hey all im new here i just bought an 86 GT last weekend with plans to do the LS4 swap. ive searched the ls4 swaps and saw nobody has used the factory 5 speed tranny but ive seen in numerous places that the engine and tranny have the same bolt pattern. so my question is why is nobody doing it? tranny not strong enough? im just trying to keep cost as low as possible and if i already have a 5 speed i thought why not use it if i can? thanks in advance for any info.

Welcome to the forum! I think the main reason is that most Fiero factory Getrags have done fairly high mileage and a rebuild will cost you more than a F40. The LS4 high torque will most probably destroy an old Getrag.

there's also the whole starter issue.

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we're in desperate need of a little more religion to nurse your god-like point of view...

Built not bought... Because bolt-ons don't.

https://www.fiero.nl/forum/Forum2/HTML/119122.html

Welcome to the formum.

The nice thing about using a 5 speed Getrag, is the flywheel is fairly simple. Just take a billet steel LS1 flywheel and turn it down to accept the 142 tooth ring gear. The mounting depth, crank bolt pattern and balance of the flywheel are already correct. (I have made one of these before).

I have a bolt on bracket to mount the stock LS4 starter in the stock LS4 postion, but the issue is the stock Fiero getrag (and isuzu and 4 speed) all have the external clutch release arm right where the LS4 starter goes. If you wanted to stick with a Getrag 5 speed, the 92-94 HTOB version has a hydraulic throwout bearing, so with minor clearancing of the case my bracket wil fit.

Here is an archived thread about the LS4 and using it with the various manual transmissions and various methods of getting past the starter issues. It also shows my starter mount bracket and the clearnace issues with the stock fiero transmissions.
https://www.fiero.nl/forum/A...130314-2-098254.html

thanks guru that link is exactly what i was hoping for. you said the hydraulic throw out bearing works with your bracket so is that something i can change on my tranny or do i need to use a whole new tranny for that option?

There are no HTOB conversions for the stock fiero transmissions. You have to start with an original HTOB transmission.

so if i were to get the newer HTOB tranny i assume it would bolt in to the same mounts? what applications would i look for to find one of these trannys. sorry for all the questions ive been working on muscle cars all my life and this front wheel drive transmission stuff is all new to me haha.

I have that tranny in my 4.9 car. Here's a thread.
https://www.fiero.nl/forum/A...130314-1-085296.html

Search for a tranny for a 93 Corsica with a 3.1. That should get you the correct one.
An added bonus is that the VSS in the later Getrag will be (I think) more easily adapted to the LS4 PCM. Guru should know for sure. It matches the 4.9 PCM directly.
It also has a stronger differential than the stock Fiero unit. It is reputed to be smoother shifting, but you couldn't prove it by me.

To directly answer your questions...
The mounting brackets will bolt up with no issues. (You didn't ask, but the Fiero axles will work, as long as the stock mounting location is used.)
You may need to enlarge and tap the holes where the select cable bracket is fastened. (I had to, but I don't recall others mentioning this.)
You will need Rodney Dickman's FWD shift cable adapters.
You will need to adapt your clutch line to the HTOB fitting.
The VSS and reverse light switch use different connectors from the stock Fiero bits.
None of this is difficult. Just needs doing.

Edit - The HTOB is much nicer than the external Fiero unit. It's a much cleaner installation, with fewer moving parts to cause problems.

[This message has been edited by Raydar (edited 04-28-2013).]

thats some great info now all i need to do is get some parts bought and start putting things together, thanks alot for all the info and i'll be keeping ppl updated once i start the build.