Differental Noise - any recommendations for repair. RESOLVED!!!

[DINO_UYU]

Hi Guys.

I'm a new Dino 2400 owner and the first of probably many problems has reared its head.

Symptoms are: Loud grumbling noise from the back when turning even very slightly, you can hear it from both inside and outside of the car, it's quite alarming. When driving in a perfectly straight line, it's fine, no vibration, no noise, but the moment you start turning, it comes back.

What I've determined so far. Diff oil is full to the brim and I presume it's the right stuff - SAE 90, and it looks reasonably clean. Some work has been done to the diff in the past - the bottom finned plate (it's like a sump plate) has previously been removed and refitted with new sealer. Some leaking is evident, from what I suspect to be the output flange seals, though not excessive.

Jacking the car up on one side, the free wheel will not turn, as if the handbrake was on. Jacking both sides up and the wheels turn with each other in the same direction, as I believe it should for an LSD. The moment you stop one wheel from turning, the other won't turn.

Can anyone recommend anyone in the South, ideally in the Oxon/Berks area who can rebuild these LSDs? Thank you!

Thanks!

[Stefan2000]

Common problem, wrong oil without LSD additives.
Replace the oil for correct LSD oil and chances are quite high that your problem is gone.

[DINO_UYU]

Hi Stefan.

Thank you. I'll update this as resolved. Sure enough, and as you suggested the PO or his mechanic had put in the wrong oil. I figured that the purchase of 3L of LSD oil would be a worthwhile investment, and it paid off. How many times does that happen!!??

I drained the diff, removed the bottom plate, flushed everything out then refilled it with 80W90 GL-5 LSD oil. Took it for a test drive last night and the noise has gone, much to my relief.

Stefan! I've ordered the carb jets that you and I have been talking about via email - yes, I'm that same guy. Thanks. Now to check and adjust valves - that'll be fun. No point in setting up the carbs if valve clearances are out.

[Luis A]

Common problem, wrong oil without LSD additives.
Replace the oil for correct LSD oil and chances are quite high that your problem is gone.

Are all Dino differentials limited slip or was it an option?

[Georg]

All Fiat Dino 2400 Differentials came from Borg Warner and were always limited slip.

The Fiat 130 both Coupé and Berlina also were fitted with Borg Warner Differentials looking externally alike the Fiat Dino 2400 Diff.

BUT: for the Fiat 130, Limited slip was an option and the diff. ratios were different to the Dinos. Dino 9/43, Fiat 130 11/41 with automatic transmission and 10/41 with ZF 5 speed gear box.

If you like to lower engine revs at a given speed, you can preplace the Dino diff. by a longer Fiat 130 diff. from a automatic gearbox version. However, you would have to gauge the speedometer.

Georg