Ok so I have a 3.8 SC fiero pushing about 300hp and it has a 4.10 4 speed. 2nd sync is going out. Now im at the point would it be to cheaper to get an isuzu 5 speed and swap it or go with the m17 gears swap?

Ok so I found an isuzu 5 speed in a fiero at the junkyard for $200 with the added costs of the other components.

To swap in an Isuzu 5 speed here is what you will need:
Isuzu 5 speed (duh!)
Isuzu shift and select cables
5 speed shifter
Shifter console trim plate with the 5 speed pattern on it
You will need the brackets for the slave and the cables at the transaxle, and the transaxle mount brackets.

Anything else I need for this to work? Please respond I need to know by tomorrow.

Also like I said mine is a 4.10. So do the axles need to be swapped too?

[This message has been edited by timenewton (edited 08-15-2017).]

I would keep the 4 speed considering how much torque your engine is making.

How do you find the 4.10 gearing with that much power?

What's good about the M17 is the ribbed case for durability, more so than the actual gears. And the ratios are different.

If you like this gearing, why don't you just keep it? Find a 4-speed transmission somewhere; there ought to be one good synchronizer ring in it.

I dont like the gearing honestly. At 60mph im at 3k rpm wondering when im suppose to shift again. It's fun up until 60 then it's just mehh. I have a 3.8 SC that tops out at 90.

You would like the M17, I think it is 3.65....so rpm would be much lower at speed. I think you would break an isuzu.

[This message has been edited by Gall757 (edited 08-15-2017).]

Yeah i've thought about it. I believe im just giving up on the manual and going auto. Less hassle to worry about. Save money in the long run anyways, and not have to worry about hearing about breaking/fixing issues anymore. The fiero trans are just to weak for the modern age and I have now been enlightened.

I don't think the Fiero transmissions are so bad, but none of them are new anymore. They're old and abused. Junkyard stuff needs rebuilding before use; cars don't end up in the JY because they still drive nice.

A crunchy synchro doesn't mean the transmission is weak. A synchro ring is a wear part requiring periodic replacement.

Saying your trans is broke because the 2nd gear is crunchy is like saying the design of your brakes suck, but you've worn the pads to the metal.

quote Originally posted by timenewton: I believe im just giving up on the manual and going auto.

Well... that'll suck about 90% of the fun out of driving the car.

Yes, I understand the synchro will be easy enough to replace. I just don't like the 4.10 gearing. The car is fun up until 60. Mine has a spec 3 clutch in it. So i'll prob keep it the way it is till it rips some gears then its auto after that. As for 90% of the fun I doubt it. About the only fun I have with manuals is on curvy roads up and down shifting. For periodic driving auto is the way it is.

quote Originally posted by Gall757: I would keep the 4 speed considering how much torque your engine is making.

How much does a 3800 SC with 300 hp make?

quote Originally posted by timenewton: Ok so I found an isuzu 5 speed in a fiero at the junkyard for $200 with the added costs of the other components.

quote Originally posted by 2.5: The Getrag is behind V8s. The Isuzu is weaker.

Agreed. Finding a FWD Getrag is easier too...
//www.fiero.nl/forum/Forum9/HTML/000038.html

Rodney has everything he needs. Adapters, cables etc.
http://rodneydickman.com/ca...h=37&products_id=143

------------------
My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

quote Originally posted by 2.5: How much does a 3800 SC with 300 hp make?

Peak torque would be around 300, as a guess, but would be at a higher RPM than a V-8.

quote Originally posted by timenewton: To swap in an 5 speed here is what you will need: 5-speed shift and select cables 5 speed shifter

Can someone explain why you need the 5-speed shifter?
How it is different from the 4-speed shifter?

One of our guys went from 4-speed to 5-speed and used the same shifter.
It's not like there's a "gate" limited to the "H" pattern.

quote Originally posted by olejoedad: Peak torque would be around 300, as a guess, but would be at a higher RPM than a V-8.

Really, that surprises me I would not think near that high.

A stock Series 2 makes 240 horse @ 5200 and 280 ft lbs @ 3600.

Your cable to transmission mount and slave mount are one and the same for the Isuzu. A question that wasn't answered was about what else you will need. You can use the same clutch and pressure plate, but you'll need to get an Isuzu throwout bearing.

One good thing about using an Isuzu behind the SC is that when you pop it, Isuzu's are fairly plentiful and cheaper than a Getrag. Tina, an old PFF drag racer ran Isuzus in her Fiero just for that reason. //www.fiero.nl/forum/A...050119-2-055573.html