greatskiiiier

is it possible to tell if the timing chain has already been replaced? truck has 135000 miles on it, PO only had truck for 4 months and said he thinks the guy he bought it from replaced it but hes not positive

Thanks in advance

SoCal4Running

You mean without disassembly just by looking at it.

Do you see any indication of colored RTV around the timing cover to oil pan or the timing cover to cylinder head?

Is the timing cover a lot cleaner than the rest of the engine?

Either of these would mean that the cover has been off recently for most likely a chain change.

85toyman

iTrader: (2)

To get to the timing chain you would really need to pull the cover off to check the guides and tensioner. Which means your already there. It is cheap insurance to just change the thing your self and know you can go another 100k before it needs to be done again. I just changed one on a friends of mine last week and I had it torn down and back together in one day. Just get all the parts you need before hand and spend a day to make sure it is done.

Just my 02

greatskiiiier

no colored RTV but gasket appears to be new/ remarkably good condition for being 24 years old, cover doesnt look "clean" but does appear to have only have a thin layer of new gunk that could come off with 1 spray of brake clean as apposed to the rest of the block

i dont want to do that because ive been a mechanic all summer and am finally back at college and dont want to spend my first weekend back doing the same ˟˟˟˟ ive been doing all summer, know what i mean? exp when ive have all snap on tools and a lift, going back to a driveway kinda sucks, plus i REALLY dont feel like pulled a head in my campus parking lot
HOWEVER, i will if i MUST

85toyman

iTrader: (2)

I understand that you don't want to do it when you have done it, but you don't need to pull the head to change it. Just tap it on and off between the head the oil pan. If there isn't any RTV silicone then it most likely has not been replaced. Good luck

toyota4x4907

Its very possible. The lifespan of a 22re t-chain is only 100K-150K miles.
Some sooner. Some people dont change it until well over 200K.
I bought my '93 single cab with 87K original miles on it. It already had the t-chain replaced and steel guides installed.

greatskiiiier

aftermarket timing chain guides arent plastic right? so i can just pull the valve cover and see if they're plastic (stock) or metal if they've been replaced. am i correct in my thinking?

85toyman

iTrader: (2)

You cant pull the valve cover and see anything. The head casting is solid under the cam shaft and distributor. There is a bolt that holds the top of the timing cover. It is located under the dist. drive gear that is off the front of the cam shaft. The point I am making is that you cant check the guides, chain, tensioner ect with out removing the timing chain cover. If your going to remove the cover then your already their and commen sense would say that you change the chain. No, metal guides are not in most aftermarket kits. You would have to look for them. The aftermarket kits usually have plastic guides.

peow130

What? No it isnt.
You can pull the valve cover and see down into the timing chain cover.
I know i did, to see that i had no timing chain guides left.

And, the aftermarket kits have metal backed plastic guides.
Meaning, the main assembly is metal, with a plastic compound on the part of the metal that comes in contact with the chain.

engnbldr.com has the entire timing chain kit, with metal backed guides, both guides, tensioner, gaskets, and chain and sprocket set..
for 56 bucks.

85toyman

iTrader: (2)

I know that I have tired to look down where the chain goes thru from the cam and while there is hole big enough for the chain to go thru, it does not give you a big enough view to see the guides as a whole or the tensioner (THE CHAIN IS IN THE WAY). I have noticed on several occasions the top of guides to look good, only to remove the cover and find the middle or bottom of the guide to be completly missing or broken. There for this is not a very reliable way of checking the guides and it does not give you the ability to check the tensioner. I have purchased many timing chain kits and the ones that most auto parts stores carry around here are plastic guides non metal backed. I just want to help him out and make sure he looks at the parts he is buying and not being told he is gettin something when infact he is not. Not everybody buys from engbldr.com. I would bet he was most likely lookin at NAPA or Autozone ect name the store.

I would guess that the noise of the chain slapping the side of your timing cover should have been a give away that the guides were gone long before having to look down the small hole the chain is going thru to let you know that the guides were gone. $56 for the whole kit is a heck of a deal does that include shipping? Last kit I bougth with all that was in the upper $70 range and had plastic guides.

Good luck looking down there to determine anything other than you have a chain. Congrats. Just pull the cover and be done with it.

peow130

Yeah, 56 with free shipping..
Check the engnbldr.com site.
It's like 80 bucks with a new timing chain cover, too.

pruney81

When I pulled my valve cover I was able to look down and see that both my guides were in good shape and still intact. After 105K miles they didn't even have so much as a scratch on them.

To the PO, aftermarket guides can be metal or plastic depending on where they were bought from.

At any rate, I wouldn't take anyones word unless they have paperwork, otherwise just listen for any noises or if you are really concerned, pull the valve cover and check it out. It helps to shine a flashlight down there if you want a better look.

greatskiiiier

no noise at all, just dont want to be left with a head full of bent valves, so the first thing to break is the guides? so if they're intact i can wait till i start to hear the chain making noise before replacing, is this a safe bet?

Olas

I just rebuilt my motor with 188K miles on it. Everything was stock, including the guides and chain. When I bought the truck I took the valve cover off and was able to see that both of my timing chain guides were broken. The passenger side's top half of the guide was just resting there and I was able to pull it out with my fingers. What made me want to look under the cover was the "rattlesnake" sound caused by the chain slap on the timing cover. It wasn't always there, it came up randomly but you could definitely hear it.

If your guides look ok i'd leave it alone till you have time to take it apart yourself for the peace of mind and another 100k miles.

I don't know how common it is for the chain to break and cause valves to collide with the pistons. But I think it's far more common for the chain to wear through the timing cover once the guide is gone and then you have coolant mixing with your oil which is not a good thing. Mine was definitely on its way to doing that.

85toyman

iTrader: (2)

I alwasy like to change just as peace of mind, if you don't hear any noise then you should be ok. It is just something I would change when you get a chance. Better safe then sorry.

pruney81

If your guides are in good shape and intact I would leave it alone until it needs to be done unless you can do it yourself no problem.

Sometimes, the guides on these will last upwards of 200K miles. Sometimes they will fail earlier than that but in the 3 22RE trucks and 4Runners I've had over the years I've never had to deal with a timing chain problem. I think a big part of it has to do with how the truck was taken care.

Maybe a lot of guys buy used trucks that have been beaten on and have to replace the chain, I'm not sure.

Teuf on this board bought his truck truck new in the 80's and now has 270K on his original timing chain components so I wouldn't worry about it if I were you.

I would just pop off the valve cover and take a look though.