Steering...high steer, assist, full hydro

[vetteboy]

It's been a long time since I had the WJ knuckles, but IIRC, the histeer arms on my WJ knuckles were about the same distance in from the KP axis as my PMP arms. Before I bought my PMP arms I argued at length with Mike that his arms would have terrible Ackerman, he insisted that they wouldn't & finally offered to take them back if I didn't like them. He was right, they're perfect, but the KP axis is nowhere near what I'd call proper Ackerman.

Paul

Well, that's how you set up Ackerman lines to determine tie rod mounting etc.

But...I think that it assumes you'll have a zero scrub radius as well. I'm pretty sure that it's most accurate when the tires rotate directly on the ball joint axis. Any scrub radius you add on top of that (less backspacing, wheel spacers, etc) will adversely affect the Ackerman configuration, and I'm not sure how you'd go about correcting for that.

Another thing to keep in mind is that wheelbase is a key factor in figuring out the angles too, and any generic D44 or D60 hi-steer arms that have offset tie rod holes are going to be designed for some arbitrary wheelbase. How far yours actually is from that will decide whether you're gonna be over- or under-steering through a curve.

 

[BrettM]

The same D44 knuckles are used on Blazers and Suburbans which have a significantly different wheelbase. I doubt it really matters for our applications if you get Ackerman nailed dead on. Although Ackerman doesn't have a unit of measure (it's either proper Ackerman or not) I would consider any steering setup that has the TREs wider than the KP/BJ axis (imaginary line converging towards rear axle) to have "some Ackerman", and a setup with the TREs narrower than the KP/BJ axis (imaginary line converging in front of vehicle) to have "negative Ackerman". I speculate that as long as you have "some Ackerman" you'll be doing alright.

Kingpin Axis Inclination is a good point. When you're running 2.5" BS wheels (as I do also) it's almost pointless to talk about proper steering geometry. Proper KIA puts the imaginary line through the KP/BJs hitting the ground near the center of the tire (actually a little towards the inner sidewall). That's the reason a lot of the high-dollar rock-crawlers run 17" wheels with ~5" BS and low profile hubs.

Everything is a compromise. Pick your battles.

 

[cracker]

When you're running 2.5" BS wheels (as I do also)

I thought you sold your junk?

 

[vetteboy]

I speculate that as long as you have "some Ackerman" you'll be doing alright.

I agree with this.

 

[dsgray16]

Im sure its just that my searching skills arnt up to par...im looking for the write-up on how to enlarge a certain valve in the stock steering box. It alows for more flow and therefor increases the output force...im sure somebody knows what im talking about, i figured this was a good thread to ask in


Thanks

 

[RalphXJ]

Im sure its just that my searching skills arnt up to par...im looking for the write-up on how to enlarge a certain valve in the stock steering box. It alows for more flow and therefor increases the output force...im sure somebody knows what im talking about, i figured this was a good thread to ask in

Thanks

I think this is what your looking for: http://westtexasoffroad.homestead.com/powersteering.html

 

[dsgray16]

yeah thats exactly what i was looking for thanks

 

[Goatman]

I don't know if you could make this work, but I think putting a tie rod from high steer arm to high steer arm at like 5" from the ball joint centerline and then connect the drag link to the passengers side high steer arm at the normal 6.5" from ball joint centerline would work best. Then you could run an assist cylinder between the axle and the tie rod and keep it all behind the drag link. The drag link would be in front of everything during compression, full left turn, and full right turn. This won't work on xj's with real coils, because the tie rod would hit the coils at full turns, but you are running coil overs, so perhaps there is room? How about posting a pic or two of the Tera High Steer arm that you have? I'm just interested to see what it looks like. It does seem like a good price! Oh, one other thing that sort of setup might allow for is to put the tie rod end holes in the steering arm further out near the rim without having clearance issues since it is closer to the ball joint centerline which would then keep ackerman angles better. If the drag link end at the pitman arm is too close to the tie rod at full stuff with the wheels pointed straight ahead, perhaps one could move the steering gear forward an inch or two on the frame? This would require cutting all or a portion of the front XJ crossmember off, but you've got a welder, and the stock crossmember is a bent piece of sheet metal anyways, so who cares, just make a better one with steering box clearance. Jeff

Jeff, I guess I missed your post. My problem is that with the axle moved forward 4" the tie rod is in front of the pitman arm joint, where normally it's behind the pitmaqn arm. So, my TR has to go in front of the DR, making fitment of the steering ram a real problem if both links are above the high steer arm.

Also, I already have the SBS system to reinforce the frame for the steering box, which is plates inside and outside and new sleeves, so there's no way I'm going to mess with that to move the steering box forward. Besides, on my rig there's nothing in front of the crossmember, so even if I could move the steering box, there's no room for it to go forward any.

I think I'm pretty well set on mounting the DL above the arm at 5.75" and the TR below the arm 1.5" forward of the DR, which is as close as I can make it and have it fit. I'm checking on getting a raised arm with holes in those locations. Since the TR has to be below the arm I'm hoping to be able to use a raised arm.

 

[BrettM]

you could get a reverse geared steering box and run the pitman arm forward...

 

[Lincoln]

you could get a reverse geared steering box and run the pitman arm forward...

With the stock mounted box the pitman would angle down and to the front. To me that would be make a real bad combo.

 

[BrettM]

With the stock mounted box the pitman would angle down and to the front. To me that would be make a real bad combo.

bent/custom pitman?

just throwing ideas out...

 

[Lincoln]

bent/custom pitman?

just throwing ideas out...

Hmmmm, may work depending on how long it would need to be.

Also, I just realized that I am running a different ackerman angle on each side in front. Not sure how I managed that (either the holes in the knuckle or I ended up cutting the two sides different). The passenger side hits about 7" inside the stock spring perch and the drivers side is almost at the cast portion of the housing. I could have parked it crooked also but I would never do that. Anyway it drives and handles better than I ever remember and I don't notice any wierd tire scrubbing. I do run a lot of positive caster if that changes anything.

 

[Jeff 98XJ WI]

Jeff, I guess I missed your post. My problem is that with the axle moved forward 4" the tie rod is in front of the pitman arm joint, where normally it's behind the pitmaqn arm. So, my TR has to go in front of the DR, making fitment of the steering ram a real problem if both links are above the high steer arm.

Also, I already have the SBS system to reinforce the frame for the steering box, which is plates inside and outside and new sleeves, so there's no way I'm going to mess with that to move the steering box forward. Besides, on my rig there's nothing in front of the crossmember, so even if I could move the steering box, there's no room for it to go forward any.

I think I'm pretty well set on mounting the DL above the arm at 5.75" and the TR below the arm 1.5" forward of the DR, which is as close as I can make it and have it fit. I'm checking on getting a raised arm with holes in those locations. Since the TR has to be below the arm I'm hoping to be able to use a raised arm.

I see what you mean, but with the steering cranked to the stops, wouldn't the drag link cross over the tie rod if the tie rod is in front of the drag link? I know mine does although my axle probably isn't as far forward as yours. It sounds like you are planning to set up your high steer arms damn near like I did. Your planned setup may place the tie rod in front of the pitman arm during full stuff pointing straight forward, but when turned, there may be clearance issues and the drag link crossing over the tie rod. With the tie rod mounted BELOW the high steer arms, you'll probably have sufficient clearance between steering components, but insufficient clearance between obstacles and the tie rod and/or ram. (BTW, I've bent my tie rod numerous times and always damaged the steering stabilizer mounted behind and slightly below the center of the tie rod when I left it on for wheeling!) Just something to be aware of. Would it be possible to place the tie rod inside the drag link connection, say at 4.5" from the ball joint centerline? That may be bad for leverage, but it would be good for clearance and ram mounting. Jeff

 

[Jeff 98XJ WI]

I would delete this screwed up message if I knew how!

 

[BrettM]

Would it be possible to place the tie rod inside the drag link connection, say at 4.5" from the ball joint centerline? That may be bad for leverage, but it would be good for clearance and ram mounting. Jeff

If you used an equally shorter pitman arm, the leverage would not be any worse.

 

[Jeff 98XJ WI]

If you used an equally shorter pitman arm, the leverage would not be any worse.

I think you misunderstood what I meant. I mean to leave the pitman arm as is, connect the drag link to the right side steering arm at 5.75" which is what Richard wants, but then put the tie rod at 4.5" from ball joint centerline on both high steer arms. This configuration would mean that more force would need to be exerted on the tie rod to produce a certain turning force on the tires as compared to if the tie rod was located further out on the steering arm lever, say at 7.5". Follow me? I guess the force exerted on the drag link would be the same in either scenario. Jeff

 

[BrettM]

I think you misunderstood what I meant. I mean to leave the pitman arm as is, connect the drag link to the right side steering arm at 5.75" which is what Richard wants, but then put the tie rod at 4.5" from ball joint centerline on both high steer arms. This configuration would mean that more force would need to be exerted on the tie rod to produce a certain turning force on the tires as compared to if the tie rod was located further out on the steering arm lever, say at 7.5". Follow me? I guess the force exerted on the drag link would be the same in either scenario. Jeff

gotcha, i thought you meant run the draglink closer to the BJ

you are correct that the tie-rod in that configuration would suffer more force. however, it would also travel less distance, so you could use a more powerful and shorter ram, like a 2x6.

 

[vintagespeed]

I ran full hydro on my white XJ. Single ended 2x8 cylinder (new cheif from surplus center), stock 4cyl XJ PS pump, Char-Lyn valve from Station on PBB (4 turns lock to lock IIRC, load reactive, with a gearotor (sp?) motor in it so it would work with the engine not running, return to center), connected to the steering shaft with a D window ujoint of the appropriate spline. Hoses were Goodyear braided cut to length with bolt together single use end fittings, I used a 11x11" mesa plate cooler to cool the fluid and a small reservoir/filter from Station. Tires were 38.5 x 14.5 bias SXs. I used standard flat hi-steer arms with 3ea 9/16" bolts on each arm. I was pretty happy with it and never hesitated to hop in it & drive it anywhere. I didn't ever notice the hi-steer arms loosen, it felt good on the street/fwy even at 75mph, turned the tires better with the engine off than a standard steering setup with 35s and with the engine running i could turn it with one finger. The load reactive feature allowed for road feel and obstacle "feel" when climbing a face with a tire or trying to ride an edge with the tire, and on the road it returned to center just like stock. Overall it was just like stock steering in almost every respect. The extra cooler was necessary to keep it from eventually overheating while crawling at slow speeds, and the unbalanced system did tend to bleed off a little fluid from one side to teh other on long drives which makes the steering wheel very slowly rotate (almost not enough to notice). I scared myself once going about 90mph down the 15fwy in the dew (wet road) because at high RPMs it was more sensitive to input, but at 75mph and below it was rock solid and very much like driving a stock rig. If it tells you anything, I was ALMOST able to keep up with Dave (back when his junk had windows) on the windy drive down from Big Bear and that says alot I think.

 

[vetteboy]

The load reactive feature allowed for road feel and obstacle "feel" when climbing a face with a tire or trying to ride an edge with the tire, and on the road it returned to center just like stock. Overall it was just like stock steering in almost every respect. The extra cooler was necessary to keep it from eventually overheating while crawling at slow speeds, and the unbalanced system did tend to bleed off a little fluid from one side to teh other on long drives which makes the steering wheel very slowly rotate (almost not enough to notice).

This has been my experience in the couple of full hydro rigs I've driven too. The load-reactive orbital is key, because not only does it give you some feedback, but it also lets you know when your junk is REALLY bound up before you start breaking off steering knuckles. I've also noticed the tendency for the steering wheel to wander off center as the fluid bleeds past, not a big deal for a trail rig but it can make using your blinkers annoying if you're driving it on the street at all.

 

[Goatman]

Jim, the full hydro is tempting. Right now, I don't have the cash for it, and if I can keep my current TR and DL, and use my current cylinder, then I just have to buy high steer arms.

With the load reactive valve and return to center, does it return to center with the single ended cylinder each time, or does the centering move a little as the steering wheel moves a little? If so, how do you get it back? I wouldn't care about the steering wheel moving around, but what about the return to center?