Replace timing chain or no?

[Johnny2Bad]

If it's stretched (too much play) it needs replacing. Doing so should result in smoother idle and slightly better fuel economy.

There is a Mopar Performance (MP) part for your Jeep 4.0 but it's expensive (unlike the one for the 5.2/5.9 V8 in my truck), they are better units in every way but you won't get the added $50 in performance out of a stock motor.

The generic OEM-quality replacement sets are dicey in my opinion but aftermarket "true roller" sets are excellent quality and probably the source for the Mopar Performance part (Cloyes, Melling, etc). About $20 less expensive than MP.

Agree, always replace as a set.

 

[Merkava_4]

^ Are true roller sets available for a Jeep 4.0 ?

 

[Revving2Redline]

Replace it. Its cheap insurance.

 

[Lubener]

Originally Posted By: StevieC
Mopar is pretty fair with their part pricing I have found. Yes they are more than aftermarket but when you consider the quality and the warranty etc. it's worth it.

Don't get hung up with OEM. There are several good aftermarket alternatives which may be better than OEM. Cloyes, Sealed Power come to mind and likely one of them supplies OEM components anyway. I have used Cloyes on many occassions.

 

[dlundblad]

Originally Posted By: Lubener
Originally Posted By: StevieC
Mopar is pretty fair with their part pricing I have found. Yes they are more than aftermarket but when you consider the quality and the warranty etc. it's worth it.

Don't get hung up with OEM. There are several good aftermarket alternatives which may be better than OEM. Cloyes, Sealed Power come to mind and likely one of them supplies OEM components anyway. I have used Cloyes on many occassions.


Rock Auto has the entire Cloyes set for $78 and the Sealed Power set for $63. Never heard of either brand, but they're worth considering. Thanks.

It's hard to say if they used stock photos or not, but the Sealed Power looks identical to OE.

 

[DuckRyder]

Sealed Power is a Federal-Mogul brand (Moog, Speed-Pro, Wagner, Fel-Pro) it will be decent stuff.

Cloyes is a respected brand, it will be very good. They make a double roller chain for it if you are planning to keep it forever.

 

[BigD1]

If you plan on keeping it for a long time, definitely go with a full timing set. Happy with the Cloyes heavy duty set I installed a few months ago on my Toyota pickup.

 

[jeepman3071]

If you are already in there I would replace it.

Timing chains seem to be hit or miss with these. I've opened up 4.0 engines with over 200k that had very little slack if any in the chain, and others that were very loose.

 

[dlundblad]

I went ahead and pulled the trigger on a Cloyes set. I bought an aftermarket guide/ slack reducer too.

It's interesting. I can't get the lines on the gears to both face straight up. One will be at about 12:00 and the other is at 11:00. I wonder if this is because the chain is so bad.

 

[WobblyElvis]

Slow down here, if the marks aren't lining up you have a problem. Look up the specs and do the job right.

 

[WobblyElvis]

Perhaps they are supposed to point towards each other, see video here.
https://www.youtube.com/watch?v=PfW_StKs3Yw

 

[dlundblad]

My Haynes book wants the camshaft mark at about 1:30 and the crank mark at about 2:45.

They also want 15 pins on the chain between the two marks.

 

[mightymousetech]

Originally Posted By: Merkava_4
You should replace the cam and crank sprockets too---otherwise, the teeth are a little worn and your brand new chain would have to "wear in" to the sprockets. You'd be wearing your new chain out faster. I don't know why they don't come as a set---pretty dumb not to have them available as a set.


Honda says all gears and chains must be replaced together. Makes for a much bigger job than just the chain. Honda also says chain wear is not normal, it is a sign of lack of proper lubrication.

 

[dlundblad]

The Cloyes kit came in today. US made too.

 

[Merkava_4]

Originally Posted By: dlundblad
My Haynes book wants the camshaft mark at about 1:30 and the crank mark at about 2:45.

They also want 15 pins on the chain between the two marks.


That's crazy. You should be able to line up the dots on the gears.

There's one cam gear and one crank gear correct ?

 

[dlundblad]

Originally Posted By: Merkava_4
Originally Posted By: dlundblad
My Haynes book wants the camshaft mark at about 1:30 and the crank mark at about 2:45.

They also want 15 pins on the chain between the two marks.


That's crazy. You should be able to line up the dots on the gears.

There's one cam gear and one crank gear correct ?


Yes. I went ahead and ditched my book and went to the factory service manual.

The marks need to be facing each other.

 

[Merkava_4]

Originally Posted By: dlundblad
The marks need to be facing each other.


Exactly!

 

[NYEngineer]

Few years back I had a 98 Yukon. I kept getting random misfire codes whenever I accelerated hard. I figured since the distributor was driven off the cam and the cam was connected to the crank by a chain and the truck had 200,000 miles on it, I would replace the chain.
I used a Cloyes roller and gears. After the swap, the truck ran awesome all over again. I think my brother took that truck after I got a new one and ran it up to almost 300,000 miles. He gave it away running fine.

If I had the balancer and timing cover off, it wouldn't have even been a question. Chain woulda been changed. And yes, those marks get lined up or the engine will never start.

 

[jeepman3071]

Originally Posted By: dlundblad
Originally Posted By: Merkava_4
Originally Posted By: dlundblad
My Haynes book wants the camshaft mark at about 1:30 and the crank mark at about 2:45.

They also want 15 pins on the chain between the two marks.


That's crazy. You should be able to line up the dots on the gears.

There's one cam gear and one crank gear correct ?


Yes. I went ahead and ditched my book and went to the factory service manual.

The marks need to be facing each other.


Good choice. I have a Haynes and a FSM for my Cherokee. The factory manual is 100x better.

 

[dlundblad]

As of now, I can't get the crankshaft sprocket off. My Hanynes book and various sources online say something about a key that needs removed. Perhaps this is for older models?

Looks like all I need is a small 3 jaw puller.