308 GT4 steering rack mount bushes

Just finished doing a series 1 rack. We ended up fabricating the poly washers and mounting sheet as the OE had completely dissolved. The metalastic bushings from the factory are quite good but the rubber washers and mounting sheets are too soft. Appears they used a latex based rubber (just a guess based on how they dissolved) for these that did not hold up very well.
The early style provides a far more positive mount but is a PITA to rebuild compared to the later style. I have used the early type to upgrade many of the vintage English race cars rack mounts with great sucess.

Dave

 

I just did a GT4 2 weeks ago... I simply made steel "top hat" shape spacers up on the lathe to solid mount the rack to the chassis, and then change the stud and nut arrangement for a normal nut/bolt.... you don't even need to remove the old buggered bushes from the housing, which is difficult/time consuming as they're in a blind hole. They're now redundant.

Makes the steering much more precise too.

 

Series 1, Dino badged car, with small parallell black bushes not larger tapered (pink) ones.

I deleted all rubber mounting components entirely. (Well, the buggered bushes stay in, but are redundant). The rubber sheet, everything, all gone. Solid mounted.

You still have to remove the rack almost entirely, as getting the stud part out requires pinion disconnect from column.

Took me 5 hours to remove rack, convert mounts and remove studs/swap to bolts etc, clean and prep, refit and align, Road test.

 

I had Norwood Performance replace the ones on my series 1 car with mounts they machined.

 

Be sure to measure twice, machine once!

My machine shop made me just one set, but I left the drawings with them, so if you need some more, just holler. It'll take a couple of days to get done.

FYI, you'll need 8 parts total, 4 big top hats, 4 small top hats. My shop charged me $100, and I provided bolts/washers/nuts etc. I could have done the machining myself in about an hour, if I had the lathe/material... which is my next investment.

 

My steering has no or extremely little play, has good road feel, but seems to follow every contour of the road and bumps can almost pull the wheel from my hands. My question is, how does it feel when the rack/bushes are going bad?

My car has 70,000+ miles.

 

The ball joint shims are purely for adjusting Caster angle. Of course, a perfectly aligned chassis and car will have perfectly symmetrical shims... but none are.

However.. I always put two shims each side of every ball joint, then trim caster at the same time as camber, using the lower camber shims for BOTH caster/camber. You effectively swing the lower ball joint back/fore with camber shims. The only time I deviate from this is for modified cars, when I move the shims to extremities for full catser... you can get about 6 deg instead of 4 std.

Tie rod end turns depends on camber/ride height a lot... but about 13 turns is ball park territory... less for more neg camber cars. What IS important, is that the rack is in the middle of the car... your tie rod ends should be within a turn of each other even at the end of the job... if not, you've probbaly got your pinion alignment wrong...

Also... check your steering column alignment.. the amount of cars I find with mis aligned Universal joints is quite alarming... and indicative of poor understanding of mechanics. UJ's must be perfectly aligned with each other.. as they change "velocity" (Hence CV joints) as they turn, if out of alignent, this will put loads on the steering and make it feel VERY different and basically bad.

Make sure your aligner can read Caster LIVE... every adjustment effects the others... you'll need to go round in several circles to get it right...check every adjustment before you finish the alignment...ie.. if you tweak the toe at the end.. re check camber/caster again.... don't check/set caster unless the toe is close anyway...., don't adjust camber without re-checking caster/toe etc etc...

...then do it ALL again after 100-200km to be really sure all new bushes have settled properly. (for economy and practicality reasons, I usually drive a freshly bushed car around the bumpiest road I can find for about 30 minutes BEFORE I align it. Somtimes they're virtually undrivable without the alignment done)

 

check your tyre condition/pressures first

Then align it. Sounds like you've got toe out on front.

 

Tire pressure was the first thing I checked regarding this problem. When inflated correctly the problem lessened but did not go away. Then I had all 4 wheels aligned when I initially got it home (4,000 miles ago). Again little or no effect.

It could very well be tire condition, however, as the previous owner had induced severe negative camber on the rears. This caused the tires to wear on the inside edge. These tires were then at some point rotated to the front. Forgive my ignorance but could this induce the same effect as toe-out?

At any rate, it's good to know that it's probably not my steering rack.

 

yes, absolutely.

Why people run around on tyres they know to be no good is utterly beyond me.

Tyres are THE MOST important thing on a car regarding safety and performance...

change them for new, and teach yourself a lesson by getting the BEST tyres available.

You'll learn AND appreciate it!

 

good work..

just to confirm the column stuff... your column should have the steering lock operate with the wheel dead straight ahead, the UJ's should be in perfect alignment to each other, and once connected, there should be exactly equal amount of turn from lock to lock each way, and the tie rod ends should be very close to equal turns on the tie rods.

You'd be amazed at how many aren't like this...

 

You're welcome (rack bush)

Installed a quick rack today. (Glass 308, had to change whole rack for type with alloy housing both ends, as it had the steel tube type previously which is non compatible with quick rack)

Goes from 3.25 turns lock to lock to 2.33.

FYI.. with 2 deg neg camber, tie rod ends are about 10 turns on.

 

Yes. It only needs to allow slip for installing the pinion onto the rack. Although, tightening it has fixed the symptom, not the cause...

Your splines are worn, as usually, they can be loose enough to slide without being slack.

No big deal, but keep an eye out for spare try carl888/ebay, or even Moretti

 

Yep, both bits, and the big nut, and also the cotter/taper pin (39 etc)

There are really soft, and getting them out often destroys them.

 

I haven't dealt with F-UK since Malcolm West left, and Jeff Howe before him.. but in the good old days they'd often negotiate.

Now, there's a worldwide Ferrari policy to NOT supply independant specialist like myself outside their own coutnry. So, for that, they've lost my (not inconsiderable) business.

Major major marketing faux pas. I hope someone at F-UK restores fairness and democracy, but right now there's hypocracy and restriction of fair trade.