How many miles is too many on 84 4 speed transmission (Page 1/2)
GabeBjerk APR 09, 01:56 PM
So I have a 87 SE 2.5l automatic, and I want to put a Manuel trans in it. I found a 4 speed in a 84 but it has 290000 on the car. the guy wants $260 for trans shifter clutch pedal and all. he said he'll send a video of him going though the gears so I know its not broke. I'm guessing with that many miles that I'll need to rebuild it. I don't if there's kits for that or what. And also I'd be driving 3.5 hours so what tools do I need to bring to get it out?

Thanks, Gabe
82-T/A [At Work] APR 09, 02:54 PM

quote
Originally posted by GabeBjerk:

So I have a 87 SE 2.5l automatic, and I want to put a Manuel trans in it. I found a 4 speed in a 84 but it has 290000 on the car. the guy wants $260 for trans shifter clutch pedal and all. he said he'll send a video of him going though the gears so I know its not broke. I'm guessing with that many miles that I'll need to rebuild it. I don't if there's kits for that or what. And also I'd be driving 3.5 hours so what tools do I need to bring to get it out?

Thanks, Gabe




Is there a reason why you want to go with the 4-Speed as opposed to a 5-Speed? I understand of course that you're getting "everything," but if you can manage to find a 5-Speed set-up... it might be much easier.

Actually... if I can be really honest... is he doing anything with the 84, or is he junking it? it might be better to just buy the entire car and perform the swap yourself. There's a LOT of components to a manual to automatic conversion. I've done it before, and I had a parts car (blown motor, no title, etc.) that I used to pull all the parts from. There's a lot of things you're not even accounting for, including the steering column (which is different because of the key lock), the neutral safety switch, things for cruise, etc.


As for miles, 290k is a **** ton of miles on a transmission. That would be like if your local high school had a track meet on Saturday, and they were short a starter in the 4x800 meter relay, and decided to ask one of the 40 year old dads to fill in... beer gut and all. It's not going to be pretty.

At 290k miles, the transmission will need completely all new bearings, shims, and you don't even know the condition of the gears itself (as in, if it's missing teeth).

My daughter's 5-Speed Isuzu transmission was well taken care of... serviced regularly behind an 85 Iron Duke, but the car had about 180k miles on it. It was mostly highway driven, and the 5th gear and reverse were "burnt." They still worked, mind you, but it was a little overheated and the transmission shop couldn't guarantee that the transmission would last much longer. They ended up buying another 5-Speed Isuzu off West Coast Fieros, and will be taking the 4th and 5th gear out of it to install in my daughter's along with new bearings, shims, and everything else. I think 290k miles means you can definitely expect it will need to be rebuilt. I just wonder if the effort is worth it. A 4-Speed rebuild is probably going to cost you around 2,500 bucks... is my guess.


I definitely don't want to poo-poo on changing transmissions... I just wonder if there aren't better options.
Patrick APR 09, 04:32 PM

quote
Originally posted by 82-T/A [At Work]:

Is there a reason why you want to go with the 4-Speed as opposed to a 5-Speed?



Getting rid of the slushbox is a great idea, but I agree... get a 5-spd instead. I swapped out the 4-spd Muncie in my '84 for a 5-spd Isuzu.


quote
Originally posted by 82-T/A [At Work]:

it might be better to just buy the entire car and perform the swap yourself.



Agree with this as well. There are a lot of things to be swapped over when going from an automatic to a manual. It's best to have the complete donor car in your yard!

[This message has been edited by Patrick (edited 04-09-2024).]

Raydar APR 09, 05:36 PM
Go to car-part.com and look around. You can sort by year, make, model, and whatever part you're looking for, as well as distance from your zip code. (FWIW, 88 Isuzus will interchange with earlier years, but there were some upgrades.)
I found a 50K Isuzu for not a lot of money. Certainly not over $250. I think it was cheaper, but it's been a while.
But buying a parts car can save you money, in the long run. Auto-to-manual swaps can nickel-and-dime you to death. (I've done two.)

[This message has been edited by Raydar (edited 04-09-2024).]

GabeBjerk APR 09, 05:43 PM
I think this changes my mind, because if it needs a rebuild I can't do it because 2500 is more then my whole car is worth. I think I'll wait and see if I can find something with lower miles and 5 speed. Or I may just wait and someday get a different Fiero with a Manuel.

thanks for the advise, Gabe
Patrick APR 09, 06:36 PM

quote
Originally posted by GabeBjerk:

Or I may just wait and someday get a different Fiero with a Manuel.



Manuel may not wish to relocate ... but yeah, getting a Fiero which came from the factory with a manual transmission would make your life a whole lot easier. It's not like they're especially rare.
theogre APR 10, 01:24 AM
Seems Missing some data---
84 stick had 2 different gearing.

If anyone think will help MPG going w/ either... Not so much or worse then MD9 & most "gear sets" in table listing Transaxle Ratio RPO vs 84 uses RPO M19 & MY8 in next table.

see https://web.archive.org/web...~fierocave/ratio.htm

Will need 87 ECM w/ 87 Stick PROM to replace current PROM.
You can't use 84-86 PROM on 87 engine & ECM

Two engine may look same for many but are 2 way different engines.
see https://web.archive.org/web...ierocave/4cylqrg.htm

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

82-T/A [At Work] APR 12, 11:30 AM
Some thoughts for those of you looking to either convert to a manual, or get transmission work done.

My daughter's transmission is being serviced by a family owned AAMCO transmission shop. They have gone ... totally above and beyond anything I could have ever asked for. I mean that. Most shops totally declined us when we'd bring the transmission over. They'd say... "A manual? We're not interested..."

But this shop did everything they could to help us out. As it turns out, the Isuzu 5-Speed (same with the 5-Speed getrag) are becoming exceptionally scarce. You can still find a few used transmissions out there, but the parts are drying up. They were able to get new seals and new bearings, but replacement parts are basically non-existent.

My daughter's transmission was running... car drove fine, and things like 5th gear / reverse were burnt (lots of highway driving, and it's the last to get oil). They've had to buy TWO cores from eBay and other shops, in order to piece together enough good parts to build a transmission that they were willing to warranty. They're going to give me everything, including the other two cores that are left over. But just wanted you guys to know, that I've been communicating with the shop, and they've had to buy parts from dozens of different places, because nothing is available anymore. They purchased one of the transmissions (from what I remember) from West Coast Fiero as well. These guys have done an amazing job so far. And they're putting it all back together this week and next week. It's likely going to be over 3 grand, FYI... and normally that would be crazy, but my daughter wants to keep the car mostly stock... so it's what it is.

My advice, don't bother rebuilding a transmission... look for the best one you can find, if you don't care about numbers matching.
Patrick APR 12, 07:13 PM

quote
Originally posted by 82-T/A [At Work]:

My advice, don't bother rebuilding a transmission... look for the best one you can find, if you don't care about numbers matching.



Well yeah... we're not talking about a mint condition '63 split window 'Vette here.

jelly2m8 APR 13, 03:56 AM
Computer don't care if you have a 4 spd or a 5 spd. throw that shift light bulb in the garbage, even Gm got rid of it.

Fiero manual ECM's DO NOT have any gear position input to them.

[This message has been edited by jelly2m8 (edited 04-13-2024).]