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Re: Unisteer Rack & pinion Turn Radius Problem [Re: finadk] #976470
04/21/11 04:32 PM
04/21/11 04:32 PM
Joined: Dec 2006
Posts: 3,533
Indiana
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Fury Fan Offline
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Indiana
Quote:

I have spent a lot of time researching a design for a rack for my 56 dodge. Good luck
Scott




I've read in some other brand-x forums that late-model Crown Vics are a modern-day donor like the Aspens were years ago. Research the Vic that has a removable front crossmember/suspension/steering.

Re: Unisteer Rack & pinion Turn Radius Problem [Re: MCTPhoenix] #976471
04/21/11 08:18 PM
04/21/11 08:18 PM
Joined: Jan 2003
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Canton, Ohio
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Sport440 Offline
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Quote:

We'll if there's a way to make it work can someone fill me on on what to modify? I'll try that otherwise I'll start hunting down a replacement steering column in preparation to put my original steering components back.





The basic problem as I stated is that currently the rack is mounted offset to the left. Thats a normal problem when using front mounted racks in A bodys withn 440,s or Hemis. Its probably the same with SB,s

With your rack being offset, instead of having equal turns lock to lock, from a dead center position. If Unisteer used a typical rack, and it sounds like they did.

Installing one offset will make your turns from lock to lock unequal. Your left turning radius will be much shorter then your right turning radius.

Is this the case with your rack? If so I can give you some ideas on how to fix it. Ive seen the offset problem fixed on the front steer racks.

Not sure if the same can be done to your rear steer without looking at the available working area.

Re: Unisteer Rack & pinion Turn Radius Problem [Re: Sport440] #976472
04/22/11 03:32 PM
04/22/11 03:32 PM
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East Brunswick, NJ
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finadk Offline
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East Brunswick, NJ
Sport440,
I am trying to understand how installing the rack offset from center will result in an uneven turning radius. If is if offcet you can compensate by adjusting the length of the tie rods. (longer on one side than the other). The lock to lock distance would remain the same on both sides. I can steer uneven bump steer problems bit not differential turning ability. unless of course the design is such that the rack is so far offset that it reaches its limit of travel in one direction before the wheel/spindle reaches its full travel.

I got lucky, in designing the rack for my 56 I was able to use a center steer rack and I can use long tie rods that attach within an inch of where the OEM rods attached to the centerlink so there is no bump steer issues.
Scott


Scott 1956 Dodge Custom Royal Lancer (408 Stroker, 4 Wheel Disc Brakes, Rack & Pinion, 6 speed) 2002 Dodge Ram 1500 Quad Cab 1976 Corvette
Re: Unisteer Rack & pinion Turn Radius Problem [Re: finadk] #976473
04/22/11 05:19 PM
04/22/11 05:19 PM
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Canton, Ohio
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Sport440 Offline
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Quote:

Sport440,
I am trying to understand how installing the rack offset from center will result in an uneven turning radius.


If is if offcet you can compensate by adjusting the length of the tie rods. (longer on one side than the other). The lock to lock distance would remain the same on both sides.



If done like that ,yes, the lock to lock would remain the same.

But the tierods need to be near the same exact length and among other things to eliminate or reduce bump steer.

If Unisteer knows anything about steering, Im sure they wouldnt do the Different length tierod trick, or at least hope they wouldnt do this. Hence my question to the OP. About his left/right radius bias.


If they used equal length tierods the rack being offset would have a unequal lock to lock. Example; If you had a typical 3.75, lets make it simple, say its 4 turns lock to lock, with the rack being offset you might end up with 1.5 turns to the left lock and 2.5 turns to the right lock.

So your left turn radius would suck and your right turn radius as good as stock.

Last edited by Sport440; 04/22/11 05:22 PM.
Re: Unisteer Rack & pinion Turn Radius Problem [Re: Sport440] #976474
04/23/11 10:35 AM
04/23/11 10:35 AM
Joined: Jan 2003
Posts: 20,165
Park Forest, IL
slantzilla Offline
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Park Forest, IL
Offset rack and unequal length tie rods will screw up Ackerman and bump steer like crazy.

One of the biggest issues with a rack conversion is that it is really hard to find a rack the correct width to keep everything in it's proper geometry. A Mopar front end has terrible geometry to start with, changing to a rack makes it worse.


"Everybody funny, now you funny too."
Re: Unisteer Rack & pinion Turn Radius Problem [Re: slantzilla] #976475
04/28/11 11:12 PM
04/28/11 11:12 PM
Joined: Aug 2007
Posts: 294
Phoenix, AZ
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Phoenix, AZ
So Steve the tech guy at Unisteer tells me to check the length of travel on the rack and if it's not 5 - 5.5 inches then I have an "early" kit and they'll replace the rack.
After unloading the suspension as told and measuring with a plumb bob I've confirmed 5 inches of travel on both sides. Back on the phone with Steve and he tells me that's all there is. I asked about a rack with the extra 1/2 inch of travel as I'm still an inch away from the factory stops on the steering arms and he tells me if it's between 5 and 5.5 inches that's all there is. I asked for clarification as I'm still confused... I'm in the auto industry and I deal in tolerances in milimeters but if I understand correctly the tolerances of their steering kits are half a F&^%ing inch?! He comes up with a halfhearted apology and says about half his customers like them and half don't. Wow a 50% satisfaction rating and they're still selling these things? They should be ashamed of themselves. Yeah I bought it a month after they were released... probably should have waited. Hindsight is 20-20. Anyone got a column shift / power column from a '70 B-Body they wanna sell? Got to find one so I can put the original steering back in the car.

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