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Discussion Starter #1
I have heard it is possiable, yet can't find any pictures of one. Any know anything about this? or has tried it? Pro and Cons would be good too.
 

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Oh hell! I'm so glad the fashion for giant lifts hasn't reached the UK.



Yet..............

Mudplugga
 

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I saw one work. On a mudracer. The guy had a chain drive (giving him 2:1 steering ratio) down to the same level as the upper driver side link, then a rod going to the rack on the axle. Good joints in the rod. Took a couple of tries to get the geometry right. The problem is that the rack just wasn't strong enough to withstand big tires getting whacked back and forth in a mudpit. Broke the threaded ends off once, snapped an end once. One time a rock somehow got into the chain case and froze the steering. Yowza!
This is on a rig that could go 150' in less than 3 seconds through the mud. Before the bottle was turned on.
After seeing the rig work for years, I wouldn't recommend the mod. Too weak, lots of complexity. Too much stuff low on the rig. And if it breaks, you are toast. And maybe some innocent people too.
 

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I think its fairly common on mud dragsters... but they have very little wheel travel. I honestly don't see R&P steering having any pro's on anything else besides that very specific application
 

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Where will you find a rack and pinion that will turn anything bigger than 225/75-15? Go hydrostatic and be done with it :)
 

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i used to make my paycheck working on mid and heavy OTR trucks... there is at least one motorhome chassis manufacturer using a standard big truck steering box MOUNTED ON A PLATE MOUNTED TO THE BEAM AXLE. ujointed shafts back from front of frame to steering box... beam axle on a 4-bag air ride.. not saying i would try it, just saying there are actual manufacturers, with warranties and liability insurance actually doing similar things...

for what it is worth

peace, Dave
 

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You don't want to use rack and pinion in a application that requires strength. That's not the strong point of that design. It's the precision and feel it gives to sports cars and light weight it affords to the modern fuel efficient automobiles that make the R+P attractive. Not as strong as the recirculating ball types,not a good idea for offroad except in lite weight (dunebuggies) or limited travel suspension designs.
 

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Discussion Starter #11 (Edited)
Got it. All Points taken.:D

Truck has R&P now, and just tryin', to see it was possiable to adapt over to solid. Sound's like it's not worth it. Goin back to the old reliable ;)
 

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Hate to revive this, but not really any other discussion on the subject anywhere else.

Why not just run the rack in conjunction with a ram assist?
I suspect the reason most guys start thinking about rack, is because you could run it with a triangulated front axle. You'd need a pretty ridiculous telescoping steering shaft, but I think that part could be done safely enough. So why's no one brought up just using the rack for show (legal reasons, as most places require a manual linkage for the primary steering axle) but let the ram do all the actual work?

I stick a ram on everything even if I don't need the extra assist, because it essentially isolates the steering gear from impacts.
 

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Hate to revive this, but not really any other discussion on the subject anywhere else.

Why not just run the rack in conjunction with a ram assist?
I suspect the reason most guys start thinking about rack, is because you could run it with a triangulated front axle. You'd need a pretty ridiculous telescoping steering shaft, but I think that part could be done safely enough. So why's no one brought up just using the rack for show (legal reasons, as most places require a manual linkage for the primary steering axle) but let the ram do all the actual work?

I stick a ram on everything even if I don't need the extra assist, because it essentially isolates the steering gear from impacts.

https://www.pirate4x4.com/forum/general-4x4-discussion/2311378-budget-steering-rack-center-mounted-arm-truck.html

Similar in U4 / Joe Thompson /Gomez Bros cars have a Saginaw box attached to a double ended ram. The ram ends are held to the front clip and the steering arms are attached to the body. The body moves back and forth...without rotating.

I believe swingers can be designed to minimize bump steer easier than a rack/ram.

All these systems have to be beefy. There is a lot of feedback from tire hits that want to push the swingers and racks around. Even the best racks have to be keyed into the bulkheads as 3/4" bolts will not hold them from moving.

Once you add a hydraulic cylinder then you have to feed it. A Toatl TT system runs about $7k including that $3k rack.

"MACGYVER"
https://www.pirate4x4.com/forum/general-4x4-discussion/1611002-ultra4-ifs-full-hydro-power-rack-pinion.html

and most importantly
https://www.pirate4x4.com/forum/general-4x4-discussion/1014416-steering-go-fast-rigs.html
that thread is full of tech
 

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I know James at Blue Torch Fab has built a couple cars with 4 Link & Rack & Pinion, including one 4500 car that raced KOH a few years back. As I recall he made it work pretty well. If you want good info contact him.
 
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