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66 GT350 Heavy Steering & no self centering

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by ross0133, Nov 2, 2010.

  1. ross0133

    ross0133 Active Member

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    Can anyone help me I've got a GT350 with a heavy steering and it won't self centre after turning a coner, I physically have to turn it back to the centre.

    I had new tyres fitted and the wheel alignment checked and the castor and camber appears to be ok, the shop did adjust the toe but still no good.

    I lifted the front wheels off the ground and the steering moves freely. I've also got a 66 Fastback GT which is fine and the steering feels the same when the front is off the ground.

    Any suggestions would really be appreciated. I've hit a brick wall this this issue.
     
  2. rsimkins

    rsimkins Well-Known Member

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    ross0133,

    Check the steering box to see if it is adjusted too tight. If someone turned the adjusting screw in too far, the symptoms you described could occur.
     
  3. ross0133

    ross0133 Active Member

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    Hi Roy,

    Thanks for the suggestion. I actaully packed the steering box with Molybond grease today and that seemed to help it return to centre a little, but not as good as antoehr Fastback I've got.

    I checked the adjusting screw and realeased by around four turns. The result was a lot of slop but no change in the heavyness.

    On turning full lock either side I feel resitance when compared to my other Fastback which goes smothely to each side.

    My next step leads me to the stearing linkages.
     
  4. rsimkins

    rsimkins Well-Known Member

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    ross0133,

    Steering boxes that are worn tighten up as they get closer to the lock on either side but are loose in the middle. Did your problem show up suddenly or has it been there since you've owned the car?
     
  5. ross0133

    ross0133 Active Member

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    I've only recently acquired the car and I'm going through it from front to back and top to bottom to get it where I like it.

    The box is a FoMoCo box which apears to have been reconditioned at some stage.

    I hear what you're saying and I guess I should drop the steering linkages on each side to determine if the probelm is isolated to the box.

    If the feeling is still there then I know for sure that it would be the box.

    Would you agree?
     
  6. AJD350

    AJD350 Active Member

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    There are two possible adjustments on the steering box. The big nut on the input side sets endplay/preload. The one on the top plate sets sector gear mesh. They must be set in that order and the difference beween too loose and too tight is very small, less than 1/4 turn on either one. It is very difficult to do properly in the car,
     
  7. ross0133

    ross0133 Active Member

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    Thanks AJD350.

    I've tried adjusting the top adjemusment screw and locking nut on the plate with no improvement, but I didn't know of the other adjustment on the box that you menionted.

    Do you have a piture or a link that shows where this located.

    ross0133
     
  8. AJD350

    AJD350 Active Member

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    I don't have a picture handy. If you look at the firewall end of the gearbox where the input shaft goes in you will see a large diameter thin locknut. you need to loosen it enough to adjust the smaller hex to take any end play out, but not enough to cause drag. Then tighten the locknut. The sector adjustment can then be made, a little at a time while turning the input shaft back and forth, being careful to watch for binding in the on-center wheel position. If there are excessively worn parts in the box, however, no amount of adjusting will make it right. Hope this helps.
     
  9. ross0133

    ross0133 Active Member

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  10. Texas GT350

    Texas GT350 Well-Known Member

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    Let us know what you find out, mine is the same way, I took it to an alignment shop and they made it better but still heavy and slow to return to center.
     
  11. 2+2GT

    2+2GT Well-Known Member

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    [​IMG]WARNING!

    Unless you follow the exact factory procedure for adjusting the gearbox, destruction of the gearbox is a likely result. If you have already experimented with these adjustments on your own, stop driving the car immediately and do the procedure correctly. Otherwise, imagine your test drive. Now imagine turning a corner at perfectly normal speed. Now imagine the ball return splits due to your un-informed adjustment. Now imagine one of the balls pops out, and jams the sector gear, and despite your sudden adrenaline rush, giving you the strength of Arnold in his prime, the steering stays locked, forcing you to drive head-on into the 10-wheel truck coming the other way.
     
  12. ross0133

    ross0133 Active Member

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    You make a good point. No point exprimenting.

    I had actual spoken with my mechanic who pointed out the same issues. I'll be taking it to a workshop for the adjustments....not willing to risk the potential disaster.

    Got it back from a competent wheel alignment shop yesterday. A good improvement with self centering mostly due to caster setup being negative n the 1st place.
     
  13. Bob Gaines

    Bob Gaines Well-Known Member

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    The idler arm may be wore out. The solid rubber bushing in the Ford idler arm is designed to wind up when you turn left or right . When you let go it is designed to snap back to center. Just a thought. Bob
     
  14. ross0133

    ross0133 Active Member

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    Had that checked out by a suspension centre and they thought it looked ok but I still will be having a better look at this. My other Fastback had the same issue and the idler arm fixed the problem big time.
     
  15. ross0133

    ross0133 Active Member

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    The steering has improved considerably but it's sill heavier than my 66 Fastback GT.

    Can anyone tell me if the set up of a 66 GT350 idler arm being slightly longer than standard would cause a heavier steering than normal, or should both a manual steering GT setup and a GT350 set up be the same???
     
  16. 2+2GT

    2+2GT Well-Known Member

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    Yes, the 65-66 GT350 steering is noticeably heavier than the Mustang GT steering. 15 years of daily driving one gave me forearms like Popeye the Sailor. It should still self-center. Once you get the preloads fixed on the gearbox, have the alignment checked. Make sure you get a geezer or an old car nut to do it, most techs today are clueless how to do an alignment with shims.

    Oh, and the Shelby called for different alignment specs than the Mustang.
     
  17. ross0133

    ross0133 Active Member

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    Thanks for that info, I probably would 've kept chasing the impossible dream in regards to steering weight as I've been compring it to my GT Fastback.

    That explains a whole heap to me.

    The Shelby self centres with no problem now. I'm happy with the alignment but I will get it checked again soon.
     
  18. Texas GT350

    Texas GT350 Well-Known Member

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    Did you replace or adjust the steering box?
     
  19. ross0133

    ross0133 Active Member

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    No the steering box hasn't been changed and I still need to adjust the box for the end play as it has about 2 inches of play before the wheels stat to move.
     
  20. Texas GT350

    Texas GT350 Well-Known Member

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    Mine has about the same amount of play, I had it adjusted but it was wandering on the road, had it loosened up a bit an it is much better now. The only adjustment done was the nut and screwdriver slotted screw, I did not know about the other adjustment screw until this posting, let me know if you get it adjusted and which one of the two adjusting screws was done.
     

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