Testarossa shifting problems

Does the clutch fully disengage when the engine is hot? Does it engage close to the floor? May need to be bled, or the disk may be approaching end-of-life thickness. Also consider slave cylinder issues. Symptoms occurring only when hot may speak to all of the above.

Jim S.

 

Was it a hot day out? Sometimes the brake fluid / clutch fluid gets very hot and boils causing you to lose the clutch a bit or call it clutch fade.. I would drain that old fluid out - replace with some new fluid, bleed and then see were it takes you.. I would not be so quick to change the clutch or clutch components. I had a simaliar problem, clutch would fade when car would get hot, in hot temps after 45 minutes or so.. After engine out service with new more durable fluid problem went away. Let us know how you make out.

R

 

Great time to replace that clutch/brake fluid with DOT5 !! I did and it performs wonders...no more wondering if the problem is or isnt the fluid. Get the specs on it online but its almost double the temp handling (boiling point) of the DOT3....plus its not harmfull to the paint!!! (my main reason why I switched)

Ski

 

If you are using silicone based DOT 5 in your Ferrari I would seriously consider removing it. Yes it has a high DRY boiling point, but it must be flushed very often. It does not mix with water, and any moisture in the system (which is unavoidable) not only greatly reduces the boiling point but can induce serious corrosion. There is a reason you will not ever see it used at the track - it has no place in the life of a regularly driven sports car.

There is a Glycol based 5.1. I would stick with a high quality Glycol based fluid and flush it on an annual basis. The silicone based stuff is best left to show-only cars.

 

In Vegas there's not too much moisture you have to worry about and my dot5 has not shown any signs of any rust or moisture in the last 5 years or so, so from my personal experience I'm sticking to it. Trust me, I do many modifications and anything that doesn't conform to my standards I always update the forum with my findings.

 

Bad idea.

Go back to DOT 4 like it is supposed to have.

 

Have you tried adjusting the shifter linkage? Sometimes the linkage comes loose or the position of the transmission relative to the stick shift gate changes as the car ages and heats up. Doesn't take much.

 

When was the last time you changed diff/tranny fluid? If you did, what type/kind did you use? TR's are very temperamental about their tranny oil. Again, I am not one of those people that use what says in the book, so I use all fully synthethic olis all around, including tranny and engine.

Make sure you got that right in the pan....then I would check if linkages have any play.
Also, did you have someone press the clutch in and you inspect visually if the clutch plates engauge and disengauge as they supposed to? I personally dont believe it would be the clutch worn out, cause you would hear it and feel it slipping before having the symptoms you're having.

If that is all good and still having the same issues, you might have synchros out of whack and that might require a mechanic with proper tools/experience to reset or fix.

I am in no means a mechanic and wont claim to know it all or seen it all. Some guys here have and hopefully will chime in ASAP!

(I also apologize for throwing my dumb DOT5 changes into the threat, your issue is way more important at hand!)

Ski

 

Poor quality gear oil is most likely your issue if the problem goes away after it warms up. Many have found the Redline 75w90NS makes a significant difference in shift quality for these cars.

 

I swear by it.

It made the difference in my old 308 and the TR. Both shifted pretty good to begin with.

 

Good luck with that.

 

Plates? Im a little lost (just woke up too hahahah)

 

I agree with Drew, you should try the shifter to gearbox linkage junction first, and try adjusting it. There is a screw one can loosen up and shorten the linkage a couple of mm (dont forget to tighten that screw . I had the same problem untill this had been done.

 

Juri and Drew - your experience is appreciated and must be respected, but I would be cautious about recommending adjustment at the shift linkage. First, this rarely, if ever, falls out of adjustment. The design simply does not lend itself to such. Second, should the shift-rod rotate during the maneuver, the fork may fall behind the selectors and then all bets are off with regard to getting it back again.

Much more common is failure of clutch disengagement owing to hydraulics or plate wear. Certainly alternative oil or treatments will help, but if this symptom arises anew in a transmission that was, heretofore shifting correctly, something other than a change in the properties of the oil is taking place.

Common things are common, and failure of clutch disengagement, I believe would be highest on my list of likely culprits.

A simple test would be to try to shift into first or second while at a rest on level ground. If the car tends to creep during shifting, the clutch is not disengaging. If, when lifting the clutch off the floor while in gear (at rest) the car moves with the slightest of pedal travel, the clutch is not fully disengaging. The synchros are working overtime doing what the clutch should be. If you had the luxury of a lift and could do the above experiment with the car in the air, you would enjoy a much more sensitive test. If the wheels begin to spin before the clutch is raised, or raised a few millimeters off the floor, the clutch is not fully disengaging.

Jim S.

 

Jim, I do agree with your logic and suggestions. It is hard to acsertain the real reason to why the shifting in this case is compromised, however. In my case, the reason was the linkage. In his case - who really knows... Neither you or I had seen the car... Let's hear what Alan will find out and what will resolve the problem at the shop.
Cheers.

 

Another suggestion is to check the clutch pedal travel - there is a stop adjustment accessible from the footwell. Mine had the same symptoms when I first got the car last year (with only 18K miles) - seemingly like slave cylinder needed to be bled, but bleeding did not improve things. I checked the clutch pedal travel (spec'd in the repair manual, as I remember), and found it to be about 1/4" short. Once I adjusted the stop, its shifted perfectly from then on.

 

If it was clutch pedal travel or the clutch it would be the same hot or cold? (or at least I would think). You advised that after an hour or so the mechanics of the gear box started acting up.. I really think your over thinking this. I would still start with the fluid then move on to other areas if it does not improve.

R

 

The Testarossa 84-91 Repair Manual (I think I purchased mine on-line for about $30) has a diagram showing the clutch pedal assemble, and clutch pedal travel of 127mm. I agree that the effect being a function of temperature is of concern. That said, it only takes a very minor amount of "not quite disengaged" to cause shifting problems, and certainly there can be some temperature effects back in the clutch area from heat. Anyway - worthwhile to check the pedal travel, and it only takes a minute (once you figure out the orientation of arms, hands, and wrench/screwdriver) to loosen the pedal stop and give it another small amount of travel. Good luck.

 

Maybe your "silentblock" is worn out!! Check both before you do any adjustments to any linkages....

There are 2 and I purchased 1 about a year ago from a dealer and those things were like $80 for 1......

Depends on your mileage, they do wear out....fortunately for me it was only a preventive maintenace.....

Ski

 

Clutch plates (friction discs)

 

Gotcha..... still he wouldnt have any problems shifting, just the clutch wouldnt grab and would possibly squeel (if the plates were that bad)?

Ski

 

He mentioned that the discs are not sliding on the splines smoothly. This could contribute to not disengaging completely.