You have heard of 4-speed, 5-speed, and even 10-speed transmissions. But what on earth is a 5 and 4 transmission?
But first, what Is a 5 and 4 transmission? Is it like a 5-speed and 4-speed transmission meshed together?
A 5 and 4 transmission is a twin-stick shift manual transmission system used in old vehicles like Peterbilt and Kenworth trucks. This was introduced in the 1980s and slowly faded out of the market.
In this article, we will go over 5 and 4 transmissions thoroughly while keeping it simple.
What Is A 5 and 4 Transmission?
A 5 and 4 transmission is a manual twin-stick transmission that allows gear changes using two levers or sticks.
A twin-stick transmission is a type of manual transmission that features two shift “sticks” rather than one. In a twin-stick shift setup, there is an additional stick that breaks each main gear into further gear ratios.
This means when you apply the first gear in the main gearbox, you can break that first gear into four different speeds using the second stick.
In a 5 and 4 twin-stick transmission, one stick is a standard H-type manual transmission with five speeds. The other stick is used to split these five speeds into four modes. So, you can split each of these speeds into four gears using this lever.
The second stick is sometimes called an auxiliary shifter. Twin sticks have many configurations like 6+4, 3+2, 5+4, etc. Mitsubishi also has twin stick shift transmission but it’s not a 5 and 4 type. It had a supershift with a 4+2 configuration.
Another popular twin stick shift transmission was the Rambler ‘63 one. It made a splash with the electronic overdrive system with a twin-stick shift. But it was not a 5 and 4 type. It had three regular speeds with two sticks offering a total of five forward gears.
How to Shift a 5+4 Transmission?
One of the main questions regarding a 5+4 transmission is how to shift them. Since two sticks are not common these days and most people drive automatic cars, it can be quite intimidating.
Here we will go through the gear-shifting pattern in an accessible manner. As mentioned before, there are two shifters; one primary and another auxiliary.
A dashboard light will indicate which mode was chosen in the auxiliary shifter. Shift timing and coordination between the two gear shifters are essential for smooth gear changes.
Source: Chevy Trucks Forum
Now, see the picture above, it’s the gear-shifting pattern of a 5+4 transmission. This particular shifting pattern is for 72 GMC MH9500. Below is a generic procedure of how to shift gears on 5 and 4.
Step 1: At first go to 1st gear on the main stick, then go to 1st gear on the auxiliary shifter.
Step 2: After that, you need to release the clutch and drive. You can shift up to the 4th on an auxiliary stick.
Step 3: Now after fourth gear in the auxiliary stick, you shift both sticks, main into 2nd, aux back to 1st, and continue on up.
Step 4: The next 3 shifts are up on auxiliary. So, shift to 2nd, then 3rd and 4th on the auxiliary stick.
Step 5: Now after arriving in 4th on aux, you can shift both sticks; main in 3rd and aux to 1st.
The gear ratio for these gears is quite close to one another. They give you more power than speed.
Vehicles That Have 5 And 4 Transmission Systems
Some Ford heavy-duty trucks including the Ford F150, Peterbilt 359, 1980 Kenworth, and some Toyota off-road vehicles have this type of transmission.
5 and 4 twin-stick transmissions are typically found in heavy-duty trucks, off-road vehicles, and some sports cars. This type of transmission is not commonly found in recent production vehicles and it’s not as common as regular manual transmission with one stick.
Are There Any Advantages Of 5+4 Transmission?
A twin-stick 5+4 transmission will give you a lot of choices when it comes to gear ratio and speed. It has a versatile range and this gives the vehicle a lot of towing power. At the same time, this type of transmission will produce a lot of power.
The additional gear ratios provide better heavy load handling capacity in adverse driving conditions. This makes it an ideal choice for commercial heavy-duty trucks and towing, and hauling vehicles.
Why the 5 and 4 Transmission Is No Longer Popular?
5 and 4 dual stick transmission was discontinued and you will see it rarely on a truck. This is because the complexity of this transmission type makes it hard to operate for drivers.
At the same time, the maintenance of this type of transmission will be more frequent than a regular manual transmission. There are reliability issues as well. The gear shifting on the 5 and 4 transmissions is a complicated process.
To get to the top speed you might have to go through a lot of gears. Drivers who want top speed quickly will skip a few gears. However to skip you have to be an extraordinary driver who has good control of the shift timing.
Now if you miss a shift, there will be a kickback and sometimes it can even injure your wrist. Overall it is a demanding transmission and drivers often complained about having cramps or stiff shoulders.
Summary
5 and 4 transmission is no longer popular since it’s hard to drive and requires physical strain.
Can You Get A Two Stick Transmission?
Yes, you can modify your vehicle’s transfer case together with a twin-stick shift. Some gearheads tried with an NP205 transfer case and added a twin-stick shifter. The transfer case provides necessary gear ratios for different driving conditions.
JB Custom Fabrication offers Twin-Stick Cable Transfer Case Shifters for 260$- 475$. Using these components you can get a twin-stick transmission if you have expertise. It is a time-consuming process and for an expert, it takes 3-4 hours. The labor cost if you hire a mechanic is $1,100 to $2,800. Installing Twin Shifters from JB Custom Fabrication [Diesel RHD TJ Wrangler – 67]
FAQs
Can a Car Have 2 Transmissions?
Yes, a car can have 2 transmissions, and it’s called DCT or dual-clutch transmission system. In a DCT, two transmissions work together. It uses two separate clutches for odd and even gears. They are commonly found in sports cars, supercars, and high-end luxury vehicles.
How Big Is A Quadruplex?
Mack Quadruplex, the 18-speed transmission comes in two sizes; TRQ7220 and TRQ770. A quadruplex transmission will typically be larger than a simple two-speed transmission, but smaller than a six-speed or eight-speed transmission.
What Is A Spicer Transmission?
Spicer transmission is a brand of vehicle transmission known for durability and reliability. They are designed to withstand harsh road and driving conditions. Spicer transmissions come in manual, automated manual, and automatic types.
Bottom Line
In this article, we tried to clarify the definition of 5 and 4 transmission systems. Even though it is rarely used now, it shows the engineering design craze of the 1980s. It is recommended to drive this transmission only for experienced heavy-duty truck drivers.
