• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

what is your preferred timing chain? do you think gears are OK for 6.5L?

GM Guy

GM Guy

Manual Trans. 2WD Enthusiast
Messages
4,838
Reaction score
846
Location
NW Kansas and SC Idaho
hey everyone.

thought I had this all figured out, but with the price, I am kinda wimping out.

what is best, Timing chain, or timing gears? if gears, does anyone besides Kennedy sell them? 400+ bucks is a tough one to swallow, but I will if necessary.

for those that believe in the chain, what brand?

all discussion appreciated and welcomed. points to consider is longevity, durability, long term accuracy, cost, etc.

thanks!
 
Barry seemed to like Cloyes (sp).....He didn't like Melling, and he's changed a few, to say the least.

You can search some of his posts, but I believe that was his choice.....I'd feel good with his take on that.


But thats just me.......Again, JMO Brother.
 
I can tell you a certain engine builder uses stock GM timing chain and gears. And his truck has gone 163mph at Bonneville. And not new ones either!
 
635 said:
I can tell you a certain engine builder uses stock GM timing chain and gears. And his truck has gone 163mph at Bonneville. And not new ones either!
Click to expand...

Good enough for me......Think about it, your OEM chain thats in there RIGHT NOW is good for at least 100,000 miles and I'll bet there are many more still spinning with twice that amount.....

Just to throw it out there, GMCTD (The Guru) jd, always said that the "sprockets" were where the problem is, the Low spot/bottom of between the teeth is what gets worn and thats where the problem is and why your timing gets skechy......I'm sure the Chain itself does stretch a bit, but the sprockets between the teeth is what sends it to the point of no return.

Jeez, that guy is Missed........Stuff we haven't learned yet, he's already forgot:???:
 
so you folks think my 250K unit might be good for another 50-100K? if so, I willl just adjust timing. I was thinking the timing hasnt been changed from new most likely, and if it was close to right, a gear drive set would be a nice way to cheat! :)

I like the fact that the gears keep the timing dead on, but not knowing of many 6.5Ls running them, IDK if they negatively affect the durability.
 
I thought they discontinued the gears for the 6.5's.

What are you building? Because gears are like head studs for a 6.5 - one of the things that makes a weak area better. How many more miles do you expect the high mile 6.5 to last? Cracks would worry me before putting $400 into a engine.

My chain stretched to sloppy in 30K miles even the loved Cloyes sets. The sudden pressure the injection event puts on the chain stretches it out. The set is extremely tight on install and is sloppy at 30K miles when I tore my engine back down. Course spec is 1/2 of slop. Your valve timing suffers as well as IP timing.

So you have an initial stretch of the chain and then wear and stretching.

Once and a rare while even a new chain can break. Watched them pull an engine out of a new 1998 gas Yukon with 42 miles on it after replacing a broken chain. The tech wondered why it didn't run right to the service adviser. "Isn't that a interference engine?" I told them. They decided to swap the engine rather than figure out what all got bent up.

Again depending on what you are doing. The chain isn't fun to get to. That high of miles I would swap the sloppy chain out. I wouldn't put gears on it unless I pulled the engine and knew the mains were crack free. I will run gapless rings before I would go gears due to my budget.
 
Gears have been said to cause unnecessary vibrations/harmonics in the engine. There are probably quite a few trucks running them with no problems though.

For me new Hoyles only if its out of spec. Otherwise im going to keep truckin.
 
warwagon,

this is on the 93 K2500, I plan on getting it to the point where it wont self-destruct with a load. It did fine this winter at 18K combo but summer out west is a new story. I take it crank failure is likely to chew up gears? as far as extra vibes, a fluidampr is going on.

I was aiming for another 100K! :) I do plan on putting reusable stuff on though so if she stuffs a rod, I can swap everything to a teds motor.
 
Brooklyn Tow said:
The OEM timing chain setup is a weak spot on the 6.5 TD?
Click to expand...

They get some slack and then set there for a while. A few main factors, maintenance, heat/load..

Based on what I've seen, I'm doing timing sets every 40-50k now with the inferior parts that are made today.

OEMS go 200k but they're loose loose.

So far i've not heard of an out and out failure as in chain slippage or breakage.

It's perpetual. A little slack here gets you altered cam timing there gets you altered fuel timing there gets you a less efficient engine that builds more heat and stress that affects all the moving parts within it, the process repeats.. (does that look right, on paper? :D)

Anyway..
 
3500GMC said:
They get some slack and then set there for a while. A few main factors, maintenance, heat/load..

Based on what I've seen, I'm doing timing sets every 40-50k now with the inferior parts that are made today.

OEMS go 200k but they're loose loose.

So far i've not heard of an out and out failure as in chain slippage or breakage.

It's perpetual. A little slack here gets you altered cam timing there gets you altered fuel timing there gets you a less efficient engine that builds more heat and stress that affects all the moving parts within it, the process repeats.. (does that look right, on paper? :D)

Anyway..
Click to expand...




"I'm doing timing sets every 40-50k now"

But your a Maniac.......A little overkill ya think :hihi::thumbsup:


"(does that look right, on paper? :D)"

:rolleyes5::D
 
Sometime this summer I have a HO water pump to install on the 6.2. It's got 12k on a new build/chain.. Bet it's got SLOP..

I'd do geared timing but I'd like to see helical cut gears. (impossible the way the timing setup is now)

Straight cut gearing would introduce more harmonicas. I hate harmonicas.
 
They all got some give.....But there are so many sloppy chains (not many people servicing them) and rigs are still breaking new ground.......On the flip side, (Like you said) that is why you hear so much about Poor mileage, or at least a serious contributer.......


Isn't it hard to play a Harmonica while your driving.......With one hand?........Slippery little Ba$tard$ :D:rof:
 
I wonder if the companies would be willing to listen to the plee of a few enthusiasts. Us small guys that depend on these rigs need servicable and reliable parts.
 
Interesting info here, makes me wonder about me timing set. Mine is all original along with most everything else on the original motor, 240k miles and still running great.
 
Our engines do not have any sort of tensioner for the chain so they just slap around in there as they wear. Some engines have a tensioner, the Series 2 3800 GM does, for example.

You will notice a gain in performance with a new timing set. I've done numerous high mile gassers and noticed some seat of the pants gains.

I remember the dreaded NYLON cam gears on the GM small blocks of old.. That was a mess.
 
so If I am deep enough for a damper replacement and WP replacement, I should put some timing gears in 250K is likely pushing it?

it sounds like my choices are made for me: the factory chain, or gear drive set, otherwise, teardown every 50K! :)
 
If WarWagon gets 50k out of a set most of us will likely get 100k. He tends to abuse his just a bit.;)
 
You must log in or register to reply here.
Back
Top