quattro

OK, I thought I was doing pretty good with getting the engine torn down and water pump replaced in 3hrs labor. I guess I got cocky and am now paying the price. I cannot get the new timing belt on AND keep the crank & cams in their correct TDC positions.

Let me rephrase that, they all line up just fine until I put the tensioner in, then the crank rotates ever so slightly. So after my 5th try the best I've gotten is when the crank is dead-nuts on TDC - both cams are .5 to 1 tooth retarded from TDC (to the left of the timing marks when viewed from the front of the truck).

So my question is this: since I run the SC; does the slight cam retardation effectively help the engine on-boost, admittedly giving up a little torque down low? I've done this in old 10v Turbo Audi cars with good results - but not sure of the Toyo.

Ideally I want this to be exact - I'm just not sure I can stand pulling the belt one more time.

[UPDATE 06-04-2006 Job finished up last night while the Chicago fireworks were booming around]

90vetteman

Hello,

There should be white lines on your timing belt. Line those up with the dots on the pulleys and all should be good. It is helpful to put a wrench on one of the cam bolts and a ratchet on the crank bolt so that you can work the belt back and forth a bit to get everything lined up. Yes, these can be a bear to install but you'll get the hang of it. I wouldn't settle for things being off...even by a little.

MorphiasX

The way I did it was to set the crank and both cams to TDC (dimples on the pulley wheels straight up aligned with the marks) then put the timing belt on with the white lines ONE TOOTH TO THE LEFT of the timing marks, pull the pin so that the tensioner tensions, then take the crank around 4 revolutions by hand with a 1/2" drive ratchet and a 3 foot cheater bar for leverage, and during that the belt jumps one tooth to the right as it is tensioning, which puts it in perfect alignment.

MTL_4runner

I find the timing belt lines on the belt are often 1 tooth off so make sure they are in perfect alignment to the marks on the cam and crank timing pulleys and don't worry much about where the belt marks fall. I do totally agree that if it was my vehicle (and esp in the case of having a S/C) that even 1 tooth off can have negative effects (reduced gas mileage, engine power, etc). MorphiasX outlined quite well how I get mine on with perfect alignment too.

quattro

I think maybe part of my problem is that I've been bolt-drawing the tensioner into place rather than compressing&pin'ing it. I don't happen to have anything to compress it with.

I think I'll try it again tonight.

mt_goat

Here's a write-up: http://www.4x4wire.com/toyota/maintenance/timing_belt/

gwhayduke

I haven't done my '99 belt yet, but when I did my '95 belt, I tried to save a few bucks with an after market belt. It wouldn't line up...belts, cams, crank...there was always something off. Finally bought a Toy belt and it lined up first try.

MTL_4runner

It really helps to have someone helping you during the procedure but I have done it by myself many times too. I do it the same way but the trick is to get the crank pulley aligned first (since it doesn't move very easily) then use a cresent wench to manipulate the top right cam pulley to it line up, get the belt on, and use the wrench to put a slight tension on the belt (in a counterclockwise direction). Then use another wrench on the other pulley to align the second pulley on the left side, slide the belt on and now apply a slight pressure to the second pulley on the left only (counterclockwise). This shows you how everything will line up (so if you're a tooth off you'll see it right away) after the tensioner is on and you can make any corrections before you tighten it all up.

quattro

The more I've thought about it, and consulting with from other mechanic-dudes; I've got a plan. Pull the balancer back off, pull the tensioner, pull the belt. Reset cams and crank to TDC. Then adjust the crank to 1-tooth BTDC (counter clockwise from the front). Then re-install it all.

Since the tensioner is doing a gradual pressure increase on the slack-side of the TB it has the effect of rolling the crank clockwise, while it's being bolt-drawn into position.. It's the point of less resistance as compared to moving two cams and the belt around the top idler and WP.

On the good side I will be changing from the stock thermostat to the 170f unit and changing out all belts and cooling hoses now that Napa is open. So I suppose there's a plus to this all. I think I need to swing past the Toyota dealer and buy some Red coolant too. The stuff in the truck is 100k miles & 9yrs old. I think it's due for replacement.

BTW: my balancer locking tool was as simple as it gets. I used an old Volvo 850 automatic flywheel which has exactly the right holes pre-drilled for everything. I bolted a x-bar to the perimeter and !voila! instant locking tool. No drilling required.

toomanyedwards

I *just* did my first timing belt on my '99 4Runner. I couldn't get the aftermarket belt to fit at all, always one tooth off. I finally got a belt from the dealer and it fit like a champ the first time. I definitely recommend getting the snap-on tensioner compression tool as well as it will save you *a lot* of time. You might be able to do the same thing with a reverse c-clamp but I didn't try it.

youngbuck

Yea definately get the Tensioner tool.

Here are a couple other write ups you might be able to disect some helpful info from:
http://www.toy4x4.net/timing_belt/index.htm
http://s94741489.onlinehome.us/album...elt/index.html

quattro

Thanks all, job is complete and truck runs perfect. For starters I was always using Toyota parts and not OEM; so that wasn't a contributing factor to the problem.

The plan of setting the crank to 1-timing-tooth BTDC (tooth on the sensor, not the pulley) worked perfectly. While bolt-drawing in the tensioner I would stop and tension the cams against each other at their TDC marks which helped keep the drive side of the belt in a single location. The effect was that the crank rolled to exactly TDC when everything was in position. For those if you wondering how I was able to get enough slack in the non-drive side of the belt to get the tensioner bolts to catch here's how I "cheated". If you loosen the idler pulley between the cams you get a 1/4 of belt play. Then you can roll the passenger-side cam anti-clockwise and get enough play to be able to use a small wedge to lift the tensioner into position. Thus you've freed up the room to be able to seat both tensioner bolts without having to deal with trying to compresse the doo-dad. Once the bolts are started with a few threads, pull your wedge out and roll the passenger-side cam back to TDC and tighten the idler back to 40nm of torque.

Before I pulled the old belt the crank-pulley indicated 5deg BTDC when the cams were at TDC. Now I'm showing a little less than 1deg BTDC - so it's perfectly within tollerance. I replaced all the idler pullies, all belts and cooling system hoses while I was in there. Flushed with a new fill of Toyota-red coolant at the 50/50 mix, after installing the 170degF thermostat.

While re-installing everything I found that when I put on the SC 2-years ago I never tightened down the intake hose between the MAF and the TB. (Dumb, don't know why I missed it), but that's all set now. A road trip around the block showed everything in functioning condition.

MTL_4runner

Great stuff, glad you got that all squared away!

mt_goat

Did you mean to say that? Because OEM means original equipment manufacturer.

quattro

Sure. I've always understood OE to be "branded" parts from a dealer. Where as OEM is generally from a possible original supplier or a potential supplier building to spec but not sold under the Toyota name.

mt_goat

Interesting, well anyway glad to see you got it going.