Three 308 gt4 questions: a.) I have brand new tires but there's a shimmy at 75 mph and faster, it was present with the old tires too- I thought new balanced tires would fix the problem but it did not. Below 75 or so there's no shimmy. The car tracks pretty straight too. Any thoughts? b.) I replaced my gearbox with one from a 1981 ish Mondial. The speedometer now reads wildly optimistic- almost twice the actual speed. Is there an easy fix? c.) While working on the power windows, I had left the key in the run position- the fuel pump was running constantly, and when I went to restart the motor it had hydro locked. I guess one of my (new) needle valves wasn't shutting the flow of gas off to a couple cylinders. The engine only spun for a second before it went clunk and wouldn't turn over any more. The questions are: could I have damaged the crank/rod/piston by the abrupt stop and the force of the starter alone? Could the timing belt have skipped a tooth? I took all the plugs out and rotated the engine by rolling the car forward in 5th gear to get the gas out. The car subsequently started and seems to run fine.
For "a" you might what to check that all of the "squeeze spline" joints in the steering column-to-steering rack are tight (especially the last one at the rack input).
Bent wheels, out of round tires and tires with hard spots can all be balanced. And they will shake. Go to a shop that has a "road force" balancer and request it. If they are all good check steering/ suspension Possible but Not likely to damage anything with the starter. Since it seems to run fine I wouldn't worry. I would change the oil if you haven't already.
In addition make sure the tires are mounted correctly concerning runout which can be visually checked while being spun on a balancer. If not correct have them remove the tire, rotate it 180 degrees and remount then check again. If still present repeat rotating 90 degrees. Even tires with excessive runout can be balanced but still cause problems. Also check steering ball joints.
Re b), i guess that you now have the later version of the Speedo sensor in the '81 Mondial gearbox, which delivers 8 instead of 4 pulses per rotation, so your GT4 Speedo/ODO shows twice the actual speed. Source a later Speedo and exchange the dial face, alternatively i could supply you with a replacement circuit board which accepts 8 pulses.
This. I used Palo Alto Speedo to correct mine, and they were great. This was prior to some of the fixes like what Adrian offers.
Are the wheels original to the car or are they Superformance 16" repro's? Some of the repro's needed a hub ring to stop them from vibrating at higher speeds.
Steve, the replacement circuit board is 58 plus 6 shipping, here is a thread about the new board: http://www.ferrarichat.com/forum/308-328/419560-308-speedo-repair-rebuild.html Best, Adrian
I think C is your biggest problem here. You may have well bent a rod. I did that with water on a Toyota PU but I was gunning it through a mud hole at the time. Ran for another few days before chucking a rod through the crankcase. At a minimum you probably have fuel in your oil so you need to change that. If it were mine, I would pull the engine apart. Thrown rod in a 308 will be very expensive and a major service is on my list of to do's FYI you can stop the fuel pump by pulling the fuse or connecting the safety switch under the front seat. Good luck whatever you do.
Something else it wrong too. The fuel pump should not run constantly. It should be on only when the engine is running or cranking to start. Maybe a corroded connection somewhere or a bad relay?
The fuel pump is supplied by the ignition lock, it starts running as soon as the ignition is switched on.
Carb 308 (without US seat safety switch present) = fuel pump runs with just key "on". CIS injected 308 = fuel pump does not run with just key "on".
If you're worried about the possibility of having damaged the engine I'd take it to a decent Ferrari mechanic before pulling the engine, which is guaranteed to be quite expensive. There are ways to check out what shape it's in, without being quite so drastic. For one thing; if a rod was bent I'd expect odd results from compression checks, and certainly some vibration. And who knows what else. Re the vibration obviously something is bent, worn, poorly adjusted or out of balance. Or maybe both. Bushings, bearings, kingpin, a-arms, shocks, steering components, whatever. Needs to be put in the air & inspected carefully. Both inspections should be done ASAP. I'm a bit surprised your tire installer didn't notice anything, apparently. Cheers, Rich
I too fought a front end shimmy. I had the tires/wheels balanced, front end aligned, new shocks, new bushings, new ball joints, new bearings, rack rebuilt, new tires and wheels, checked steering shaft spline, etc etc etc. all to find out it was the front end alignment!! The Shop that charged me extra $$$ for Exotic car alignment didn't understand that the ball joint moves in the A-Arm, they adjusted the A-Arm to set the caster as you would do in most domestic cars. I finally bought an alignment tool and VOILA!!!!. If you want it done right, do it yourself!!!
Ossa I had this exact same scenario on my GT4, and just two weeks ago on my Fiat 124 (they use almost the same bearings, and the hubs on the Dino say "Fiat!") Replacing and greasing the bearings & races solved the entire thing. It COULD be your problem, too. The GT4 uses a commonly available and inexpensive set of wheel bearings in the front - an inner and an outer on each side. You should be able to check if they are the culprit: 1 - raise the front end and remove the wheels. 2 - hand turn the hubs and see how easily they spin. There should be no binding and you should be able to turn them fairily easily, but they should stop spinning the moment you remove your hand - they should not keep going. This is a feel thing, but a good bearing should be smooth and feel like it has nice thick grease in it. It should not spin and spin like a bicycle wheel! Any wobble or freewheel or thunk or if it is hard to turn by hand means the bearings are bad. 3 - they are adjustable. If they spin super easily, you can tighten them down with the giant nut. But take note - this is not a solution, only a very very temporary "fix" - almost more of a diagnostic: if the bearing seems super loose, then tighten the nut down a bit and see if that makes it better. Then go buy new bearings. 4 - the nuts are crimped in place, and are basically single or double use. They are also pretty cheap! IF they need replacement, I fonce ound this somewhere on FChat: "Outer: Bearing: LM11949 Race: LM11910 Inner: Bearing: LM67048 Race: LM67010 The above are industry standard numbers. Any auto parts store should have them, often as a set. If you buy them at NAPA, the inner set is BR6, the outer set is BR2. Auto Zone calls them BS6 & BS2 I believe. " Photo is of the GT4 Hub - not "FIAT" nomenclature Image Unavailable, Please Login
Steve, Does or should a US 1975 Dino308GT4 have a "seat safety switch" ? If yes where is it or is it a relay? Is it connected with the seat belt, buzzer/light? Thank you!
