legacycentral bbs

I finally got around to doing the job. I tore everything down and replaced the oil pump, oil pump O-ring, water pump, water pump gasket, thermostat, thermostat gasket, crank seal, all cam seals, timing belt, drive belts, upper & lower radiator hoses, oil, oil filter and coolant. I think that's it. Oh yeah, and I swapped a little blood with oil, but not as much as usual. You'll have that.

So how did it go with the DOHC? Well, not TOO bad. I'll try to keep it as short and informative as possible.

Removing the radiator w/fans, drive belts, tensioners, belt covers, etc., off the front was much easier than the gen 1. The front of the motor is angled upwards and there is more room to work than there is with the gen 1. The alternator, A/C compressor and all related drive belts and tensioners are all pretty much identical to the gen 1 components. The timing belt cover is also a much better design than the gen 1. It easily dissembles without breaking bolts, etc. The rubber seals on the center cover still get impregnated with oil and contaminates and swell up complicating reinstallation though. Not too big of a deal.

The camshaft sprockets: PITA.

Seeing in the manual that these sprockets had a hex head on each one, I was thinking that it should be easy to hold them in place while I broke loose and torqued the sprocket bolts back down. Wrong. With the MT in first gear, I broke each bolt loose, but it was kind of nerve-racking since the crank still moved a lot even then. Still, I got them loose. Reassembly was another issue.

Although I have never replaced a gen 1 oil pump, the gen 2 oil pump also appeared identical to the gen 1. As for the water pump, I think it’s identical to the gen 1. If you cross-reference both of the parts, I bet they’re the same, just as the installation. Installation of them was a bit of a pain, just because you have to try to line everything up from the crank angle to the oil pump to the fastening bolts and seals while trying to keep the rubber O-ring in place and the bead of sealant on the oil pump (I used the recommended Permatex Ultra-gray). I got the oil pump almost in place and had to pull it back off three times for various reasons, including the new crank seal folding outwards instead of sliding into place once. That sucked. The oil pump was a PITA. I was getting tired at that point though. The water pump wasn’t too bad. The metal gasket was bent, warped and uncooperative as usual, which was aggravating, but not too bad. The crank seal was easy since I replaced the oil pump, which is where it’s seated. The cam seals weren’t too bad. Breaking the cam sprocket bolts loose wasn’t too bad since I did it while the old T-belt was still installed and the car was in gear. I then used and broke my ultimate best various-use tool ever (a bent screwdriver that I made when I was 14) to pull the two right seals, in which it was doing a killer job (email me or post here and I’ll explain) so for the other two cam seals, I went back to using my old method of carefully drilling a single small hole in each seal with my dremel tool and carefully screwing a drywall screw into the hole until it got a firm grip, then prying it out by using a needle-nose plyer to grip the head of the screw and carefully leveraging it against the camshaft, while, when necessary, placing another small screwdriver between the screw and the camshaft in order to keep the two from touching and scoring. To replace and seat the new seals, I used the old big socket and mallet method to seat them firmly in place, oiling everything up first, of course. That’s the easy part.

The next step was to replace the cam sprockets. No big deal, but also no way to torque them down, so as planned, I waited until the belt was in place. I tried to snug them up a little anyway and the exhaust cam on the left side spun under pressure since it was, well under pressure. I just grabbed it with my channel locks and rotated it (counter-clockwise, which is the only way you want to spin that one) back to its happy place and it sat there again by itself. Apparently it was balancing on the top of its cam lobe. That was the end of day one.

The following day, I cleaned up the idler pulleys, tensioners, etc., while powering down my caffeine and rubbing out the eye boogers. I then followed the directions, installed the necessary idlers, compressed and installed the tensioner and prepped everything for the timing belt, then ate an eggy sandwich while I looked everything over.

I put the belt on in the order recommended for the DOHC motor. All went well. Too well. Made me nervous. Got the belt in place. Checked the timing belt marks, and then pulled the pin on the tensioner. Smiled. Thought all was good. Since I then had the belt in place and under tension, I decided to rely on the belt to hold the cams in place while I torqued down the sprocket bolts since it worked the other way. Note: DON’T DO THAT. When I thought my torque wrench was signaling that it was hitting 55 ft-lbs, it was actually the belt jumping a tooth on the crank sprocket. DOH! In hindsight, it made sense since, by cranking the right intake cam sprocket, I was relieving belt tension at the next sprocket, which was the crank. Everything else was still in check. I considered taking up smoking again and/or placing my head in my vice for being such a damn fool.

Fortunately, my plan to VERY CAREFULLY pull the idler pulley to the left crank sprocket and VERY CAREFULLY rotate the crank back a couple degrees via my torque wrench and put everything back in place worked. Whew.

I have been drinking a lot at this point. Not while doing the work, but now while writing this and celebrating the fact that I’m done working on this god-forsaken car. So… thanks for reading this far. I’m just trying to help the next poor sap that has to go through this <g> actually, it’s really not so bad. I just like to bitch. Read on…

At this point, the belt was on and I double and triple-checked the marks on the belts, sprockets, etc., and it was all good. Yay me.

Now for the ugly part. I had to get 55-61 ft-lbs of torque on each of the four cam sprocket bolts. That was a major pain in the ass. Since I managed the make the belt jump a tooth on the first attempt, I realized that relying on the belt was incredibly stupid. My bad. SO.. back to the channel locks on crappy plastc sprocket hex heads. Yes, plastic. Getting my channel locks on the right side and trying to hold that while I powered down the torque wrench with the other side wasn’t easy, obviously. I finally got them both after about a half hour of shouting profanities and throwing tools across the street (then going to find them)

The other side was twice as bad.

This side, the hex head was deeper inside the sprocket. The best I could do with my channel locks was probably about a total of 8mm surface coverage and the best death grip I could do after two days of working on this thing. It took another hour and I actually considered giving up at 40lbs of torque (instead of 55) because I couldn’t get any further. Did I mention that these sprockets are PLASTIC???? Junk. Well, I persisted and got them all to 55-58 ft lbs.

It was all down hill from there.

The rest was your usual reassembly. No big deal. Had to put the T-belt covers back on, main pulley, drive belts, radiator and fans, hoses, etc. Pretty easy.

Drove it for a while and it seems to be fine. Doesn’t seem to be leaking any oil. Happy car. Should be good for quite a while now.

To summarize, it was a lot more work, a LOT more stress and, while I would do it again if I had to, I would rather not. The SOHC design is much easier. I could do that in my sleep now. I think I did my SOHC 2.2T in 6-8 hours, this one probably took me twice as long, but this is the first time I did the oil pump. I take my time and clean the sh*t out of everything, etc., so that’s why it seems excessive. That’s also why I do everything myself.

All is good now.

Thanks to everyone for their input in this. I hope this helps anything that plans to do this themselves. Email me and I’ll be happy to help.

Thanks,

Dave

I rigged up a tool to lock the three pulleys on a SOHC in place that could be modified for DOHC in a couple ways. I got some 90 deg angle iron long enough to span the engine and drilled six holes. The crank pulley has four holes in it ... these can be tapped by I forget what thread, but they're the perfect pre-drilled hole for some common size. Anyway, I used the center two holes in the iron to line up bolts to mount the angle iron to the crank pulley. The two outer sets of holes were used to hold a U-bolt on each end to lock the pulleys in place by stringing the curved part through the spokes on the cam sprokets. This locks everything suitably together for disassembly (when the engine is off the car without accessories or any other way to keep the crank from turning. This was PIW - Pre-Impact Wrench). I also found it useful for reassembly, but it was more difficult to mount the U-bolts. The U-bolt part can probably be adapted to work better. I also think I clamped vise grips to the sprokets and flat top of the angle iron during reassembly for extra hold due to the poor U-bolt purchase.

Steve

Good idea and you could do stuff like that on the old metal spoked sprockets, but not on these later ones. It's one big (probably, I don't know, 35-40mm) hex head in the center of the sprocket, no holes around it whatsoever and, again, it's plastic. You pretty much have to get the OEM tool or a weld something up with large sockets with large holes in the center (for your 17mm socket) or something.

Dave

Good work Dave,

Glad to hear you got it back together.

Thanks. I'm really stoked about having it done. It should be a long time before I have to do that again. Let's hope anyway.

Dave

Good to hear it worked out in the end. I have never been a heavy smoker, but ALWAYS have a pack in the garage when I am doing extended work sessions. You can smoke a lot more cigarettes than you can drink beers and not have your abilities impaired (plus a recovering alky like me has no business drinking any beers. )

I think when I undertake this in the near future, I will be purchasing the Subaru cam sproket tool. Seems like the path of least resisitance. And my understanding on the change to plastic was an attempt to decrease rotational inertia. And since it is not a high load area of the engine, it should have to be metal to be strong enough...

I definitely could have used a smoke or two during the job. I made up for it with beer afterwards. I had so much last night that I'm surprised my post was coherent and only had one noticeable misspelling

I'm curious what that cam wrench would cost. I was considering ordering one with the rest of my parts if it wasn't too expensive, but it's not something Liberty Subaru keeps in stock. It defitinitely would have made life easier yesterday. If you were replacing just the belt and not the cam seals, it really wouldn't be necessary, but it would still be nice to slap on there while you're doing the job.

And speaking of seals, just like the last job I did, the new seals are brown as opposed to the earlier/original black seals. I'm hoping/assuming that that means it's a better material. I don't want to have to replace them in another 50k miles.

Dave

Nice work Dave!

I can't believe that those cam sprockets are plastic! I have found a rubber strap wrench works really well for holding SOHC cam sprockets while breaking the bolts loose, but for valve-valve interference DOHCs, I think I will try to rig up a proper tool based on your experiences! It seems too easy for those to spring off the cam lobes...

Thanks for the write up!

Dave

(P.S. The Neon head gasket is done at last and I am sticking it all back together - I've managed to break the crank shaft timing gear trying to change out the crank seal so I am stuck on that at the moment - Mopar insist on requiring non-standard puller tools for practically everything.)

Thanks. Heh.

Yeah, a rubber strap wrench, if it could hold up to the required torque, would have been really helpful. I was considering a chain wrench, but I didn't think anything good would come from that.

I have fabbed up some tools in my time, but I think that cam one would be too complicated, at least for the left side since the 'hex heads' are set in about, hmm...probably 4-6mm from the outside of the sprocket. It's possible, but it would take some time. The other side would be much easier since the offset of the hex heads is well outside the sprocket. That's the side that is, what I would call 'at rest' though, with the valves in the seated position, so you really don't have to worry abou those. They spin quite freely since they're not under load and you just have to spin them back into position before doing anything with them. As for the other side, mine didn't spin at all, even though the FSM said that they would spin to the seated position (makes sense), but apparently they were balanced on the tip of the lobes and I kept them in check all throughout the procedure until I tried to snug up the cam sprocket bolt on the exhaust cam. Then it spun a little, but as long as you spin them back -independantly- in the correct direction as described in the FSM (I think it's clockwise for the intake and counter for the exhaust on the left side), you have nothing to worry about.

It's really not a big deal at all. It's just twice as much work replacing the cam seals, twice as much work R&R-ing the cam sprockets, twice as much hassle reinstalling the T-belt (not too bad at all in my case, but I'm thinking it was beginner's luck) and a little more stress over the possibility of potential valve-to-valve contact.

While I'm glad that it's over and I don't look forward to doing it again any time soon, now that I've done it, I realize that it's really not that much more difficult that our SOHC motors, and I wouldn't stress nearly as much the next time. Get in there and you'll see. It's no big deal. The extra room and better design of a few things including the belt covers almost made it worthwhile.

I didn't take many pictures during the process since I was wearing gloves most of the time, but I did get a few at the end of day 1 with the new pumps, seals and cam sprockets installed. I'll shoot those over to Josh to see if he'll host 'em and post 'em since I don't have any place worthwhile to put them. For whatever that's worth.

Dave

Aha I see - the inset hex's would cause issues thats for sure. From what you say its probably overkill anyway.

Those strap wrenches are pretty tough. I have used them for breaking camshaft bolts loose after I removed the timing belt then said 'Doh!'. Torquing them up is relatively easy compared to breaking them loose I think. Unlike the chain types they won't damage the sprocket either .

Anyway - glad you got it done your way, but if you are in there again try a strap wrench - you might be surprised how well they grip! I'm going back to my shady tree now .

Oh yeah, I definitely would have tried a strap wrench if I would have had one handy. I would have tried anything. Now, if I would have only thought of a strap wrench at the time, I probably would have driven the 4 miles to Sears hardware and picked one up. Heh. Oh well. It's done. Josh posted the three pics I took:

http://www.main.experiencetherave.com:8 ... engine.jpg

http://www.main.experiencetherave.com:8 ... llies1.jpg

http://www.main.experiencetherave.com:8 ... llies2.jpg

Dave