what started all this ?

what started all this ?
C

cjnewbie

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plainfield indiana
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79 cj7 360 3 speed
im sure it realy doesnt matter at this point but i got my jeep with the motor pulled apart and this is what i have been told and found. so the guy said he was driveing the jeep and the timeing chain broke when he pulled it apart he found a few bent push rods so he replaced them and had the heads rebuilt just in case but now that i am putting it back together i have found that several of the rocker arm guids or what ever you want to call them the "U" shaped pieces broken so now i am starting to wonder what realy happened anybody have any ideas? by the way it is the AMC 304
 
cjnewbie said:
im sure it realy doesnt matter at this point but i got my jeep with the motor pulled apart and this is what i have been told and found. so the guy said he was driveing the jeep and the timeing chain broke when he pulled it apart he found a few bent push rods so he replaced them and had the heads rebuilt just in case but now that i am putting it back together i have found that several of the rocker arm guids or what ever you want to call them the "U" shaped pieces broken so now i am starting to wonder what realy happened anybody have any ideas? by the way it is the AMC 304
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he had the heads rebuilt, were they on the engine or did you put them on? these "U" things of which you speak are they bridging the intake and exhaust rockers?:cool:
 
i think the u shaped things you are talking about are the valve guides. either way if the timing chain broke, the cam stops rotating, and sometimes depending on the motor and clearance tolerances a piston could of hit a valve causing push rods to bend, the jolt from that impact could very well break the valve guides. even if i am wrong, i would seriously consider pulling off the heads and carefully inspect the pistons, and conecting rod bearings. iff all seems good, spend the 40 or 50 bucks for all new push rods and also maybe the rockers if you didnt already. check all the internals in the motor make sure it is all good before you waist your time putting it together and something is actually broken.
 
I would like to see some pictures of these "U" things broken and not.:cool:

I am still trying to picture a situation where the push rods bend, I have seen broken but not bent, and broken rocker bridges. The only possibility I can see is if the rocker stud nuts worked loose. That could cause both symptoms.
I would for sure check the cam timing. and take a look at the timing gears and chain before I hooked a battery to it.:cool:
I don't think you have all the pieces of this puzzle.:wtf:
 
ya i pulled the heads back off before i started and there were valve marks on two pistons but im confedent after seeing the marks that they didnt hit hard enough to realy hurt anything but i realy wonder what broke the rocker guids or bridges what evr you call them
 
IOPort51 said:
I would like to see some pictures of these "U" things broken and not.:cool:

I am still trying to picture a situation where the push rods bend, I have seen broken but not bent, and broken rocker bridges. The only possibility I can see is if the rocker stud nuts worked loose. That could cause both symptoms.
I would for sure check the cam timing. and take a look at the timing gears and chain before I hooked a battery to it.:cool:
I don't think you have all the pieces of this puzzle.:wtf:
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X-2 on that;)
 
no i dont think i have all the whole story on what realy happened he claims that when the heads were rebuilt none of the valves were bent witch i realy find hard to belive but the heads have been gone through for sure so i hope who ever did them knew what they were doing
 
cjnewbie said:
ya i pulled the heads back off before i started and there were valve marks on two pistons but im confedent after seeing the marks that they didnt hit hard enough to realy hurt anything but i realy wonder what broke the rocker guids or bridges what evr you call them
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can you do a picture??
If one side came loose it may have just forced one side of it up and broke it that way, I am reaching pretty hard on that one.:wtf:
 
ya i put all the rockers back on mostly just to get the big picture so far everything seams ok except the rocker bridge witch i need to ordor tommorow and here is the best picture i can get and yes i replaced all the push rods and just inspected the rockers and am hopeing for the best at his point LOL
 
cjnewbie said:
ya i put all the rockers back on mostly just to get the big picture so far everything seams ok except the rocker bridge witch i need to ordor tommorow and here is the best picture i can get and yes i replaced all the push rods and just inspected the rockers and am hopeing for the best at his point LOL
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Yep definitely a rocker bridge.;)
 
i talked to him some more and he says that he drove the jeep to work witch is like an hour and a half from his house on the interstate so now i wonder if he wasnt just running the thing at like 70 for an hour and a half and it is a three spead with 4:10 gears so who knows what kind of rpm it was seeing and for how long so now i am even realy wondering if i shouldnt pull the motor and take a better look
 
cjnewbie, Remember the main issue is a Dependable Jeep. Now that the engine is apart or half back together make it reliable for your daily trips
Wilurb
 
For the money it might pay to find a 360 AMC.
There a lot of them laying around so they are cheap.
Don't for get, there's no replacement for displacement.;)
 
I would have to do forensics on this one. check the PO's work and have a look at the cam and/or lifters. I don't think high RPM highway driving would be a major problem, it's a lot easier on the motor than low RPM stop and go. IMO something came unputtogether it would be interesting to see what it was.:cool:
 
Was it just those two push rods that you had to replace??
looking at the picture I an still thinking it was the rocker bolt came loose or were not tightened evenly when they were put on. that would have broken the bridge.
I would pull the timing cover and see if it were even a new set of sprockets and chain. and check the cam timing to make sure they had been put in correctly. Or you could just put things back together and trust in luck.:cool:
 
well the jeeps up and running and seams to be doing good i have only put about an hour on run time so far i am going to pull the valve covers back off tommorow and double check the rocker bolts becuse i agree that is what camw lose and caused my problem to begine with but thanks everybody for the input
 
cjnewbie said:
well the jeeps up and running and seams to be doing good i have only put about an hour on run time so far i am going to pull the valve covers back off tommorow and double check the rocker bolts becuse i agree that is what camw lose and caused my problem to begine with but thanks everybody for the input
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just two words Lock tite.:cool:
 
yes sir i tapped all the wholes brake cleaned them out and used red loctite on them !
hopefully that will never be a problem again
 
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