Transmission gear Oil

[MadFiat]

Anyone remember what weight gear oil is used in the Abarth 5 speed? Is it 75 weight lube?

Alldata says the C510/C514 transmission uses "C510/C514 Castrol BOT 350 M3". Mopar lists their own.

As I understand it, it's esentially NV3500 gear oil that's used for years. Looking that up it says API GL-4 75 weight. That correct?

Guess I'm mostly thinking aloud here... any comments on gear oil? I don't relish ordering an expensive dealer bottle just to top off what came out when I pulled the axle.

[NGEN]

Just order the mopar stuff - it’s not that expensive.

[ice445]

Just order the mopar stuff - it’s not that expensive.

I disagree. From the dealer it's $33 a quart, which is hilarious. Even on Amazon it's still $22 a quart. Yeah, you only need two quarts. But that's hilarious. But yes, it's GL4, 75W90

[NGEN]

Depends on your dealer - I didn’t pay near that much.

[FartieBartie]

I recently changed my transmission oil and replaced it with Royal Purple Syncromax based on admittedly sparse information found on a few other Fiat and Dart forums, here is my impression.

-Cold shifting is greatly improved, it was always stiff into gates before, now it slips in.

-Reverse engagement has always been a back and forth ordeal of not going in, popping it in first, then trying again. Now it goes into reverse effortlessly from most other gears.

-I had a decent amount of gear whine right before the change, that has mostly gone away.

-Once the transmission is fully warmed up it is extremely smooth, no stiff gates, no vague engagement and all gears engage with a similar feel.


I'm extremely happy, with that being said, I don't know if my transmission is in the norm. I think the previous owner may not have been very experienced with manuals and ground some gears (see pictures). The amount of debris on the plug surprised me, I'm glad I did the change.

Do I recommend adopting a more conventional oil change interval (30-40K) compared to the OEM "lifetime" claim? Absolutely.

I believe if I attempted to used the filthy oil that came out of the transmission for the life of the vehicle I would have a major failure.

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[texanbrit]

How was that cost wise?

[FartieBartie]

How was that cost wise?

I purchased 2 quarts on amazon for $19.15 a quart.

[MadFiat]

Apparently grinding can be caused by oil that's very thick, it spins the disengaged gears with hydraulic action thus they're turning before you even try to engage them.

Not having any grinding or shifting issues, though it is very notchy and stiff with the cravenspeed shifter.

I definitely need to do a full oil change on my trans. My engine blew due to some kind of oil failure most likely, don't want the trans to do the same.

[NGEN]

Apparently grinding can be caused by oil that's very thick, it spins the disengaged gears with hydraulic action thus they're turning before you even try to engage them.

Not having any grinding or shifting issues, though it is very notchy and stiff with the cravenspeed shifter.

I definitely need to do a full oil change on my trans. My engine blew due to some kind of oil failure most likely, don't want the trans to do the same.

Alvin,

You need to make sure your shifter cable is adjusted correctly. That can cause what you are experiencing.

[doverosx]

The adjustment instructions don’t really make any sense. The way I understand it from how everything works is that you adjust the cables so that the shifter stays in neutral. I’m not sure how you’re supposed to use an elastic to keep it in reverse as per the fsm.

I’ve had the bushings go before and what I have doesn’t feel the same.