The 700R4 and 4L60E transmission are not siblings. It is better to think of them as the continuation of the same design. From the early eighties until quite recently it has been in service in GM passenger vehicles and light trucks. Throughout that whole period, they have constantly improved.
When the 4L60E made it into production, it went to electronic control. This makes these transmissions incompatible with one another when looking to replace your transmission. There are solutions to get around this, but they aren’t very cost effective. Remember this, the biggest difference between these transmissions is computer control.
Here is the complete evolution of this transmission design through many names.
700R4– This is the original design that made its debut in 1982.
4L60- Same transmission as the 700R4. It’s still not computer controlled, but it is more desirable. This is due to the fact that it is newer and all the bugs were worked out.
4L60E- The 4L60E was almost identical to the 700R4 at first, but gradually began to look different as improvements were made.
4L65E Many Upgrades were made for reliability and power handling. If you want to know more about what they were, just click the article. It’s short.
4L70E– Even more improvements over the 4L65E.
Both transmissions use the same exact gear ratios with a final overdrive of .7:1, which is a 30% overdrive. This makes either of them a fantastic replacement for the TH350 and TH400 transmissions.
700r4 and 4L60E Gear Ratios:
- First- 3.06
- Second- 1.62
- Third- 1.00
- Fourth- 0.70
700R4 and 4L60E Differences
The biggest difference between these two transmissions is going to be the way that they are controlled. They identical in terms of length and where they bolt to the crossmember. The problem is that the 700R4 is controlled by the TV cable, which is basically just a basic throttle position sensor. The 4L60E, on the other hand, is controlled by computer. If you bolt it to a vehicle that is not computer controlled, it won’t know when to shift.
While they are physically similar, the 4L60 and 4L60E have many design improvements over the 700R4. The original 4L60E that GM started using in the early nineties looked exactly like the 700R4. They both used a one piece case. The 4L60E eventually adopted a two piece case. This let GM add different bellhousings to it easily, creating a more adaptable transmission.
It is possible to confuse an early 4L60E with a 700R4, since they use the same transmission pan and are virtually identical on the outside. By 1996 though, GM began moving to the two piece case that they use for their transmissions to this day. So realistically, if you are looking to tell if it’s a 4L60E or 700R4 it’ll only be difficult for the extremely early ones. There are two in depth articles on this site that can help you identify these transmissions down to the year.
Here they are:
If the only thing you are looking for is to tell them apart, use the info below. There are two primary ways of telling them apart:
- RPO Codes– The 700R4 will be stamped with the code MD8, while the 4L60E will have the code M30 on it. If the transmission is still in the vehicle, check for the code label and you’ll find the stamp on there to tell you what transmission is actually in the car. You’ll just look for one of these two codes on it.
- Plug– The 4L60E will have this nice and large plug for the vehicles wiring harness above it. This makes it nice and easy to identify. If it doesn’t have it, than it’s not a computer controlled transmission. Be aware that other GM transmissions use this plug. That’s why it’s good to use the RPO code too.
4L60E vs 700R4 Length
Both transmissions are 27 3/4″ long overall, and both mount to the crossmember in the same location. This makes swapping them for one another physically no problem at all. Since they are the same length, you can even reuse the driveshaft. You should still try and find the transmission that was originally intended for your vehicle, since some are made to handle more power or different engines. Of course you could just go aftermarket and not have to worry about that at all.
When swapping one of these transmission for each other, far and away the most difficult obstacle that you are going to face is how the transmission itself is controlled. With that in mind, from a cost perspective the 700R4 is cheaper to put in place of the 4L60E than vice versa. There’s a lot of good info about it in the LS swap transmission guide.
Really, it’s better if you have a motor that already has a 4L60E to keep it, or vice versa. The only time that it might be worth doing is when you are doing a motor swap, and the transmission is still in the car. You’ll need adapters to make any of this work. For more see the LS swap guide.
700R4 to 4L60E Swap
Swapping a 700R4 out for a 4L60E is going to require an independent transmission control unit. They cost a couple hundred bucks. You than program some information about your vehicle into the unit, add a throttle position sensor, and you are off to the races with your 4L60E.
4L60E to 700R4 Swaping
Putting a 700R4 behind an LS series motor is a popular swap option. You’ll find that you need to find a bracket to bolt the tv cable to. Some people put it on the gas pedal. There are some aftermarket kits available depending on the vehicle. After that the ECM will need to be tuned to not care about the transmission, or I’ve heard there can be stalling issues. If you are going to put a 700R4 where an LS engine was, you’ll need to buy a spacer so that the torque converter will engage properly.
700R4 versus 4L60E strength
These transmissions had a 25 year production life between the two of them. As far as which one is stronger from the factory, the 4L60E is stronger. They improved as time went on. So, it’s better to get a later 4L60E than an early one. The same holds true for the 700R4. Examples from the early nineties are much stronger than ones from the 80’s. If you end up buying either one from the aftermarket, it won’t matter at all. They will be plenty strong. All of the kinks have been worked out for quite some time.
The naming of these transmission causes quite a bit of the confusion people have with these transmissions. A lot of people are confused by the 4L60 name. The 4L60 is the 700R4, just a later model. GM switched the transmission naming nomenclature to a more standardized format during the 700R4’s life.
So the 4L60 means:
- 4 forward gears
- Longitudinal drive (rear wheel)
- 60 is a representation of the torque it’s supposed to handle
The E in 4L60E is for “electronic”, which signifies the transmissions need to speak with a computer to work.
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