Timing Chain R and R

[Jukelemon]

OK.

It is way past time on my truck so I am looking at doing this in the next few months.

Anybody have a good bit of experience in this i.e. has helped or has completed the timing chain replacement process?

I have read several website posts on it and their instructions but wanted another resource before I start.

Interested in time from start to finish, potholes to watch out for etc...

Thx

 

[WristPin]

first time it took me a week.
now i can do it in a day.

search 4crawler.com

i think he has a write up on this.

 

[WristPin]

oh,
the bolts that hold the timing cover on, most are different size.

you dont need to pull the water pump.

use fipg to reseal the oil pan.

youll have to pull the pan to remove the debris.
unless theres a lift kit, youll have to either drop the front axle or raise the engine.

take out the radiator to give you more room to work.

replace the front oil seal, the tensioner the guide, the gears and chain.

use a wire to hold the chain up, after taking it off the cam gear.
fasten the wire to the hood.

im sure ill think of other things later on.

i have done this job many times.
if you cant reach me on this post, PM me or check in TUT...

 

[KliersLC]

You might want to mic it first and see what it specs at. If you are in specs then there isn't any reason to change it. Th "timing chain" problem on these motors is mostly related to the tensioners, not the chain itself. When I grenaded my first 22r, it had 276k on the motor, and the chain was still w/in specs. I changed it anyway, but just FWIW.

Dan

 

[WristPin]

You might want to mic it first and see what it specs at. If you are in specs then there isn't any reason to change it. Th "timing chain" problem on these motors is mostly related to the tensioners, not the chain itself. When I grenaded my first 22r, it had 276k on the motor, and the chain was still w/in specs. I changed it anyway, but just FWIW.

Dan

thats true.
infact its outlined in the Service Manual.
But like i had mentioned about replacing the other things,
since its a realitivly big job, it is a good idea to just replace it all.
that way your not doing it again in 60K (or whatever) miles.

 

[Jukelemon]

Thanks fellows.

I have read that the engine must be lifted 4 inches or so which requires a floor jack and removing the engine mounting bolts.

When I last did the valve adjusment, the chain seemed real loose but the tensioners/guides were in tact.

When I mean loose, I mean there was easily 1 inch of play in the chain.

 

[KliersLC]

Thats not good, even a worn out chain shouldn't have that much play. I wonder if the RE's have hydraulic tensioners (a la 1fzfe) rather than spring tensioners. WP might know that one, but that would explain it.

 

[2ndGenToyotaFan]

The tensioners are spring loaded, but work off oil pressure when the truck is running.

 

[Jukelemon]

Yes, then that would explain why the chain was loose i.e. engine not running means no oil pressure which means no tension.

 

[WristPin]

The tensioners are spring loaded, but work off oil pressure when the truck is running.

yep.

 

[WristPin]

Jukelemon,
do you want be to post any specific pics of my engine, in relation to your timing cover repair?
I ask cuz i have an engine out of the truck, and am in the process of rebuilding it. i am not in a hurry to do so, but i will take pics of whatever, for you.

 

[WristPin]

Yes, then that would explain why the chain was loose i.e. engine not running means no oil pressure which means no tension.

This explains the proper method of measuring the timing chain. It is in PDF.

And this is the site index, regular html site, but links to PDF.

 

[KLF]

I have read that the engine must be lifted 4 inches or so which requires a floor jack and removing the engine mounting bolts.

Yup.

Take off the valve cover. Drain the oil.

Unbolt the engine mounts, slide a jack under, stick a chunk of 2x4 on the jack so you lift the front of the engine, use the very front lip of the pan, NOT the crankshaft. Lift the engine as far as you can, you should be able to slide a small scrap of 2x4 in each engine mount.

Unbolt the fixed end of the steering stabilizer, swing it out of the way.

Unbolt the pan, pop it off the bottom of the engine, let it fall down as far as possible.

Reach in and unbolt the pickup tube.

Wiggle them both out from under the truck.

 

[Jukelemon]

Jukelemon,
do you want be to post any specific pics of my engine, in relation to your timing cover repair?
I ask cuz i have an engine out of the truck, and am in the process of rebuilding it. i am not in a hurry to do so, but i will take pics of whatever, for you.

Very kind of you.

I am pretty clear on the methods now. I have the FSM for my truck and I have printed off the 4crawler article. Seems like a lot of work so I am goiong to need to clear the shop and have the space ready for a nightly work process through the week.

One question though, the FSM references a key mark for the crankshaft sprocket and a notch for the camshaft sprocket. Also mentions the bright link.

Anybody care to share, in simple terms, the best way to make sure the sprockets/chain is aligned for proper valve timing?

Thx

 

[WristPin]

the dots and bright link dont actually have to line up.
you want them to, so its easier to get every thing alinged.
put the crank so the woodruff key is pointing up, and make sure #1 piston is @ tdc. then when you put the cam gear on, it should have the the dot on top, woodruff key is up. the bright link goes on the dot on the cam gear.
you cant mess this up. the dots, and bright link are fool proof.
the only thing is the #1 has to be at TDC.

if you take the head off, somtimes you have to, you can install it first, but just dont tighten it. cuz the timing cover has to wedge in there. somtimes i like to do it this way, to assure the chain didnt bunch up.

the only thing you have to be careful of is, the head gasket where it contacts the head and cover, can easily get smashed.
i have not been carefull in the past, and mutilated it, where the layers got all frayed. and since it was late and the parts houses were closed, i couldnt replace it. so i put a dab of rtv where it was boogered, and there is no leaks.

 

[Jukelemon]

Remove Head...yeah, that was a concern too. The FSM states this must be done BUT others, including the 4crawler guy, does not mention it.

How can there be a discrepancy to that magnitude? Removal of the head is not like a bolt or two.

 

[2ndGenToyotaFan]

You don't have to remove the head. The book says to because it's slightly easier to replace the chain with it off (I guess), but removing the head makes the whole job harder overall...... You don't even have to remove the pan to do it, but it's a good idea so you can get any junk out of there...

 

[Jukelemon]

I see.

That makes sense.

Do you have to raise the engine regardless i.e. is that pan related or for some other reason? If the tensioners/guides are in good shape, it would seem unnecessary to remove the pan.

Thanks fellows.

 

[WristPin]

I see.

That makes sense.

Do you have to raise the engine regardless i.e. is that pan related or for some other reason? If the tensioners/guides are in good shape, it would seem unnecessary to remove the pan.

Thanks fellows.

the only reason to lift the engine is to remove the pan.
if the guides and such are in good shape, you may not have any debris down there.
but its good measure to do so.

 

[WristPin]

sometimes the head has to come off because the cover is stuck on there, and taking off the head makes it easier to take of the cover.

its really not tha much more work, and since you might end up mutalating the head gasket, (where it seats on the cover) it is a good idea.

but if you do, make sure the coolant is drained out.