4.0 rocker arm resurface

[deathbyaudio]

Hey I was wondering if resurfacing my rocker arms would help my valve train noise. I used a fileto smooth the rocker arm where it contacts the valve stem. Will this cause issues? Do need to just buy a new rocker arm/shaft assembly if so where would I get one. I don't want to pay 20 a piece for 12 rocker arm.

 

[deathbyaudio]

Here is a better picture

 

[Big Jim M]

Nope! It'll make the noise louder. You are causing even more wear on the surfaces. That will make more slack in the movement of the system.
If the rockers are adjustable then simply adjust them if NOT then purchase slightly longer pushrods. That makes the system tighter and shuts up the noises.
Big Jim

 

[Will]

No no no no no no no.

These are a common problem and the reason many, many pushrod 4.0 vehicles go to the junkyard. It has to do with low oil pressure from a worn engine causing poor oiling to the top end. 15 years ago my Ranger started whacking away and I installed a real oil pressure gauge (the oil pressure gauge in the dash isn't actually a gauge--it's a mechanical idiot light) and I saw I was in single digit numbers at idle. So I pulled my motor, replaced the lower end bearings and found my rockers had holes hammered in the from the valve stems. I pulled the lifters--which means pulling the heads--and they were all frozen. I got them all free and took them apart and cleaned them. I replaced all of the rockers and pushrods. I put the motor back in and it is still running strong and quiet. I think the previous owner (a Fuller Brush salesman) didn't change the oil much. Using roller lifters was a first on the 4.0 and I don't think the oiling was well sorted. There wasn't enough pressure to the top end through those heavy roller lifters. They stick and become solid lifters and beat the valve train up.

You need to get a real oil pressure gauge on the motor. With fuel injection, these motors are way more durable than in the past. You can have good ring seal even though lack of maintenance has trashed the bearings. get the oil pressure back up to the top end and replace all of the worn stuff. Pull those lifters apart--actually, you blow them apart with air pressure.

 

[deathbyaudio]

I actually have a aftermarket oil pressure gauge. It ran 45 to 50 when first cranked up and in the 20's at idle after it warmed up. I also have a mechanical temp gauge. I'm always watching my gauges. So I need to just cough up the money for new rockers and pushrods. I thought the lifters would compensate for the material I filed off. If I do have to buy rocker arms can i buy the whole assembly. Also since I do have the engine out and the heads off and the lifters out of there bore. how do i blow apart or take apart the lifters to clean them

 

[Big Jim M]

Ya got it out? Would be no question for me! Depending on the miles on that engine, here come new cam, lifters, rockers and pushrods. Now I'd have another 150K without any worries. I might even investigate which camshaft would be best for my daily chores.
With the head off I'd investigate the thickness of each valve and might be lapping in a new one here and there.
But as for artificial wear such as valve grinding and filing..... Nope none of that.
Ya might tell us why that engine is out of the vehicle. Valve noise should be no reason to take an engine out.
Big Jim

 

[35Remmy]

Delta cam hardened pushrods and rockers quieted my 4.0 right down. It was instant.

I just posted in an earlier post today that after that engine was replaced with a new rebuilt one the lifters were noisy as hell, at start up and after it warmed up at idle. They rebuilt the top of the engine again and the result was the same. That was 50,000 miles ago and she still clacks away at first start and after warming up. Frustrating but cheap reliable transportation to and from work heh.

 

[deathbyaudio]

I took the engine out because I was in search of more power and aftermarket support. I changed my mind after I got the engine out and decided to just fix what i had. I don't trust delta can read to many bad reveiws and I'm going to eventually upgrade to the 410 cam. Thanks for all the input