Put simply, a transmission clutch pack is made of round friction lined pieces that can be squeezed together to engage a particular gear. Transmission clutch packs allow modern automatic transmissions to shift through multiple gears quickly and smoothly. So let’s take a closer look at how they operate and what happens when they go bad.
What Transmission Do I Have?
Anatomy of a transmission clutch pack
A transmission clutch pack typically includes 6 – 10 friction lined clutch discs and an equal number of smooth steel discs placed in between. The outer edge of the ‘steels’ have a notch pattern that fits into the outer edge of the clutch drum. The clutch discs have a smooth outer edge, but the inner edges are notched so they lock into place with a ring gear. When no pressure is applied, the clutch discs and the steel discs can spin independently of each other. But when the clutch pack is called into action, pressurized transmission fluid pushes a piston that squeezes the two types of discs together. This causes the ring gear and the clutch drum to spin the two together in the same direction.
Things that can damage a transmission clutch pack
Because of the friction material bonded to the outside of the clutch discs, they can be very susceptible to damage and premature failure. The two biggest contributors to automatic transmission clutch failure are dirty transmission fluid and excess heat. The dirty transmission fluid can contain dirt, metal fragments and other contaminants that can seriously damage the friction material. That dirty transmission fluid will also be very thin and unable to remove heat from the clutch pack. This excess heat can cause the friction material to delaminate from the clutch discs, as well as cause the steel discs to warp.
Symptoms of a bad automatic transmission clutch pack
Slipping – The transmission may not be able to hold a gear and slip back into neutral
Delayed gear engagement – Due to the bad clutch discs, the transmission may not be able to engage a gear very quickly
If you have a bad automatic transmission clutch pack, you’re going to need a transmission rebuild at the very least. But if you plan to keep your vehicle for a while, investing in a remanufactured transmission might be a better option.
How much is it going to cost to fix my transmission?
Unfortunately, the problem described here will require the removal and disassembly/partial disassembly of your transmission. Given the labor time involved to remove the transmission from the vehicle (this is not a simple task), most repair shops will recommend that you go ahead and rebuild the entire transmission while it’s out. Since they already have to tear it down, it sort of makes sense to spend the extra money to do that. After all, you should get a lot more mileage out of your transmission once it’s rebuilt. And since they’ve already got the transmission apart, might as well, right?
Things to consider with a transmission rebuild
You’re the test driver – Most transmission repair shops and mechanics will only put a few miles on your vehicle to make sure the transmission works. But it’s not uncommon to experience transmission problems during the break-in period.
Everything might not be fixed – Most mechanics and transmission repair centers don’t have the equipment necessary to perform a thorough inspection on hard parts like gear sets, clutch drums and valve bodies. This means that your rebuilt transmission could actually have small cracks in key parts that aren’t visible to the naked eye. As time and mileage progress, these cracks can grow and create an even larger problem. Similarly, a slight warp in the valve body can seriously impact shifting performance over time.
Warranty – Although most mechanic shops and transmission repair shops will warranty their work. That coverage is usually only good at the shop or franchise that did the work. If you travel out of town and suddenly experience transmission problems, you’ll be on the hook for any transmission repairs unless you pay to have your vehicle towed back to the shop that did the work.
Quality – Nearly every time you get a transmission rebuild, all of the work is performed by a single technician. This may or may not be a good thing, depending on your point of view. But the end result is dependent on that technician’s level of experience working with your specific type of transmission. In addition, there is usually no standardized quality control checks at a mechanic shop. So an improperly torqued bolt or gasket that isn’t fully seated, might be overlooked and cause you major problems in the future.
Why a remanufactured transmission might be a good option
If you plan to keep your vehicle for as long as possible, then getting a transmission rebuild is certainly a viable option. However, a remanufactured transmission is a much better alternative. You’re getting as close to a brand-new transmission as it is possible. Companies like Street Smart Transmission also modify the transmission to correct all of the factory design flaws, allowing you to get a much longer service life from the transmission. You also get a 3-year/unlimited mile nationwide warranty, which allows you to get necessary repairs performed at any licensed repair shop of the country. So in terms of value for the money, a reman transmission might be the better way to go.
Remanufactured transmission companies like Street Smart Transmission put each of their reman transmissions through a rigorous build process that ensures a quality product every time. It starts with nearly 100 trained technicians that specialize in different aspects of the build process.
This remanufacturing process begins with the inspection team that test all of the critical components from the donor transmission to ensure that they meet the original equipment (OE) tolerances and specifications. The case, pumps, gears, shafts, valve body and torque converter are checked for hairline cracks, metal tensile strength, warping and other parameters. If any component fails to meet the required specifications, it’s discarded and replaced.
All the parts are then cleaned and sent to the appropriate stations on the assembly line for reassembly. Throughout the process, quality control managers inspect the build to ensure that it meets the desired specification. Any necessary modifications or upgrades that are needed to correct factory design flaws are also performed or added. The valve body is rebuilt and tested on a special dyno machine to ensure that it performs according to the specifications. All of the solenoids are also tested prior to installation.
Once the build is complete and passes its final quality control inspection, the newly remanufactured transmission is sent to the dyno room, where it’s tested on a special dyno machine using a proprietary software program called C.A.R.S. (Computer Aided Real-world Simulation). This cycles the transmission through a number of real-world driving situations, to ensure that it performs according to the factory specs. It also helps to break in all of the friction components, that way it’s completely tuned and ready to go once it’s installed.
Warranty – One of the benefits of buying a remanufactured transmission vs. a rebuilt transmission is the warranty. Street Smart Transmission for example, covers all of their reman transmissions with a 3 Year/Unlimited Mileage Nationwide Warranty (there is a mileage restriction for commercial vehicles). This covers parts and labor for transmission repairs performed by any licensed repair shop in the country. It’s also completely transferable if you ever decide to sell the vehicle. Compared to a mechanics warranty on a transmission rebuild, a remanufactured transmission warranty offers superior financial protection.
What Transmission Do I Have?
Is a remanufactured transmission worth it?
If you plan to keep your vehicle for as long as possible, then getting a transmission rebuild is certainly a viable option. However, a remanufactured transmission is a much better alternative. You’re getting as close to a brand-new transmission as it is possible. Companies like Street Smart Transmission also modify the transmission to correct all of the factory design flaws, allowing you to get a much longer service life from the transmission. So in terms of value for the money, a reman transmission might be the better way to go.
