How To Distinguish A 20det Gearbox R32

[theDETlife]

Calling all gear box guru's.

What are some key defining features that are unique to the Rb20det gear box in r32 skylines? (Also is the same gear box is found in the 25de models?).

I've heard the that 20e/30e/20de gearboxes are a lot weaker than the rb20det/25de box's and where I'm from people try to play off the weaker gearboxes as 20det boxes for a little extra coin.

So if anyone knows of any features that are visible from the outside of the box that will allow you to distinguish which gear box is which with out opening them up, please feel free to spread the love. for example - do they have different bell housings, breathers, shapes or even a number stamped on the side of it?

Thanks! And have a fine day.

[GTSBoy]

Much of a muchness really.

[niZmO_Man]

Nah they're all pretty similar.

Externally, you can usually tell R32-onwards gearbox by the ribbing.

[iruvyouskyrine]

RB20DET gearbox is skinny and has a flat shifter plate. Easy to be confused with a SR20DET box as they are practically the same thing.

RB25DET box is physically a lot bigger and has a slanted shifter plate.

[GTSBoy]

Yuh but he was only asking about the skinny ones.

[jiffo]

Here's an R32 Rb20det box.

Think they're called an FS5W71C.

[theDETlife]

I think the rb20de and 20det boxes are both under the same code "FS5W71C"
As far as I know the 20de box's also came peer'd rb30e vl commodores, R32 gxi with a 1.8l carburettor engine and i think some laurels with the rd28 diesel engine.
Some one must know their r32 box's inside out.

Cheers guys!

Edited February 5, 2015 by theDETlife

[Mikha1]

Plenty of information out there about FS5W71C boxes. Google it!

Off the top of my head, they were used behind the rb30e, rb20/(d)et, rb25de, ca18/i/de/t, ca20e, sr20/de(t),ka24.

Pretty much most Nissan RWD only applications from the early- mid 80’s up until the latest R34 Rb25de incarnation use this gearbox. The later model ones had minor updates to synchro configuration and oil control.

They are known to spit the dummy at various power applications. I have seen them hold well in s13’s drifting at 280 rwkw and I have seen them break at 180 rwkw. It all depends on how they’ve been treated.

Identifying the vintage of an FS5w71C box is tricky from the outside. I would start by:

• Inspecting the webbing on the bellhousing. Early iterations have less webbing than the later model ones.
• Determine what bell housing is bolted to it. CA/RB/SR are all different
• Measure rear housing length. Rb20 R32’s are different in length compared to an sr20 s13 one. This is because the output shaft is longer (or shorter, I cant remember).
• I.d. the crossmember if it has one on it.
• The style of shifter on it might give away some detail. There are skinny long ones, bent stubby ones, etc.
• I know there are numbers stamped on the housings but I have no idea on what they mean.