Manual Transmission questions

[Outlaw1846]

I've got a 1992 GT that came originally with the 3.1 MPFI and 5-speed. Whats the easiest way to determine which 5 speed, i'm getting confusing stuff about Getrag/Muncie 282 and 284. 284 seems to be a transmission with either unicorn status or discontinued, like everything else i seem to need when i break it.

I've also seen somewhere about a swap to 6-speed swap, the f40 i believe. Anyone know how this works?...

All in all i'm looking to either pick up a second one to rebuild and replace mine or at least know what i'm looking for for rebuild kits so that i do it right, mine has 200K on it officially now and i'm running a 3.4 and i'm being fun with it of course and don't want to totally toast it but it's not really stopping me either.

Any info to share would be great folks

[Cliff8928]

The 284 was only used in the 3.4 DOHC W-Bodies.

You have a 282 or NVG T550

[Barry]

Get a 282 or a nvg550. There really strong.

[Rettax3]

I've got a 1992 GT that came originally with the 3.1 MPFI and 5-speed. Whats the easiest way to determine which 5 speed, i'm getting confusing stuff about Getrag/Muncie 282 and 284. 284 seems to be a transmission with either unicorn status or discontinued, like everything else i seem to need when i break it.

I've also seen somewhere about a swap to 6-speed swap, the f40 i believe. Anyone know how this works?...

All in all i'm looking to either pick up a second one to rebuild and replace mine or at least know what i'm looking for for rebuild kits so that i do it right, mine has 200K on it officially now and i'm running a 3.4 and i'm being fun with it of course and don't want to totally toast it but it's not really stopping me either.

Any info to share would be great folks

Yes, the Getrag 284 only came in the 3.4 DOHC W-bodies from '91-'93, and in some Chrysler TC's (ooo, "By Maserati"! ooo, ahhh! ). They are a little heavier, about the same case size (I have one, so DON'T argue), and a little different-looking from the 282. They are much stronger, but require special high-pressure presses to rebuild (mine is rebuilt), so they cost thousands to rebuild, the clutches are a special pull-type, like the Tremec T-56 six-speeds used in the fourth-gen Camaros, and they cost 2-3 times as much as a standard 282 clutch. The output shafts are also much bigger (as is the input shaft), so the stock Beretta CVs won't just plug in to them, have fun making a hybrid axle.

An Isuzu five-speed from a 2.0 or 2.2 Beretta will also probably work fine, so long as your engine is stock and you don't beat on it a lot, but they are not as strong as the Muncie/Getrag 282s (NVG T550 is the same tranny, just made by New Venture Gear later on, after Muncie quit building them. Getrag is the designing company in Germany), so you are best off with one of those if you can find one. I'm not even sure the CV joints swap between the 282 and the Isuzu...

So far as the F40 is concerned, you will need a custom clutch to mate one up to your 3.1 because the dual-mass flywheel that is supposed to go with it is (IIRC) over an inch thick (and weighs something like 78 pounds, or so I've heard -go ahead and argue with me on this though ) -that will typically run ~$400-$500 for quality, and you will still likely be facing a custom spacer for the throw-out bearing. Check out V-8 Archie, in the Pontiac Fiero circles for more info -they make complete kits for that swap to different engines, and I've never heard of anyone complaining about the quality. You could adapt or have built a custom flywheel instead of custom clutches. CV joints will also trip you up on that one, as will the shift-cables and clutch hydraulics. The F40 is simply not meant to go in a Beretta with a 3.1... Now, in a Beretta with a Super-Charged 3800.... Stay Tuned!

[Barry]

Dont forget about the f23 either. Its a vary capable trans in itself. I bought one to swap into my beretta but unfortunately never got around to it.

[Rettax3]

...F23 is from Cobalts or later-model J-Bodies, do they have a model in the series with the GM Metric pattern (2.0 & 2.2 OHV, 2.8, 3.1, 3x00, 3800, ~Northstar, etc)? I know one of those newer 5-speeds does, I just can't remember which one... There was a write-up by a Fiero owner who did a build with a SBC (Small Block Chevy) V-8, bolted onto one (it obviously required an adapter-plate, as the SBC does NOT use GM Metric as the bolt-pattern) that I was looking over recently, might have been the F23. Strong tranny, reportedly, and very easily rebuildable.