The first generation Chevy Tahoe was a very popular full-size SUV. But it suffered from unusually harsh 1-2 upshifts. So let’s take a closer look and find out what might be causing the problem.
What Transmission Do I Have?
What is causing your Tahoe 4L60 hard shifts?
Back in 2002, GM issued a technical service bulletin; TSB 01-07-30-023B, which you can read right here. According to their engineers, there was a problem with the 4L60 control valve body that made the powertrain control module/PCM command maximum line pressure, causing the unusually hard 1-2 shift.
This problem happens because the bores inside of the valve body which houses the TCC isolator and regulator valves, can develop premature wear. This can result in hydraulic leaks that can keep the torque converter clutch/TCC from either not applying fully, or not at all. When this happens, the check engine light and DTC P1870 will be triggered.
The Solution
In order to fix this common Chevy Tahoe transmission problem, the entire valve body will need to be replaced with a later design. But if the problem is not caught in time, the maximum line pressure can result in further damage to the transmission, as in torque converter damage, clutch damage, and metal shards and debris circulating throughout the transmission.
Replacing the valve body is no easy task, and if there is further damage to the transmission, you may want to just consider replacing the entire transmission with a quality remanufactured 4L60 transmission from a company like Street Smart Transmission.
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? Well let’s take a closer look and find out.
Why a remanufactured transmission might be a good option
While you might not be able to buy a brand-new transmission for your particular vehicle, a remanufactured transmission is a terrific alternative. They’re completely reengineered from the ground up and put together on a factory assembly line. They often contain a lot of upgrades over their stock form, which means that many of the design flaws that result in premature failure of components, can be eliminated. This can give a reman transmission a much longer service life than it originally had.
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 begins with nearly 100 trained technicians that specialize in different aspects of the build process.
Once the build is complete and it passes the 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?
So is a remanufactured transmission worth it?
If you plan to keep your vehicle for as long as possible, then getting a rebuilt transmission is certainly a viable option. However, a remanufactured transmission is actually a much better alternative in the long run. You’re getting as close to a brand-new transmission as possible. Companies like Street Smart Transmission also modify the transmission to correct all of the factory design flaws, which allows 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. To learn more about the remanufactured transmission for your vehicle, click here.
