Broken Rocker Arm?

[justinray]

Looking at getting back in the idi world, and found a truck that I like and the price is decent, guy said a rocker broke and bent a pushrod, and I'm wondering if I can pull the rocker arms and pushrods off of my truck (7.3) and put them on his (6.9) to get it going or should I just pass it up?

 

[BDCarrillo]

How it broke is more critical than "it's broke"....

 

[justinray]

Thats what I'm wondering. He basically told me it broke driving down the road and pulled over and towed it back home.

 

[chris142]

I think thats why they upgraded the rockers in the 87 and up engines.

 

[justinray]

I'm just wondering if it would be okay to swap them to known good arms and drive it or if its likely that it messed something else up?

 

[IDIoit]

can you swap them? YES
will it be ok?
not even the most experienced person thats delt with these engines for decades could tell you without digging into this engine deeper.
what caused it?
maybe youll be ok, maybe theres another issue at hand.
how much for the truck, and what truck??
where theres a will, theres a way, even if it needs an engine swap.

 

[chris142]

I'm just wondering if it would be okay to swap them to known good arms and drive it or if its likely that it messed something else up?

Wont know till you try it

 

[Knuckledragger]

When did it last run? Is that verifiable? If everything else is great, maybe a rocker arm (or pivot) just broke, maybe the owner wants it gone. Changing a rocker arm and pivot is not difficult in the world of IDIs, if he doesn't want to do that to keep it running, perhaps something else is wrong and he is not saying.

 

[justinray]

I'll just go with gut and tell him to get it running before I look at it. Its a bullnose bronco, 6.9-t19-bw1345-d60/13.25(3.55:1) basically everything I want in one package, he wont give me a price, wants an offer.

 

[IDIoit]

what are texas's laws on vehicles and inspections?

 

[Wvdirtroad]

Buying a truck that doesn't run is one thing. Buying a truck that doesn't run because of a broken rocker is a whole nother' thing.

 

[justinray]

20 years or newer has to pass emmisions in certain counties (not mine), other than that, its a safety inspection, headlights taillights, brakes, wipers, blinkers and horn.

 

[icanfixall]

This advice is just s best guess. If the rocker broke because its the old style I sa buy it but.. Usually any broken rocker is because the valve hit a piston and that used up the rocker and broke it plus bent the pushrod. So knowing how and why this damage happened tells you lots.. Like am I needed to remove a head and replace the possible bent valve. Hopefully this bent pushrod and broken rocker is on the drivers side because thats the easy side for valve cover removal.. Lets say you have the older style rockers. I sure would be replacing them all if you buy this rig. BTW all we can buy these days is the 7.3 rockers but thats a good thing. They are a much better rocker. Worst case is a hydraulic roller lifter failed and now you need new rockers too because if one failed the others are not far behind. Normally the cam is not damaged when a rocker fails or a lifter fails but it has been noted that some cams have been ruined but that is a very rare issue. A bad lifter NEVER ruins an idi block so thats a safe thing to know.

 

[jaluhn83]

How does he know it's a broken rocker? Did he look at it?

The older aluminum pivot type rockers could certainly wear out a pivot and wind up with the actual rocker coming loose though the truck would have been 'chuffing' for quite some time before that due to the valve not opening. Not sure why the pushrod would be bent though.

I also had a rocker break (pivot broke in half) and cause the rocker to work crocked not closing the valve completely and eventually (over several hundred miles) crash the valve into the piston with catastrophic results.

Big question for me would be how much he wants and how hard it is to go see it. I would want to see (in person or picture) the rocker and damage and I would also want to bar the engine over several turns. It is possible that it's just a rocker issue, in which case you could swap the rockers and pushrods and probably be good. However, I think it's more likely the rocker damage was caused by other worse damage internally. Additionally, you have the question of what else has gotten messed up sitting however long it has been and what shape the engine is in overall.

If it is just a rocker issue the engine should still run okay.... certainly have a miss but should still crank and run. If it doesn't bar over freely then there's almost certainly major internal damage.

 

[Waystro]

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