Are they the same? The M284 was on a 3.4 Lumina V6 from 1991 - 1993.

Will it bolt to the 2.8? Is it a stronger unit?

Thanks.

John

In short... Yes and Yes. It will bolt up the 2.8 just fine, but if all you have is the 2.8, upgrading to a M284 is a bit over kill for what you have to do in order to do it. From what I know the conversion isn't that difficult as for the most part it mounts to the existing tranny mounts. The main gotcha is the half-shafts. The splines are different on the M284 and won't match up with the stock fiero half-shafts. Not to mention the shift and shift-select cable mounting. Also, while the M284 is beefier, it is alot rarer then the M282, so that should also be taken into account.

I will be doing this conversion as I have the 3.4 DOHC, and the stock getreg is geared a tad too high for it IMO.

[This message has been edited by 88-DOHC (edited 08-05-2002).]

The 284 mounts differently. It uses the same mounting method as the automatic transmissions in '88 Fieros (A single mount to the left of the trans instead of one to the front and one to the back).

The 284 is RARE. When it eventually needs it, it will be over $2000 to overhaul and must be sent to Detroit for the procedure.

AFAIK, it uses the same inner CV spline as every other FWD GM car ever built. I'm not sure if you could use stock Fiero axles or if it needs different length shafts.

I hate to disagree with my venerable coleague but...

[QUOTE]Originally posted by Will:
The 284 mounts differently. It uses the same mounting method as the automatic transmissions in '88 Fieros (A single mount to the left of the trans instead of one to the front and one to the back).

The 284 that I have mounts nearly identical to a 282 with two minor exceptions...

The rearward tranny mount sits a bit farther forward that the stock 282 so it has to be redrilled to fit. Not a problem.

The forward tranny mount is a bit to narrow to go around the bellhousing seal, so it must be cut and widened.

Other than that, they fit perfectly and... there ARE two on the tranny and only one for the motor.

The 284 is RARE. When it eventually needs it, it will be over $2000 to overhaul and must be sent to Detroit for the procedure.

Rare? Yes $2000 to overhaul? No way. Local tranny shop did mine, bottom to top, here in town for $750 including pulling it out. Maybe I got the deal of the century, huh?

AFAIK, it uses the same inner CV spline as every other FWD GM car ever built. I'm not sure if you could use stock Fiero axles or if it needs different length shafts.

The 284 does NOT have the same splines as a stock Fiero. You must combine the output splines of a 3.4L DOHC's vehicle with the shafts from the Fiero to get it all to work right.

After that, test fitting them in may include a slight mod to the passenger side where you will have to move the retaining ring in the inner CV inboard a bit more so you can set the 3-angle bearing farther downt he shaft. Then you'll cut about 1/4 inche off the splined end of the 3.4 DOHC's output shaft assembly.

If it's to long, you'll feel the car shutter around corners as the shaft binds inside the tranny.

It's not a hard fix and not needed on every car. However, you'll know it if you need it

Also, the gearing is slightly different between the two. The 284 is a bit "taller". Not much, but a bit. Helps in 3rd gear. 1st goes by entirely to fast but 2nd pulls long and hard. Third is to the moon. 4th is great too. You'll never find the end of 5th

I've taken to starting out in 2nd from time to time. Still get a great launch off the line and no shifting until 65 or so. Kinda fun when the guy running next to you is waiting for you to shift so he can "get ahead"

Either tranny is OK. I hear the 4 speed is REALLY well suited to the 3.4L DOHC though... I might have to look into that one!

DKOV -

[This message has been edited by DKOV (edited 08-06-2002).]

The synchro set, seals, bearings, and bushings for a Getrag 282 cost more than $600 (and a lot more than that for a 284, if you could even find them).
So, you may of had a very poorly done rebuild.

[This message has been edited by 00lE (edited 08-06-2002).]

quote Originally posted by DKOV: The 284 that I have mounts nearly identical to a 282 with two minor exceptions... The rearward tranny mount sits a bit farther forward that the stock 282 so it has to be redrilled to fit. Not a problem. The forward tranny mount is a bit to narrow to go around the bellhousing seal, so it must be cut and widened. I got my information from a Lumina FSM. It's possible that the Fiero mount brackets will fit with modification. I've never had a 284 in my hands. However, it should bolt directly to a cradle from an '88 automatic Fiero. The 284 is RARE. When it eventually needs it, it will be over $2000 to overhaul and must be sent to Detroit for the procedure. Rare? Yes $2000 to overhaul? No way. Local tranny shop did mine, bottom to top, here in town for $750 including pulling it out. Maybe I got the deal of the century, huh? All of my research told me that GM and Getrag have an agreement. Getrag sells internal parts for this trans to no one but GM. The case is stamped "Do not disassmble". Will 282 parts work? I don't know. I'd be very interested in talking to the guy who overhauled your trans. I can't see $750 for a rebuild unles he only replaced half the synchros, which no self-respecting trans guy would do. The 284 does NOT have the same splines as a stock Fiero. You must combine the output splines of a 3.4L DOHC's vehicle with the shafts from the Fiero to get it all to work right.

I have more research to do.

What I failed to mention about the tranny rebuild is that the owner of the shop is not only a personal friend but owed me bigtime. Still, it didn't seem like he discounted it to much.

When I had the bottom end of the motor rebuilt at a local GM dealer and had the synchros replaced in the tranny, that bill was only around $4600 for both and most of that was the motor.

As I said, maybe I got the deal of the century. I'm not complaining though. Tranny pulles just as hard as it ever did.

Oh, and when was the last time something marked "do not disassemble" kept any of you out of it

DKOV -

quote Originally posted by DKOV: Oh, and when was the last time something marked "do not disassemble" kept any of you out of it DKOV -

I don't think that's ever happened.