Been lurking for a while, and saw it mentioned a couple of times that the th325-4l could be beefed up with commonly available parts. My question is what needs to be strengthened and what parts are interchangeable with other transmissions? Thanks.

Josh

Also if anyone knows of any fieros for sale in the southwest Texas region, let me know. Doesn't matter if they're running or not.

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fieroless........for now

325=350
325-4 = 700? if thats the 4 speed version of the GM in line trans

a better 4speed auto for a fiero would be a newer 60 or 65
heck even a caddy N* 80 is lighter the the old 325 was
plus the 325 install needs to realy cut up the car to fit
and the result is a tail heavy beast that willnot handel
125s are cheap and will live behind a V8
anyway wecome to the forum

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Question wonder and be wierd
are you kind?

To beef up a 325-4L , purchase a thm325.

To beef up a thm-325, purchase a thm425.

The 325-4 was severely compromised, when designed for weight savings & a fourth gear. It has a skinnier chain drive and weaker internal components.

The 425 was massively overengineered, at the expense of extra weight.

The reason I didn't want the 60 or 65 was that I prefer the looks of a longitudinal setup. I don't even have a fiero yet though, so I'm really just sort of throwing ideas up in the air.

Here's a 325. It's a chain driven inline design with a final drive (differential) unit used on front wheel drive cars ie Eldo, Toro, Riv.

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quote Originally posted by opm2000: ...The 325-4 was severely compromised, when designed for weight savings & a fourth gear. It has a skinnier chain drive and weaker internal components...

I can't confirm any of this but my research turned up the opposite for the TH325-4L. From what I understand it has TH200-4R guts inside. The TH200-4R can be built to withstand about 600hp/500lb-ft.

This is a company that specializes in the TH200-4R http://www.bowtieoverdrives.com. The guy I talked to had no knowledge of the TH325-4L though. My plan was to get a 325-4L and a TH200-4R, rip them apart, and see how much they were actually similar/different. As for the chain, I planned to replace that with a gear setup like cardealer did on his. Not necessarily for the reverse option, but for my own peace of mind.

I speak of all this in past tense because I am going a different route now, and won't be using any of the Eldo/Toronado transaxles. I was considering it because I wanted the overdrive gear. I hate being on the highway and hearing my motor straining for an hour, or two, or...

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perk - todd's hot rods
Shotgun - the ultimate toy toter
Blade - the street-legal Fiero-based race car
Rock-it - the Fiero that will soon be for sale

quote Originally posted by perkidelic: I can't confirm any of this The guy I talked to had no knowledge of the TH325-4L though.

Ok, I give up.

quote Originally posted by perkidelic: I can't confirm any of this but my research turned up the opposite for the TH325-4L. From what I understand it has TH200-4R guts inside. The TH200-4R can be built to withstand about 600hp/500lb-ft.

The TH200s were never as strong as the TH350s which the 325 is based on.

Overdrive is nice, but they did fine without them in the 60s and 70s. 3K@60 is fine with me, I'm used to it

GL!

quote Originally posted by opm2000: Ok, I give up.

By saying I can't confirm it I mean I didn't open up the two transmissions and see it for myself.

The guy at Bowtie Overdrives had no knowledge of the TH325-4L but I really called him to talk about the parts he had available for the TH200-4R. I just noted that he wasn't familiar with the TH325-4L so that it wouldn't seem like I was telling people here that they specialized in the Eldo/Toronado trans.

I am merely passing along the information, because for someone considering the swap it may be what they need to hear. On PFF everyone says the TH325 (3spd) is based on TH350 guts, but the transmission shop I talked to about it told me it's actually TH200 guts. For the time period in question that could actually be possible because GM was using the TH200 in all low-power front-engine/rear-drive cars. My mom had one, and had a TH350 swapped in when it gave up - behind a weak-kneed 305/4bbl.

The transmission shop is a nationally-known builder of racing transmissions (and regular rebuilds). They have worked with all three of the Eldo/Toronado transaxles before, for regular street cars. I know they could be wrong but, I tool their words at face value until I could dig in and see for myself. Again, I pass the information along because I think it's worth looking into. If someone got a couple busted transmissions and compared the parts it may be worth the effort to find that you can build a 500lb-ft 4spd auto trans.

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perk - todd's hot rods
Shotgun - the ultimate toy toter
Blade - the street-legal Fiero-based race car
Rock-it - the Fiero that will soon be for sale

Well, a quick look thru a couple of parts lists shows that the 325 & 325-4l share some of the same intermediate bands, bushings, clutch plates, sunshells, sprags, seals, lock-up solenoidd, and thrust washers with the 200 trans.

They also share these same parts with the 200-4R, 700-R4, 350, 400, Powerglide, 4L80E, A500, 270, 700, 125C, and 440-T4.

I wouldn't confuse GM interchangability with lineage.

I base my "325 stronger" statement on a guy who had a '94 LT1 mated to a 325-4L. After a few days of hot launches, the overdrive gave out. He replaced it with a 325 and had no problems. Both the local and national rebuilders I spoke with said GM had a good thing going with the 325, but really cut too many corners with the 325-4L. They said they saw the 4L in the rebuild shop more often.

But heck, if your building a daily driver with long distance travel in mind, the 4L would be fine. Use a 325 for daily and occasional hot rodding, and use a 425 for serious hp & time related endeavours. If your really devoute, find a 425 with switch pitch and you could probably hook up unlimited hp & torque.

That was the motive for me - long distance touring - until my plans changed. I looked into parts to build it up a little just for peace of mind, but I didn't plan on torturing that car.

perk