Timing Chain schedule replacement? When? 3.7L v6 liberty 02-08

[bratt]

Timing Chain schedule replacement? When? 3.7L v6 liberty 02-08

When are the timing chains supposed to be replaced?

I do not see it on my Haynes manual!

[2000izusu]

Originally Posted by bratt

When?
I do not see it on my Haynes manual!

you don't see it in the manual because the three chains are usually good for the life of the engine. their is no replacement recomendation.

now with that said: keep in mind, timing chain failure (which is rare) is caused by not keeping the oil changed. when oil looses its lubricity the chain stretches.

so just keep up on your maintenance and enjoy. mike

[typesix]

Also minimize hard acceleration and wide open throttle conditions.

[bratt]

Originally Posted by 2000izusu

you don't see it in the manual because the three chains are usually good for the life of the engine. their is no replacement recomendation.

now with that said: keep in mind, timing chain failure (which is rare) is caused by not keeping the oil changed. when oil looses its lubricity the chain stretches.

so just keep up on your maintenance and enjoy. mike

Give me a break, Timing chains stretch out and will fall off over the miles!
I'm looking for people who know when the timing chains have started to make rattling noise, or when they actually fell off. please log your miles and report so I know about how long they last. The ford mustang 4.6l modular motor has similar timing chains to the v6 liberty. *2 chains around the cams and crank* they typically last 120k miles

[2000izusu]

Originally Posted by bratt

Give me a break,
I'm looking for people who know when the timing chains have started to make rattling noise, or when they actually fell off.

Bratt, (fitting screen name by the way) Did i say something wrong? or do you always come off arrogant and unthankful for free advise (that i took time out of my day for, to answer a question that can be found with searching any liberty forum)?

in my experience i have never seen one "come off." there is a guy over on jeep forum with 325,000 miles on liberty with the original timing chain (link below)

Link: Look in colorado's gallery he has a picture of the odo before he traded it in:

http://www.jeepforum.com/forum/showt...47%2C000+miles

good luck with your life and you entitlement complex! mike

[bratt]

I am very liberal.

I know chains on motorcycles stretch and break too. I have seen it many times. It is mere physics sir.

Im sorry to burst your bubble. I am in awe that the timing chains lasted 325k on a liberty. I would never think that would be possible with the new crank to cam designs. I know the single overhead cam in the middle with 1 chain on the crank did last much longer than the new design where the crank is wrapped around 2 cams on each side. I am guessing 120k max on the new design.

I did follow your link to see the posts about the liberty
I do not believe all maintenaince has been stated in words. I read this part here and I can see he had a mechanic performing regular maintaince on this liberty

COLORADO
Registered User
2007 JK Wrangler
My Specs
Engine: 3.7L
Transmission: AUTO
Axle Gear Ratio: 4.1 REAR AXEL
Future Mods: IN DASH COMPUTER
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Join Date: Mar 2007
Location: COLORADO SPRINGS
Posts: 116
Profile
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iTrader Rating Liberty in the shop for routine service at 320,000 miles. Transmission flush, rear axel and transfer case fluid change. Only problem dealer found was a leaking transducer on the transmisson. I told him to replace it. I don't know how much longer my luck will hold on this vehicle.


Not to mention, your role model claimed he used this car mainly for only 200mile daily trips on the highway. This means the stop and go pull of the city lights on the chain were minimal as claimed below! This is a rare case!

COLORADO
Registered User
2007 JK Wrangler
My Specs
Engine: 3.7L
Transmission: AUTO
Axle Gear Ratio: 4.1 REAR AXEL
Future Mods: IN DASH COMPUTER
User Profile



Join Date: Mar 2007
Location: COLORADO SPRINGS
Posts: 116
Profile
Gallery
Classifieds
iTrader Rating I have a 100 mile one way commute to work, 200 miles a day

[2000izusu]

it might be rare but what about the courier vehicle in the first post with 247,000 miles it has the original timing chains!

go over to the lost liberty forum lots of libertys with 150,000 + miles and original timing chains. in fact i don't even remember hearing about somebody replacing one?

just because the ford 4.6L eats them at 120,000 doesn't mean they all do!

[bratt]

I have a family liberty here not a delivery courier liberty. We run to the store and back and thats about it!

Originally Posted by 2000izusu

it might be rare but what about the courier vehicle in the first post with 247,000 miles it has the original timing chains!

go over to the lost liberty forum lots of libertys with 150,000 + miles and original timing chains. in fact i don't even remember hearing about somebody replacing one?

just because the ford 4.6L eats them at 120,000 doesn't mean they all do!

True, the liberty has 3 timing chains not 2. The liberty is not a v8. a v8 will put more power torque and stress on the chains during acceleration. That does make a lot of difference! I can see your point!

I was merely trying to find information so I dont loose my motor when the chain falls off or slips

[Oppenheimer]

To clarify, chains don't 'stretch', they simply wear between the pins and links, and that minute wear from each link adds up to a longer overall chain. so the chain does grow longer, but it does not actually 'stretch'.

That wear means the chain pitch no longer precisely matches the pitch of the sprockets, so they begin to wear to try and match that pitch. (so always replace chain and sprockets together, if one is worn, so is the other).

While its true that bicycle and motorcycle chains wear rather quickly (compared to a timing chain inside an engine that can last the life of the motor), think about the environment they live in. They are out in the elements, with no continuous lubrication source. Any lube they do get, tends to attract more dirt and grit, which works its way in between the pin and link, greatly accelerating wear.

Contrast that with an engine timing chain. It lives in a sealed environment, with a constant supply of filtered oil. Consider also the ratio of length to width between engine timing chains and bicycle and motorcycle drive chains. The timing chain is much more robust. Think about the load, all the timing chain has to do is spin the cam(s), and bear the load of the valve springs and all the friction points, while a vehicle drive chain has to bear the load of moving the weight of the entire vehicle and cargo up hills, from a dead stop, etc.

Stop & go driving was mentioned, but I’m struggling to see how the load on an engine timing chain would vary much between stop & go and steady highway cruising, except that the rpm’s will likely be higher from time to time during stop & go. That of course isn’t true for other internal parts of the engine, say rod & main bearings. More acceleration means more load, but all the timing chain sees is the load from the valve train and the rpm’s, it won’t care if you’re pulling those rpm’s while accelerating like mad up a hill, or the same rpm’s cruising downhill.

To be sure the timing chain WILL wear, but so does the rest of the inside of the engine. The question is did the designers of your engine build a chain that will wear out about the same time as the rest of the engine, or not? I’d bet that barring problems with metallurgy, etc, that most engine timing chains will outlast stuff like main & rod bearings. So who cares if the chain does wear, so long as it doesn’t wear out before things like your engine bearings?

Unlike a bike chain, where you’ll end up needing to change it out many times over the life of the vehicle, an engine timing chain should last until its engine rebuild time.

[pies]

if any of you had ever changed a timing chain, you would know that the chain wears very little, the gears are what wearthe most. putting anew chain on will seem tighter but if put new gears in you can put the old chain on and it will be tight. i have done many

[fredjacksonsan]

Bratt, just check the owner's manual. It will tell you the recommended change interval. Obviously you're used to a vehicle with a timing belt, which generally need to be changed at intervals.

On the old Chrysler 318/360 from the 70's through the mid 80's, the timing chain would wear and cause timing problems every 75k miles or so; this issue was solved in later designs, so while it's possible for a chain to wear, it's unlikely.

Drive your Liberty and don't worry about it, until and unless you reach the mileage in your owner's manual.

[radioads]

Wow its really great to know that how brilliant people are here, i did not knew these facts before, thanks for all of you.

[jeffwilliams2241]

Bratt the reason that timing chains on bikes do not last long on bikes is that fact that they are not constantly riding in oil. The chains on motors do not have a recommended service/replacement date because if the oil is chained regularly then the chain will only have minimal to no wear! 2000izusu is correct when he said that these chains last the life of the engine.

[Crazyeye]

I know that this post is old but to put this to bed I have a Jeep Liberty with 240.000 kilometres on it and have taken this jeep off roading plenty of times, it has been through a lot of bud and some sticky high throttle situations but yet still has original timing chain on it. Never been replaced or repaired.

[Crazyeye]

Been through a lot of mud not bud