Toyota Tacoma 3.4L V-6
The Toyota 3.4L engine timing belt is due to be replaced at 105,000 miles or every 8 years. These engines are not a interference engine, meaning that if the timing belt happens to break the pistons will not hit the valves. On an interference engine if the timing belt happens to break, the pistons will hit and bend the valves causing catastrophic engine failure and possibly needed replacement. I am not for sure but believe that most all Toyota engine’s are freewheeling engines (non-interference). This doesn’t mean that you should wait till the timing belt breaks to replace it though.
When replacing the timing belt on this engine I wanted to share a very cool tool that helps cut at least an hour out of the replacement time on these engines. The timing belt tensioner is a hydraulic tensioner. Take a look below to see the two different type of tensioners.
The hydraulic tensioner has to be removed and compressed so you can insert the locking pin and install the belt. You would usually use a big bench vise that opens wide or a shop press that can compress the tensioner. I personally have always used the bench vise. On the Toyota 3.4L engine you have to remove the Air Conditioning compressor and compressor mounting bracket just to get access to the tensioner for removal to compress it. The tip I’m going to show you today is a special tool that you can put between the water pump and tensioner pulley to compress the tensioner on the car and avoid having to remove the A/C compressor and A/C mounting bracket. When compressing the tensioner I have found it best to insert the pin and slowly compress the tensioner while pushing the pin until you feel it drop in it’s slot. There is a rubber grommet in the way so you cannot really see when the pin holes line up. I will usually compress the tensioner all the way then slowly back it out while pushing the lock pin in until it drops in it’s slot. That is it, you have now shaved off and hour of timing belt replacement time. The job pays 3.8 hours and with this tool you can complete this job with experience in about 1.5 hours. I’m not sure what the deal is with Toyota and there timing belt tensioners but on the Mid 90’s Lexus V-8 engines have the same deal. You have to remove the A/C compressor to gain access of the tensioner. That’s it for today, I have displayed a image gallery below for you to take a look at the tool and how it’s used for this job. This particular tool is a Snap-On or Bluepoint but I’m pretty sure that if you look around you can find the same tool from another manufacturer. They do not have a patent on the tool. The only other problem you may run into is holding the harmonic balancer for breaking free and tightening the crankshaft bolt. This bolt is torqued at over 100 ft lbs so good luck. I have a special harmonic balancer holder but for years have got around it by a couple of different ways.
Front Crankshaft Bolt Removal & Installation Tips
- Hold the harmonic balancer with a large set of channel locks, be careful to not damage the drive belt grooves
- Gain access to the flywheel and hold it in place with a wedge or flat bladed prybar, this way requires two people.
- Remove the radiator and use an impact gun on the front crankshaft bolt. This is a time killer if it’s a AT transmission because of the cooler lines.
- timing belt tensioner compressor mounted between the water pump and tensioner pulley.
- example of a timing belt tensioner lock pin for hydraulic tensioners
- Tensioner compressed with lock pin installed.
- here is a better view of the timing belt tensioner compressor.
- Blue Point Tensioner Part# YA9730
What else would you recommend changing if I’m doing the timing belt and water pump already?
Check the timing belt tensioner and idler pulleys and also replace the cam and front crankshaft seals if they are leaking. If you replace the seals get them from Toyota, they are not that expensive.
Timing belt broke on 1999 Tacoma 3.4 engine. How do I line up the timing gears before installing new belt.
If you cannot identify the timing marks then I recommend to buy a service manual or timing belt book. Both cam pulleys and crankshaft sprocket have timing alignment marks. Line up the crankshaft first then the cam gears. After installation of timing belt rotate 2x’s and recheck timing marks.
I understand (from watching a YouTube video) that if the tensioner is removed prior to installing the timing belt, that it makes the installation of the belt much easier. I purchased a new tensioner anyway.
Yes you have to remove the tensioner to compress it anyways unless you have the special tool that compresses the tensioner from the water pump pulley. If you buy a new tensioner it should already be compressed.
Great blog! The content is indepth and informative and all readers have something to learn! We all hate repairing our timing belt. This blog gets 5 out of 5 from me! Well Done.
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