Apologies if there's an answer for this out there, I searched on juddering, shuddering etc. and didn't find anything. 2000 360 Modena, 6spd, 25,000 miles, recently developed an annoying "juddering" through the driveline on a trailing throttle once the revs get below about 3000rpm, any gear but worse in 2nd, 3rd, 4th. Example - driving along, encounter slower moving traffic, lift off the gas, maybe brake, maybe just let the engine brake the car, car is fine until revs drop to about 3000rpm then it starts to judder and make a repeated clunking noise from the back, sort of an "about to stall" forward/back jerking motion but nowhwere near stall revs. It's started doing it on the entry to corners if I brake without dipping the clutch and let the revs get too low. Any thoughts?
Loose/worn transmission mount? Check the large one in the center of the transaxle visible looking from top down, for cracks... Its rubber and dries out/seperates. Be my guess as a common failing item...
Sounds like an engine misfire to me, and a worn mount will pass the resulting shaking to the passenger compartment. Engine misfire could be fuel related (e.g. bad tank of gas, dirty injectors, dirty air filter element), or spark related (e.g. failing spark plugs, old plug wires causing the spark to bypass the plugs), or both. How many miles since the last tune up? Messed up ignition and/or cam timing can cause low rev judders - did you have a belt change recently? Jeff
Jeff, under power the engine is running fine, idling and pulling very strong. The problem is when there's no throttle; when the engine is being turned by the road speed, that's when it starts to judder. Belts 2 years ago, tune-up, 6 months.
http://ferrarichat.com/forum/showthread.php?t=230723&highlight=transmission+mount http://ferrarichat.com/forum/showthread.php?t=218557&highlight=transmission+mount http://ferrarichat.com/forum/showthread.php?t=168425&highlight=transmission+mount
The sound you are hearing is from the differential clutch packs chattering. You can make it go away by putting friction modifier into the transmission, but then the car is difficult to shift. Replacing the clutch packs won't help either. I ended up running straight Redline in the gearbox and putting up with the chattering. Having said that, my transmission mount has broken a couple of times, so it wouldn't hurt to have that checked. Brian Crall had a super beefy custom transmission mount made for me, and it has been working great.
When is the last time the gearbox oil/filter were changed/cleaned? As mike says above, it could be chatter coming from the LSD or something. Either that or perhaps a broken motor mount maybe. If it's related to lack of friction modifier in the gearbox (or something along those lines), it might tend to exhibit itself more around corners and/or when backing up around a corner, etc. You might also check to make sure nothing is loose and/or broken around the half shafts or CV joints. Also, there are some heat shields which ride dangerously close to the CV joints back there. On the 360 I used to have, I had to loosen the bolts holding the heat shield and reposition them a bit, as there was evidence of rubbing between the shield and the outer diameter of the CV join rim. I would also have someone watch the motor from the passenger seat when it happens and see if you can see the motor moving (i.e. broken motor mount or transmission mount, etc.). Normally, however, with a broken motor mount, you will see the motor torque up under acceleration (depending which side is compromised of course). When I was a kid, I had a 66 mustang that broke a motor mount. The car would make a strange noise/vibration under hard acceleration, but I could never figure it out. One day, I was test driving the car with the hood off to see if I could figure out why the car was over heating or something. I went down a wrong turn while trying to get on the highway. At the end of the road, I turned around and tried to burn out. However, instead, the motor mount snapped and the engine lifted up out of the engine bay about 2 feet! In the process, it ripped the hoses right off the radiator. All my fluid went into the dirt road and that was that. Luckily, a woman behind us (I was with my girlfriend at the time) also took the wrong turn and stopped to help. She gave us a ride back into town (some 20 miles). My Dad and I spent the night fixing the car on the side of the road with a flash light and head lights from his car (I was about 18 or 19 at the time). Anyway, I would get to the bottom of it in case it's something serious... Ray
Great story Hopefully Brian Crall will be able to pinpoint the problem, although the symptoms are more irritating than alarming at the moment.
Clutch (hot marks on the flywheel and/or worn disc) or Motor mount. We'll be awaiting the outcome. Oh, and nothing is cheap on these cars so hang on.
Well she went to see Brian and the gang on Thurs/Fri. He just needed to look at the engine through the cover to diagnose it; he and John must be two of the most experienced Ferrari guys in the country. Amazing. Worn transmission mount causing some sag. Fixed (replaced with a F430 mount which is stronger). Plus annual service and she's perfect. Attached a pic of the mount. You can see it's squished on one side (that was the side facing the ground and bearing weight), pulled and split on the opposite side. Thanks to Brian and everyone at the shop, great fun meeting you all. Image Unavailable, Please Login
Judging from the threads linked above it sounds like doing it yourself is a major PITA How much was the labor on the job?
I have just finished resolving this very problem on my 2000 model 360 (32,000 Kms) and it turned out to be a dry/poorly lubricated left hand side outer CV joint. The driveshaft was removed, CV joint dismantled, thoroughly cleaned, inspected and then repacked with high quality moly high pressure grease. The driveshafts were then swapped side for side and symptoms have disappeared completely. No problems since. What a GREAT car!!!!!!
I have an update on the clutch packs chattering thing (which really is a common problem). In my earlier post, I mentioned that if you put friction modifier in with your gear oil that the problem would go away although the car would be harder to shift. This is still true. However, Brian [Crall] put another kind of gear oil in my car and I have to say that this stuff is a miracle! The car is three times easier to shift than it has ever been, and the chattering has gone away completely. It's like a brand new car! The old gear oil was straight Redline. The new gear oil is still Redline, but it's called "Redline shock proof lightweight gear oil". Brian told me that it has friction modifier built into it and is formulated for racing applications. Hope this helps someone.
Light weight. There are three types of this shock proof gear oil. Super light weight, light weight, and some other weight which I cannot recall at the moment.
