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swap a Fiero 5 speed getrag into my 91 Pontiac?


carnut62

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My Pontiac has a weak second gear sycro. and a leak at the output shaft seal. Will a Fiero Getrag 5 speed interchange? My Pontiac has a pull forward release bearing and linkage, the Fiero hasn't. I think it will bolt up as the 3.4 was derived from the 2.8 engine. Are the axle splines a different diameter? Will my hydraulic clutch slave cylinder work? Are they vastly different in gear ratios? Thanks for any assistance. I joined because there seems to be some knowledgeable people here.

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I'm not well versed in the Fiero's but I think they have completely different mounting provisions and therefore will not mount in a w-body. It will bolt up to the engine fine as long as it is a variant with a 60* engine bellhousing casting.

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The 3.4 TDC swap is actually pretty common in the Fiero, so yes the trans bolt up. That's not the problem. Your problem lies in that the Getrag in the Fiero can totally different from the Getrag in the W body due to the fact that GM changes stuff every 5 years. Take this riddle for example... I actually considered using a 3100 SFI 4T60E in my 3.4 TDC Vert, The 4T60E mated to the 3.4 has a 3.42 gear ratio, whereas the 3.1 (which would be closer to the 2.8) had a 3.32 ratio. On top of that, there's 3 variants of the same 4T60E's. There's the 91-93 4T60E that's electomechanical, there's the 94-95 that's fully electric and runs OBD1, then there's the 96-97 which is OBD2. Considering the Fiero's last year was 88 and the 282 in the W's would be 91, it may be well be why they look different to you and have different things missing.

 

Also, the 1st and 2nd gear ratio might have been different in between both 282s. The final drive is 3.61 in both but it might act funky with an engine not designed for it.

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I have a 3.4 DOHC / 282 combo in my GTP, and it works.... just not as good as the 284 which was designed for the power band of the LQ1

 

Sent from my Z30 using Tapatalk

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I have a 3.4 DOHC / 282 combo in my GTP, and it works.... just not as good as the 284 which was designed for the power band of the LQ1

 

In other words it will work but don't go racing it all the time :lol:

 

And Matt, if you bring the GTP to a meet I'd like to drive it, see what the differences are.

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