4L60E Transmission Problems after Rebuild - What's Wrong?

General Motors presented the legendary 4L60E transmission in 1992 and was making it up until 2013. The transmission was installed in so many car models that we won't even try to publish the list because you will be bored reading it. We've counted 40 models of GM and its partners that used this transmission, so it was extremely popular. Even now, a lot of cars are on the road with this transmission.

4L60 transmission highlights

• Average lifespan:230,000-250,000 miles
• Reliability Score:High
• Prone to minor issues:No
• Price for repair after failure:$1,000-$1,400
• Price for replacement:$2,500-$3,700
• Availability of parts:Good
• Common problems: Solenoid issues, friction plates wear, fluid pump issues, overheating problems.

How many miles do 4L60E transmissions usually go?

This is a key question because you should know when you will need to have the transmission rebuilt. The average lifespan of these transmissions should be considered at 120,000 miles. That's not bad and not good, just the average longevity.

It means that somewhere near this mileage, you will need to have the transmission repaired. By repair, we mean rebuilding because if someone takes apart the automatic transmission, they should replace some parts that are likely to break down soon.

We should say that the GM 4L60E transmission is quite simple in its construction and is not very expensive to repair and rebuild. Parts are still available and you will not have problems finding a good specialist. But still, you will have to pay some money. The average price for rebuilding this transmission is about $1000. It's not expensive if you compare it with other trannies, but still, that's not a little money.

What problems can happen after the 4L60E rebuild?

We've asked technicians and owners and come up with a list of some most common issues that may happen after the rebuild and may need proper reaction on your side.

Here are some of them:

• No reverse. Most likely, the mechanic has done something wrong and because of this, the clutches don't work as they should. It means the transmission needs reassembling.
• Punches when shifting. You will most likely feel these punches when shifting from the 1st to the 2nd gear. It means something is wrong with the fluid or maybe the clutch system in the transmission.
• The transmission goes mad, the speedometer reads zero. This is a problem with some sensors like VSS, for example. Its readings are superbly important for the proper work of the transmission.
• 3rd and 4th gears are missing. If your 4L60E transmission only operates in the first two gears, the clutches for the 3rd and 4th gears are not working properly.
• Only manual operation is possible. If your transmission doesn't shift automatically and also the CEL light is on, it's more than possible that the transmission is in limp mode. You should have this checked and diagnosed.
• The transmission shifts between the 2nd and 3rd gears only. This is the problem that has something to do with the PCM. A good diagnosis will answer all your questions immediately.
• Horrible sounds from the transmission when driving. This will most likely be experienced on highways. Clutches may have been installed incorrectly and now overrun issues are presented.
• No movement at all. If your engine works properly but the transmission doesn't engage any gears and doesn't move the vehicle, the issue is possible with the fluid or pump.

Whatever happens, good diagnostics is the key to success. You should check it up properly and understand what's going on. Unfortunately, nearly all of these issues may happen right after the rebuild and you will likely need to have the transmission removed and diagnosed again.

How to avoid these issues?

Sometimes, the 4L60E transmission is so badly destroyed that you should avoid investing more money in it. Buying a rebuilt transmission will be a good option in your case. If you try to rebuild the transmission after it's completely dead, you will invest a lot of money with poor results.

Also, choose a good mechanic for this. Inexperienced guys will happily take your money but they can't offer good results. Make sure your mechanic knows what to do with this transmission.

Also, avoid economizing money on liquids and parts. Good fluid and optimal rebuild are extremely important for the health of your transmission. If you pour inappropriate liquid, your transmission will live a couple of miles and then may need another rebuild.

Keep in mind that after the transmission has put on over 300K miles, it's not worth repairing anymore. It should be probably replaced.

Why do transmission problems appear after the rebuild?

In most cases, a transmission rebuild should help you get rid of possible issues and keep driving your vehicle for at least 100,000 miles without any transmission problems. But this doesn't work out in all situations. Very often, drivers report serious transmission problems and mishaps after they take their vehicle from a service station, right after a transmission rebuild.

This may mean that some job wasn't done perfectly or some parts were chosen without proper knowledge. We have to be careful and only let professionals work with our vehicles.

Here are the most possible reasons why this may happen:

• Your transmission is pretty old and has a lot of miles on it, so after a thorough lookup, the specialist should have recommended you buy a new transmission and replace your old one.
• The parts are of poor quality. You may have used the wrong parts or maybe used parts and this could lead to problems. Some parts are just not working properly.
• The mechanic lacked knowledge. A lot of people who say they are mechanics and do work for little money appear to be newbies in transmissions and just can't repair or rebuild these complicated units.
• Something was wrong when assembling the transmission. Even if the mechanic forgot to check the bolt tightness, this could easily lead to problems.
• The mechanic forgot to check the fluids. No transmission will work properly without a proper amount of fluid in it. This is the key factor for all trannies, and this is why your transmission could have failed.

It may seem like a crazy idea to you - to forget to pour some fluid into the transmission after rebuilding. But this is not a rare situation as you may think. We've seen people buying new transmissions after they tried to drive their cars with empty rebuilt trannies.

Anyway, you should check everything twice before you take your vehicle for a test drive. We know for sure that a small mistake can lead to bad consequences.

What to do if your transmission fails after the rebuild?

First of all, we would go to the mechanic who did the labor and would ask them what the problem may be. A good mechanic will certainly be responsible for the work they've done, so in most cases, they will agree to diagnose the vehicle. Sometimes, the problem is very straightforward like a forgotten sensor or missing wire connection.

But in many cases, the problem will need taking off the transmission for repairing or even diagnosing the issue. Before you agree, find out the possible price of these actions. In many cases, you may find a decent replacement transmission on the market that costs exactly the same as the labor for your old transmission.

If the automatic transmission has more than 200K miles on it, the best way is to replace this transmission if all other units of the vehicle are OK and keep working like new.