Philtog

OK, I have my 2000 3.4 Tacoma all apart...waiting on the
tool to compress the tensioner...I'm questioning myself as to where TDC is...as it relates to the cams and the crank.
Can I re-assemble this thing 180 degrees out ?
Is there a difference between TDC Compression and TDC exhaust ? If so, how do I insure that I re-assemble in the right configuration ? Thanx, in advance.

rworegon

The FSM shows how to line everything up in step 6:
http://www.ncttora.com/fsm/2000/Repa...nical/inst.pdf

Philtog

So...in reviewing the FSM...as long as both cams and crank are set at their respective TDC marks, I can't screw up ?

kuzbro

The piston is at the end of compression and top of power stroke at "marked" TDC.

rworegon

Pull the #1 plug and be sure it is at TDC when the mark on the crank lines up. [Edited: removed a poorly worded sentence.]

Philtog

That was what I am worried about...Firstly, which cylinder is # 1 ? ( facing the motor from the front of the truck) ...then, how do I know that when #1 is at the top of it's stroke, that this is the exhaust stroke ?
Another thing, I can't seem to find a "mark" on the crank as to TDC...is it on the front of the crank gear ? I've seen pictures where it is marked at the back of the gear, up against the oil pump, but I see no mark there when I turn it by hand...even on the oil pump. Is the key on the crank any clue?
Got the water pump and new idler bearings installed and I'm waiting on the tool that compresses the tensioner...but
the timing issue is where I'm in trouble.

rworegon

Post 69 shows the cams and crank lined up. See the molded arrow on the oil pump and the little dot on the crank gear is the crank marks. At approx 90 deg on the crank gear there is another mark where the belt lines up marked CR and a white arrow.

http://www.ultimateyota.com/index.ph...&topic=7462.60

The #1 cylinder is on the passenger side (left side of engine) closest to the front (radiator). Remember, left and right on the engine is from the perspective of sitting in the drivers seat.

One way to get to TDC/Compression on #1: Remove the #1 spark plug and rotate the crank clockwise until you feel air rush out of the cylinder and hit your fingers...you should be on or near the mark on the crank gear aligned with the oil pump housing. This is the end of the TDC/Compression stroke and start of the power stroke. Air will not go past your fingers on the exhaust stroke.

Others may have other ways to ensure crank TDC and will chime in....

Philtog

Thanx RWOregon...I think I have it now..let's review:

If the camshafts are set at their TDC's , #1 cylinders valves are closed for compression. By turning the crankshaft ( and having #1 plug removed ) I should feel air coming through the plug hole because the valves are closed for compression...right?
And further...as I'm standing in front of the truck, #1 cylinder is on the left ( passenger ) side of the engne, the very front of the engine...correct?

Haven't done this much engine work in over 20 years...and I thought I was retired???

rworegon

[quote=Philtog;51785280]If the camshafts are set at their TDC's , #1 cylinders valves are closed for compression. Yes, since #1 cylinder is at TDC/Compression at the crank when properly lined up. Cams are easy to line up...align mark on cam gear with backing plate. They cannot be 180 out.

By turning the crankshaft ( and having #1 plug removed ) I should feel air coming through the plug hole because the valves are closed for compression...right? Correct. The air goes by right when or a split second before you come up on the TDC mark on the crank and oil pump. Feel air, align marks, and crank is at TDC.

And further...as I'm standing in front of the truck, #1 cylinder is on the left ( passenger ) side of the engne, the very front of the engine...correct? Yes. Cylinder #'s are:
Pass Driver
5 6
3 4
1 2
Radiator/Front

Haven't done this much engine work in over 20 years...and I thought I was retired??? And, I've done a few of these for side $$ lately. [/quote]

Hope the responses help clarify.

Philtog

Thanx again...now I'm an expert...as long as the truck cranks up when I'm done...I'll keep you posted. I had to make the tool to hold the the crankshaft pulley...and ordered the tool from Amazon to compress the tensioner...and bought a 19mm socket for my 1/2 inch drive....guess I'll need to buy my own torque wrench ( borrowed one from a buddy )...the local shop wanted $700.00...but that was before I discovered the whole thing had "melted down"...water pump was frozen, top idler bearing was in pieces...other idler bearing was missing parts...and the belt was no longer a belt...was holding on by threads...but what did I expect at 220,000 miles!
Got a parts package on EBay for $100.00...in this economy...it's worth a couple broken knuckles.

rworegon

At 220k, I'd replace the tensioner too. No sense leaving a potentially weak tensioner in there after all that work.....about $40 from the dealer, I believe.

Also, I'd Replace the thermostat and gasket too since it's open (but can be done later)...about $20 from the dealer.

Philtog

I thought about the tensioner...but I have to remove the AC compressor to change it. I'll definitely do it the next time...if there is a next time...hoping to trade or sell my 2001 for a 2012 soon. Love the Tacoma. This is the first time I've ever had work on the engine (other than regular oil changes)...bought it new.
I did change the thermostat and gasket...gonna change the plugs also.

rworegon

Sounds good. Bought mine new also. Last fall, I replaced the head gaskets due to slow external seeps and the timing belt prior to that and the rest has been routine maintenance.

Philtog

Thanx RWOregon...she's back together and sounds like a sewing machine. Going to put some new coolant in and change the oil and plugs...just to reward her.
Thanx for all the advice.

rworegon

Excellent! Welcome!

rworegon

So, how did you go about assuring yourself that the crank was at TDC?

Philtog

Sorry...been busy driving my fixed truck. I found TDC...after much trial and error, but here's the trick I used. I pulled the plug on #1, and got the cylider to the top, with the main pulley at TDC. Then, I put a piece of irrigation pipe in the
plug receptacle that fit quite nicely. I got the other end of the pipe damp and put a piece of kleenex tissue over the end. When rotating the engine by hand I could "see" the puff of air come out, indicating that the valves were closed.

I'm thinking about buying one of those little video rigs for the next go round. Harbor Freight sells a cheap one.