Originally Posted By: wag123
Originally Posted By: KrisZ
Originally Posted By: wsar10
No your very incorrect here, a chain just like ANY mechanical part will wear
PERIOD. I work with a mechanical engineer on my team at work, we have this conversation all the time.....
I agree that a belt should need maintenance before a chain. Contact ANYBODY with an engineering background or a professional engine builder and they will tell you the same. To make that decision based on what a manufacture says is "maintenance" is foolish ! Thats half the purpose of this forum, dismissing the "maintenance schedule" and educating yourself through science about your REAL maintenance needs of a vehicle.
Since you already know that
every moving part will be subject to wear during engine operation. Why are you suggesting to change only the timing chain at 100k miles? What about cam shafts, valves, pistons, main bearings? They all wear and you can be sure that they will not be exactly the same as brand new.
What you're not getting from your engineer friend is that all mating parts are made to specific clearances and unless those clearances go beyond the maximum specifications, the engine will not be considered worn out by any mechanic or engineer. Same thing applies to the timing chain.
The "foolish" part is squarely on you
+1
wsar10, have you priced the replacement cost of a timing
CHAIN in a modern OHC or DOHC engine lately? Call a Ford dealer and ask them how much it would cost to replace the timing chain, gears, and tensioners in the Explorer you are looking at. If/when you do, you are in for a rude awakening! On some FWD/AWD vehicles the engine has to come out to do this.
Yes, timing chains DO wear, but so do all of the other internally lubricated engine parts like pistons, rings, cylinders, bearings, oil pump, camshafts, followers, valves, etc, etc. One would hope that the engineers have designed their engine in such a way that all of these internally lubricated parts wear out at about the same time, including the timing chain. That is what is SUPPOSED to happen, although we all know that it rarely works out that way.
I understand the expense, 4 guys at work just had theres done (1 4.0 Ranger and 3 explorers, and the guy I spoke of earlier just did his own in his V10 F-350 @160K. We have an old Subaru that we just had done last winter (Ive owned many subarus and had every timing belt replaced as normal 100k maintance. Out all the fords that were done only 2 exhibited issues, (v10) lost all its power and dipped to less than 10MPG, the other (03 explorer) just had allot of valve train vibration and noise due to the tensioners being worn so bad therefore the chain was vibrating around (due to the normal stretching that happens to chains). On all 5 engines the highest mileage was 160K and the lowest was 110K, and the tensioners on all engines were maxed out out.
As far as our explorer I was quoted 2 grand today, If we are going to keep this truck until the wheels fall off than I will have the service done next summer or if I start hearing the oh so common slap or vibration. The only (long term use) vehicle that I have NEVER done timing chains on are my 4.0 JEEP's, IIRC they are a dual style chain. Wait till some of you guys have one fly apart without warning....THAN you'll wish you had spent the money on the service vs a motor rebuild.