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Discussion Starter · #1 ·
I own an '86 Ferrari Testa

I own an '86 Ferrari Testarossa, which has had a shifting problem all summer long. There are periods of time, lasting weeks, where it will only upshift into second gear 50% of the time. All other upshifts and downshifts are normal. There are also periods of time, lasting weeks, where all shifting is 100% normal. The car now has 35,300 miles and the clutch was replaced at 29,000 miles in September 2001. I do not drive the car hard, and it is not tracked.
There is also a squeaking/grinding light metal noise coming from the rear wheels. The noise alternates between right and left sidesand if I press on the accelerator to any degree the noise stops. If I let off the accelerator the noise comes back. My local garage has inspected the wheels and their fitment and all is well, nothing is rubbing or even close to it. The noise started this summer and previously there was none. The car has SAC RS30 wheels specifically for Testarossas and Yokohama AVS Sport tires that were both fitted in 2001.
Can you give me possible differential diagnoses on these two problems? I will e-mail you next week.

Sincerely, David P. Alan
 
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Discussion Starter · #2 ·
Hmmmmm...pretty hard to figure

Hmmmmm...pretty hard to figure this one. Have you detected any kind of pattern to the shifting problem? Like does something else happen at the same time shifting is poor? Does it seem related to temps...like gear oil warm or cold? When it does not upshift properly...is there a grinding....or just a notchy feeling like you can't locate the "slot"? When it's not engaging 2nd gear, if you go to nuetral...where does the shifter position itself? It should be right in the center of the shift pattern cutout, even space from left to right and front to back. For the noise from the rear....could it be the differential/trans and not something wheel related? I would at least consider changing the fluids unless it has already been done, and verifying the shifter linkage per the shop manual procedure.
 
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Discussion Starter · #3 ·
I agree with Jeff regarding ch

I agree with Jeff regarding checking the linkage.

The three shifting problems I have encountered, including a 308, 275GTB and Boxer were due to the linkage coming loose and not aligning properly.

Have no guess as to the noise.

Can you put the car in neutral and just let it roll a bit in your driveway to try to recreate it and then maybe if you can recreate the noise have a helper listen to see where it is coming from?
 
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Discussion Starter · #4 ·
David,

A couple of areas to


David,

A couple of areas to look at concerning the noise...

The emergency brake shoes, dragging ever so slighlty can cause the noises you describe. Loose and/or broken hardware, or mis-adjusted shoes can cause "unusual" noises. Try lightly pulling on the e-brake and see if the noise goes away.

The other possiblity is worn differential carrier bearings. This is a real problem to contend with, particulary if the car has seen a hard life...and/or run with low oil levels in the transaxle. Before condemning the diff, I'd do a oil service first. Normally, if the diff bearings are going bad the noise is more of a growling type...unless they're just starting to go away.

Loose wheels can also make the noises you describe...even though the shop says they're tight. The condition of the hub and wheel cone are important...and should be throughly lubed with a moly type grease before tightening. I presume that this is a single lug car...Yes? Very careful inspection is required to ensure that the nut tightens down over the stub axle versus the trim ring. Roll the car in your garage by hand and see if you can hear creaking from the rear wheels. If so, this eliminates the diff issue...and points to a wheel/brake issue.

As to the second gear engagement issue...
Background: When you engage 2nd, you're moving to a different shift rail in the gearbox, which requires a precise angular movement of the shifter. As the Ferrari has a gated shifter (versus most car which don't)...shifter alignment is critical.

When ever I set up a BB or TR, I engage 2nd gear...and visually verify the position of the shifter. If it is resting hard against the gated plate, adjustment is needed. Before I raise the car and adjust the linkage at the tranaxle, I first verify that the shifter box (in the car) is not full of loose parts and junk. Secondly, I'll just loosen the screws on the gated plate...and engage second. If the plate moves considerably, adjustment is needed at the transaxle, else just tighten the plate up...and see if the small "tweak" solve the problem.

There are other issues, in the transaxle, that can cause the problem you describe...though they are rare.

Regards,
David
 
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