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Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Alignment Service 02

Rating: 2 votes, 4.00 average.
6 Comments
by
Kaz-kzukNA1
, 30-09-2011 at 11:34 PM (14142 Views)




During the last Health Check, I noticed that there was a tiny up/down movement at the FL rack end.

Also, from time to time, when I turn the steering wheel, I heard clicking sound.




Click image for larger version.  Name: FLrackEnd.JPG  Views: 2886  Size: 150.0 KB  ID: 10500

These are quite common issues on the power steering rack but in order to confirm that it was not caused by the loose rack end, opened up the rubber boot and checked the condition of locking washer as well as any movement at the rack end.


There was no movement at all so wiped off the old grease and re-greased it before closing the boot again.


This confirmed that the movement and noise were coming from the power steering rack.


The bush/collar holding the spiral assist rack got worn and unfortunately, Honda doesn’t sell this part alone.

They only supply it as part of whole steering rack that is mega expensive.


In Japan, KSP Engineering developed their own jig and know-how on refurbishing the EPS steering rack and nowadays, even some of the Honda garages are sending the rack to them to solve this small movement and noise at the EPS rack.


I will touch on this in the future.







Click image for larger version.  Name: FLtierod.JPG  Views: 1085  Size: 131.2 KB  ID: 10501

What a tight locking nut and corroded thread at the FL tierod.

Managed to move the lock nut but the thread of the rack end screwed into the tierod was heavily corroded and seized that it was almost impossible to turn the shaft with 12mm spanner.

I thought about even applying the heat if acetone/ATF fluid didn’t do the magic.

After soaking it over night, finally, it started to rotate slowly.






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Click image for larger version.  Name: Caster02.JPG  Views: 1146  Size: 177.8 KB  ID: 10499

As seen on many NSX, both Caster adjustor were already seized.

Will see how they go at the alignment place.


So, all of the alignment adjuster bolts and nuts were checked and treated so I’m ready to book the alignment platform.

It will be early next week.

Time for the test driving session.
Categories
Alignment

Comments

  1. greenberet's Avatar
    When you touch on the steering rack refurbishment in the future, could you comment whether the service KSP Engineering offers for EPS steering racks in Japan similar to the refurbishing goldNSX offers for manual steering gearboxes here in Europe? goldNSX and a friend developed a replacement for the bushing between the steering rack and the steering gear box on the passenger side that Honda doesn't sell separately but that develops play over time (http://www.hondansx.de/phpBB/phpBB2/...hp?f=10&t=1531).
  2. Kaz-kzukNA1's Avatar
    Hi, greenberet.

    I think you were asking about the difference between the service by goldnsx and the one from KSP.

    If that is the case, I don’t know the detail on the service by goldnsx so can’t comment based on my actual experience.


    Having said this, I’m quite comfortable to say that it would be completely different because the structure of the rack as well as the failure mode is different between the EPS and the manual racks.


    In Japan, it would be more cost effective to replace the manual rack with a new one than trying to refurbish the rattling one.


    Most of the rattling at the EPS rack was caused by the wear at the bushing/bridge between the recirculating ball screw and the rack.

    You can see the actual rattle in this file at about 8sec into the movie.
    (This file is courtesy of Mr. Toyoizumi at KSP Engineering in Japan.)

    http://ksp-eng.co.jp/tyiz/mpg/GearboxOH.wmv



    Will try to find some time to further comment on this once I have finished working on this NSX.

    Kaz
    Updated 03-10-2011 at 09:37 PM by Kaz-kzukNA1 (Managed to link the video file now)
  3. greenberet's Avatar
    Dear Kaz,

    Thank you for the video and yes, KSP Engineering and goldNSX replace completely different bushings.

    For the manual steering gear boxes Honda sells lots of replacement parts for the driver’s side but they don’t sell the bushing that goes between the rack (part #10 in the picture below) and the body of the steering gear box (part #1) on the passenger’s side (where the red circle is).



    When that bushing wears the rack develops play on the passenger’s side that you can hear and feel. goldNSX took some videos. If it gets really bad it sounds like this when you turn the steering wheel: http://www.youtube.com/watch?v=IkfFnEyuyww and like this when you push up and down on the end of the rack: http://www.youtube.com/watch?v=IkfFnEyuyww.

    I replaced my manual steering gear box with a new OEM unit before the play got to be as large as it is in the videos. However, goldNSX and a friend have developed a bushing that allows you to replace just the part that wears instead of the entire manual steering gear box. I believe they took an NSX steering gear box to EMPA (the Swiss national materials science laboratory) to determine the best material for a bushing in that location in regards to materials compatibility, friction, wear, etc. Then they had the bushing machined and now they sell it and also offer to install it if desired.

    My replacement steering gear box is also slowly starting to develop play on the passenger’s side and before I replace the entire thing again, I think I’m going to try replacing just the bushing instead.

    On another topic: it’s good to read that the acetone/ATF mixture worked its magic on the tie rods overnight. If it’s OK to ask - did you apply it once and then let it sit over night while the acetone evaporated and the ATF penetrated, did you build some kind of container around the tie rod to keep it immersed in the acetone/ATF solution, did you stay up overnight to keep applying the mixture every hour (hopefully not), or did you do something else?
  4. goldnsx's Avatar
    Having seen the video of KSP, the source of the noise is different between the manual and electric steering rack. It has been around 10k km since I've had a new part inserted in my rack and it's still quite and working And: still no play in it. I'll inspect it over the winter season a little bit further.
    I was informed that the manual rack is discontinued in the USA, you can't order it anymore, not very nice.
  5. Kaz-kzukNA1's Avatar
    Quote Originally Posted by greenberet

    .......     On another topic: it’s good to read that the acetone/ATF mixture worked its magic on the tie rods overnight. If it’s OK to ask - did you apply it once and then let it sit over night while the acetone evaporated and the ATF penetrated, did you build some kind of container around the tie rod to keep it immersed in the acetone/ATF solution, did you stay up overnight to keep applying the mixture every hour (hopefully not), or did you do something else?
    Hi, greenberet.

    I didn't make any special container but applied it every hour during the day while I was working on other areas.
    I think I applied it 5 - 6 times before leaving it overnight.

    Not sure whether leaving it overnight helped or not and possibly, it was ready by the time I applied it so many times over many hours but just too tired to give it a try on that day....

    I have my own policy of taking break or even stop working once I get too tired or when it is time to eat.

    When I used to look after lots of boys and girls, they started to make mistake when they were too tired or tried to skip dinner when we were extremely busy.
    Based on this, I set the rule to stop working and take break or dinner at proper time and then go back to work after that.
    Also, this will reduces the chance of getting injured by mistake.

    As I operate on alone these days, needs to be very careful.....

    Kaz
  6. greenberet's Avatar
    Dear Kaz,

    Thank you for the information and taking a break when you get too tired / cold / hungry to do your best work sounds like a very wise policy!