the shelf of your local auto parts store.

 

Good to know, it sounds like the J20 box with 4 mounting tabs would be worth searching for. I’m going to call the local jeep recycler and see if they have one. Sounds like a pitman arm from a chevy astro van might be the way to go as well, I’m going to check the wrecking yard this week for one.

Checking the part numbers it appears the CJ5 and J20 used the same PS pump despite having different steering gears. Will that effect the performance at all if I use a CJ pump?

 

I expect the power steering pump is whatever was used with the commodity engines supplied to Jeep by AMC. Don't know if there is a better alternative, but I expect any extra power in the large bore gear comes from the pressure of the fluid on the increased area of the rack piston nut.

 

I would be interested what you wind up with, my AGR pump is leaking. Costs more to send off for rebuild than I paid for it. My AGR pump mounting tab on the bottom are 3" on ctr. The Pump on my C1500 chevy has 4" on ctr tabs.

 

I stopped by J&W Jeep Recyclers today to see if they had a J20 box with the 4 bolt mount. They did not have any, and they did not have any boxes with 4 bolt mounts in general except for a used AGR box they wanted $550 for... It seems these steering boxes are even more rare than I had previously thought. It's looking like getting an aftermarket unit is going to be the way to go for me.

18502: 1975 – 1976 JEEP J20

I can get a red head "J20 box" for about $450 shipped, it's not clear if this will have the 3.5" bore or not, but it does have the 4 bolt mount, 18:1 ratio and 4.25 turns lock to lock which is what I am looking for. I sent their customer support an email to get clarification on this before ordering.

 

used to run AGR 3x1 ratio with ram assist. Nice set up when running 36 x 12x50 tires. DID you check with WFO for a box?

 

I'd recommend just giving them a ring. At least before the rona they were easy to get a hold of and very knowledge.

 

This was the answer I got from RedHead's support:

The fact that it's a 3.5" bore and comes with the fourth mounting tab is good news. Although I think variable ratio would be best for highway driving, it seems all the other pros outweigh the lack of variable ratio. I went ahead and ordered it, using a coupon code I got my total to $456 shipped. This steering box is probably way overkill for what I need, but loss of steering is a show stopper on the remote trails I do and I would rather have the extra strength. Next I will need to acquire an astro van pitman arm, power steering pump, pulley, V-belt, and hoses. I believe my manual saginaw box shares the same 13/16" splined input shaft so I will be able to use my same steering shaft.

 

I honestly think the 4.25 turn gear Could be better for the road. The perk of the variable ratio is less turns lock to lock on the trail while maintaining road manners. That said, thats why I ended up with that Cadillac gear. It all bolted up in place of my existing PS gear. In terms of the pitman arm, look at maybe Thejeepuy or R&P4wd for an unkeyed pitman arm. This allows you to clock the steering where you want. Im still planning to upgrade to a higher volume pump to take advantage of the larger bore gear. One of these days...

 

what year J20 did you order the steering box for and was it the 3 1/2" bore? what pump did you end up with?

 

I believe it was for a 74 J20. And yes I received a box with the larger 3.5” bore. It was the # 18502 box.

 

thanks, i have a saginaw box i just put on my 69 cj5, it was used and not working as good as i think it should, could be the pump, it was used also....i have the 5691676 box that is only 3.25 turn, so the one you have has the 4.25 turns ....thats what ill get when i decide to replace it...