S70 Timing Belt Replacement Update (Long)

I changed the timing belt & associated other parts over the weekend on my ' 99 S70, and thought I'd share some observations I made during the process to
help others contemplating "doing it yourself". :)
(Many thanks to Tim C. for sending me the detailed instructions for the mechanical tensioner version!)
First off, let me say that there is confusion here in the states regarding hydraulic vs mechanical tensioners on 1998-2000 S70's. Although I have seen info on the web that Volvo switched from hydraulic to mechanical tensioners sometime during the 1998 model year, specifically with engine # 1266128, both Volvo dealers here in San Diego state that this is not a certainty. They cite instances of servicing 1999 S70's with hydraulic tensioners. Anyway, mine has the mechanical, but I didn't end up buying the parts until I had the cover off, which meant I had to pay dealer prices.
This car just turned 105K miles; which is the recommended service interval for the timing belt according to my manual. I wouldn't normally wait the full interval, but at my last plug change at 90K, the timing belt looked OK. (It still looks OK, with only very light cracking under sharp bend) Can't say the same for the serpentine belt; it should have been replaced a long time ago.
Since I had it apart, I decided to replace all moving parts:
- Serpentine belt
- Timing belt
- Tensioner
- Idler pulley
- Water pump
Total bill for parts = $ 450. The water pump was the most expensive item. Total time = 5 hours. (if I had to replace just the timing belt on my S70 again, I believe I could do it in under an hour; maybe as quick as a half hour)
Preparing for this work, I brushed up on the general procedure with the Volvospeed, Bay 13 info for an 850. Let me just say that the 850 procedure is really not relevant to the S70. I'm glad that Tim sent me the info, as it helped out dramatically.
I have seen numerous references that the belt can be removed without removing the crank pulley. I investigated this first, which ate up a half hour of my 5 hours, and I believe that it is either not possible or a total, royal pain in the ass. The reason is that there is a fuel line that runs just under the lower belt cover that is not there on an 850. I investigated loosening the brackets for the line, but still it wouldn't move much. So I gave up and went the "remove pulley" route. (I only really spent the time to see if could easily be done)
Let me just emphatically state that if you have an impact and a 6" puller, the "remove pulley" route is the ONLY way to go! Since I was timing everything, I noted the time when I started to remove the pulley. It took me exactly two minutes to remove it, which included marking the crank nut. It was far easier to remove than many other cars I have worked on. Note that I used the impact to remove the four bolts as well, which speeded things up. The pulley is only on with a very light interference fit.
A comment on timing marks. The Volvo engineers really did a horrible job on the crank end. With the pictures on Volvospeed of the 850 with hydraulic tensioner, you can see the mark pretty readily. With the later mechanical tensioner, the belt angle obscures your vision, so you cannot see it straight on. Why didn't these dumbasses put the mark directly vertical, i.e. at 12 o'clock position? Then you could be assured of no parallax error. Anyway, with the mark aligned with belt off, the roll pin on the pulley is at 12 o'clock, so you can use this as a check after belt installation.
The only tedious part of the job was the water pump. This took me the longest time of all. It has seven small screws with sealant material on the threads, which take a long time to remove. (I would have used the impact ratchet, but by this time it was late at night & didn't want to wake the wife & kids. I have a big 5HP industrial two stage compressor mounted in the loft of the garage, & it tends to shake the house a bit when it runs) Removing the pump naturally leaves part of the gasket on the block, which took forever to remove. Additionally, it takes a bit of fiddling to figure out how to get the pump out of the general area. Hint, move it to the right, then up to clear at an angle. Plus, even though I drained most of the coolant, I still ended up with a big puddle of coolant when the pump was removed.
Inspecting the water pump, tensioner, and idler, I determined that all were still serviceable, but wouldn't feel comfortable that any of them would make it another 50K miles, let alone another 105K. BTW, when I was at the Volvo parts counter, a mechanic came up to the counter for parts, noticed the tensioner in my hand, and said "you are replacing that when you replace the belt, right?) I stated I was, and he said, "good, there was a problem with them blowing up after 100K, so Volvo now recommends that the tensioner be replaced along with the belt." I told him that I was replacing the water pump and idler too, and he said "if it was my car I was working on, I would do the same thing"
After fiddling with the belt for about 15 minutes, unsuccessfully trying to fit it, I came up with a trick that made the job far easier. (The problem was I couldn't apply any tension to the belt on the crank to intake cam side without the belt invariably slipping off the crank end a tooth.) I went to the wood scrap bin & pulled out a short piece of 1/4" thick hardwood, and wedged it between the lower belt cover and the belt (at 6 o'clock position on the crank pulley), which held the belt tight against the crank. Now I could apply tension to the belt, slip it on the intake cam pulley, then back down at the tensioner, then the water pump, finally the exhaust cam pulley. (note; I held the tensioner pointer to the right to give it more slack) With this trick I was able to fit the belt in about a minute with no hassle or obscenities.
Adjusting the tensioner is quite easy, using a 6 mm hex key rotating it against the stop, then back until the pointer reaches the middle slot (between the tabs). Then rotating the crank a couple of times thru & recheck that it hasn't moved.
One cautionary note; I noticed as I was turning the crank in the final steps that the belt had picked up a small blob of oily mess from the seepage around the crank seal. While it was not large, any oil on the belt is not good, so I would recommend thoroughly cleaning around the lower crank area to prevent this from happening. Plus, if I was doing it again, I would replace the crank seal at the same time. (it is not leaking per se, but there is a bit of seeping going on.)
Jeff
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