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EDIT: It's ALIVE! BWAHAHAHA!Why you change your timing belt:


Sir Sam
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New belt - $80

 

16 new rockers - $752(with shop discount)

 

116k on this belt, belt looked fine, I believe it skipped a tooth on the crank pulley, it REALLY fubared the exhaust rockers, and only moderately fubared the intake rockers.

 

So 116k on this Jeep, only 16k past the change interval, after seeing this failure I see no reason to push the 100k change interval, in fact now I feel that much worse about pushing my own change interval to 113k on my own CRD.

 

Bad rocker:

KJ_TB69.JPG

Not as bad rocker:

KJ_TB70.JPG

 

New rocker($47 each at my shop price):

KJ_TB71.JPG

 

From front to back, worst, bad, new:

KJ_TB72.JPG

KJ_TB74.JPG

 

Left to right, new bad worst:

KJ_TB73.JPG

 

Worst bad new:

KJ_TB80.JPG

 

Worst: roller pushed way down, seized, surface highly spalled:

KJ_TB83.JPG

 

Bad: Roller pushed down:

KJ_TB84.JPG

 

New: No play in roller bearings, roller height higher, surface somewhat rough from manufacturing:

KJ_TB86.JPG

 

Left new, notice height of roller above rocker, protrudes about 1mm, right bad, roller surface about flush with rocker.

KJ_TB87.JPG

 

Left new, right worst, roller collapsed to below rocker surface:

KJ_TB88.JPG

 

Collapsed roller, spalled surface, cam wore grooves into the rocker metal:

KJ_TB90.JPG

KJ_TB92.JPG

KJ_TB93.JPG

 

Compare to new:

KJ_TB95.JPG

 

Notice height of new roller on new rocker(right):

KJ_TB96.JPG

KJ_TB97.JPG

 

Bunch of bad ones laid out:

KJ_TB76.JPG

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yeah. not changing the belt at the proper interval is NOT a good think. in my experience, most vehicles with a timing belt are interference motors. you'd be lucky not to damage the valves.

 

 

direct experience was with 2.1l turbo diesel in an 86 comanche.

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the VM 2.8 L is designed that should the valves impact the piston the rockers are what fails, not the valves.

 

Pricey buggers though.

 

it's nice that engineers took that into account. typically, in my opinion, engineers over-think things and the end result is that common sense is never taken into account.

 

 

is this on your motor, a project jeeps, or a customers?

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the VM 2.8 L is designed that should the valves impact the piston the rockers are what fails, not the valves.

 

Pricey buggers though.

 

it's nice that engineers took that into account. typically, in my opinion, engineers over-think things and the end result is that common sense is never taken into account.

 

 

is this on your motor, a project jeeps, or a customers?

 

This is a jeep I picked up to flip in new jersey.

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the VM 2.8 L is designed that should the valves impact the piston the rockers are what fails, not the valves.

 

Pricey buggers though.

 

 

That goes without saying for most everything about the VM, no?

 

So this was the source of the odd noise, even though the timing belt looked fine, right?

 

That said, I still want one. And now I'm seriously thinking about changing the timing chain on my 2.5 while I have the radiator off.

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Dr. Frederick Frankenstein: [to Igor] Now that brain that you gave me. Was it Hans Delbruck's?

Igor: [pause, then] No.

Dr. Frederick Frankenstein: Ah! Very good. Would you mind telling me whose brain I DID put in?

Igor: Then you won't be angry?

Dr. Frederick Frankenstein: I will NOT be angry.

Igor: Abby someone.

Dr. Frederick Frankenstein: [pause, then] Abby someone. Abby who?

Igor: Abby... Normal.

Dr. Frederick Frankenstein: [pause, then] Abby Normal?

Igor: I'm almost sure that was the name.

Dr. Frederick Frankenstein: [chuckles, then] Are you saying that I put an abnormal brain into a seven and a half foot long, fifty-four inch wide GORILLA?

[grabs Igor and starts throttling him]

Dr. Frederick Frankenstein: Is that what you're telling me?

 

So the rest of my rockers came in today, actually several days early, after a quick dinner of a few pounds of chicken we hopped out to the garage and got to work, got the rockers in, the injector sealing surfaces cleaned up, the intake carefully put back on(this is nerve racking as its easy to knock the rockers off of their perches as nothing really holds them in place). Then injectors, fuel rail, wiring etc, and cranked it over. After a bit of cranking and me forgetting to connector the whatever it is on the back of the fuel rail it fired up and puttered nicely.

 

 

 

So after only $1000 in parts it running, and just needs to be reassembled, interior cleaned, title paperwork done, then its up for sale!

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Although the rockers weren't cheap, glad it wasn't something worse. Now you still have your spare CRD engine and can get back to work on that CRD MJ. That's going to be my next project after my 5.9L Magnum MJ project :D

 

I actually got a little bit of work done on the CRD MJ yesterday.

 

the VM 2.8 L is designed that should the valves impact the piston the rockers are what fails, not the valves.

 

Pricey buggers though.

 

 

That goes without saying for most everything about the VM, no?

 

So this was the source of the odd noise, even though the timing belt looked fine, right?

 

That said, I still want one. And now I'm seriously thinking about changing the timing chain on my 2.5 while I have the radiator off.

 

Yup, belt skipped, fubared rockers, and yes you do want one, want to buy mine? Can arrange delivery to alaska.

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