Hi Wiley, Have a similar problem (355 F1 GTS). Operating the paddles, gearchanges are jerky and most of the time don't obey me. Most problematic shifting occurs between 2nd and 3rd. Sometimes from N to 1st, gear engages immediately on the display but mechanically it doesn't do it smoothly. From the outside I must seem a newbie trying to learn how to drive a stick. RPMs go high as if neutral before 1st actually is in place. No problem whatsoever in auto mode. Warning sound and F1 warning light are permanently on, speedo working perfectly. I'm guessing a sensor has gone bad (?) Why the gearbox works perfectly on auto mode but is completely unreliable and unpredictable while operating the paddles is beyond me. I'd expect the problem to occur on both modes. Kind regards, Nuno.
Nuno - as you mention, this makes no sense. Are you keeping your foot on the throttle when you pull the paddles? (you should, if you are not). Also, don't shift below 4-5K RPM's and always stay in sport mode.
Hi Dave, thank you for your input. Means a lot to me. I was indeed keeping my foot on the throttle during up and downshifts. Problem occured indeed mainly below 5.000rpm, but at least on two-three occasions I couldn't shift up at 6.000 something rpms. Sport mode engaged. Again: on auto mode, business as usual mechanically speaking, once I'd still get the warning horn sounding from N to 1st and warning light always on the entire time. Tried to stop the car, turn it off and disconnect battery. Waited a while, turned the battery and the car back on, waited some more (10-15min) and set off. Same symptoms, same problem(s) and same/only solution to deal with it: auto mode (which, by the way, is the supreme kill joy on a 355 F1, imho). Kind regards, Nuno.
Could we confirm the part number first, guys? If it is P/N 149095 (Item 34), it won't be easy to replace. I wouldn't recommend trying it yourself if you have limited mobility and resources. Here's the procedure for changing P/N 149095. http://www.ferrarichat.com/forum/348-355-sponsored-bradan/391234-diy-355-speed-sensor-lh-radiator-write-ups.html It involves taking a wheel off, removing wheel arch liners, grinding sockets, etc. Ugh... On the upside, this one doesn't involve draining the gearbox I'm currently trying to match wiring diagrams to pictures of the sensor... Cheers
Of course, Ian. My apologies, didn't mean to make the thread veer off course. Almost everything on a 355 involves a lot of removing when replacing/installing! Kind regards, Nuno.
Its the other one not the one under the gearbox but the one on the side near pil cooler lines. The one underneath is more for shifting maybe into reverse or in sport mode. My transmission works with the bottom one unplugged but not in sport mode. In sport mode with the bottom one unplugged it hessitates but will still shift through all gears.
Dave I have changed mine twice without draining gearbox. It has an oring just loosen it while holding it in place, take out and plug with finger, install new one. Just be quick and you loose maybe an once of oil.
This is kinda what happens especially if you floor it. If you shift lower down in rpm, maybe below 5500 it shifts fine. This is with the bottom gearbox sensor malfunctioning.
Its best to left the car remove the wheel/plus wheel well.I will post a photo of a special socket i made with a grove for the wire to make the job easy.
Michael, there's a tutorial here. https://www.dropbox.com/sh/kufk5c92mfqd50n/AABQnT5MSW3R2UiMRKvZkoNfa/Ferrari%20DIY/F355%20Speed%20Sensor%20Replacement.pdf?dl=0 Sounds like you did the same socket modification Crowfoot spanner no good? BGS - 32 mm - 1/2" Drive - Crowfoot Spanner - 32 mm - Pro Range - 1757-32 | eBay
Really good write-ups. Thanks. Not a total invalid yet I am able to put the car up on jack stands and remove the wheels. Also removed/installed the fender liners when I replaced the fans on both sides. So that part is no problem - may even slow the aging process by getting me off my *ss. Might have to find someone to grind the 32mm socket though as my garage is minimally equipped.
The crow foot is to thick because you would have to undo one of the cooler lines.Just wait till friday i will post a photo of the socket i made,then you will all thank me how easy the job become's..lol Michael
I guess if you had no reason to keep the old sensor, you could just cut off the wiring harness and use a regular socket (and wrench or breaker bar). How critical is the torque on the new one? Would a 32mm ring spanner go over the plug (wiring connector)?
I did the speedo sender swap about 10 years ago on my 97 F355 spider (manual trans), and I swear I used an adjustable wrench to swap that thing out....I certainly did not need a modded 32mm socket, which is way beyond my means to make. I have a pretty basic set of tools, jacks and jack stands, but did it in my driveway. Funny thing is those speedo senders in general, suck. I replaced it on my previous 78 308 GTS, 87 328 GTS and 97 F355 spider. Just waiting for the one on my current 07 430 Scuderia to fail next.
I just had a look at my sensor from below the car. I have a Quickjack which lifts my car 21" off the ground. If you can get the car high enough off the ground without too much bother, you don't need to mess around taking off wheels and liners. Access is not brilliant, but it's not terrible, either. 1998 Speed sensor By the way, that's not a leak, I gave the sensor a spray with isopropyl alcohol. I see the conductor of the green wire is exposed. I wonder if both conductors were exposed, you would get current flow between them interrupting the signal. Maybe all yours needs is a clean? And if you're really keen, you can fix the sensor yourself... I forgot they had electronics in them. Veglia Borletti Speedo Sensors 68 1005, 68 1041, 68 0517 (See Type 2)
Interesting... According to the standard Euro Ferrari wiring schematics, the speedo sensor is powered by the same fuse as the HVAC system. Wiley, is your airconditioning behaving normally? It would be interesting to find that the fix was a $1 fuse
After the dramas I've had recently I'm interested in anything that will help take the system back to the super reliable one it was for the first five years of my ownership. I really didn't enjoy losing confidence in the car for six months, and wondering if it would actually change gear when I pulled the paddles or leave me stranded and embarrassed in the middle of the road... With that in mind I could be interested in changing any sensors etc. that would help as long as the cost is not ridiculous. I'm trying to confirm for sure which sensors you are talking about. Superformance list part no. 168729 as a "Gear linkage electromagnetic sensor" and 149095 as a "Speedo sensor unit" Is it worth replacing both of those?
Thats the problem with the F1. I also always had that uncomfortable feeling everytime i got in the car wandering if im gonna hear the pump prime, or is it gonna let me shift or leave me stranded at a red light...Always an uneasy feeling
