Rambling about timing chains and stuff

Though it seems to be widely know that timing belts have to be replaced as a preventive measure, every 60,000 mi or thereabouts. I'm still not sure if my timing *chain* needs attention or not, despite researching a lot. (Sorry If I've missed something obvious) I have read that 2.6L engine is an "interference" design so the potential damage is real.

So, for a truck with 172,000 mi and still running great, no apparent problems visible from inside the valve cover, but of unknown history . . . . am living on borrowed time? or should I be good to go? or is the truth somewhere in between?

And if the chain & guides etc. do need replaced, I kinda think with that big an operation I should also be pulling the head off at the same time and checking everything there - MCA delete, check for cracks, check the valves, etc . . . . .

Reliability is a big deal to me as we have plans for fully loaded cross state trips with this machine, and would hate to get into a mess that I should have avoided.

these motors are non interference actually, which means that the pistons and the valves could never possibly meet. if the tolerance is good then you should be good to go. turn the crank and see how long it takes for the cam to start turning. these motors can last a long time with good maintenence and preventative maintanence, as will any motor.

THe one issue you can run into is timing chain stretch. This occurs especially on poorly maintained engines, getting so bad they can tear holes in the valve cover for chain slap! You can check your chain through the little 2 bolt cover on the timing chain cover - it is there where you can adjust the main chain guide to take up chain slop, but don't go to far - binding and chain guide wear or breakage can occur if you tighten it up too much.

When a timing chain is dead, it'll be noisy. No mistaking the sound they make when they're toast. As a rule of thumb, the chains and guides should've been replaced by 125,000 miles. If the engine hasn't been punished but nobody has taken a wrench to it in decades, the noise almost sounds like diesel knock lol.

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Originally Posted by Salteen

these motors are non interference actually

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Cool. Guess I'm never sure what's the right information, I had read several places saying interference.

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Originally Posted by geezer101

When a timing chain is dead, it'll be noisy. No mistaking the sound they make when they're toast. As a rule of thumb, the chains and guides should've been replaced by 125,000 miles. If the engine hasn't been punished but nobody has taken a wrench to it in decades, the noise almost sounds like diesel knock lol.

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Good info, thanks!
125,000 miles in australia, what does that equate to up in north america?

About 125,000 miles lol. I would think that the norm would be about the 90-100,000 mile mark. In kilometres it's about 150,000 kms. at 125,000 miles/200,000 kms the chain would be thrashed. It would need a full kit of sprockets, guides and chains.

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Originally Posted by geezer101

..... if the engine hasn't been punished but nobody has taken a wrench to it in decades, the noise almost sounds like diesel knock lol.

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So yeah my engine does make some mild knocking noises at times. Is this an indication I need to adjust tension? The Haynes manual does not seem to cover this.

Timing chain sound is a chatter.

Though the knocking sound could be from wandering timing. Hard to diagnose a knock over the internet. Could be old rubber engine mounts, or bearings, or pistons and so on
(I once had a weird suspension sound on left turns, couldn't figure it out, I had just rebuilt the lot, a free a week of head scratching and going over every nut again I knocked the horn with my elbow. It flopped around on the mount, it had been knocking the body on turns lol)

Here's an old thread that discusses your questions about the timing chain noise and age:
http://www.mightyram50.net/vbulletin...-to-be-changed

The chain tensioner is integrated into the oil pump and it's not adjustable. It has an internal spring to apply pressure at start up and until there's sufficient oil pressure to take over and drive the tensioner. Until the tensioner is fully pressurized, some light knocking may occur briefly.

With the valve cover removed and using a flashlight (torch) and a large screwdriver, carefully and gently pry the chain away from the left chain guide just enough to view some of the guide's rubber surface. As best you can, look for cracking of the rubber, grooves worn into the surface, and general thinning of the rubber. If present, it's definitely time for a new timing set. And while you're in there, it's a good time to replace the oil pump and the tensioner as well.

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Originally Posted by pennyman1

The one issue you can run into is timing chain stretch. You can check your chain through the little 2 bolt cover on the timing chain cover - it is there where you can adjust the main chain guide to take up chain slop, but don't go to far - binding and chain guide wear or breakage can occur if you tighten it up too much.

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Pennyman, I don't want to doubt you since you've owned your D-50 for 40 years and I'm barely coming up on ... 40 days.

But it looks to me like the *timing chain* has a self-adjuster controlled by oil pressure and not user-adjustable. And then there is the *silent shaft chain* which has an adjustment, shown below in the manual. That's the one you adjust thru the little 2-bolt cover. Do I got this right so far?

Since the manual tells you how to set the silent shaft tensioner with the whole front removed, one can only guess how much to tighten this if you only have the little 2-bolt cover off. (like you said, don't go too far) Should I assume that going clockwise on the "special bolt B" is the way to tighten it?

I'll definitely be checking the timing chain and guides more (per the post from Mr. FMS88 above).

Attachment 24505

I have to check now to be sure - the one on Geronimo is at the top, not at the bottom.

Following this thread. I have a 1989 Dodge Ram 50 with a massive timing chain issue. Literally sounds like the engine is tearing itself apart. Do you think it's past the point of just tightening the chain up? Repair shops want an arm and leg to do the replacement work. Does anyone know of a good "how to" video or guide on performing this repair?

Camcopper, you can download a Haynes manual for this truck here on this site in the manuals section. It'll give you the procedure. I've read it & am comfortable with it (I think). But I'm still not sure if I'm going to do it. You say you have a massive timing chain issue with significant noises happening so you should get to the bottom of this soon. I don't believe you have the option of just tightening the chain up. It doesn't have manual adjustment. It has an oil pressure driven tensioner. Good luck.

One more thing - somewhere on here is some advice on what brand of timing chain is best. If you go forward with this, I would be sure to read up! Maybe someone will be nice enough to post that info here.

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Originally Posted by camcopper

Following this thread. I have a 1989 Dodge Ram 50 with a massive timing chain issue. Literally sounds like the engine is tearing itself apart. Do you think it's past the point of just tightening the chain up? Repair shops want an arm and leg to do the replacement work. Does anyone know of a good "how to" video or guide on performing this repair?

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If the timing chain is that noisy, you can be guaranteed that the guides are worn past their serviceable point. When exposed to that level of wear they also wear the chain sprockets are well. This isn't a 'complicated' fix but is time consuming - one of the reasons why this site is so popular is it allows novice mechanics access to info needed to DIY repairs. Be prepared to have the engine in pieces for at least 2 days and take the engine out to do it. Added bonus is you can give the whole engine a super clean which will make working on it easier. Yes, more work removing it but once it's on a stand it'll be far more forgiving to take apart and install. There are cheat ways to replace a chain like feed it in from the top but this is a short cut to a disaster. As charger_john has posted there is a service section on the site. The hardest part of this might be removal of the crank pulley (they can be stubborn) You will need the whole timing kit and I would replace the water pump while it's in front of you (unless there's a feasible excuse not to due to recent replacement)

Cam - I agree with charger_john on this. The Haynes Manual helped me first time through, and I had little / no mechanical experience. I'll save you some headache upfront and say that you will want to drop the oil pan and remove the radiator; the latter is a no brainer since it gives you more room to work. You can do this with the oil pan in place, but putting the timing cover back on can cause gaskets to break/bind and cause leaks at the top of the oil pan. Since the timing cover is sandwiched between the head and the oil pan.

I'm not sure where the timing chain information charger is referencing is located, but read up on recommendation on the site (as well as past stories from other) to learn a few dos and don'ts before you tackle this yourself. It is not a terrible process to get to the timing chain, just follow manual.

Hope I'm not hi-jacking this thread. I just replaced all chains and sprockets on my '89, THEN noticed I could pull out on the spocket on the upper silent shaft and it would move about 1/4". Surely it is not supposed to do this. Is there a retainer clip or thrust washer, or something that is missing or broken? I did have the bolt out to replace the sprocket. Could something have fallen that I didn't see?

I believe there's meant to be a retainer clip holding the sprocket in place. I had someone replace timing chains on a 4G52 and something was overlooked on that side balance shaft. It blew a hole in the timing cover when the guy started it :shakehead:

thank you geezer. there is so little clearance there I felt the shaft would eat the cover. looks like I un-time the small chain and do a look-see. thank you. you earned the site a little donation!

geezer101 is the MAN :helpsign:

Site gets a win - I'm good with that. And you don't destroy a timing cover! One less thing you have to chase :thumbup:

I have a 4g54 in my 87 ram50 but the previous owner i got this from said there was a timing issue but it would run and it ran but you could hear the timing chain slapping around - what i found was the long timing guide was completely sheared off and they ran it long enough to reduce the bolts holding the remnants of the guide almost completely flat none of the junk yards have replacement timing guide bolts and i am looking for the bolt replacement size

Are the damaged bolts for a cam chain guide or a balance shaft chain guide? If the balance shaft, is it the upper guide that’s sheared off?

balance shaft has been deleted it is the main timing chain guide on the driver side tried uploading a photo but it wont let me

I believe the bolts threads are 6x1.0mm, 15mm in length and take a 10mm socket. I think they're stamped with a "7" (hardness rating?). Should be the same number as stamped on the bolts for the oil pump.
Look at this post:
http://www.mightyram50.net/vbulletin...reaking-guides
Does your chain guide look like user rworzala's? Can't tell for sure, but it looks like his fix was to replaced the oil pump and tensioner, too, since he found them badly worn and grooved.