PFF - Pennock's Fiero Forum, PDA Edition

Fiero automatic trans swap (Page 1/1)

jjd2296

FEB 08, 10:34 AM

Need a little help, im converting a 5 speed to auto for my dad as he can no longer drive a manual. I have all the parts except the trans clips that hold the lines in place from the rad to the transmission. I also need the ruber trans line hoses from the trans to the hard trans coolant lines.

anyone know where to find them?

theogre

FEB 08, 12:21 PM

AT Coolant Rubber lines are Not "standard" rubber.
Make to take Hot Oil w/o self destruct in hours to days. Do Not use vacuum or engine coolant rubber. AT oil lines have near 0 PSI because how they work but Hot Oil "eats" normal rubber even w/o pressure and piece plug up lines and screens/filters.
Often get thru most local part store often in 2-3 feet sections to install aftermarket AT coolers.

Trans end hoses have a loop in 1 to stop oil draining after shutdown. Loop has a bracket on trans case to keep loop in place.

Often missed by people doing same...
You need ECM "chip" for auto trans and rewire the shift light circuit for TCC control to get best mileage and cool operation.
If only drive in city or short trips still need AT chip and pull shift bulb in dash.

Need shifter interlock and disable stick lock button in s-column. See my Cave, Auto Shifter
Otherwise only a matter of time before driver forgets and "park" w/o shifter being in Park and car rolls at hits something, worse someone.

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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

Pyrthian

FEB 11, 09:49 PM

I did the opposite - auto to manual. if I remember right, the underside clips that hold the trans lines up are the same clips used for holding the clutch line up.

greenturnedblue

MAR 01, 10:07 PM

I have the ruber tranny hoses from the tranny to the coolant lines as well as the bracket that holds the loop in place from a 3spd auto. In Vancouver

Dennis LaGrua

MAR 02, 04:28 AM

With all the work that needs to be done you might have considered the 4T60 for better driveability. The 3 speed auto ECM will provide the TCC lockup function, easier finding one used than trying to find a new chip. You will need the auto radiator for the cooler (or an external cooler up front). You can run the cooling lines using 5/16" aluminum or copper line but flare the ends a little so the trans cooler lines don't come loose. Don't forget the larger auto brake pedal.

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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 "

jjd2296

MAR 02, 10:53 AM

thanks Denis, I have all those parts. I went with the T125 because I found a NOS 1993 Windsor built unit that was meant from a transport van and from what I have read that version has the best gearing our of all the T125's. The car will run on a 7730 ecm, so does you comment on the TCC apply still? I do need some guidance on where to get the trans lines that run from the transmission and connect to the ss lines running to the rad.

[This message has been edited by jjd2296 (edited 03-02-2022).]

Dennis LaGrua

MAR 06, 08:06 AM

quote

Originally posted by jjd2296:

thanks Denis, I have all those parts. I went with the T125 because I found a NOS 1993 Windsor built unit that was meant from a transport van and from what I have read that version has the best gearing our of all the T125's. The car will run on a 7730 ecm, so does you comment on the TCC apply still? I do need some guidance on where to get the trans lines that run from the transmission and connect to the ss lines running to the rad.

Sounds like you are in good shape. Yes the 7730 will activate the TCC on the TH125. On the auto swap that I did I purchased a roll of aluminum tubing from Summit Racing Equipment. Rather than trying to duplicate the complex bends of the OEM lines, I just ran them nearly straight underneath tight to the floor plan using metal rubber lined P clips held in place with large head 1/8" pop rivets. To keep the line straight I had to drill a hole through the cross member and put the line through a piece of rubber hose ( to stop abrasion) but all worked well with limited bending. Transmission cooler line and hose clamps made the connections at each end to the tubes going to the oil cooler and transmission. Decide what size line you need. I used 3/8" tubing as that is what the transmission used but it did require an adapter fitting at the trans cooler side. I believe the TH125H used 5/16" cooler line.
While it sounds easier to use an aftermarket trans cooler near the mid engine, that location doesn't provide the airflow needed to properly cool. IMO, the trans cooler must be up front.

82-T/A [At Work]

MAR 09, 11:10 AM

quote

Originally posted by jjd2296:

Need a little help, im converting a 5 speed to auto for my dad as he can no longer drive a manual. I have all the parts except the trans clips that hold the lines in place from the rad to the transmission. I also need the ruber trans line hoses from the trans to the hard trans coolant lines.

anyone know where to find them?

Fiero Store and Rock Auto should have everything you need, otherwise The Fiero Factory can get you used parts.

ALSO... if you haven't already done so or haven't already thought about it... EVERYTHING you took off from your Fiero in the conversion process (lines, clutch master and slave cyl, brackets, transmission, etc...) are all very valuable. Most people are looking to do the opposite of what you're doing. If you're at all interested... it would be great to package all that up, crate it up, and put it up on eBay for sale.

Couple of other things:

1 - I have a GX3 / 3.33:1 Th125 that runs perfectly if you have any interest in it. I can offer it to you for free, but it's going to take some time. It's still in the car, and the car has been in storage for 11 years... haha. But if you're super inclined, are in the Central Florida area... I'd be happy to remove it with you. I have a hoist and all the tools. Just haven't had the time.

2 - Have you thought about going with a 4-Speed? There's a whole conversion to a 4-speed 4T60 that might be worth a look... better performance and fuel economy: https://www.pontiacperforma...es/4_Speed_Swap.html