when did Ferrari start mounting steering racks in rubber bushings?

I will rebuilding the steering rack on my 246GT soon.
I have never been impressed with the Dino steering in terms of feedback-- actually it seems pretty numb-- and I note that the rack is mounted with rubber bushings.

Did even the early cars have rubber-mounted racks?
If not, what point did they change to rubber mounting?

Has anyone taken out the rubber and mounted the rack solidly?
What effects were noted?

Jim O

 

Most (if not all) of the earlier cars did not have rack & pinion steering. Bolted right to the frame.

 

Jim,

On the cars with rack and pinion steering, Ferrari used two types of mounts, with a variation on the second type, as well. The Dino shared the same "washer-internal rubber bushing" style mount as the early Boxers. I too was never happy with the numb "on center" feel. Although some of the numbness is die to the rack and the steering geometry, a fair amount is due to the deterioration of the internal rubber pieces used in the rack mounts. In the thread referenced, take a look at posts 14,15 and 29. You'll see how I converted my car from the early style to the later style. If you'd like to do this to your car, I have all of the components needed, as well as some custom hard poly bushings.

http://www.ferrarichat.com/forum/showthread.php?t=185783

Best,
David

[email protected]

 

Thank you very much, David.
I don't have time to read the whole thread now, but it is apparent to me we think the same regarding this rack mounting issue.

Few on this forum were likely ever poor enough to drive a humble 1974 Opel Manta when it was new, but that car had absolutely wonderful steering-- excellent feedback, quick, with good weighting. I had an Alfa Alfetta GT at the same time and it's steering (also rack and pinion) was pathetic in comparison. The Dino (which I had at the same time as the Alfa) was similar to the Alfa's.

I can't see going thru the expense of rebuilding this rack and ending up with the same mediocre steering-- it's just not up to the rest of the car.

Jim O

 

I rebuilt my rack a few years ago and my GT4 (probably) has the same style mounting blocks as your 246.

In the end, I decided to replace the rubber Silentbloc bushings with solid billet bushings I made on my lathe. The mounting blocks don't rest directly on the chassis brackets, so to support them better, I made steel spacer plates (less than 1/16" thick) and placed them behind.

Night-and-day difference in response.
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David,

What prevents the rack mount from sliding up and down on the bushing along the axis of the mounting bolt?

Is the bushing that tight a press fit into the mount?

thank you,

Jim

 

sorry-forgot to upload the photo
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Jim- When new, the steering was nearly perfect on the Dinos. I bought mine in 1975 with only about 15,000 miles on her. I would take David up on his offer. Nothing sweeter than a Dino R&P, especially since all other Ferraris of that vintage were worm and roller.

That is even in comparison with a 1969 911S, which I sold to buy the Dino.

Taz
Terry Phillips

 

Jim,

It's what you can see that answers your question...
Inside of the two conical bushings is a cylindrical "crush" collar. And, between the chassis and the bushing, is a very thin steel thrust washer. Once the bolts and nuts are tightened, the rack mounts are extremely solid in both axis's. In that the bushings are conical in shape, as you tighten the mounting bolts, the bushings become near solid.

Best,
David

 

Nice solution, Peter...

 

I've been thinking about doing the same thing on my 308 - it's even on my to do list down on the workbench. It's always nice to know the result is worth it before you start.

 

Since the Pantera and 308 share the same CamGears/TRW rack, Jim will tell you the solid mounted rack gives you a bit better feel... which is fine for a track car. But you also feel every grain of sand you roll over if you have low profile tires.

When Keegan was at Ted's shop he tracked down some urethane bushings for me that are much stiffer than the factory pink things that turn to cottage cheese. Seems to be the best of both worlds. More precise than factory and yet not as harsh as solid mount.

I ordered enough to do the A/C mounts too.

Since then the source seems to have dried up but I had Keegan track down two more for me last year (Rob Stewart?) cuz I miscounted how many I needed for the A/C... Doh!

Rick
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Hi, Rick!
Fancy meeting you here!

So the Pantera and 308 share the same rack.
Does anyone know if the 308 and Dino racks are the same, therefore the Dino and Pantera racks being the same? (Yes, I have both cars in my garage-- but just because they look the same or different on the outside does not mean they are the same internally.)

Rick, I don't know about 308's but the Pantera has MUCH faster steering than the Dino. Of course it is also much heavier as a result even though I only run 215 tires on the front vs the 205 on the Dino.

My attention was actually brought to the Dino rack because the passenger side carrier bushing (thru which the tie rod slides) is worn and requires replacement. This happened on my Pantera also and replacing it was done in situ and easily, while on the Dino the rack must be removed and requires 6.5 hrs just to R+R the rack. (!)

Jim

 

Just to be sure-- is the mounting bolt still removable after the bushing is crushed?
There isn't much room to work in there to try to pry out a stuck bolt.

Jim

 

I decided ranps would give me enough space to see the Pantera steering rack, so I drove it up:

The racks are exactly the same, part numbers 21461 on the pinion area and 21465 on the passenger side end.
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Those part numbers may refer only to those specific castings... Cam Gears made steering racks for many cars including the original Mini, so these "ends" would have been used there too (it's why you'll find the screw threads are all imperial, not metric).

The difference between all of these models of steering racks would have been matching the different track widths for these cars and that would result in different length steel tubes (that goes inbetween these 21461 and 21465 ends) and the rack inside itself.

Forget about using Mini parts to rebuild these racks. They've long since been NLA (except the boots, they're still available).

 

Yes...no additional issues, regardless of which type of mount you use. For perspective, it takes me about 2+ hours to remove an replace a steering rack.

 

I bought all of the remaining stock from the manufacturer....and have enough remaining for a few cars.

 

Those red bushings look like Energy Suspension parts to me. They have a pretty good online catalog, and their prices are nice.
BT

 

The important thing is that since they are the same casting the internals are almost certainly the same also. And Pantera mechanics can fix the worn end carrier bushing issue with the rack still on the car. What is done is to install another, longer-lasting bushing outboard of the worn bushing.

Jim

 

David, are you willing to sell me enough for 1 car?

Jim

 

But they're not...

 

If I've got a compete bushing set (for the new style mounts)...yes. Back to you tomorrow.

David

 

Hi, David,

My Dino has what is the "old style" Boxer mounts.
Do the bushings fit it?

Thank you,

Jim

 

Is this Jim C.??

As to the quickness... I thing thats more a product of the length of the arms on the uprights than the gear ratio of the rack. I've rebuilt many and never noticed a tooth difference, size or count. But, as always, I could be wrong.

Mike Drew and I have rebuilt so many Pantera racks at tech sessions, I've lost count... yes they are the same internally. The lengths of the tubes and the internal "rack" may be different lengths but that does not impact the parts or the parts needed for rebuild. I posted threads on this a long time ago. You are right the bushing needs to be replaced with something bronze and not the stock POS that is plastic and gets pounded to bits. Yes, it can be done in the car but it is just SOOOOOO much easier if you take it out. If you need the pictures:

http://www.flickr.com/photos/moseley_ferrari/sets/72157602899521527/

Rick