Yotaleigheehoo

Tomorrow I will do my first ever Toyota timing belt (94 Toyota 4x4 3.0 v6 5spd) I tore it down this afternoon with about an hour or so of that fabricating my own version of a crankshaft holder. I'll post pics of said tool later.

My question is this: Once I remove the belt and If i accidentally bump the DOHC's sprockets off their marks, what is the proper procedure to get the cam back in the correct position? Would I turn them clockwise back into position? Counterclockwise? I'm hoping the above doesn't happen at all.

I have a new t-belt, t-stat, water pump, both tensioner/ idler pulleys and misc gaskets. Anything else I should replace?

I have a set of cam seals but mine look great and are not leaking so Ill leave that for another day.

Kiroshu

Engine..?

Year make and model...?

I'm assuming by your post its a 3.0 SOHC 3VZ-E engine.

Moving the camshafts with the timing belt removed is "ok" on this engine as the valves do not occupy the same space as the pistons travel. Direction does not matter.

Sounds like you got all the good parts for this job.

Fraser

Crank seal? Mine was shot on the last one of these I did- rock hard and spewing oil. I went ahead and did the cam seals while I was in there after seeing that. If you have the cam seals, I would do them too.

scope103

The cams will "bump themselves" off the marks by a little, just from the pressure of the valve springs. As Kiroshu says, you can just turn them back as you install the belt. Once you get the tensioner back on, you can turn the crank (in the running direction) two turns to confirm that the crank and both cams come back to the marks (some timing belts are marked to assist initial installation; those marks will NOT come back to the same place with two turns of the crank.)

Replacing the cam seals requires removing the cam sprockets. You'll need a tool to hold the cam against the wrench force (80 ftlbs to tighten, ?? to loosen), and since you've fabbed the crank-holding tool you've got an idea of what this involves (the best way is the 27mm flats on the cam itself, but the valve covers have to come off for that). I can't tell you whether you can remove the old seals without removing the cam bearing caps (the method shown in the FSM). Perhaps Fraser can say.

In other words, if your cam seals are leaking (at all), replace them. But if not, it's a big enough job that I wouldn't do it "prophylacticly" during a timing belt replacement.

Fraser

You can in fact replace the cam seals with removing the bearing caps. My seals we nice and hard just like the crank seal and they pretty much fell right out.
Be aware that while the spec for the cam sprocket bolts is 80 ft/lbs it will take considerably more force to remove them. My impact gun didn't even budge them. I ended up making a giant strap wrench out of the old timing belt and a 4' length of 2x4 to hold the cams in order to break the bolts free. Even then it took almost all of my weight on a huge breaker bar to get them.
On my last truck I just left the seals since they weren't leaking but I'm glad I did them on this one just for peace of mind. I can get some pics of the big sprocket holder tool I made if it helps. (Others have done something similar, I think there's even a YouTube video)

jb451

The seals arent that much more work to replace, it just takes a good amount of force to get the cam pullies off. I had to take my crank tool and wedge it against the water neck (probably not the best idea lol) and get a 3 foot breaker bar with another 6 inches of extensions to break each pulley off. After you get it off you just take the metal shield off and pull them out with a pick. I took some old white nail polish my gf had and marked each pulley D & P, as well as their position on the cam, just for extra insurance.

Yotaleigheehoo

Well, I goofed up somewhere. Today I buttoned up everything and its obvious I made a mistake somewhere.

Upon startup, engine immediately reved up and stayed at 1300/1400 Rpm. A quick blip of the throttle brought it back to about 6/700 with a slight miss or stumble off throttle. Running a bit rough also. I shut it down and started it up again. Now it's about 1k RPM but quickly reduces to about 5/600 RPM with a slight rough idle.

All of my timing marks are spot on. I rotated the crank twice, several different times and every time, all timing marks are in check. With the hydro tensioner set, my belt feels a little on the sloppy side but I really don't know what kind of belt tension is okay for this 94 3.0 engine.

I had no issues installing h2o pump, new lower/upper pulley's, hydro tensioner or timing belt so I'm at a loss and not sure where else to check. I partially disassembled the front engine portion this afternoon and to my surprise, all timing marks are still spot on.

rworegon

Check that all vacuum hoses are in good shape and connected correctly. A vacuum leak could cause what you describe including starting the engine without the air intake tube installed.

Yotaleigheehoo

I'll also mention that prior to the timing belt change, I replaced cap, rotor, wires, plugs with OEM parts from Toyota. I only drove the truck for about 30 miles and was running like a champ.


When I was trying to slip the belt over the passenger pulley, I had a socket/ratchet on that pulley trying to grab the right tooth. At one point, the pulley spun towards the driver side about a 1/4 turn but since I had the ratchet on it, I prevented from going all the way. I rotated it counter clockwise back into position.

Mike.Jax

It's probably worth taking the timing belt cover back off and verifying the cam and crank positions and doing the two rotations with a breaker bar on the crank to make sue they come back to the correct positions.

If they are good check the air intake to be sure it is tight end to end and no large cracks. Common sense stuff like is the air filter clean and and a mouse hasn't built a nest underneath it as was the case with my Mom's truck. I experienced similar symptoms when the engine side my intake cracked, came partially off, and was sucking in large volumes of air the AFM didn't know about throwing off the fuel mixture.

Also does the roughness level out after the truck gets to temperature? It seems like everytime I drain my radiator and engine of fluid inlcuding during the timing belt/ water pump change the truck ran rough until it warmed up, then it was fine going forward. Your first reaction is oh @#$&# I've screwed it up, but then it clears up.

Good luck. Mike

Yotaleigheehoo

Alright guys, I got her fixed.

I was one tooth off the belt. Hard to believe that it would make such a dramatic change but it did.

I'm gonna park this thing in the shop for now until I get more free time. I wanna double check with a timing light and possibly adjust the idle a smidge.

I bought this about 4 weeks ago and have only driven it maybe a hundred miles. I put in a new Aisisn clutch kit, rebuilt the front suspension/ steering and now the water pump and timing belt. Hopefully this will be a nice little run around rig for me and give my big 1-ton Dodge diesel a break.

Thanks guys.

Sawbilly

Hey man when your truck was off one tooth how did you correct it. I have the same problem going on. It looks like it is in time when manually rotated but with a timing light shining on the cam it looks a tooth away. It runs but i have to adjust distributor all the way to right to get to 10 degrees btdc. It has no power at all. Thanks for your reply.

scope103

This sounds like the distributor gear is off; I'd check that first. The helical gear has 13 teeth, so if you are off one tooth it's about 28°. Very easy mistake to make.