Timing belt tensioner questions

[rollingon]

Following my recent timing belt query, I have an Aisin timing belt tensioner on my 1998 Volve V70 XC AWD turbo. This is the one that comes from FCP under the following part number; Aisin (OEM) 9146693. I'm replacing my timing belt after only 40,000 miles (when the tensioner and rollers were also replaced) because the water pump, which was replaced at the same time, has failed. I have been intending to keep the tensioner, which I understand can be good for 140,000 miles. It seems to work properly, and I was able to remove it from the car easily by loosening both bolts, and pushing it to the left. It looks fine and has the white collar in place around the piston. I have pushed on the piston to see if/how easily it will compress, and it will not push in under considerable pressure, though I stopped short of trying too hard to make it compress. I also don't have the steel retaining pin it would have had with it when it was initially put in the car.

From what I have described, does my tensioner sound like it is in good working order? I am not intending to push my luck with it, but as it is relatively easy to replace, unlike the water or oil pump, I feel it should have a lot of miles left in it, and I don't feel the need to spend money on an unnecessary replacement just because the part is out of the car now. I would replace it if it had been in the car for two timing belts, or even just one, but it has barely done 40,000 miles. Does that sound reasonable?

How difficult should it be to compress the piston on this tensioner if one wanted to locate a retaining pin through the hole in the piston?

Thank-you.

[Ozark Lee]

From your description and based on the relatively young age of the tensioner I think it should be fine to reuse. Re-compressing the tensioner should be done very, very, slowly. If you have a large vice that will work or you can use a pipe style clamp or a very large C clamp.

When I re-compress a tensioner I turn the clamp until it puts up decent resistance and then repeat again after several minutes. On my clamp I turn the clamp handle about 1/4 turn per iteration. Keep repeating the process until the holes line up. You will need to remove the plastic spacer before you start and you can use a small hex key to retain it after it is compressed.

...Lee

[cn90]

Here is a comprehensive DIY I wrote recently...

DIY: 1998 Volvo S70 Timing Belt Overhaul, Water Pump, Cam Seals, Serpentine Belt Overhaul:
https://www.matthewsvolvosite.com/forums ... hp?t=53722

You seem to know your stuff, so I won't bother with detail. To lock the Hydraulic Tensioner, use a drill bit to lock it.

This is the consensus from this forum:
- TB ~ 80K-90K
- WP (Aisin or Hepu) ~ 140K-180K
- TB Pulleys x2 (INA) ~140K....when I removed these at 148K, they made a bit of noise, had slight play but still somewhat serviceable, although they are on borrow time.
- Hydraulic Tensioner: 140K-180K.

PS: I need to find the exact cause of your TB jumping teeth!

[erikv11]

I totally agree with what has been posted; just to clarify Lee's post: in total it will take like 15 minutes to compress the tensioner.

[donis222]

I think that this 5 min. wait between compressions is not necessary. These units are like shock absorbers with springs. Therefore when they have moved x amount within seconds the fluid has transferred.
What is important is the pressure used to compress the cylinder rod.
I take around 5 minutes to compress a tensioner, but never use more pressure than my initial effort, i.e. when I fell the pressure increase -Stop and wait 15 seconds. This means that my vise gets an 1/8 of a turn then momentary wait, then the same original effort to go another 1/8.
This is intuitive, but I have changed many belts (some 2 times) without ever replacing a tensioner.

I have changed a number of serpentine belt tensioners, as they get flex from the load changing a lot.
The timing tensioners have virtually a steady pull at RPM. Sure, we can feel the cam load and unload from the springs. This is a very smooth load at running speed. The momentum probably reducers load to constant, hence they rarely wear out.
Remember, Volvo's service manuals are designed to sell parts. It used to be design that they designed parts so they can be rebuilt cheaply. That ship sailed even before Ford got their fingers on the philosophy.
FYI: I used to rebuild starters for the cost of brushes, 1 bushing and the bendix or override clutch. The solenoids copper washer was made to turn over and be like new. The contact bolts rotated 180 degrees and it was good as new. Brushes and a new front bushing and you were good to go.
Today most solenoids won't even come apart!

[Ben850]

This is what a bad tensioner looks like after you compress it.


When I saw oil in the top after removing it, I dried it off and compressed it again. The fluid was indeed coming from inside the tensioner.
I don't know how long it was bad for, but there was a noise coming from the front of the engine that I couldn't figure out. It was the tensioner pulley bouncing on the bad tensioner. The plastic retainer clip saved the valves. (engine)

I use the C- clamp method.

**Photos are not loading at the moment. I'll try later.

[cn90]

I happen to own a 2007 Honda Odyssey van, and Aisin also makes WP and Hydraulic Tensioner for Honda vehicles.

In contrast to Volvo HT, which typically lasts some 140K-180K, the Honda Odyssey Van HT sometimes goes bad at 60K-80K range.

For those who want to know what noise a bad HT can create, here you go. It sounds like a "valve train noise". This video has clips of 2007 Honda Odyssey Van has clips of "before" and "after" replacement of HT: