OK, let's just say that someone is working on a '99 6G74 for the first time and has managed to let the cams and crankshaft rotate independently of one another. After said travesty, all the timing marks were aligned again, the timing belt loosely installed (tensioner not set yet) and the engine rotated by hand 8 crank revolutions with no interferrence and with all marks remaining dead on. Would it be safe to proceed with assembly or is it possible one or both cams could be 'out of phase'.

Yes, I know this is lame, but the timing gear came off the crankshaft with the balancer/pulley and I proceeded to make a couple of rookie/stupid moves after that. Laugh if you want, I certainly deserve it, but if you can also help I'd love the info. I haven't been able to find any info about this and I further apologize if this has been covered before..... <img src="/forums/images/graemlins/confused.gif" alt="" />

Well, some mistakes are fatal. but not this one. If the marks are aligned and stay aligned, and you did not turn anything one full turn while not connected by the belt, you should be ok.

Just read your smog post, but replying here as this is the more relavent one. When you put the A/C bracket back on, make sure you get the ground wire back on too. It's on the farther back bolt that you can't even see from above. Easy to not even know the ground was there when you pull the bolt, and then obviously easier to not put the ground back on.

You also questioned how to get it back on from the side. Remember that there is the bolt on the front as well. Start with it from above and just don't tighten until all the side bolts are in.

Cool, thanks for the replies. fasteddy: here's the thing. Certain things did get turned a full turn. So, when I was attempting to bring the crankshaft to the mark, it came to a hard stop. I'm assuming that was a piston contacting a valve. I was gentle, hopefully gentle enough. So, at the stopping point, I backed off the the crankshaft 1/4 turn or so, then turned the passenger side camshaft. After that, I was able to get the crankshaft into position, then was abble to get the cam back into position, then installed the belt and gently turned the engine over a few times with no binding. I felt 6 distinct compression "resistances" with every complete turt of the crank and the marks all remained aligned.

How screwed am I, if at all??

BTW, MontyMcV, that sounds like good advice re the a/c bracket. I did, in fact, notice the ground wire when I finally found and removed that bolt but I'm not sure I would've remembered it without this reminder. I'm still dubious about getting a ratchet (or my fingers, really) on the compressor bolts to re install that but I'll probably fully remove the tire before giving it a try. It sounds like you guys have done it, so that gives me hope.

All this, of course, will have to be done again if I've screwed up the cam timing and the thing won't start.

It also comes to mind that since my crank shaft timing gear came off I had to reallign the crankshaft position sensor (or whatever its called) on the two small dowel pins on the back of the gear. I wasn't exactly sure what that was so I didn't pay attention to which way it went on. It can be mounted to the back of the timing belt gear in one of two 180' opposing directions. Not sure if that matters.

Man, I hope I can actually drive this thing soon...

Get the service manual.

I usually do my A/C bracket from above, with a pivoting stubby ratchet. I use a 3/8 breaker to crack them loose. My garage is tight and low (and full of crap!), so as long as they loosen it's just as easy to do it this way, versus jacking and pulling the tire.

If pulling the crank gear caused the sensor ring to come off, then that says to be it was trapped within the sensor. In which case you'd better check the sensor for damage. If it is fubar'd, you will have trouble with it running.

What Grasscat said... You can pull a 98 FSM from the link in my sig.

Re cam timing, what's important is the phasing of the cams and crank. The cam turns one half turn every turn of the crank. The crank doesn't know if it's on a compression or exhaust stroke, it just pushes the piston up. The cam decides if it's compression or exhaust. If the marks line up, all should be well.

And a BIG ditto. Get the manual. You can't do this work without it. For example, it will show the proper positioning of the crank sensor. All you are doing is getting an excessive amount of practice in tearing down the front of the motor and in restraint over throwing tools...

> and in restraint over throwing tools... [/quote]

Ha! Who says I've exercised that kind of restraint? LOL!

Its definitely true that I don't need any more opportunities practice if I can help it. I'll be examining the manual shortly thanks to the link.

I haven't seen anyone mention the timing gear coming off in any of their posts, nor in the rather complete set of instructions that came with my Gates belt kit, nor did it come off in the videos I've watched..oh well. I've got the T belt installed, the engine turns correctly by hand, and the large front accessory bracket is back in place. Before installing the rest I'm going to test fire the engine. If it runs, score! If not, I'll be going back in after the sensor...

A stubby PIVOTING ratchet sounds like a brilliant idea. I'll be shopping for one shortly. A set of rubber arms would be helpful, too, but I guess I'll just keep the ones I was born with. I've only got a 1/2 breaker bar...a 3/8 unit also sounds like a great idea.

Thanks for your responses, I'll update again next weekend after I've had a chance to get my hands on the truck again...

> If the marks line up, all should be well.

Well, that's what I THOUGHT to be true...true of all 4 stroke engines...but I just wanted to check myself.

...and, it doesn't SEEM like I would bend a valve with the piston using hand pressure, but, I really have no actual experience to base this on b/c I've never done this with and interference engine. Again, thanks for the response