If the tensioner and water pump are near new, turn smooth, and show no undue side or endplay, and have not been marred,
it should be sufficient to replace the belt.
Are there any markings on the water pump to indicate its maker??
It should be possible to slide the crank sprocket off the crank for closer examination.

 

I'm with millball. "Conventional wisdom" says to always replace the water pump when doing the timing belt, but there are only a few ways they can fail. If it looks new, it probably is.

There are 2 kinds of tensioners; originally a spring provided the force, then at some point Toyota switched to a hydraulic tensioner. (I don't know which year.) The spring tensioner is just that; a spring and a pulley. Does the pulley feel good? It is. The test for the hydraulic tensioner is just to push it firmly against a hard surface; if it moves it's broken. http://web.archive.org/web/201204051...67timingbe.pdf (page EG2-40). I would replace it if it failed the test, otherwise I would (and did) keep it.

 

I do know this one, its mid year 1992.

 

Rattlewagon's correct. The 1990 pickup had a spring tensioner. The water pump on my truck has "GMB Japan T80" written on it, so not OEM.

 

With photo.

 

Ok, finally got my parts lined up. I was reading through the FSM again to make sure I understand the steps. I went ahead and ordered replacements for both the idler and tensioner pulleys (along with new studs and nuts for the radiator hose inlet because the old ones were more rust than metal). My first question is whether I need to remove the cam pulleys. The FSM says they should be removed, but several videos on the topic didn’t show them being removed. I know the FSM is the Bible for these procedures, but I can’t see what the benefit of removing them would be. The other question is if I’m not replacing the water pump and thermostat, do I still need to remove the crankshaft pulley or can I slip the timing belt around it once the accessory belts are removed? 181 foot pounds doesn’t sound like a lot of fun to work on.

 

You cannot remove the lower timing belt shroud without removing the harmonic balancer.

 

Millball (as usual) is correct; there is a cast pin that keeps the belt from slipping off (or jumping teeth) while the "timing belt guide" is in place, and it's under the No 1 Timing Belt Cover which is under the harmonic balancer.

So yeah, 181 ft-lbs (plus what ever age has added) will be needed to remove the crankshaft pulley bolt. And the crankshaft is happy to turn while you're trying to remove the bolt. There is a for-real SST to hold it https://toyota.service-solutions.com...9213-58012A-01, but it's pretty expensive, if you can find it. If you have a manual you can put it in 5th gear and block the wheels really good, just remember that your truck is still going to try to move while you're leaning over the radiator. You can remove the starter and fabricate a holding clip against the ring-gear teeth, but you really don't want to break a tooth there. I've heard of folks sliding a couple feet of nylon rope into the cylinder through a sparkplug hole; once the cord compresses the crankshaft shouldn't turn.

Me, I prefer a fabricated holding tool. I'm (obviously) partial to this one: https://www.yotatech.com/forums/f116...h-3vze-137934/ The price was right.

Someone will inevitably suggest bracing a "breaker bar" against a frame member, and then using the starter to loosen the bolt. Sounds a little scary to me, but I guess it works. The only problem is that you will still need a crankshaft holding tool in order to put the bolt back in with 181 ft-lbs. Don't be the guy who just tightens it as far as his impact gun will go, and hope for the best.

You do not need to remove the cam pulleys to replace the timing belt. I'm not sure why the FSM says that, but you can (and probably should) leave them alone. http://web.archive.org/web/201204051...67timingbe.pdf

There are a lot of really good write-ups for the timing belt on this site, but it will take a while to find them all (still; probably worth most of the time). One thing that might come up is the markings you will probably find on the new timing belt. They're just a convenience for the initial installation. You still need to confirm that the pulleys and crank all line up at the same time, and still line up after you turn the crank through 2 revolutions. (Why 2?) The belt markings will not line up after 2 turns, and will probably not line up again for several dozen turns (this is by design).

 

All good info. Thank you. I won’t be the guy who just wrenches the crankshaft bolt with an airgun, because I can guarantee I would be the guy to lose the bolt on the freeway. I actually went so far as to buy an OEM replacement bolt because the one that’s installed now is old and who knows how many times it’s been wrenched down and abused. I have a camshaft pulley holder that I think will work to hold the camshaft in place, though it may need a cheater bar to help. My bigger concern is that my torque wrench only goes up to 150 lbs. my plan was to torque it to 120 and mark the bolt position. Then I’ll torque it to 150 and see how far the bolt turned. If I turn the bolt the same distance it took to go from 120 to 150, it should put me pretty close to 180.

The timing belt I bought is from Mitsuboshi (not a typo) and it didn’t come with marks on it. I was wondering how critical that was. The cam pulleys are marked so I think I’m ok as long as I make sure there is no slack in the timing belt between the two cam pulleys when I install it. If there were, I would see that the marks didn’t line up after cranking the engine forward two revolutions, and misaligned marks are an absolute fail, correct?

 

You won't need that much on the cam pulleys. Because of the valve spring tension, they will move out of TDC on their own, but a simple wrench on the cam pulley bolt will allow you to get them into place long enough to get the toothed-belt engaged. Then just install the belt tensioner.

If moving the cams against the valve spring tension with a wrench causes the cam bolts to back out, then they are way too loose. (spec is 80 ft-lbs)
Not the marks on the belt (you don't have those any way), but the TDC arrows on the crank and cams. I've heard that trucks can sorta run with a cam off a tooth, but it is surely a bad thing. You'll either be off an integer multiple of teeth (1,2, ...) or it will be correct. Don't sweat the arrows being off by 1mm or so; that's just parallax.

 

I'm well into the disassembly. Timing cover, belt, #2 idler pulley, #2 timing cover, crankshaft pulley and water pump have all been removed. I either have superhuman strength or the camshaft bolt wasn't even close to 180 ft lb of torque. I've struggled far more with lug nuts than with that bolt. Good thing the fan bracket broke before I lost the crankshaft pulleys at speed. Speaking of, I noticed that the bracket on the tensioner pulley that should hold the tensioner spring was cut off and the bracket opposite that the spring attaches to is missing. It looks like there was no tensioner spring installed on the engine. I looked up the part number (13558-65010), but the part is out of production. Nothing listed on Rock Auto or Ebay that I could find. Should I start checking the wrecking yards around town or does someone know of a supplier who carries that bracket?

Other things I noticed include the water pump was installed without a gasket, just frosted with RTV, most of the gaskets were missing from the timing covers, the idler and tensioner pulleys are both old so neither were replaced on the new engine. By this point, I kind of knew that's what I would find so I went ahead and ordered replacements. The mounting hardware is all pretty shot and rusted so I'm replacing as much of it as I could find part numbers for. I'm ready to start installing the new parts once I figure out where to source the tensioner spring bracket.

 

Well, I got the new water pump, idler and tensioner pulleys installed and everything put back together. Added coolant and It started right up. The idle is a bit high, but I’m pretty sure there’s a problem with the power steering idle up valve. Dorman brand. Lesson learned.

The other thing I noticed after I shut the engine down is a low grade hiss/humm sound coming from the engine on the driver’s side. I can’t pinpoint it exactly. It seems to be coming from around the distributor, alternator or behind the timing cover. The engine’s been off for 10 min and I’m still hearing it clearly. Any thoughts about what it might be? (See attached video).

 

I figured it out. It’s the cooling system equalizing pressure. I haven’t had a chance to burp it yet. That should go away once I do.

 

Well, this sucks. The seal blew on the water pump on the first brief test drive. So much for trying to do things the right way. An Aisin pump and gasket, OEM thermostat and gasket and new bolts all around torqued down to 14 ft lb with a torque wrench.

The belts got soaked including the new timing belt. Time to start over. Should I go ahead and replace all of the belts? I’m pretty sure I need a new timing belt, but maybe I can salvage the power steering and alternator belts.

 

That does suck.

I wouldn't worry about replacing belt. Just pull it back apart and rtv everything.

 

I was tearing the engine down again and I got to the step where I remove the timing belt. I forgot to turn the engine to TDC before loosening the belt on the cam pulley for cylinders 1, 3, 5. When the belt tension was released, the cam pulley rotated about a quarter turn counter-clockwise. Oops.

I rotated the cam back to where it was, reattached the timing belt, then rotated everything to line up with the timing marks. Does that fix things? I’ll carefully check the timing marks on the cams and the crankshaft and make sure the marks are exactly lined up when I install the timing belt. Is there anything else I should be worried about or that I should check?

 

This is where the 3vze helps you out. It is a non-interference engine, so rotate everything to the correct position and continue on. 👍

 

I wish I could. I spent five hours trying to mount the timing belt. I tried with the one I’d just mounted a couple of days ago, and with a brand new one. With the missing tensioner spring bracket, I guess I can’t get the correct tension on the belt, or I’m lining the marks up incorrectly. Each time I try to rotate the engine and check the marks, they end up being off by a good bit. The cam pulleys stay in synch, but the crankshaft is way off. I tried for five hours and couldn’t get it right. I tried to fashion a replacement spring bracket that seemed to work, but no go on keeping the marks aligned. I guess the truck just sits there until I can figure out where to scrounge up the missing part.

 

Most 4Runners have the 3vze. I’ve had decent luck looking for part-outs on Facebook marketplace. Car-part.com hooks you into the salvage yard network. Toyauto mart in California is a place on there I have gotten parts. They have a ton of those engines. I would call them and they will fix you up.👍

 

sound that I assumed were the valves letting me know they needed to be adjusted. The ticking was still there after I put the new belt on the first time. After reinstalling the belt, the ticking is gone. Good news, I guess, but I’d love to know what was causing it. If the old timing belt were misaligned a little, could it cause a ticking noise?

The bad news is I think the old fan did eat a piece of the radiator when the pulley bracket failed. After the test drive, I saw some coolant splatter. It could be because it was raining and the fan shroud wasn’t back on yet, but I can see a dark wet streak on the otherwise dry radiator (see pic). If it is a leak, it’s a really small one. Something I could patch on my own, or should I go to a radiator shop? I’m not super enthusiastic about dumping a bottle of leak fix into the coolant if I can avoid it. Is the some other way of patching a radiator?