Post by
DAEDALUS »
https://forums.nicoclub.com/daedalus-u128.html
Sun Sep 01, 2002 3:07 pm
For anyone considering doing the job themselves, here's an email I sent out a bit back...Feel free to downright disagree if you think I've made any errors.
Chain guides can be a real bear if you run into any snags, but they are straighforward (but time consuming) if you understand the process and have all the right tools. I will send you a few emails, as I don't think I can cover it all in one sitting. Are you an experienced mechanic or a weekend DIY'er? I'm a learning-as-I-go type.First of all you will need the manual. Not a lot there for this job in particular (they didn't think it was a design flaw, afterall) but the information is mandatory and can be boiled down from what's in the EM section (1st 40 pages or so, I think).Hopefully your guides are fine and none of them are in your oil pan. If they are in the pan, I'm not sure you can get them out without removing the pan.
TOOLS NEEDED Garage tools (jack/stands or ramps, creeper, etc) Common metric sockets (8, 10, 12, 14, 15, 17, 19mm) plus a large one (30 or 31mm I think, not entirely sure) for the crank bolt. You will use the 10mm the most by far. See if you can measure the crank bolt if you don't yet have sockets that large. No sense buying tools you won't need. I'll take a look later to see what I have in my garage. Ratchets and 10 mm wrenches. 18" breaker bar and an extension pipe. The installation of the main bolt requires about 270 foot lbs of torque, so I figure 90 lbs of force on a 3-ft bar will do. A 300 ft-lb torque wrench (maybe). These can be bought or rented, but I just estimated the torque using the 3 X 90 feel. There's always some "margin" built into designs, so I'm probably OK even if I missed the range a little. Large puller--I used one from Sears, about $30. It has done the trick 3 times so far. A 5mm allen wrench socket. This is CRITICAL. We lost an hour the last time I did this job because we didn't have this tool. A chain wrench with a chain long enough to wrap around the main pulley. I used a Sears strap wrench the first 2 times I did this job, but it did fail on me the 3rd time. Whatever you use, you will need a 2nd extension pipe for this as well. If you use a chain wrench, you'll need some scrap fan belt material just long enough to wrap around the pulley. Other common shop tools--pliers, vise grips, magnetic tool pickups, etc.
PARTS NEEDED This will depend on whether you want to replace the timing chains or not. Keep in mind that replacing the chains will take 2x as long, as you will need to remove the valve covers to do it. This may be necessary anyway, as the valve covers tended to leak after several years. The chains *should* last well toward 300k. Mine are at 213K. Scottsdale Infiniti (infinitipartsusa.com) sells a chain guide kit for about $500. This includes the tensioners, chains, sprockets and gaskets you'll need to do the entire job. BUT, if you don't want to do the chains, then just buy the other stuff. I had a post on the old NICO forum about the parts list:http://www.nissaninfiniticlub.....html You won't need the plenum gaskets in the kit, unless you plan to remove the plenum at some point (cleaning, knock sensor replacement, hose replacement, etc). These parts are probably OK at 60k and you can do them later as needed. Not much job overlap. If you do remove the valve covers, you will need to replace all the hoses. Scottsdale also has a kit for this, though I bought them individually so I don't know how complete their kit is. You will also need the cam end seals to do the valve covers. These are small rubber half-moon pieces that go under the valve covers. RTV, oil, coolant. Just replacing what you will remove. Permatex Blue RTV is MUCH easier to work with than Gray, but is rated for a lower temp. Probably just fine, though.
MAIN STEPS IN COVER REMOVAL AND GUIDE REPLACEMENT (NO CHAINS) Remove all plastic trim pieces above and below to expose radiator and cover Drain coolant and remove radiator Remove all belts Remove all belt tensioners Remove metal bracket on PS fluid pump covering front cover Remove coolant hose running across front cover Align the pulley to TDC Remove pulley main bolt and pulley Remove front cover screws--know where the lower cover ends and the upper covers begin. You don't need to remove the upper timing covers. Remove the lower front cover Remove the oil pump chain, guide and sprocket Cinch the timing chains up real tight to prevent jumping a sprocket tooth. This is the most critical step. If you jump time you will either have to do the job over again and have it professionally timed, or you could even destroy the engine Remove the old chain guides, being very aware of the chains loosening as you remove the guides. Re-cinch if needed to be safe. The odds are small you will jump time, but keep in mind there are rotational forces at work on the cams that might suddenly induce some dangerous slack into the chains if they're loose enough Remove the old tensioners Install new tensioners and guides, carefully loosening the chains as needed If you have pieces in the oil pan, now is the time to *try* to fish them out but it might be impossble Install new oil pump chain, guide and sprocket. Clean the mating surfaces of the cover and degrease Apply fresh RTV and install cover with all bolts. Use a torque wrench here if possible Install everything in the reverse order or removal Fill up coolant and oil
That is the outline of the job guide. Straightforward, but it would probably take me 8-10 hours, even on my 4th time. I am willing to expand on any of the steps, but only if you still want do to the job. Keep in mind I did this off the top of my head, and I didn't go into any details. If you have any questions, go ahead and ask. If you decide to do the job, let me know. I'll think of some more tricks for the job. Also, I didn't go into cover removal--that is a larger job, IMO, and I would need to spend more time on that.
Removing the bolt can be done 2 ways...you can use the chain wrench and 2 people (same as installation) OR you can just put the breaker bar on the bolt and rest the breaker bar against the top of the suspension member (driver's side NOT passenger side) and then "pop" the starter motor for a split second. Ensure the injector fuse is pulled first to prevent the motor from firing up. This is a neat trick, though I'm not sure if it shortens the life of the starter. A 2jaw puller will work fine, but it needs to be pretty big. I'm not sure I've ever seen a "bolt on" puller that would work...the bolt pattern on the pulley is very tight and is only for balancing, I think.If you're not planning on doing the chains, I would suggest you do the plenum hoses and the chain guides separately. Again, very little labor overlap between the 2. Take a weekend to do the guides, then after you recover, you can tackle the hoses. Those are far less of a concern.I too was concerned about messing up the car, so I took REALLY good notes on what I did and put colored tape on every disconnected hose and harness. A digital camera is a good investment overall, and a great item to have for working on cars. When I was in college I (thinking I knew it all) took apart my motorcycle and never got it back together. Luckily it was a cheap lesson and it prepared me well for working on a complex car.I've heard good things about Jerry Tucker, but I have never been there myself. My budget being what it is, I am resigned to doing everything possible on my own. Aside from being cheaper, I get better results than the yahoos at the local shops. After doing the plenum, valve covers, chain guides, and suspension, there are only a few things I'm not willing to tackle to save a few bucks. Plus, I like the work most of the time. I am sure too that Jerry Tucker will do a good job, and a SD vacation might be nice.