Question regarding 308 Steering Rack nut tightening: | FerrariChat

Question regarding 308 Steering Rack nut tightening:

Discussion in 'Technical Q&A' started by christopher, Apr 30, 2007.

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  1. christopher

    christopher Formula 3

    Nov 29, 2003
    1,136
    Ontario California
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    Christopher
    #1 christopher, Apr 30, 2007
    Good day fellow "F"-Chatters,

    Got some quick questions for anyone that's done a 308 steering rack R/R:

    1.) How tight should the nuts/bolts be that mount the rack to the frame? Should both the inner metal bushing sleeves meet inside the rubber bushings, causing the 4 nuts to reach the end of their threads?

    2.) Also, I didn't remember this upon removal, but the steering column end spline (that couples to the rack) has two areas of splining, separated by a groove. How far should the coupling go over the splines? To the first set, or the 2nd set of splines?

    Thanks Guys.

    Chris.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
    25,123
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    Steve Magnusson
    #2 Steve Magnusson, Apr 30, 2007
    1) You said this a little strangely -- the nut is tightened until the washer-spacer-washer goes "solid" (which puts a fixed amount of displacement into the flexible bushing), but the nut is not at the end of the bolt threads, and

    2) You don't get a choice here -- the cross-bolt is cleverly designed to intersect the splined shaft (which makes the splined joint inseperable unless the bolt is completely removed -- i.e., "just loose" doesn't cause catastrophe).
     
  3. christopher

    christopher Formula 3

    Nov 29, 2003
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    #3 christopher, Apr 30, 2007
    I did struggled with the words for my questions......

    You saw through it though, that was what I was looking for! I just wanted to insure that I had the nuts/bolts are tightened just enough, not to over tighten. It would appear that all metal parts are connected (washer-sleeve-sleeve-washer), and a light fit. Which brings another question: Since the metal parts are now joined and the rubber bushings are mashed down, how does the bushings function?

    Also, the steering column's first set of splines are now covered by the coupler, and the bolt and nut are seated, so I guess I did well. Please correct me if not.

    Thank you very much.

    Chris.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,123
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #4 Steve Magnusson, Apr 30, 2007
    The (static) bushings act as a (passive) "soft" mounting for the steering rack -- if the steering rack was rigidly connected directly to the frame via metal parts, it would transmit a lot of vibration and harshness into the "feel" at the steering wheel.

    You're good to go -- the bolt shank passes thru the groove machined in the splined stub.
     
  5. christopher

    christopher Formula 3

    Nov 29, 2003
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    #5 christopher, May 1, 2007
    Thanks Steve, I apprecaite your help and time in responding to my question!

    Thanks again.

    Chris
     
  6. CarlH

    CarlH Karting

    Feb 5, 2004
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    Carl H.
    #6 CarlH, May 5, 2007
    Chris -
    If you are replacing the passenger side bushing, which is usually the cause of play in the steering rack, there is an additional thing you should check. The original bushing was a rubber inner with a metal case. The replacement bushings tend to be solid nylon. The retainer screw which holds the bushing in place works well with the metal case, but not so well with the nylon replacements. I had to go with a slightly longer screw to keep the new bushing in place.
     
  7. christopher

    christopher Formula 3

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    #7 christopher, May 7, 2007
    I had the entire rack rebuilt.

    They used a copper bushing, I didn't want to ever have to R&R this rack again, so I won't have an issue anmore.

    Thank you for the response.

    Chris
     
  8. maurice70

    maurice70 F1 Rookie

    Jan 25, 2004
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    #8 maurice70, May 8, 2007
    Chris are you sure they used copper?Usually they make them out of Bronze-brass or delrin.I would think that copper would wear quick
     
  9. christopher

    christopher Formula 3

    Nov 29, 2003
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    #9 christopher, May 8, 2007
    Come to think of it, I think it was brass.....

    How's everything in the Land Down-under?

    Thanks, Chris
     

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