What is the most a stock 4 cyl Fiero axle can handle and is there a hd that will drop right in??

4 cylinder axles are same as 6 cylinder axles. The manual axles are thicker and stronger than the stock auto axles.

OEM fiero manual axles are quite strong and will hold more power than most people will have.

Wheel hop with sticky tires at any power level will break them.

Thank you so much for chiming in . Will the straight shift axles fit in the Auto?? I am assuming not

The driver side manual axle will fit the driver side auto transmission.
The passenger side do not interchange.

TY a lot Joe .

quote Originally posted by olejoedad: The driver side manual axle will fit the driver side auto transmission. The passenger side do not interchange.

The DS Auto axle has a female tripot and the Manual DS axle has a male tripod. The axle shaft lengths might be close to the same length, but I haven't ever tried to swap the Tripot assembly between a fiero auto and manual axle.

The driver side manual axle also has a female tripot.
It can be used on the TH125C, 4T60, 4T60E and 4T65E and 4T65E-HD.

The tripots can not be switched between manual and auto, due internal roller diameters and axle splining differences.

I am striking this post, as I am not able to verify this information at the moment.

The driver side manual axle, as guru stated, has a male tripot.

Sorry for the misinformation.

[This message has been edited by olejoedad (edited 05-20-2019).]

Thanks so much again Ole Joe

quote Originally posted by RussellCupples: What is the most a stock 4 cyl Fiero axle can handle and is there a hd that will drop right in??

Forum member Darkhorizon (Scott) ran a 9.87 sec @147 mph 1/4 mile time in his 86 GT with a heavily turbocharged and nitrous fed 3800 engine with a 4T65eHD transmission. AFAIK, he ran stock GM axles . To run that time his engine must be making 600 HP .

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "