when did Ferrari start mounting steering racks in rubber bushings?

The original bunch I got were more of a clear urethane (think SIMS Pure Juice for those kids of the 70's). The last two Keegan tracked down for me were more opaque. Were there two different batches or two different vendors? Or is this how they age out.

Rick
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No, the bushings that I have only fit the new style mounts. This is what I was referring to when I sent you the link to the BB suspension rebuild thread. The new style mounts are far more robust that the early ones...

 

Ferrari offered those bushing in a pale red, black and gray. The black and gray ones were specified for the AC compressor mounts, as they were a bit stiffer that the OE pale red (almost pink) steering rack bushings. Once could use the AC mounting bushings for the steering rack, as they were a bit stiffer. The red bushing that you depict are part of a private production run (not OE), of which no more are being made.

 

Pale red... I like that. They always looked to me like they were made out of Pepto Bismol. And were about as durable as if they had been.

Is this Private production person still willing or capable of making more? I mean, I have mine but it would be great for others to benefit from these bushings. It would be nice to use one of the few that still exist to generate some interest from other vendors if the original is uncooperative or incapable at this time. Everybody who sees mine, wants some.

Rick

 

No, it's Jim O

That makes sense-- shorter steering arm on the upright means quicker steering and less leverage therefore heavier.

Do ALL rack rebuilders use the bronze bushing, or just the Pantera community guys?

Jim

 

Peter, what did you make your billet bushings out of?
Is aluminum OK, or does it have to be steel? I have a friend with a lathe, so maybe that's the best choice for me.

Jim

 

I just used cold-rolled steel bar. I would avoid aluminum due to corrosion issues with it being in the steel housing. Carefully measure the depth of the bores in the mounting blocks when cutting the bushings to length, I found discrepancies (a few tenths of a mm) that would've allowed slop between the shoulder and snap-ring.

 

When I was trying to track down my steering wheel shimmy I thought it might be due the OEM pink bubble gum rack bushings & had a set of these plastic bushings machined. If anyone is interested I'm just trying to get my investment back $50 set shipped in conus.

http://ferrarichat.com/forum/showthread.php?t=260688&highlight=steering+308

ps it didn't cure my shimmy & there was too much road feel for me so I went with the stiffer darker red polyurethane bushings but if you want a go-cart feel........
Bill

 

As far as I know, no...We've had a few conversations on this subject, as I do a few suspension overhauls a year.
As I recall, a few hundred bushings were made...and very slowly sold over a couple of years. As production costs were high, coupled with limited demand, no more were produced. I bought up his remaining inventory for my own car, as well as for use on customer cars where they wanted a bit more out the suspension. As I recall, I have roughly 40 bushings remaining, of which some are rack mounts and other are for the sway bar end links. I also have a large stock of the 34mm Energy suspension bushings. If you're interested in these bushings, just send me a PM and we'll go from there.

Best,
David

 

Is the opening in which the billet or bushing sits in a Dino mount cylindrical, just a straight tube, or is it hourglass shaped as the "late Boxer" ones seem to be?

Jim

 

It is straight.

 

So if I am converting away from the Silentblok bushings I just need to machine a simple cylinder to fill in the space between the bolt and the inside of the cylinder, no?

I have a friend with a lathe but don't know much about such things

I'm thinking one of the hard plastics / nylon / delrin / whatever is easier to machine than steel and will work just as well.

What should I use and where do I buy it?

Thank you,

Jim

 

Yes, just a simple cylinder.

FWIW, for inside, for the rack bushing, I used a higher grade of nylon ("MDS" see link: http://www.plasticsintl.com/datasheets/Nylon66MDFilled.pdf). It had been debated before on here in previous 308 rack threads (and as you mention for Panteras) of the use of brass, but I chose this nylon for fear that the steel rack could be damaged if I'd use brass and so I suppose you could use nylon to replace these silentbloc bushings too. I don't think it'll "give" under these side loads. I got the nylon from a local (BC, Canada) industrial plastic supplier (the link above is just an info sheet I pulled off of from Google), so I'm sure you can find similar where you are too...

I think whatever material you end up using in the end, will provide much better steering quality than the squishy rubber silentblocs

 

Assuming that one plans to use through bolts rather than the two-ended thingy and silentblocks Ferrari used to mount the rack, one can quite easily remove the rack.

1) undo the forward nuts holding the rack to the chassis
2) remove the 6mm bolt holding the rack to the steering column threaded shaft
3) push the rack rearward about 5-7mm-- it will slide up the steering column shaft that far
4) transect the two-ended thingy in the plane previously occupied by the flat rubber sheet between the rack mount and the chassis. All are accessible with a power reciprocating saw except the left upper one, which required a manual thin hacksaw. The thingy must be grade 8.8 metal because it cuts easily. Keep an eye on the main coolant tube near the lower part of your blade when you do the upper left one.
5) remove the nuts holding the rear "C" portion of the rack mount to the forward portion of the mount
6) by holding the rack rearward the forward portions of the mount can be moved parallel to the long axis of the rack and removed.
7) undo the nuts and bolts holding the ball joint supporting the steering column just rearward of the rack
8) pull the rack forward and down and it will come off the steering column.
9) separate tie rod ends and pull rack out one side

 

You cut those special studs ("two-ended thingy")?

Although very difficult, I was able to extract and later, install the steering rack assembly with the barckets in place. Even did a final torquing of all nuts in situ. I suppose I was lucky and the GT4 has more room in there than the Dino 246...

 

the special studs are only useful if you intend to install new Silentblock bushings. If you plan to use through bolts and make straight nylon bushings you will not be using the special studs anyway.

What I describe removes the "very difficult" part of the operation.

 

True, but just make sure that you have a large and thick enough washer that'll fit properly over the hole, to keep the rack mount securely held to the chassis.

 

You're right.
I might use the end pieces that sit at the hole and extend into it on the rearward side.

 

Actually they're not, at least on mine.

The bore is smaller on the rearward side than on the front side because there is a shoulder or step-down in the bore near the rearward side.

I had a friend with a lathe make white nylon bushings to fit the bores. Each bore was slightly different in size so each required a custom bushing. The bushings extend about 0.010" beyond the metal bore so the nylon will compress and eliminate any play (of which there is none anyway)

1/16" nylon sheet was used to replace the rubber cushion that sits between the rack mount and chassis.

I'll be reinstalling the rack tomorrow, if all goes well.

Thanks to everyone for your help and advice
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Is there a supplier for suitable nylon/Delrin/billet/etc. bushings as replacement for the SilentBloc steering rack mount bushings (part number 103369)?

All the usual sources seem to have the SilentBloc version, for instance Superperformance has "Steering Rack Metalastic Bushes":

Steering Parts for Ferrari 206 & 246 - Superformance

What alternatives exist without making your own?