Do you own a 700r4 transmission? If you do, then you’ll want to read on to learn more design specifications and features of the 700r4 transmission as well as how to identify it.
Knowing your transmission specifications can help you make better choices regarding repairs and upgrades, and transmission identification is useful if you ever need service.
Whether you are just looking for information on or need transmission repair information, continue reading for all the details about 700r4 transmissions.
What is a 700r4 Transmission?
The 700R4 transmission is a 4-speed automatic transmission introduced by General Motors in 1982. It is based off the TH350 3-speed automatic transmission, but with an overdrive 4th gear that provides a 30% improvement in fuel economy compared to the TH350.
The 1st and 2nd gears got a lower gear ratio and the transmission case got slightly longer and bigger itself.
The 700r4 transmission would be found in many GM cars such as the Chevy Blazer, Suburban, Camaro, Corvette, Impala Oldsmobile Cars and many more. If we had to list every car model they installed the 700r4, it would be long.
The 700r4 is a durable transmission which is why so many people like it. It is also popular which makes it easy to find replacement parts for the transmission.
The 700r4 transmission is not electronically controlled, meaning it uses hydraulic pressure with a TV cable (which acts as the throttle position sensor) to control how the transmission shifts. In 1991, the 700r4 transmission was replaced with a more popular transmission called the 4l60.
The transmission from there on, became an electronically controlled transmission instead of a TV cable. There were also additional changes and I will go through that further into the article as I discuss the 4l60 transmission.
To conclude, the 700r4 transmission is a 4 geared hydraulic automatic transmission with the 4th gear which is an overdrive gear (30% increase). The 700r4 was made between 1982-1992. The case length is apprx 23.5″~ and would weigh apprx 170 lbs~ without fluid. The transmission case has 16 bolts and the transfer case is aluminum.
The recommended transmission fluid for the 7004r transmission is Dextron VI with a total capacity of 11 Quarts. The transmission is relatively reliable and has torque capabilities around 350nm~; but keep in mind, these are just reported numbers and could be higher or lower based on the age and maintenance.
K-Case Differences
The K-case 700r4 transmission was introduced with the “K” stamp on the case. The K-case 700r4 transmission was developed to work in heavy-duty 4×4 trucks, and it is thought of as one of the best-off road transmissions. The K-case is heavy-duty with a thicker transfer case.
How To Identify a 700r4 Transmission?
Most GM automatic transmissions look almost identical. It is difficult for new people to know which one they are looking at.
There is however a few ways to determine if you have a 200-4r, 700r4, TH350, or 4L60 transmission.
#1. Transfer Case Gasket Bolt Pattern.
The easiest way to figure out if you are looking up if you have a 700r4 is to raise your car and look at the bolts around the transfer case.
The 700r4 and 4L60 transmission have 16 bolts in total, so if the transmission looks like the picture and you can see 16 bolts the odds are you have the 700r4 or the 4L60 transmission. So how can you find out which one you have?
Well the 700r4 uses a TV cable as the speedometer and the 4L60 is an electronically controlled transmission, so if you can see wires coming to the transmission on the rear of the transmission on the passenger side you have a 4L60.
#2. Identification Tag.
The safest way to find out if you have a 700r4 transmission is to check the identification tag.
You will find the identification tag on the rear side of the transmission on the passenger side. It can be pretty difficult to see on older cars, so you may have to clean up your transmission to find it.
If you can see it well enough, there is an identification number that consists of 7-8 characters and letters.
The 1st number is the year model of the transmission. For example, if the number is 0, the transmission is from 1990. But it’s not so simple, because the transmission was made in the 1980’s also. So you will have to look at the next few letters also.
| 2 letters 80’s | 3 letters 80’s | 3 letters 90’s |
| 9 = 1982 | 6 = 1986 | 0 = 1990 |
| 3 = 1983 | 7 = 1987 | 1 = 1991 |
| 4 = 1984 | 8 = 1988 | 2 = 1992 |
| 5 = 1985 | 9 = 1999 | 3 = 1993 |
The next 2 or 3 letters are the model number for the transmission; they give us the application, the engine size, the wiring type, and the solenoids.
If you find two letters, the transmission is from 1982-1985.
If you find three letters, the transmission is from 1986-1993.
The last thing we can look for to tell if it’s a 4L60 or a 700r4 is to look at the rear of the transmission for the Aux TV Cable, or the wirings we talked about.
- Wirings = 4L60
- Aux TV Cable = 700r4
The ending letters and numbers are the manufacturer, rebuild, manufacture, and serial number.
These steps are everything you will need to identify your transmission properly. If you’re still unsure, please feel free to ask any questions about the 700r4 transmission in our community.
700r4 Trouble Shooting Guide
700r4 transmissions are tough and reliable, but they do break. We have to keep in mind that these transmissions are “old,” and old stuff sometimes break.
Here I will present some common symptoms of a bad 700r4 transmission, and add a short line underneath it to explain where to go next for the problem.
#1. Torque Converter will not lock and slipping.
When your 700r4 transmission is slipping, or will not lock, odds are its an issue within the torque converter inside the transmission. When your transmission slips, try first to replace the fluid, and may even want to do a transmission fluid flush. This should be done before going with more in depth repairs.
700r4 Transmission Fluid Level Checking
Get your transmission fluid up to temperature and let car idle in Park while checking the dipstick. If fluid level is low, see if you can fill it up to solve the issues.
When checking the fluid, if the fluid level looks dark red, brown, or even black, it is time for a fluid change and flush. Even if the fluid is fine and converter is slipping, I still recommend you change the fluid and flush your transmission as good mechanic’s practice.
There could be an issue with the converter itself and the converter will need to be replaced. Another possibility is the TV cable adjustment, that I will discuss further down in the article.
#2. Starts but won’t move.
If your vehicle starts but will hardly move, your first course of action is checking the transmission fluid level and condition (as noted previously). Make sure to check the level and the colour.
- Red = Good
- Brown = Bad
- Black = Bad
If you don’t see any problems with the fluid, you can check the adjustment between the throttle body and screw on your transmission television cable. Also, check your brake light switch is working properly.
#3. Speedometer does not work properly.
If your speedometer is not working, there are two separate types you need to know before starting to diagnose. There are both mechanical speedometers and electronic speedometers for 700r4 transmissions. You will have to determine if you have a mechanical or electronic speedometer.
With the vehicle raised, look at the back of the transmission. If you see a thicker cable coming out of the back of the transmission, then you probably have a mechanical speedometer. If you see a speedometer sensor, you have an electronic speedometer.
If you have a mechanical speedometer – you can check for issues with the speedometer cable. If there are signs of wear and tear, you can just replace it. These wires sometimes loosen from the instrument cluster sometimes, so make sure it’s installed correctly.
If you have an electronic speedometer – be sure to check the wiring between the cluster/control unit and the transmission and check for corrosion inside the connector. If everything appears in order with the wiring, then you’ll want to replace the sensor on the transmission. If that doesn’t solve the problem, there may be an issue with your instrument cluster.
#4. Vibrations during acceleration.
If you feel vibrations during acceleration, it’s most likely an issue with your driveshafts, prop shaft, or torque converter. If you feel vibrations all the time, and not just when accelerating, you likely have unbalanced tires.
#5. Not shifting properly.
If your transmission is not shifting properly, you need to check the TV cable adjustment, as described above. You will also need to check the transmission fluid level and replace the fluid if it doesn’t look good.
Common 700r4 Transmission Issues
There are several common ratel issues that you should always check first when you are troubleshooting your 700r4 transmission. These issues include:
#1. The Brake Light Switch.
First, there is a switch on the brake pedal that you should make sure is functioning correctly. There are two different variants: a combined switch that contains the brake switch and cruise control switch, or 2 or more individual switches.
Check the wiring diagram for specifics, and to find out if the switch is working correctly and there is power going to the switch.
#2. Worn TV cable/Adjustment.
Also, a common problem for the 700r4 transmission is a worn TV cable or faulty adjustment. Please make sure that you are using video above to properly set the TV cable adjustment. If you see any visible wear or damage on the TV cable, replace it!
#3. Low fluids level/Burned (fluids).
The 700R4 sometimes leak, which can result in low transmission fluid levels, so you should always verify the level first to be sure.
Sometimes people let their transmission go for many years without a transmission fluid change, which can damage the transmission due to not maintaining the vehicle. Check your fluid level. If it’s burnt or very dirty, replace the transmission fluid and flush.
#4. Poorly performing Select torque Converter.
Unfortunately, the torque converter is a common fault with the 700r4 transmission. These can be very expensive, and you need a certain amount of skill to replace.
If you have done the things mentioned previously and the transmission still slips, you may have to replace the torque converter. There are various YouTube videos on how to replace the 700r4 converter.
700R4 Transmissions for Sale
If you have found a serious problem with your 700r4 transmission, it may be time to replace the whole one. The great part about 700r4’s popularity is the parts are relatively inexpensive – both new as well as used parts. Also, you can find both used and new transmissions for a decent price.
Although, when you’re in a situation where you’re going to replace parts for your transmission, I always suggest going with new components as opposed to used parts. Most of these transmissions are already old and worn, and in most cases, it is worth buying new parts.
Bran New Transmissions & Parts
If you are looking for just any parts for your 700r4 transmission or a brand new transmission, I suggest checking out, if you are located in the USA or Europe, Amazon or eBay. They have many new parts for this transmission, many of which are quite good quality.
Just check the recent reviews from customers on the part to get a feel for the quality product.
Used Parts
If you’re looking for a used transmission, you can find it online. You may also find one at any local junkyard. Make sure to examine the transmission closely before purchasing it.
Always try to obtain as much information about the transmission as possible including mileage, how many times the transmission fluid was changed, etc.