Journal: Replacing my rocker arms and push rods on 1993 Ranger 4.0

[ryanthevan]

Just creating this thread to document me replacing my rocker arms and push rods on my 1993 Ranger 4.0 OHV. Just in case it proves helpful for someone looking to do the same.

The reason I am doing this is because the engine has a loud ticking noice. I tried a tune up and multiple rounds of seafoam (crank case, intake, and fuel tank), with minimal results.

My research suggested it may be a lifter tick. But when a stethoscope was applied, the tick seemed to be coming from all over. Another thread suggested the tick may actually be coming from worn push rods or rocker arms. This is a much easier fix because I don't have to take the cylinder head off (compared to doing the lifters) and also that there aren't many good replacement lifters versus the OEM already in the engine.

So, to address the tick, I'll be replacing all of the rocker arms and pushrods. I purchased replacements from rockauto, and will compare them against what I'm taking out.

Seems like I'll just need to take off some things to access the valve covers. Take those off. Remove rocker assembly. Then follow this video for rocker arm replacement:

It seems that the pushrods should just slide out. Then slide in replacements, making sure it sits comfortably in rod cup. Applying assembly lube (in my case, permatex ultra slick) and appropriate torque. I'll also be replacing the valve cover gasket while I'm at it.

I think before I begin I'll need to drain the coolant and the oil? I am doing this replacement in winter temperatures that may get below freezing. Is it okay to drain the coolant in potentially freezing temperatures, complete this project (may take a couple weeks in total if I need to order something unexpected), and then refill with 50/50? That's the only part I'm still unsure of. Thanks! I'll attach pictures and work documentation once I begin.

 

[SenorNoob]

IIRC you should be able change pushrods and rocker arms just by pulling the valve covers. That means only the upper intake comes off. I wouldn't touch the cooling system. As long as you don't drop any dirt into the engine, just change the oil after you run it a few minutes.

 

[ryanthevan]

That's great news. So no messing with the coolant (I'll just wait til summer to flush that, change thermostat etc).

Just to clarify, you're saying do the swap, and only then drain the oil and do a change? I've got FRAM high mileage filters with Molygen oil I'll be using, plus replacement oil pan gasket and magnetic plug — hopefully will help clear some more things up.

Parts arrive Jan 4. Will begin log then. Hopefully this will help others seeking to do the same.

 

[SenorNoob]

That's the way I'd do it. Yes that means some old oil is gonna run on/thru new parts, but if you do drop a little crud into the engine it'll come out with the oil change.

Here's a pic of the wear on the rocker arms of the engine I swapped in.

Be careful driving the pins out of the ends of the shafts. It's REALLY easy to mess up those little spring clips.

 

[ryanthevan]

Nice. I'm guessing my rocker arms will look similar. Excited to share some pictures when I have it out. The video I attached in my first post has a guy show exactly how to take the pins out, and which tools. But he of course made it look "easy". So I'll take caution. Thanks for the warning. I'll follow your advice and change the oil after swapping.

Did you use anything to clean the sludge/buildup on the assembly?

 

[SenorNoob]

Dropped em in the parts washer at work. Since it's all metal, I'd use brake cleaner at home. Mine still fought coming apart but I just used a small hammer, punch, and couple chunks of 2x4.

 

[ryanthevan]

All makes sense. I’ll update in a couple weeks when the parts arrive. Much thanks

 

[ryanthevan]

12x pushrods just arrived. I'll double verify that they are the correct length versus original pushrods upon installation.
12x rocker arms also just arrived. I'll visually compare new versus old ones upon swap.
Both made in USA, EngineTech brand. Seems quality.

Also have a Mahle gasket set someone here recommended I buy. Rubber mallet for disassembling/reassembling the rocker arm shaft. And some Liqui Moly hydraulic lifter additive I'll add to the oil when I change it post-repair, just to see if that also helps the tick a bit. Worth a shot.

Expecting to start this weekend. Would appreciate any last minute tips if anyone has one.

 

[ryanthevan]

I've seen people "soak" their lifters in oil overnight before installation. I don't think that's necessary for rocker arms or push rods?

I think some of the videos I posted previously in this thread show the process of getting to the valve covers to take them off on a 1993 4.0 OHV. But if anyone has some good resources there that would be great!

 

[ryanthevan]

Curious whether this wear was causing a tick. And if replacing them fixed that. (That's my goal with this swap).

That's the way I'd do it. Yes that means some old oil is gonna run on/thru new parts, but if you do drop a little crud into the engine it'll come out with the oil change.

Here's a pic of the wear on the rocker arms of the engine I swapped in.

Be careful driving the pins out of the ends of the shafts. It's REALLY easy to mess up those little spring clips.

 

[SenorNoob]

I never heard the engine before replacing them. I bought it from the junkyard that way. I will say it made an AWFUL noise for about 15 minutes after my 1st startup.

 

[ryanthevan]

Nice. This one is running fine minus the tick. So we'll see what the rocker arm/pushrod swap accomplishes. Tick is likely either worn rods/arms or old lifters.

 

[ryanthevan]

Curious whether this wear was causing a tick. And if replacing them fixed that. (That's my goal with this swap).

I'll update with more info. But essentially removed all electrical harnesses, vaccuum tubing, and alternator. Got to valve covers. very difficult to get off, but took 8 bolts off (which were somewhat loose after spraying penetrant) and then heat gunned (hair dryer'd) the cover til I could rock it off.

15mm bolts on rocker arm assembly required a large makeshift breaker bar. Then removed each slowly, equally since it's under load. Honestly didn't look too bad sludge wise inside. But clearly some wear on the arm pedestals, and some wear on the rods. Wondering if you guys think that could have been all the clacking ive been hearing since there is likely now some travel between these components. This seems like a common issue for these engines (read: https://www.broncocorral.com/tech_library/ford-ranger-explorer-4-0l-v6-engine/).

I'll replace rods and rocker arms on this side, then work on the driver's side for the same.

Any tips or thoughts at this stage would be very appreciated! I haven't inspected worn rocker arms or pushrods before, so tough for me to gauge the level of wear.

 

[ryanthevan]

I guess a question I have is whether I should do something with the valves as well, as there was (probably?) some wear on those since they made indents on the rocker arm pedestals. I don't want to replace rods/rockers and there still be some play do to some wear on the valves. But also don't really want to do that if not necessary obviously.

 

[ryanthevan]

old rods definitely look "flat" on each end. new rod on left for comparison.