Adjusting front camber on 330 GTC

After some spirited driving in the mountain roads here in Big Bear, my front tires (Michelin XWX) have worn down on the inside in about 500 miles. Using a right angle tool, I observed that the front wheels have negative camber. I have the workshop manual which specifies front camber to be 0 deg to 0 deg + 20 minutes. Besides heavy understeer, the negative camber certainly was the main cause of wear on the inside of the tires.

The manual shows the camber shims to be behind the bolts attaching the front suspension to the frame. After removing the wheel and stabilizer bar, is it possible to just undo the 4 bolts and remove the entire front suspension intact? Then the shims can be measured and adjustments made.

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Jim: The shims are slotted. Just loosen the nut and the shims slide out. You may have to pry the arm out a little to free up the shims.

 

Awesome. I knew there had to be a trick to make adjustments other than disassembling the whole front end. Of course, there's no mention of this in the manual - the one translated by Angelo Wallace.

Is there any merit in actually setting the camber even more positive to counter the wear on the inside of the tires?

(Here again, more proof of the value of the expertise on F-Chat!)

 

Jim: You do not want positive camber on the front. While it was the thinking many years ago, we know today that negative camber makes the car handle and corner better. On the 330 GTC, for street driving, I would aim for 0 degrees front camber. This is a good combination of tire wear and handling. Actually, toe can have a large effect on inside tire wear, so go for 1/32" Toe IN per side (1/16" total toe) in the front. For caster, shoot for 2 1/2 degrees positive, but many GTC's do not have enough adjustment to get that amount. Whatever you do with caster, make sure you make BOTH sides EQUAL. Otherwise the car will tend to possibly pull one direction and it will feel different when turning one way or the other.

 

Thank you, DWR.

I just went out and looked at the front suspension while the wheels are off. Despite what the drawing shows, the only camber adjustment is via the bottom shims. The upper arm attachments bolt into the steering brackets on both sides. Likely the drawing is from another model.

 

But sometimes you want mismatched caster to deal with crowning in the road. So it depends. Set to Factory settings but note that ride height is very important to handling so that should be factory to 1st then alignment to factory 2nd. Worn rubber bushings will make for dynamically unstable alignment setting and increased wear and bad handling.

 

Jim, if the 330 GTC front suspension design is similar to 365 GTB/4 ("Daytona"), the upper control arm has a shim adjustment similar to lower arms, but only in the rear mounting point, while front of the (upper) arm mounts directly to steering/idler gear housings (= non-adjustable).

P.S. If need arises, I have very good local wheel alignment shop here in Riverside , CA which allows me to access/use their adjustment rack on all cars I need adjusted.

 

Timo is correct, the upper rear mounting point is adjustable.

 

Don't forget to check your correct toe-in.

 

Hi Timo,

Thank you for the generous offer, I will definitely take you up on the alignment. Right now I'm getting tires mounted. I've been talking with Tom Martinez (Jumprun) and he suggested that I make sure the tie rod ends are tight. The car has 40,000 miles but I don't know the history of the tie rod ends.

On my last drive I noticed that above 80 the front end seemed to wander. I have a rebuilt steering box, which I have adjusted to within about 5 degrees of the adjusting screw between too tight and usable. The steering wheel movement does seem to be excessive, but I've never driven another car with manual steering so I don't know how it should be.

When I was adjusting the tie rods to straighten the steering wheel, I did notice an inconsistent change in the steering wheel position as I made adjustments (followed by going for a drive to check it). Also, the steering wheel position does seem to change slightly when I drive the car.

How do I verify that the tie rod ends are tight? Or should I just go ahead and replace them all? AW Italian sells the set for the 3 RH and 3 LH.

Thank you.
-Jim

 

Jim,

There are several methods to determine condition of the tie-rod ends and any other suspension/steering components subject to wear, but the effectiveness of such inspection can depend on person’s experience or preference to perform it, available equipment and/or facilities, etc.
For example, I usually inspect/test condition of all this with the car on the lift or jack stands and, if available, with an assistant moving suspension/steering components in various manners according to my instructions.

Arbitrary replacement of any or all components can be easier in some cases (as in “while you’re there”), but may not allow/help mechanic or owner to determine/learn if the replacement was even necessary or contributed to originally perceived problem, especially if it still persists afterwards.

OTOH, at 40K+(?) miles and 50+ years of aging, any (“subject-to-wear”) Ferrari type suspension/steering component that has not been replaced or regularly serviced since the car was built is potentially at the end of its service life and depending on its life experiences, possibly way past due.
For example, I’ve seen OEM equipped Daytonas with less 20K mile (15-20 years ago !) requiring complete overhaul/rebuild or replacement of almost all their brake/suspension/steering components.
I usually recommend all such items to be serviced every 10-15 years or 15K miles, whichever comes first.

 

... to maintain car's originally intended mechanical integrity, performance and safe use.