It’s not unusual for manufacturer design flaws to cause major problems for owners down the road. Such is the case with the 2002 – 2013 Chevrolet Avalanche 4L60E transmission. Owners experience a complete loss of reverse, fourth and/or second gears. All due to the weak metal used in the reaction sun shell.
What Transmission Do I Have?
Okay, so let’s get this out of the way first. According to TSB 00-07-30-022D, which you can read right here, this problem affects the following trucks:
2002 Chevy Avalanche
2003 Chevy Avalanche
2004 Chevy Avalanche
2005 Chevy Avalanche
2006 Chevy Avalanche
2007 Chevy Avalanche
2008 Chevy Avalanche
2009 Chevy Avalanche
2010 Chevy Avalanche
2011 Chevy Avalanche
2012 Chevy Avalanche
2013 Chevy Avalanche
All of these trucks will have been equipped with either the 4L60E or 4L65 transmission.
The Problem
Alright so, the 4L60E transmission uses this sort of cylinder shaped bowl to house planetary gear sets, which give you the different gear ratios. This thing is called the reaction sun shell, and at the very top of it are teeth that the sun gear is threaded into. Unfortunately, the 4L60E reaction sun shell is made from a very weak metal, and those teeth that the sun gear fit into, can break off, allowing the sun gear to spin freely. When this happens, you’ll lose the aforementioned gears, and all those metal shards will circulate throughout the transmission causing damage to everything from seals to the valve body.
The Remedy
Obviously General Motors recognized their mistake and issued a much stronger heat treated reaction sun shell. But of course, the entire transmission has to be torn down, inspected for damage, and reassembled with the new part. This isn’t going to be a cheap process, and you might as well rebuild the entire transmission while it’s out. However there are a few things you should consider before doing that.
How much is it going to cost to fix my transmission?
Unfortunately, the problem described here is going to require the removal and disassembly/partial disassembly of your transmission. Given the labor time that will be involved to remove the transmission from your 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.
Things you’ll need to think about before getting a transmission rebuild
Who is actually doing the work? – Years ago, automatic transmissions were fairly similar in their design. But now, each manufacturer’s take on automatic cog swapping can be so unique that it would give NASA scientists a headache trying to keep up with the differences. That’s why taking your modern vehicle in for a transmission rebuild can often yield different results each time.
There are many qualified mechanic’s out there who can do a stellar job rebuilding a transmission. However finding those mechanics is often a hit-or-miss situation. This leaves you reliant on your particular technician’s level of experience working with your particular type of transmission. Plus there are no standardized quality control checks at a mechanic shop. So if the technician doesn’t torque a bolt exactly to spec, or misses a gasket that isn’t properly seated, you could literally be paying for that mistake in the long run.
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. So at the end of the day, you may be spending several thousand dollars on a ticking time bomb.
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, which can be annoying, time-consuming and potentially dangerous. If you’re going to spend several thousand dollars getting your transmission repaired, you shouldn’t have to be inconvenienced by more transmission problems.
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 in the first place.
What Transmission Do I Have?
Is a transmission rebuild 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. 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.
