Thursday, February 23, 2012

"It lives once again!" Volvo D24t timing belt replacement update


Almost a year ago, I wrote about a somewhat obscure project car I rescued/bought.  My 1985 Volvo 740 turbodiesel - powered by a Volkswagen-made 2.4 liter engine which Volvo called the D24t - drove fairly well when I bought it, but was way overdue for a timing belt. The belt had over 100,000 miles on it and was over fifteen years old, which is a recipe for failure. When timing belts fail in these engines, they become scrap metal: the valves will hit the pistons and the party is definitely over.

Over the next few months, I bought the parts I would need:
  • Volvo OEM timing belt which I ordered through Tasca.
  • Bosch water pump: these are preferred by enthusiasts over the more widely available GMB pumps, but can be tough to find. Oddly, I found it at Amazon.com (link opens to product.)
  • Gates T082 timing belt, for injection pump. I also found this at Amazon.com. They have a lot of very hard to find parts for these cars.
  • Valve cover gasket set, again at Amazon.com. I have since read that the updated rubber design is much preferred over this cork style, but I have not experienced leaks yet, possibly because I used a film of Hylomar sealant on the gasket.
  • Oil seals for the camshaft. These were leaking profusely on my engine. NAPA and other parts stores list the wrong parts; they will sell you the seals for a redblock/gasoline Volvo, which can be incredibly frustrating. I finally found the seals at a local import shop; you can use the seals for a Volkswagen diesel engine. The part number is 026 103 085 D - same for front and back of camshaft.

Click "read more" to continue after the jump.





Overall, the job was not terribly difficult. As long as you have a few special tools and follow the instructions, it is doable. Special tools I needed included:
  • crankshaft damper holder, Volvo part number 9995187 (or simply 5187), which holds the damper stationary when loosening the bolt. There isn't really any substitute for this tool. I borrowed one from a forum member who was kind enough to mail it to me for a deposit.
  • Plate to hold camshaft in proper TDC position: the Volvo manual calls for tool number 5190 (9995190) but it is easily substituted with VW tool number 2065A as long as you unscrew the studs at the rear of the head, which isn't a big deal at all. You can find this tool on eBay.
  • Dial gauge for timing the injection pump: It must be the correct size. I also found this on eBay.  
  • Don't forget that you will need the adaptor/stand so that you can screw the dial gauge into the injection pump. Volvo tool number is 5194, easily substituted with VW tool P/N 2066. I found these to be rather expensive on eBay, and eventually found them for much less- shockingly- through Snap-On. You can buy tools off this website even if you are not a dealer or mechanic, just register for an account. The tool I received was a genuine Audi/VW tool. Link here. Note that if you use a non-genuine adaptor you might have to remove the vacuum pump from the block for clearance: not a big deal, but still an extra step.
  • If you don't have one already, you'll need a tool to hold the cam pulleys steady when you loosen the bolts. If you rely on the 2065A plate or the belt, you run a significant risk of breaking the camshaft, which is generally a bad thing. The Volvo number for this tool is 9995199 (or 5199), and it is widely available because it is also used on many gas engines. But I was able to get by easily with a universal pulley holder like this one. 
  • I did not find the 9995197 (listed in the manual as just 5197) necessary. It is important not to overtighten the belt, but it obviously shouldn't be flopping loose, either. It should not make howling noises. Here is a video from a very reputable D24t mechanic.
I experienced a lot of confusion when attempting to time the injection pump, probably because I have never done anything like this before. A forum member at D24t.com (extremely helpful site!) posted a video on YouTube that really helped me figure out how to do it. It's important to note that you don't actually have to loosen the pump, though. It is much easier to simply move the sprocket on the back of the camshaft to adjust the timing. Once you figure out how the process works, it's really ridiculously easy.
The most valuable tool for this job is the Volvo "green book" service manual! Available here for free download: part 1, part 2, part 3.

I won't write up a How-To - if you're this far, you have probably already read about it on D24t.com and read the relevant green book pages. But here are some highlights:




Installing the new Volvo OEM timing belt. Routing is self-explanatory. The belt is tensioned using the water pump.
Using the 2065a camshaft timing plate, along with a feeler gauge to compensate for timing gear clearance per green book.

Timing the injection pump. I set mine to .95, which is higher than Volvo spec but generally recommended by enthusiasts.

The end result is fantastic! The oil leaks seem to be gone thanks to the new camshaft seals, and the car runs so smooth you can't even tell it is running except for the unmistakable diesel sound. Smoke is nearly non-existent.


I just filled it up with B10 biodiesel and it's running super! Hopefully the engine has another 216,000 miles left in it; I would love to find a 740 or 940 wagon and do a transplant. If you own a wagon with a bad engine or transmission, or know where I can find one, please let me know!






    3 comments:

    1. nick, thanks very much for the post. i have a D24t which is currently in need of a(nother) head job. problem is, i'm not having much luck finding someone reputable here in houston with the knowledge and tools to do the job. i've already put quite a bit of money into an engine rebuild about 5 years ago prior to moving to UK, so car hasn't been driven much since then, however, the mechanic who performed the rebuild did an awful job, which lead to overheating as a result of warped cylinder head, cracks b/w almost every intake/exhaust seat, severe damage to 7 of 12 buckets, etc. i have video of this for further details, which i'm happy to pass along to you if you provide an email address. otherwise, many thanks in advance for any recommendations you have to offer.

      john (john.beal@hotmail.com)

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    2. Hi John, sorry I didn't see your comment sooner.
      Finding someone with the knowledge and tools is indeed very difficult. I tried to find a shop in my area (Columbus, OH) to do the belt. Nobody I contacted was even willing to try.

      If you haven't already, go check out www.d24t.com. It's a small but active forum and many members are very knowledgeable and helpful. I'm no D24t expert and these guys helped me do a quality belt job.

      I have heard that the D24t's are just not very tolerant of subpar rebuilds. It sounds like it might be easier to just swap your motor out for a used one. Car-part.com is useful for finding used motors, it's essentially a salvage yard directory.

      That being said, I have also heard that some head cracks in these engines are harmless. I don't know enough details to advise you on how to assess your head though, that's where D24t.com would come in handy. I'd post those videos there.


      Nick

      ReplyDelete
    3. I just got my self a 745 wagon with the d24td engine 4spd overdrive gearbox .fantastic car... but have to do timing belt/water pump etc .nervous as hell !! Jimmy

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