eps steering rack.... delvin into the deep!

[goldnsx]

92 in Town - unacceptable

Please keep in mind that one major variable is missing here and that's the ET (not the alien of Spielberg) of the wheels, I mean their offset.

A stock NSX with stock wheels/tires (all years) is very, very acceptable in town, even during parking. The forces dramatically increase when people run lower offsets (40 mm or less) and wider rims on the front. So, it's not the car's fault or even the one of the engineers. The lower offset values also contribute to the detoriation of the bushings within the steering gearbox and so on.

I took this into consideration while ordering my wheels and choose an offset of close to stock, 50 mm on a 7.5'' wide rim in the front. It doesn't look 'sexy' but the car drives close to stock and much better than with the previous aftermarket wheels which were ET 43 on 8'' wide rims.

Hondas are a little bit tricky and special about the offset of the wheels chosen by the factory, esp. the models with FWD. It has always been hard to find aftermarket wheels with an ET close to stock. See Integra, Civic Type R, S2000...

Enough of OT, sorry for that.

[ozon02]

let's not clutter up this beautiful thread. Is there a sense to open a new one?
As you know, I respect your opinion and knowledge of the model. I shared my impressions.
92 auto had factory wheels 15 front 16 rear ,tires I do not remember.
This thread shows that I am not a fan of correcting the factory (plastic gear for brass gear,....... supercharger etc.)
After the first Track Day I bought a Big Brake front but it involved buying the offset disk. But I noticed the deterioration of traction. I bought a Big Brake wheel friendly but in size 17 front 18 back. Another change for the worse. I bought Tein Suspensions RA-good for track bad for Town I bought OS Giken 4.40 LSD. More fun. The next step would be turbo but enough - it's a bad direction. I bought a different car.

[britlude]

getting back on track.......

this looks somewhat better.....


no clunking now.....

one thing i did note.... there wasn't any dowels/location for fitting the ball screw mount to the motor when assembling the rack... there's holes through the various components (motor bearing mount, ball screw mount and end cover) so some pins were made up to align during assembly, and make sure there was no looseness/backlash between the motor and ball screw gears.....

one side was a small hole....
IMG_20190316_140618 by jon sutherland, on Flickr

the other side was a larger hole through the top 2 items, but a flatted hole cast in for the motor bearing plate....
IMG_20190316_140628 by jon sutherland, on Flickr

just to be awkward, so a pin was tweaked at the end.... ok, probably overkill, but, anyway, no backlash and everything moving fine!

re. the passenger side bush.....
IMG_20190316_141125 by jon sutherland, on Flickr

.....i decided to leave it as is for the time being, the play was minimal before i stripped it, and a good grease will lose that.... so i put the circlip back in.... btw.. if you get a 'knock bush' it'll just go in to the slightly larger stepped end (ironically circa 27mm, you know, standard industrial bearing size!!!)

so the rack is buttoned up and complete with new rack end knuckles, gaiters and steering ball joints! it's smooth with no knocking, brushes rattling or play anywhere. it's slightly stiffer, but that's down to the motor bearings now being new and tight, rather than 150k miles old rattly ones! i'll just have to be careful on the first few drives, making sure the self centreing is ok (a D1guy scare story on one of his messages! along with various references to 'bushings' when meaning 'bearings'!)

i can push the steering rack by hand, so steering geometry doing it should be fine!



....now i can get back to other stuff!!!!

[britlude]

as it was a pleasant day i got a chance swap in the steering rack....

! started at about 10:15....
IMG_20190330_101753 by jon sutherland, on Flickr

once i had the car on the front axle stands, i fashioned a simple tracking gauge to mark the current alignment (a laser pointer taped to a stick that sat against the front wheel edges, and put a dot on a bit of tape stuck on the rear wheel, when marked, this gave me a reference to get everything basically in the right place with the new/old rack!)....i also marked the input shaft and seal to show me where the exact centre point is!

.....and an hour later....

IMG_20190330_111942 by jon sutherland, on Flickr

and another hour and a half it was all back together....

pleased to say it's all working as it should, no play, slack spots, tight spots, or anything else untoward! took it out for a test drive, wary of the 'won't self-centre' scare comments, and all was well, no knocks or unusual noises!

so, if you have any of the mechanical symptoms, they are, touch wood, cureable, as they are essentially a basic mechanical system that's just bearings and gears!!

[britlude]

update, now its been in a week....

when i put it together, i set the preload clamp bolt ( the one that presses the rack onto the input shaft) as per the honda service manual instructions, tighten to 4nM, release, do it again, back off 20 degrees and tighten the lock nut.

the weight on the input shaft was then checked as per manual at 3Kg at 100mm lever length (ie. gently clamp on some grips on to the input shaft, measure out 100mm from shaft and pull at that point with a spring balance...) so i double checked it was about that, it was, and fitted it all in....

if this is how it's supposed to be, then no wonder auto cars get a bad press with 'dull' steering.... it's like driving in treacle.... yes it all does what it's supposed to but its heavy going.... i expected it to be tighter, as there's more drag on the shiny new motor bearings, but the motor assist will offset that...so a bit more investigation....

the eps rack, according to the service manual is set to a load of 3kg on the 100mm lever....
the manual rack is set, according to the book, at 1.5kg... so it's half the turning force when there's nothing connected to start with!

i then checked the rack i removed, which was comparable to the original rack when i swapped it in..... 0.7kg!!! no wonder Sarah thought it was really light when she drove it!

fortunately the rack clamp bolt is easily accessible under the car, so a quick jack up, back off the lock nut, do the double torque up, and back it off about 40 degrees, check there's no play or issues, there's not, so all back together... i did a spring balance check on the steering wheel before and after, and i suspect i'm closer to 2kg/100mm now, not as loose as the manual rack, so splitting the difference!

the result, much nicer

so, lost the knock going over bumps, the other rack had a small dead point when you rocked the steering (probably a combination of the torque sense mechanism getting sticky and play in the ball screw mount as well and hence this whole investigation) so obviously lost that, and lost a 'knock' from the input shaft every 360 degrees (probably that loose plastic gear related)

so that's the steering rack sorted!

...and i've got the one i took out to go through too..... at my leisure!!

[Heineken]

All thumbs up for the work, I'm truly, truly impressed!

PS: My rack got serviced at KSP when the car was still in Japan (google translator version of their procedure here).

[pralognan]

I'm also impressed and want to thank you for sharing this with us. Can I ask for comment on my power steering?
Its a 1991 UK car,all original. When I bought it I thought the steering was heavy when cornering at moderate speeds,but felt fine whilst parking. I read an old 1991 Motor Sport road test,"The steering felt light and deft whilst parking but any kind of cornering effort felt so heavy that we thought the power steering had failed. Over a thousand miles it became less disconcerting....."
Car magazine in 1997 said that "at speeds of more than 87mph assistance is virtually nil"
Has anyone else had similar experience and is there any adjustment possible?