I am doing a small bock Chevy and have realized that the engine I want to use is going to be too much for the 5 speed Fiero trans and I may need to go with a 4 speed auto I am thinking of using the 4T60 has anyone used this combo? I did a search and found a little info but nothing on a small Chevy with a 4-speed auto. If you have any experience or info I would really appreciate it.

I asked the same question! go to this string...

https://www.fiero.nl/forum/Forum2/HTML/045149.html

I have an SBC/4T60 combo in mine. I had the tranny built special for me, starting with a '92 Grand Prix unit with 3.33 gears. Shift points are quite firm and it works great. (I also have a B&M ratchet shifter to make it a bit more fun when I want it).

What questions do you have?

Brian

quote Originally posted by bwayne: I have an SBC/4T60 combo in mine. I had the tranny built special for me, starting with a '92 Grand Prix unit with 3.33 gears. Shift points are quite firm and it works great. (I also have a B&M ratchet shifter to make it a bit more fun when I want it). What questions do you have? Brian

What kind of small block are you using? WHat are the numbers it puts out, and how hard do you drive? My LT1/4t60e will be done in about a week, and im curious as to the durability of the tranny. Its always better to have someone else test the limits if you know what I mean Cant really afford to find out the fun way

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My first question was, would a SBC/4T60 work together, I see now they do. What SBC do you have? Do you have TPI or a carb set up? I too what to know what kind of numbers it puts out? I also am curious how durable the transmission is. Have you ever taken it to the track, Drags or road race? Right now the engine I want to use is around 400 horses with ram jet fuel injection and I just want to make sure I get a tranny that can handle it or I need to back off the horse power and torque so I do not go thru tranny’s like crazy.

quote Originally posted by bwayne: I have an SBC/4T60 combo in mine. I had the tranny built special for me, starting with a '92 Grand Prix unit with 3.33 gears. Shift points are quite firm and it works great. (I also have a B&M ratchet shifter to make it a bit more fun when I want it). What questions do you have? Brian

In Colorado, your swap engine must be the same year or newer than the engine being swapped out. You must also have fuel injection, because your Fiero came with it. Check with the Colorado Emissions people first, and save yourself some grief.
Dave

[This message has been edited by Dave Mathis (edited 01-06-2004).]

This is the combo swap I'm planning on when I rebuild the V8 Fiero I bought last month. It currently has the TH125 but I want the extra highway gear. I'm planning on a reusing the 87 350 with TPI and add shorty headers. I understand that, with the exceptin of the OD, the internals of the 4T60 tranny are almost identical to that of the TH125 so the same reliability should be expected.

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Roy

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It might have just been my swap, but the standard sanderson headers would not work. I needed to get 81 corvette manifolds to fit. The OD tranny is just to big. If thats the case for swaps with the od tranny, start looking for the headers now. I found a pair for $61, but I got lucky on ebay. They usually go for $90 a header. So start looking to save a significant amount. Then again, it might have just been my combo.

I did the 4T60 conversion for BWAYNE last spring. He has a carbed 350 in which I would have to say is around late 70's vintage. We used a 90 or 91 4T60 (non-electronic) version of the 440-T4. These last years of the non-elec OD FWD tranny are the best and the strongest if you don't want to run an electronic version of the tranny.

There are a few things to note about his particular swap. It is NOT and Archie V8 swap. The guy who did the swap used a special flexplate and 1/2" thick steel adapter plate which gave me a lot more room to work with. As said before, BWAYNE's Fiero has a carbed motor so I had to hook up the TCC circuit in conjunction with the 4th gear pressure switch located inside the transmission to turn on the TCC anytime the tranny went into overdrive. Furthermore, I did have to notch the cradle slightly on the left side in order to compensate for the increased size of the OD trans on that side. Yes, custom length axles had to be used but Moser Engineering shortened the stock ones for a reasonable price.

Furthermore, the rear header on BWAYNE's 350 had already been modified to route exhaust between the oil pan and trans. It wasn't a very tight fit with the 125-C, but the 4T60 really pushed the limits becuase the trans is longer. If I remember correctly, the headers used looked like your standard, run of the mill, block hugger header design.

To make a long story short, BWAYNE's 350 swap is unique, and I have never seen anything like it as I think it was a very well thought-out design. Most notibly, the chassis of the car did NOT have to be cut to get the SBC to fit. It uses a remote water pump that is belt driven. I like this approach because you can find good cradles almost anywhere but good luck finding a rust-free space frame for the Fiero body.

As far as durability, the 4T60 trans is the strongest non-electronic FWD, transverse mount transmissions that can be found. If you need more strength you can step up to one of the E-models but then you will have to run some kind of transmission controller or an engine PCM that will be compatible with the E-trans.

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Is there any certain years of 4T60s to avoid for this swap because I've been offered a good unit that came out of a 91 Buick Centry?

Darth - You mentioned custom axles... It was my understanding that the 440-T4 and the 4T60 used the same stock Fiero axles (with the larger tri-pots). Were BWAYNE's custom axles necessary because of the different engine/tranny adaptor?

Roy

Glad to see you, Darth--you know more about my car than anybody.

The engine in the car is a '77 2-bolt main from a Monte Carlo. The headers are Hooker block huggers, and the rear one was modified to fit.

I think the '91 Century transmission should work, but check the gears--most Buick's came with fuel-miser gearing. I searched for several weeks to find the one I used, then had it built for my purpose. The base unit was from a '91 or '92 Grand Prix (can't remember the year) and had 3.33 gears. When it was built we kept that ratio, figuring that the SBC had enough torque that the 3.73s weren't necessary. If you're rebuilding the Buick unit, you can change the gears during the build of course.

As Darth notes, there isn't a lot of room in my engine bay. The engine swap was engineered very well with little extra space. Darth worked hard to shoehorn the 4T60 into place, but it works very well and lopes along at 2000 rpm on the highway.

The carb is a Holley 750 double pumper, and clearance on the top side is very tight as well, even with a custom scoop over the middle of rear deck.

I can email pics if you want them.

B

quote Originally posted by bwayne: ...I think the '91 Century transmission should work, but check the gears--most Buick's came with fuel-miser gearing. I searched for several weeks to find the one I used, then had it built for my purpose. The base unit was from a '91 or '92 Grand Prix (can't remember the year) and had 3.33 gears. When it was built we kept that ratio, figuring that the SBC had enough torque that the 3.73s weren't necessary. If you're rebuilding the Buick unit, you can change the gears during the build of course. As Darth notes, there isn't a lot of room in my engine bay. The engine swap was engineered very well with little extra space. Darth worked hard to shoehorn the 4T60 into place, but it works very well and lopes along at 2000 rpm on the highway. I can email pics if you want them. B

So, you left the gearing in the transmission 3.33? DO you know which chain ratio your using?

I'm surprised that you got the block hugger headers to work at all. They seem too long. I was looking at some sanders-type headers like these: http://www.sandersonheaders.com/pagesbypartnum/cc2.htm
Do you think that there will be clearance problems with this header?

Roy

Id definately suggest forgetting the 125 and go with the 60. I basicly threw a brand new 86GT away after putting about $7,000 worth of T125s in it with my V8.

quote Originally posted by mrfixit58: Is there any certain years of 4T60s to avoid for this swap because I've been offered a good unit that came out of a 91 Buick Centry?

Like I said before, the later units (91-92) are the best to go with. Like BWAYNE said, you might want to watch the Buick gearing as they tend to be a little more geared toward economy and not take-off performance. 3.1L W-bodies like the Lumina, Cutlass, and Grand Prix usually had 3.33 final drive with 1:1 ratio chain sprockets.

quote Darth - You mentioned custom axles... It was my understanding that the 440-T4 and the 4T60 used the same stock Fiero axles (with the larger tri-pots). Were BWAYNE's custom axles necessary because of the different engine/tranny adaptor?

The only larger tripod you need is on the driver's side. BWAYNE needed two custom-length axles because his engine/tranny were moved slightly to the left because of the adapter plate and the way the powertrain was mounted. IF you don't move the tranny any, you will still have to use a 94 Beretta 3100's stock LEFT axle as it is shorter than the Fiero. I have used the stock right axle from the same beretta in the right side as well just to keep things simple in my 4T60-E swaps but if I remember correctly the 440-T4/4T60 is slightly shorter on that side so a longer axle may be needed. Might be able to get away with using the stock left axle from a Fiero w/manual trans in the right side but you need to check your lengths. Like I said, I don't know for sure because the only 440-T4/4T60 swap I did was in BWAYNE's car which is a totally different animal compared to what I have seen.

Tell you what I would do. We know the 94 Beretta 3100/4T60-E left side axle is the right one no matter what OD trans you are using (as long as it is not a 60/65-E HD), but the right one is anyone's guess. We know the 125-C is shorter on that side so the stock right axle from a Fiero will not work. HOWEVER, there is no size difference as far as spline is concerned on the right side whether we are talking 125-C or OD unit. So, all you need to do is get the powertrain mounted in the car, put the suspension together on the right side without an axle in it and go out to your local junk yard armed with a measurement you took from the transmission to the spindle and look thru their stash of CV axles. The Fiero hub uses the smallest spline in GM which as does the Grand Am's, Cavalier's, amoung others. I have also heard the Pontiac 6000 axles may work but I have not tried them. If the Pontiac 6000 axles are compatible with the Fiero then you might be right on the money as the 6000 was offered with a 440-T4.

quote So, you left the gearing in the transmission 3.33? DO you know which chain ratio your using?

BWAYNE has the 3.33 final drive unit with the sprocket ratio of 1:1 so overall is still 3.33.

Thanks to everyone that posted to my question the information and opinions were very helpful.

I don't really hate to throw a wrench in the works here folks, so I'm inserting my 2 cents. I think a 4T60E totally defeats the purppose of a SBC. If you want a 4T60E, then stick with the 4.9, the 3800, or the 3.4. The 4T60E is a chain drive and I have broken (destroyed or disintegrated are better words) a 4T60E with a non-supercharged 3800 using a 2500 rpm stall converter. WHY on earth would any performance nut want a 4T60E with a SBC. And if you really want the advantages of the 4T60E, WHY do you want a SBC???????????? Makes absolutely no sense to me. OK. here I am folks - shoot me!!

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Tom Corey
Melbourne, FL
87 Green T-Top GT 5Spd SBC ZZ3 V8
88 Yellow T-Top GT, 4.9L Caddy, 4T60E

quote Originally posted by Tom Corey: I don't really hate to throw a wrench in the works here folks, so I'm inserting my 2 cents. I think a 4T60E totally defeats the purppose of a SBC. If you want a 4T60E, then stick with the 4.9, the 3800, or the 3.4. The 4T60E is a chain drive and I have broken (destroyed or disintegrated are better words) a 4T60E with a non-supercharged 3800 using a 2500 rpm stall converter. WHY on earth would any performance nut want a 4T60E with a SBC. And if you really want the advantages of the 4T60E, WHY do you want a SBC???????????? Makes absolutely no sense to me. OK. here I am folks - shoot me!!

Not going to shoot you but what do you think the 125-C has? It has a chain too. Sorry about your luck with the 4T60-E but there are several people running them and going fast without any problems. In fact, I would go as far as to say that they are the most reliable tranny you could put in a Fiero. Every month there seems to be another thread about how someone granaded their Isuzu or Getrag or 125-C, but I have yet to see massive 4T60/4T60-E/4T65-E/4T80-E failures. To put it in perspective, my 4T60-E only has a stock rebuild and it has survived 10,000 miles and several excursions down the 1/4 mile running 12's and I just pulled the pan at the end of last season and it was so clean you could eat off it, no clutch material or anything.

I have no doubt that if one tries, they can blow up just about any tranny using any engine. And I have 2 friends who rebuild them so I have heard many many horror stories about every type of tranny made by any automaker. However, with that being said, GM makes the best auto trannys and their FWD OD family is amoung the best in the world.

Not discounting your chain failure tho, it can and does happen... Just depends on the situation and how rough of a life that tranny had.

Darth - Thanks for the great detailed info. The car I purchased already was a running car until he started having engine problems. After that, it's been stitting for at least ten years. The V8 kit in this car is an older kit and a little different than I've seen. I uses the cogged pullys to turn the water pump like an Archie's kit but the tranny adaptor is made of steel and it looks thicker than the aluminum adaptor that Archie sells. From what the old owner said, the kit was purchased in 91-92. It's either an early version of Archie's kit or an early cheaper knock-off.

The owner said he had to have custom axles made and that the first two sets he broke. The third set was heat treated and they have held up well. My fear is that the axles won't work with a 4T60. I really don't want to re-make custom axles. I'll know more when I get around to pulling the motor this fall (hopefully).

Thanks again,
Roy

quote Originally posted by Darth Fiero: Every month there seems to be another thread about how someone granaded their Isuzu or Getrag or 125-C, but I have yet to see massive 4T60/4T60-E/4T65-E/4T80-E failures.

this could be because 370,000 fiero's didnt come with these transmissions...... just my opinion ya-know, but since less than 1% of the fiero community has these tranny's (maybe 2%) you probably wont see too much about them.

If your staying under 400HP then use your getrag it will be fine, unless you drive like tina For the most part, ladies tend to drive more cautiously, you may be an exception, but as long as your not power shifting it or anything i think the getrag will be fine.

the later model getrags were always better i think, but require alittle more to install them, but i hear a 282 getrag from a 92-94 cavalier/beretta is the best bet.

matthew

quote Originally posted by mrfixit58: The V8 kit in this car is an older kit and a little different than I've seen. I uses the cogged pullys to turn the water pump like an Archie's kit but the tranny adaptor is made of steel and it looks thicker than the aluminum adaptor that Archie sells. Thanks again, Roy

Archies automatic kit is Different from the manual kit. The auto kit is and always has been steel as far As I know. It is also 1.5 inches thick.

His manual kit is 1 inch thick. He told me he changed it over to aluminum 5 or so years ago.
So you probably just have an older archie kit. Which is the same as the newer ones for the auto.

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quote Originally posted by KissMySSFiero: Archies automatic kit is Different from the manual kit. The auto kit is and always has been steel as far As I know. It is also 1.5 inches thick. His manual kit is 1 inch thick. He told me he changed it over to aluminum 5 or so years ago. So you probably just have an older archie kit. Which is the same as the newer ones for the auto.

Well now.... That's interseting. The previous owner wasn't sure who he bought the kit from but when I mentioned V8 Archie, the light seemed to go on. If it is an old Archie kit, I wonder why he needed special axles? Again, maybe when I start to break it down, I shoot Archie some pictures and see if he has some ideas. I'm wondering if the previous owner installed the motor mounts incorrectly and, if corrected, I may be able to use stock axles.

Thanks for the info (big "+" for you),
Roy

My auto kit from Archie is a 2" thick aluminium plate. Its a big sucker. Unless he sent me a manual?? Might be LT1 specific, never did find out.

So, if I'm reading this right, A 4T60 will work with Archie's kit the same as the TH125?

i am sure i will be corrected here if i dont recall everything, i have tried to forget everything transverse as i like mr. garrison spent big bucks th125s. the 4t60 should be a much better trans than the th125 due to it having bigger clutch bands a o.d. or 4th foward gear. but i think the greater advantage is in the tuning of the trans with a v8. the weights on the governer are balanced for higher off throttle torque and the trans shifts off a vaccum modulator (which can be adjusted for varied shift points) instead of a tv cable. i think the radius control for the tv cable and some carb throttle brackets never really get perfectly tuned right causing to much power being applied to the engine and not enough fluid flowing through the valve fast enough and causing the bands and the clutch bands to overheat and fail. the 125 will seem alright for about 500 mile then the 2-3 shift will go out or the trans wont shift out of 1st. at least thats what happened with 5 of mine. so to answer your question, yes "i" think the 4t60 would be better than a th125 with a carbed v8. but you are opening a new dilema getting a true 400hp without some good flowing exhaust. the 400hp really wont be the problem its your peak torque is what is going to be the problem.
detuning a motor to get the trans to handle it, wouldnt be my choice of direction.

quote Originally posted by Darth Fiero: Not going to shoot you but what do you think the 125-C has? It has a chain too. Sorry about your luck with the 4T60-E but there are several people running them and going fast without any problems. In fact, I would go as far as to say that they are the most reliable tranny you could put in a Fiero. Every month there seems to be another thread about how someone granaded their Isuzu or Getrag or 125-C, but I have yet to see massive 4T60/4T60-E/4T65-E/4T80-E failures. To put it in perspective, my 4T60-E only has a stock rebuild and it has survived 10,000 miles and several excursions down the 1/4 mile running 12's and I just pulled the pan at the end of last season and it was so clean you could eat off it, no clutch material or anything. I have no doubt that if one tries, they can blow up just about any tranny using any engine. And I have 2 friends who rebuild them so I have heard many many horror stories about every type of tranny made by any automaker. However, with that being said, GM makes the best auto trannys and their FWD OD family is amoung the best in the world. Not discounting your chain failure tho, it can and does happen... Just depends on the situation and how rough of a life that tranny had.

It's becoming obvious that you folks just don't want to hear the truth! But I'll try again anyway. If you want a sports car (you know run through the hills and around curves), you really don't want a 4T60E or 440 or even the 125, you want/need a manual transmission. If you don't enjoy sports car driving or spend all your time driving on the interstate or in like downtown New York City for example, then I highly recommend the 4T60E. I have one in my daily 4.9 driver, I took it to Waterford last July and it has been to RFTH twice, but the 5 spd is more fun and better to drive in those situations. If you are considering a 4T60E you are welcome to try mine out first to see if it is what you really want. I will be at Daytona. or if you're in Florida, give me a call. If you personally like it, great - go for it. I'm just trying to pass you accurate and honest info on whatever subject I respond to in this forum. Take it or leave it.

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Tom Corey
Melbourne, FL
87 Green T-Top GT 5Spd SBC ZZ3 V8
88 Yellow T-Top GT, 4.9L Caddy, 4T60E

quote Originally posted by cardealer: the weights on the governer are balanced for higher off throttle torque and the trans shifts off a vaccum modulator (which can be adjusted for varied shift points) instead of a tv cable.

Actually on the 440-T4/4T60, the modulator only controls line pressure, the TV cable still controls all shift points. Tho you are correct that it is better as a modulator can better sense load via manifold pressure which will give your tranny that line pressure boost when the vacuum in the manifold drops.

quote but you are opening a new dilema getting a true 400hp without some good flowing exhaust.

Very good point. This is something that I have been trying to communicate to this board for a long time as there always seems to be a few V8 equipped Fieros that I see at car shows with high-HP "crate" motors and 2" exhaust. Got to flow the air before you can make the power.

quote Originally posted by Tom Corey: It's becoming obvious that you folks just don't want to hear the truth! But I'll try again anyway. If you want a sports car (you know run through the hills and around curves), you really don't want a 4T60E or 440 or even the 125, you want/need a manual transmission. If you don't enjoy sports car driving or spend all your time driving on the interstate or in like downtown New York City for example, then I highly recommend the 4T60E. I have one in my daily 4.9 driver, I took it to Waterford last July and it has been to RFTH twice, but the 5 spd is more fun and better to drive in those situations. If you are considering a 4T60E you are welcome to try mine out first to see if it is what you really want. I will be at Daytona. or if you're in Florida, give me a call. If you personally like it, great - go for it. I'm just trying to pass you accurate and honest info on whatever subject I respond to in this forum. Take it or leave it.

I see exacltly what your saying. But I simply cannot afford to replace gears/clutches/trannys all the time. It might not be as fun in your eyes. But im sure it will be a blast. AT least with this combo, I will have a little piece of mind. And if I wish to upgrade in the future, the options are there for both engine, and tranny. I totally agree with you on the manual is more fun argument. But I want to do smokey burnouts, floor it off the line, and find out its max speed. This can be done with a Getrag to a certain extent, but I wont feel easy doing it. Its my only car after all.