[torqhead]

After paying others to build auto transmissions for me I decided Covid would help me learn how to work on automatics since once again I found myself on the side of the road. Keep in mind this is the 4th build on this transmission.

I've worked on cars for 40+ years and worked on every part of a car, including manual transmissions but never an automatic. Well now that I've actually opened up a 700R4, I would confidently say it's nuts to put one of these transmissions behind anything that makes any power. The main input shaft to aluminum drum is the weak point. And contrary to using a sonnax reinforcement ring, it's just a plain waste of time. Take a look at the pic and you'll see why as I had the reinforcement ring installed in mine. All the power goes into the main input shaft that's pressed into the aluminum drum, the input shaft is 1.1 inch's thick. Seems like a basic physics problem to me...

So I've decided not to install this back in the car and looking at putting a 4L80 in place. Anyone ever done this swap? I searched the forum first before asking here., don't yell at me if my search skills suck. I would like my factory speedo and quadrajet in place. Any guidance would be appreciated.

[OCMDGTO]

T400

[Chief of the 60's]

Hmmmm……

Pulls the wheels and goes high 10's on a 10 year old 700 with plenty of street and interstate miles. I guess it takes the right builder.

[78w72]

Originally Posted by Chief of the 60's

Hmmmm……

Pulls the wheels and goes high 10's on a 10 year old 700 with plenty of street and interstate miles. I guess it takes the right builder.

hmmm...

pulls the wheels & goes low 9's with a 200r. guess it takes the right builder.... didnt you say 200r were junk?? there are countless 200r doing low to high 10's & stockers doing 11's. any tranny can support big power with the right build.

wish we could tag members, i think hwystr455 has or has done a 4l80.

[ErikW]

Just ticking time bombs

[Sirrotica]

To answer the OPs question, yes there is a thread by Half Inch Stud (Mark) of documenting pulling a T400 out of his 68 GTO and replacing it with a 4L80E:

http://forums.maxperformanceinc.com/...d.php?t=823023

He did the conversion to make his full manual, to circumvent buying a controller and wiring harness. If I'm not mistaken he also used the stock GM convertor, and retained the lockup feature. The lockup is is good for roughly 100 RPM reduction at cruise speed.

BTW, I did some calculations just yesterday, and for under $2300, you could buy a good working used 4L80E, install a Trans Go 4L80E, HD2 shift kit, and buy a aftermarket convertor, plus a top of the line controller and wiring harness. That unit in good working order would be plenty sufficient to handle 700 ft lbs, or 700 HP, with stock parts. If you're going to be exceeding that point, a new billet input shaft is recommended.

Most 4L80Es will run between 150,000 and 300,000 miles before rebuilding, if you were to find a used one with low miles, or one that had recently been rebuilt you could probably use it for sometime with just the installation of the Trans go HD2 shift kit, before having to rebuild it, if you are on a shoestring budget.

With the shift kit it will improve some of the factory shortcomings, raise the torque and HP rating, and further extend it's useful life. It's your money, and car, so you should make the call.

I know for a fact that there have been many of us on this forum that have put used T400 transmissions in our cars with satisfactory results, so putting a used 4L80E in, isn't a far stretch, since the internal workings are the same, except for an added OD unit designed by the hydramatic division of GM.

Also the T400/4L80E has been around GM cars and trucks for over 50 years, it's a well thought out design and proven to be able to be used in vehicles up to 18,000 lbs in stock configuration.

Here's another thread on an average Joe rebuilding his 4L80E on a GM truck site:

https://www.gmfullsize.com/threads/t...-4l80e.315433/

Here is an article from Super chevy on installing a 4L80E into a 67 chevelle:

http://www.superchevy.com/how-to/tra...-installation/

Jakes performance makes 4L80E convertors in house, and is one of the best prices I could find when doing the cost analysis for a shoestring budget. Jake also used to be one of the top 200 4R builders in the country, before he decided that the 4L80e made more sense, and switched his business model over to to specializing in these transmissions:

http://www.jakesperformance.com/

This is a quote directly from Jake's site:

4L80E
REAL power with reliability
Have you broken a Level II, V, or MXXVII 4L60E that is supposedly 700 HP capable with 450 HP? Multiple times? Have you ever read a build list for a 4L60E/65/70 and wondered why it sounded like everything in the trans was replaced for a performance build? That is because it’s the wrong unit to use in a big power application. We’re not here to mislead you. We could build and sell a very well built 4L60E that would compete with anybody’s on the market. But there is more demand for 4L80s, so business wise, it makes sense to pursue that market. We specialize in 4L80Es because we KNOW it is the only real option for REAL power with reliability.

Other builders are afraid to cut into their sales and tell you this. We’re not. We just want to be sure you get the strongest option available at the best price the first time. If this makes sense to you, take a look at our 4L80E options below.

The 4L80E is the descendant of the “Ole Reliable” TH400 transmission. It shares many components and design features. At Jake’s Performance the 4L80E is our most popular transmission. We have built them for applications ranging from heavy towing vehicles to 1800+ HP street/strip cars. The 4L80E has proven reliable like it’s predecessor.

Hopefully this will help you out to swapping what I consider the best possible 4 speed OD transmission into your car.......

[Formulajones]

Originally Posted by torqhead

After paying others to build auto transmissions for me I decided Covid would help me learn how to work on automatics since once again I found myself on the side of the road. Keep in mind this is the 4th build on this transmission.

I've worked on cars for 40+ years and worked on every part of a car, including manual transmissions but never an automatic. Well now that I've actually opened up a 700R4, I would confidently say it's nuts to put one of these transmissions behind anything that makes any power. The main input shaft to aluminum drum is the weak point. And contrary to using a sonnax reinforcement ring, it's just a plain waste of time. Take a look at the pic and you'll see why as I had the reinforcement ring installed in mine. All the power goes into the main input shaft that's pressed into the aluminum drum, the input shaft is 1.1 inch's thick. Seems like a basic physics problem to me...

So I've decided not to install this back in the car and looking at putting a 4L80 in place. Anyone ever done this swap? I searched the forum first before asking here., don't yell at me if my search skills suck. I would like my factory speedo and quadrajet in place. Any guidance would be appreciated.

4L80E in the A-body is a piece of cake.

Not sure who you plan to use or what direction you're going, but since you're like me and want the factory speedo to work/hookup like OEM I've only found a couple of places that offer that option. Hughes is one and I believe Jake is the other. They make their own tail housings for the 4L80E and then machine the output shaft to accept the drive gear, so it's an option you need to opt for during the build process, otherwise you're pulling the entire trans down to access the output shaft for machining.

I ended up going with Hughes for a couple reasons. Their prices were hard to beat and they are local to me as well. I went for their stage 1 850 hp 4L80E, with mechanical speedo option and a US Shift Quick 4 controller. Hughes was running a 10% off sale for orders placed at the show (Goodguys) so I took advantage of that. I'm sourcing the converter and some other parts separately.

As far as the year/model of trans and where the cooler lines are located, that used to be a concern for a couple reasons but they have been addressed.
One was GM changing to the rear cooler line for better lubrication. That's not really a big concern now as most all of these transmissions shops make their own internal lube updates on the older models so it doesn't matter anymore. I talked to Hughes in depth about this. As long as that's done, the older model with both front cooler lines is a great option.
The other concern, if you want the later model trans with the rear cooler line, is room to install the fitting as it gets pretty close to the floor back there. That was a problem years back but they now make banjo fittings to address the issue.

US Shift as well as others offer various TPS sensors to mount up to different carbs and EFI so that's pretty easy to deal with now.

The swap is pretty straight forward, other than the typical cross member and driveshaft differences that are self explanatory.

[Bluesugar]

Thanks for that info Sirrotica, and
Happy New Year!!

[Sirrotica]

Originally Posted by Bluesugar

Thanks for that info Sirrotica, and
Happy New Year!!

You're quite welcome, and Happy New Year, right back at ya.

[torqhead]

Thanks Brad and Larry for the info. As for the others that responded:

There's an OD requirement as I drive this car 3-4000 miles a year easily and as proponents of the 700R4/4L60 I can only assume your vehicles are much lighter or you've been very lucky. I've done enough research and confident this isn't a builder issue, plain and simple you can't put decent power through a 1.1 inch shaft and expect it not to break, especially going into an aluminum hub. Sonnax supposedly makes a steel version but you can't get them and it doesn't address the 1.1 inch input shaft issue which can't be changed or increased in diameter due to design of the trans.

I've always been a fan of the 700R4, I put it in the car back in 1990 before the 4L80 was around but as I said, now that I've seen the guts it's foolish to think you can put any good Pontiac torque through it especially if you put sticky tires on and if your car is heavy.

Now I know sometimes people get a little snippy on here, I'm not interested in a lengthy debate, just my humble opinion and my 4200 lb car has tested this and consistently won!

[Cliff R]

GN's breaking 200's, I remember those days only too well. I was cutting my teeth on GM OD units from day one and the Buick GN's certainly found ALL the weak spots in the little 200's. I was pretty well known for making them work well so typically had a nice line of them outside the little makeshift garage attached to my house I was building them in back in those days.

At pretty low power levels they broke EVERYTHING inside of them, pump rings, stators, sun shells, planetaries, fwd drums, bands, smoked clutches and the single disc converters didn't last much longer than it took me to type this as the GN crowd locked them on the 1-2 upshift so cease all torque multiplication to maximize boost/torque with those little engines. You could be the best "builder" in the World and still get one right back in your lap.

The factory and the aftermarket stepped up with improvements to the "weak" areas so they fair better these days than they used to. By 1986 GM had figured out some of the hard part issues and the GN's got improved valve bodies with better shift programs and improved holding power in the drums. The aftermarket has filled in the gaps with billet internals to address hard parts breakage and improved holding power for the band over what the GN servo can supply.

I still don't get a "warm and fuzzy" with them and still seeing them having issues. Even so I broke my own rules and built one a couple of years ago for a friend of mine who owns a 1984 Olds 442. At the time he had a 350 in it about 350hp, then he upgraded to a 425 around 450hp, and as I type this is building a 455 around 500hp for it. It's bothering me not in the least because the build I did for him came with my exclusive "Arkansas Warranty"......"If you break in in half.......You get BOTH halves!"

Anyhow, had another customer recently have some grief with his 200-4R. He purchased one of my custom converters for it with a multiple disc TCC. The trans was purchased by one of the bigger names in that industry telling him it was it was full of all the latest upgrades and good for a zillion HP or so. The first day he was test driving it behind his pretty stout SBC engine he decided to go to full throttle rolling along in OD about 40-45 mph. Turned out to be an INSTANT death sentence for it. He had to pull it out and send it back as he twisted one of the shafts right out of a drum. Never did get the exact details on all of that but I was glad my converter held up fine! I also remember him telling me he got a "lecture" from the folks that supplied it about NOT repeating that scenario as it takes parts spinning very slowing to about a zillion RPM's almost instantly, which is never a good thing.

Just goes to show you that even full of the latest and greatest parts and most meticulous preparation you just never know when and where you are going to find the weak link......FWIW.......Cliff

[Sirrotica]

It's also telling when going onto some of the light truck sites that the ford and dodge guys are swapping 4L80Es into their high HP/torque build trucks. Of course an Allison is the next step up if you're serious about building a truck for high performance use, but the 4L80E is stronger than the best ford and dodge have to offer.....

[mgarblik]

I think your really saying, "do I want to be on the very ragged edge of disaster with a 4L60 even with upgraded parts, or comfortably in the wide service window of a 4L80 trans". Other than the weight penalty of the 4L80 trans and a little tighter fit, who wouldn't want a transmission that starts out 30-40% stronger from the factory as determined by the engineers who designed it?. At 4200 Lbs. with Pontiac torque, the 4L80 would be my choice. Good luck with the swap.

[sjdiesel]

I swapped in a 4l80e in my 1967 GTO and love it! I bought mine from Vons Transmissions in San Bernardino and bought a torque converter from Tri Shield Performance. I used a USShift controller that works great! Super easy to hook up and tune. I was running a quadrajet so had to buy a TCI throttle position sensor. No big deal.

The install is pretty easy. I opted to purchased a replacement crossmember that fit perfectly! Also did a Dakota digital digital to mechanical speedo converter.

A must is these cooler line banjo fittings. That is probably the tightest part of the trans tunnel and the banjo fittings make it possible. I bought these, some stainless 5/16 tubing and a couple AN fittings. I bent them up to come out in the same location as my TH400 cooler lines did from the factory. Cut my factory cooler lines, installed AN fittings and it works perfectly!

https://www.ebay.com/itm/6AN-x-1-4NP....m46890.l49292

Here’s a list of parts I put together before I did my swap:
Transmission
converter
Dipstick
Remote TPS (TCI 377450)
USShift Quick 4 & harness
Trans crossmember (RCAE-4)
Shiftworks brackets
Cooler fittings
Stainless Cooler tubing
Trans fluid
Dakota digital Mechanical speedo converter
Driveshaft

BTW I am selling my USShift controller and TPS because I am switching over to EFI and the Holley system has all the trans controller stuff. PM me if you’re interested.

[torqhead]

Originally Posted by sjdiesel

I swapped in a 4l80e in my 1967 GTO and love it! I bought mine from Vons Transmissions in San Bernardino and bought a torque converter from Tri Shield Performance. I used a USShift controller that works great! Super easy to hook up and tune. I was running a quadrajet so had to buy a TCI throttle position sensor. No big deal.

The install is pretty easy. I opted to purchased a replacement crossmember that fit perfectly! Also did a Dakota digital digital to mechanical speedo converter.

A must is these cooler line banjo fittings. That is probably the tightest part of the trans tunnel and the banjo fittings make it possible. I bought these, some stainless 5/16 tubing and a couple AN fittings. I bent them up to come out in the same location as my TH400 cooler lines did from the factory. Cut my factory cooler lines, installed AN fittings and it works perfectly!

https://www.ebay.com/itm/6AN-x-1-4NP....m46890.l49292

Here’s a list of parts I put together before I did my swap:
Transmission
converter
Dipstick
Remote TPS (TCI 377450)
USShift Quick 4 & harness
Trans crossmember (RCAE-4)
Shiftworks brackets
Cooler fittings
Stainless Cooler tubing
Trans fluid
Dakota digital Mechanical speedo converter
Driveshaft

BTW I am selling my USShift controller and TPS because I am switching over to EFI and the Holley system has all the trans controller stuff. PM me if you’re interested.

Sean, thanks for all the great info! I really like the nice job you did with the cooler lines and will steal that idea! I'll PM you.

[JLMounce]

I just wish the 4l80 had a taller overdrive. With a 3.73 axle and a 26” tire you’re still close to 3000 rpm at 75 mph. I can get decently close to that by doing a low gearset in my th400 and swapping to a 3.08.

This is one of the things that drove me to having a 4l60e built. I’ve never installed it though simply because of these threads. I just don’t know how it’ll hold up, if at all.

[Sirrotica]

Originally Posted by JLMounce

I just wish the 4l80 had a taller overdrive. With a 3.73 axle and a 26” tire you’re still close to 3000 rpm at 75 mph. I can get decently close to that by doing a low gearset in my th400 and swapping to a 3.08.

This is one of the things that drove me to having a 4l60e built. I’ve never installed it though simply because of these threads. I just don’t know how it’ll hold up, if at all.

The difference between the two transmissions is 5% that takes you from 3000 RPM down to 2850 RPM. Is it going to make that much difference for the tradeoff of strength?

There are plenty of chevy/LS guys that will probably buy the newly rebuilt 4L60E transmission from you.

The difference is wear factor, the 60 wears much quicker than the 80, all things being equal, same goes for the other automatic ODs, which I won't name. One wears quicker than the other just due to the engineering designed into the original transmission. Even if there isn't a catastrophic failure, the clutch/band surface area is much more from the start. I already posted the 4L80E was designed for up to 18,000 lb vehicles, no other GM OD has anywhere near that GVW rating.

[torqhead]

Originally Posted by JLMounce

I just wish the 4l80 had a taller overdrive. With a 3.73 axle and a 26” tire you’re still close to 3000 rpm at 75 mph. I can get decently close to that by doing a low gearset in my th400 and swapping to a 3.08.

This is one of the things that drove me to having a 4l60e built. I’ve never installed it though simply because of these threads. I just don’t know how it’ll hold up, if at all.

I know we talked about this a few years ago and I was still trying to have faith in what I was being told by some of the "best builders" in the business. You might recall one of them, Performabuilt, sent me two that ended up being POS' from the get go. Those two I didn't include when I said 4. these were actual failures post initial install and operation. The last one built was done correctly, it just took out the weak link.

I kind of wish I knew more about the internals sooner as I probably would have bailed a while ago. I've seen post that indicated the 4L60 wasn't up to snuff, but don't ever recall anyone taking the time to explain the weak point, hence why I put it on the post. Every bit of power from the motor to the rear wheels goes through that "weak link" part. Ironically it failed when it hit 3rd gear on a decent pull even though it was on street tires. Amazing I didn't strip it out when we were at Bandimere in Sept

I'm running a 29" tire which helps on RPM...

[Half-Inch Stud]

Been enjoying the 4L80 behind the 470 PMD.
Recommend 4L80 due to TH400 pedigree with OD and improvements. Obvious.

I think you can get lucky enjoying the factory Gasoline Converter as-is. Diesel converter i dunno.
Promised meself a 2-clutch high stall 4L80 converter, but NOT Needed. Think i saw 25 rpm and maybe 50 rpm drop for unlock-to-lock at highway cruise.

If you can find the Vacuum Modulator kit $100-$130 then you can be confident in manual-shift approach. I did, and would never add a processor. Shifting is stupid optional with a 455, but hey i like 1st gear and like to fast-flick to 2nd. In 3rd pretty quick (like a TH400). So pulling away in 2nd or 3rd becomes a feel-like-it choice..

Be sure to get a 4L80 with "TH400 location" cooling line pair. The other case type puts cooling line back too far to enjoy connecting. Yet, also be sure to get a 4L80 Core that has not been cooked. Coworked got a nuclear-brunt unit that melted-fragged the rear planets from driving home in 2nd gear for 1/2 hour.

[pastry_chef]

Originally Posted by torqhead

Performabuilt

Performabuilt one of the best?
LMFAO.
I guess some are easily swayed by verbal claims, marketing etc. Many out there talk about being great. Very very few are.