DIY SS Riveted Rocker Retainers (With Pics and PN's)

[emmott]

The stock 6.5 rocker is held in place by a nylon button. I had one break on me, now I'm replacing the piston rings in cylinder 6 because of it. No way I'm putting nylon in again. I could have gone with expensive HS roller rockers, or the bolt method, but I thought I'd try something similar to what Peninsular uses - rivets!



It should be about a 3 hour job to do all 16 rockers.
Here's what you need:

• 1/4" by 1/2" long stainless steel rivets (NOT ALUMINUM!) - available in pack of 50 at Gregg Distributors (PN XX88-50) They are 0.245" in diameter and expand to 0.335" (~40%). The hole they go inside is exactly 1/4".
• Extra thick Black Iron M6 washer - Available at Fastenall (PN 11128411) - Sold per.

I measured everything and you get the same lateral movement of the rocker as stock with the above parts (±0.005"), so it should perform just like stock but waaay less likely to break. The important thing is to not tighten until the rivet pops, just tight enough that the washer can still rotate. You need the washer to rotate so there is minimal rubbing against the rocker. One could drill a 1/4" hole into the old nylon retainer and use that instead of the black iron washers I used, but was worried about the nylon breaking on me again. Others have used brass, but the washers I used are dimensionally the closest to the stock retainer that I could find.
If you fasten the rivet too tight you can use a hammer & chisel lift the washer then tap back on the rivet then the washer should rotate freely. Oh and oil everything up first. I used engine assembly lube.





And for tools:

• Big-ass rivet gun (these things are built like bolt cutters)
• Cylinder File or Dremmel tool
• Pliers
• HD wire cutters
• Flat cold chisel
• Hammer

Step 1 - Disassemble and label your pieces so the rockers go back in the same order & direction.
Step 2 - De-burr the inside of the tube where the factory drilled the holes for the retainers, I used a file for a bit then got a dremel tool, that tube is hard AF. I cleaned out the shavings like a gun barrel then rinsed it.

Spoiler: Photo

Step 3 - Slide on the rocker and lube up
Step 4 - Insert pop rivet and washer. The washers are concave (shaped like a crescent moon) I shaped the arch down so it would rotate easier. Note that the thick washers also have a slight taper, to match with the taper direction of the stock rivet you would have to face it the other way from how I did it. Your call. Remember to put the rocker in before the retainer!

Spoiler: Photo

Step 5 - Fasten! But don't pop the rivet! Go until you see the expansion of the rivet just about touching the inner wall of the cylinder. Double check you can rotate the washer on the other side. When it starts to feel snug you're done.

Spoiler: Photo

Step 6 - go grab a beer.
Step 7 - You were an idiot and you over pulled on the rivet and now the washer won't rotate. That's ok! Just use a cold chisel & hammer to wedge the nut up a bit, tap down on the rivet, then the washer should be freed up.

Spoiler: Photo

Step 8 - Cut off the excess rivet stem. I used an HD wire cutter to notch/weaken an area the stem close to the washer then pliers to bend/break it off. File the end if you don't like sharp edges, but file upside down so the shavings don't fall into the rocker.

Spoiler: Photo

Rinse and repeat.

I checked to see if the stem left inside the rivet would fall out by hammering on the top, it didn't budge so it's not going anywhere.

 

[FellowTraveler]

Good write up and idea too.

 

[Will L.]

Thanks for sharing Emmott. WAY better than the cheap plastic retainers.

The only 2 concerns I have are the hardness of the washers vs rocker arms creating a wear situation, not that big a deal if the rocker arm is harder, not like the plastic ever gets worn.

The rivet pin vibrating loose long term- I see where you’ve tried knocking them out and they didn’t come free. I would experiment with drilling them out or air chisel maybe. I just get scared from FOD.

Many engines make it over 300,000 miles and never break one, but I have also seen some let loose in under 100,000 and NEVER have I seen one not do damage when it happens. Dumbest idea in the engine imo.

Moderators: Is there any way to make sub headings under the 6.5 section for valve train? Then have this thread, the bolt with concave brass washer method, and the roller rocker threads, valve spring stuff, etc. all under it?
Maybe too finicky, but just thinking would be easier for folks to find them when they get to during searching.

 

[Jaryd]

Great write up and very detailed

 

[Big T]

Not sold on the stainless rivets. Stainless will crack from fatigue.

 

[emmott]

@Will L. I ran a file over the rocker and the washer, the washer seemed to get more scarring so I think the washer is softer. The rivets are just black/ductile iron and I think the rockers are steel alloy.
As for drilling out the rivet pin, I'd be worried about unintentionally taking metal away from the rivet. I think if the pin that is sticking out was bent over with a hammer, so the trimmed stem overhangs the top of the rivet and washer, it would never come out.

Not sold on the stainless rivets. Stainless will crack from fatigue.

That's certainly worth looking into. I just did some googling on the fatigue strengths of steel vs. nylon for piece of mind.
The endurance strength of stainless steel is 490MPa (71000Psi) while nylon is 35MPa (5080Psi). Sources in the hyperlinks. Comparing just the materials SS has a higher endurance.
However, the rivet has a hole in the centre while the nylon is a solid stem. So we need to consider the end-areas of both the rivet and the nylon stem when discovering which has higher endurance strength against shear forces (shear force is the force applied perpendicular to the rivet or nylon stem by the rocker and the hole in the tube).

• Both the rivet and the nylon stem have a diameter of 0.245"
• I measured the hole diameter inside the rivet at 0.160"
• The end area of the nylon is π(0.245")²÷4 = 0.04714 sq.in
• The end area of the rivet is [π(0.245")²÷4] - [π(0.160")²÷4] = 0.02703‬ sq.in
• The shear fatigue strength of the nylon stem is (0.04714 sq.in)(5080Psi) = 240 Lbs.
• The shear fatigue strength of the SS rivet is (0.02703 sq.in)(71000Psi) = 1920 Lbs.

Comparing calculated shear fatigue resistance, the SS rivet is eight times more resilient than the nylon stem.

Stress is one fatigue factor, another is temperature and chemical degradation. This is where SS really wins over nylon. Nylon naturally degrades with the thermals and chemicals an engine subjects them to. Notice how brand new retainers are white and the ones in used engines are yellow? The yellowing is an indication of thermal and/or chemical degradation, indicating the retainer is weakened. Break an old one and you'll notice the core of it is still white. Nylon also loses half its strength as it nears 100°c or 212°f. If you are towing on a hot day, that's when your old nylon retainers most likely fail. SS does not degrade under the same conditions.

I'm confident the SS rivet will far outlast a nylon retainer; due to greater fatigue strength; and resilience to heat, oils and blowby gasses. I noticed the nylon retainer that failed on me was close to the PCV valve (#6 in).
Of course the mechanical fatigue is more complicated than recurring basic shear. Most of the forces will be shear, there will be some normal pull force against the expanded rivet. The steel there is already strained from expansion.

Like anything testing and results are what matter. I can test how much shear the rivet will take brand new, then remove a valve cover after a few thousand miles with this setup and see if they break any easier. While the valve cover is off I can also check for rubbing wear on the rocker.

 

[Big T]

@Will L. I ran a file over the rocker and the washer, the washer seemed to get more scarring so I think the washer is softer. The rivets are just black/ductile iron and I think the rockers are steel alloy.
As for drilling out the rivet pin, I'd be worried about unintentionally taking metal away from the rivet. I think if the pin that is sticking out was bent over with a hammer, so the trimmed stem overhangs the top of the rivet and washer, it would never come out.


That's certainly worth looking into. I just did some googling on the fatigue strengths of steel vs. nylon for piece of mind.
The endurance strength of stainless steel is 490MPa (71000Psi) while nylon is 35MPa (5080Psi). Sources in the hyperlinks. Comparing just the materials SS has a higher endurance.
However, the rivet has a hole in the centre while the nylon is a solid stem. So we need to consider the end-areas of both the rivet and the nylon stem when discovering which has higher endurance strength against shear forces (shear force is the force applied perpendicular to the rivet or nylon stem by the rocker and the hole in the tube).

• Both the rivet and the nylon stem have a diameter of 0.245"
• I measured the hole diameter inside the rivet at 0.160"
• The end area of the nylon is π(0.245")²÷4 = 0.04714 sq.in
• The end area of the rivet is [π(0.245")²÷4] - [π(0.160")²÷4] = 0.02703‬ sq.in
• The shear fatigue strength of the nylon stem is (0.04714 sq.in)(5080Psi) = 240 Lbs.
• The shear fatigue strength of the SS rivet is (0.02703 sq.in)(71000Psi) = 1920 Lbs.

Comparing calculated shear fatigue resistance, the SS rivet is eight times more resilient than the nylon stem.

Stress is one fatigue factor, another is temperature and chemical degradation. This is where SS really wins over nylon. Nylon naturally degrades with the thermals and chemicals an engine subjects them to. Notice how brand new retainers are white and the ones in used engines are yellow? The yellowing is an indication of thermal and/or chemical degradation, indicating the retainer is weakened. Break an old one and you'll notice the core of it is still white. Nylon also loses half its strength as it nears 100°c or 212°f. If you are towing on a hot day, that's when your old nylon retainers most likely fail. SS does not degrade under the same conditions.

I'm confident the SS rivet will far outlast a nylon retainer; due to greater fatigue strength; and resilience to heat, oils and blowby gasses. I noticed the nylon retainer that failed on me was close to the PCV valve (#6 in).
Of course the mechanical fatigue is more complicated than recurring basic shear. Most of the forces will be shear, there will be some normal pull force against the expanded rivet. The steel there is already strained from expansion.

Like anything testing and results are what matter. I can test how much shear the rivet will take brand new, then remove a valve cover after a few thousand miles with this setup and see if they break any easier. While the valve cover is off I can also check for rubbing wear on the rocker.

Alright, you'll be my guinea pig.

 

[emmott]

I redid the retainers and instead popped the mandrel out and used a cold punch to knock out and remove the mandrel head from the centre. The punch was just small enough to fit in the head and pin. Now there is no material that could fall out from the centre.
Here’s a pic of the final product:

 

[emmott]

 

[Will L.]

I like it. Way better than the plastic. I like the bolt method also.

 

[FellowTraveler]

Great video...

 

[Will L.]

I’m just adding a link to the other method.

Replacing Rocker Buttons

My rocker buttons were all holding up just fine, but with nearly 300K miles on this engine, I just couldn’t bring myself to put the rocker shafts back on with the nylon buttons still in place. I did some searching to see what other options were out there. Just replacing the buttons with bolts...

www.thetruckstop.us

How many miles and results so far @emmott ?

 

[Big T]

I’m just adding a link to the other method.

Replacing Rocker Buttons

My rocker buttons were all holding up just fine, but with nearly 300K miles on this engine, I just couldn’t bring myself to put the rocker shafts back on with the nylon buttons still in place. I did some searching to see what other options were out there. Just replacing the buttons with bolts...

www.thetruckstop.us

How many miles and results so far @emmott ?

IMO big mistake to go with anything but the OEM nylon buttons. They go 300K which is more miles than 95% of the 6.5s saw. Most all production cars will have nylon parts in the valve train. They are there simply to keep the rockers centered. They do not provide any structural support. You replace with metal and you will get wear and metal filings going through the oiling system. I know people sleep better thinking they have over engineered it for life, but it’s a false crutch.

 

[Will L.]

IMO big mistake to go with anything but the OEM nylon buttons. They go 300K which is more miles than 95% of the 6.5s saw. Most all production cars will have nylon parts in the valve train. They are there simply to keep the rockers centered. They do not provide any structural support. You replace with metal and you will get wear and metal filings going through the oiling system. I know people sleep better thinking they have over engineered it for life, but it’s a false crutch.

You already have metal to metal- notice the arm on the shaft? And there is force applied there with the push rod and spring both pushing upwards.
Where adding the steel or as I suggested bronze washer- there is no force loading. And bronze is a self lubricant for those that don’t know why I made that suggestion.

As to the plastic retainers lasting that long- NO. They do not. Some do, but I have worked on too many of these engines that were pushed to 300-400,000 miles. And many of them were doing near or over 100,000 miles PER YEAR. So aging of the plastic wasn’t even a consideration. If I had to guess, I bet I have replaced 300 sets of retainers due to failure. I saw one that was low mileage- maybe 75,000 miles- ok that was an anomaly. But many of them were under the 200,000 mark.

Remember I mentioned how to remove the valve covers and reuse them without leaks? Most people have to replace the valve covers to avoid leaks. Why? I am not magical. I learned the technique from doing it a ridiculous amount of times.
Almost never had lifter failures- 2 times I can think of. Never had a pushrod fail that didn’t happen from retainer failure. All those covers came off for one reason- retainer failure.

GM realized that people burning to death in cars would get them sued, but not enough to make them invest in $2.40 per car.
PEOPLE BURNED TO DEATH vs $2.40.

You think plastic retainers is not cost savings instead of a more reliable design?
The roller rockers are now $750. Not an option for many, price per efficiencies gained is not impressive.

Idk current price on retainers but guess $2.50 each is average, need 16 so there is $40.
So the amazing additional cost of $100 to never have this failure- that is a no brainer to me.

The stock turbo, exhaust, fuel system and ip it feeds lasts many of these trucks to over 300,000 miles. Yet you replaced yours. Just because you haven’t dealt with a problem doesn’t mean there isn’t a problem.
When the retainer fails the rocker arm goes completely off the valve stem and pushrod. The push rod gets bent and often damages other stuff. Sometimes the rocker arm gets jammed holding the valve open and the piston hits it. This can and has forced a rebuild.

 

[Husker6.5]

You already have metal to metal- notice the arm on the shaft? And there is force applied there with the push rod and spring both pushing upwards.
Where adding the steel or as I suggested bronze washer- there is no force loading. And bronze is a self lubricant for those that don’t know why I made that suggestion.

As to the plastic retainers lasting that long- NO. They do not. Some do, but I have worked on too many of these engines that were pushed to 300-400,000 miles. And many of them were doing near or over 100,000 miles PER YEAR. So aging of the plastic wasn’t even a consideration. If I had to guess, I bet I have replaced 300 sets of retainers due to failure. I saw one that was low mileage- maybe 75,000 miles- ok that was an anomaly. But many of them were under the 200,000 mark.

Remember I mentioned how to remove the valve covers and reuse them without leaks? Most people have to replace the valve covers to avoid leaks. Why? I am not magical. I learned the technique from doing it a ridiculous amount of times.
Almost never had lifter failures- 2 times I can think of. Never had a pushrod fail that didn’t happen from retainer failure. All those covers came off for one reason- retainer failure.

GM realized that people burning to death in cars would get them sued, but not enough to make them invest in $2.40 per car.
PEOPLE BURNED TO DEATH vs $2.40.

You think plastic retainers is not cost savings instead of a more reliable design?
The roller rockers are now $750. Not an option for many, price per efficiencies gained is not impressive.

Idk current price on retainers but guess $2.50 each is average, need 16 so there is $40.
So the amazing additional cost of $100 to never have this failure- that is a no brainer to me.

The stock turbo, exhaust, fuel system and ip it feeds lasts many of these trucks to over 300,000 miles. Yet you replaced yours. Just because you haven’t dealt with a problem doesn’t mean there isn’t a problem.
When the retainer fails the rocker arm goes completely off the valve stem and pushrod. The push rod gets bent and often damages other stuff. Sometimes the rocker arm gets jammed holding the valve open and the piston hits it. This can and has forced a rebuild.

Yup. Ask @3bals about the barfed 6.5 in his motorhome due to rocker failure that led him to do the P400 build.

 

[Big T]

You already have metal to metal- notice the arm on the shaft? And there is force applied there with the push rod and spring both pushing upwards.
Where adding the steel or as I suggested bronze washer- there is no force loading. And bronze is a self lubricant for those that don’t know why I made that suggestion.

As to the plastic retainers lasting that long- NO. They do not. Some do, but I have worked on too many of these engines that were pushed to 300-400,000 miles. And many of them were doing near or over 100,000 miles PER YEAR. So aging of the plastic wasn’t even a consideration. If I had to guess, I bet I have replaced 300 sets of retainers due to failure. I saw one that was low mileage- maybe 75,000 miles- ok that was an anomaly. But many of them were under the 200,000 mark.

Remember I mentioned how to remove the valve covers and reuse them without leaks? Most people have to replace the valve covers to avoid leaks. Why? I am not magical. I learned the technique from doing it a ridiculous amount of times.
Almost never had lifter failures- 2 times I can think of. Never had a pushrod fail that didn’t happen from retainer failure. All those covers came off for one reason- retainer failure.

GM realized that people burning to death in cars would get them sued, but not enough to make them invest in $2.40 per car.
PEOPLE BURNED TO DEATH vs $2.40.

You think plastic retainers is not cost savings instead of a more reliable design?
The roller rockers are now $750. Not an option for many, price per efficiencies gained is not impressive.

Idk current price on retainers but guess $2.50 each is average, need 16 so there is $40.
So the amazing additional cost of $100 to never have this failure- that is a no brainer to me.

The stock turbo, exhaust, fuel system and ip it feeds lasts many of these trucks to over 300,000 miles. Yet you replaced yours. Just because you haven’t dealt with a problem doesn’t mean there isn’t a problem.
When the retainer fails the rocker arm goes completely off the valve stem and pushrod. The push rod gets bent and often damages other stuff. Sometimes the rocker arm gets jammed holding the valve open and the piston hits it. This can and has forced a rebuild.

I have followed your described method for removal of the valve covers, making sure they are flat, reinstalling and they leaked every time at the lower rear corner on the passenger side. I installed brand new valve cover and it still leaks in the same spot, but less. It must be me.

In contrast, plastic valve buttons….never an issue….must be me.

My ‘99 came with ATT turbo installed by PO, not me. IP was replaced by PO based on the green tag. i replaced IP after a water in fuel evenf grenaded the optic sensor wheel. That was my mistake.

‘94 we installed fhe ATT and exhaust for improved performance and reliability. IP went out at 292K miles and was replaced.

 

[Will L.]

I have followed your described method for removal of the valve covers, making sure they are flat, reinstalling and they leaked every time at the lower rear corner on the passenger side. I installed brand new valve cover and it still leaks in the same spot, but less. It must be me.

In contrast, plastic valve buttons….never an issue….must be you.

On the valve cover- probably 1 thing you’re doing that needs altering. The draw back of folks not being around to see in person.

Rocker buttons:
Well lets see..all the different social media forms and people using rivets, some bolts with nuts inside, some tap a piece of round bar and slide that inside, some just schedule planned times like at the 100,000 mile intervals and replace them all,while this is the reason others now buy the roller rockers. And others just wait till there hear a sound and pull the cover hoping nothing went dramatically wrong. No. No, I don’t think it’s just me- haha.

Remember, just because you haven’t experienced something doesn’t mean it’s not real.
You have 2 trucks in your 6.5 history, right? Didn’t you find old loose rocker buttons laying around the battery tray or something from a previous owner? Maybe he just used them as flavor additives and sprinkled some like salt.

The odd and most annoying is a new one is installed-when they fail. Wether the little edges don’t hold or it was seated too hard or not hard enough, idk. But I have seen it. A guy on the hummer forum bought a new optimizer, made it about 2,500 miles and had to have a new one replaced. It happens. In the fleet we had a truck throw one at about 4,000 miles. One of a couple thousand trucks- really really rare.

Remember that it was a different design in the 6.2? The sideways springs and all.
This is a cost savings move, nothing more. No one is holding a gun to your head and say you have to do it. The ROI may not make sense- I get that. But because I have seen more than 2 of these trucks over the years- I figure something is worth doing.

 

[dbrannon79]

So, I know someone posted a link for the round stock that they threaded and slid into the rocker tube. but I can't seem to find it. would anyone know what the ID is of the rocker tube? I want to see if our bolt vendor here at work can find some pre-made nuts like this. also what is the OD of the rocker buttons. I can see if I can find a set of curved washers like @Will L. was talking about too.

making plans to get mine done just for peace of mind.

 

[Big T]

On the valve cover- probably 1 thing you’re doing that needs altering. The draw back of folks not being around to see in person.

Rocker buttons:
Well lets see..all the different social media forms and people using rivets, some bolts with nuts inside, some tap a piece of round bar and slide that inside, some just schedule planned times like at the 100,000 mile intervals and replace them all,while this is the reason others now buy the roller rockers. And others just wait till there hear a sound and pull the cover hoping nothing went dramatically wrong. No. No, I don’t think it’s just me- haha.

Remember, just because you haven’t experienced something doesn’t mean it’s not real.
You have 2 trucks in your 6.5 history, right? Didn’t you find old loose rocker buttons laying around the battery tray or something from a previous owner? Maybe he just used them as flavor additives and sprinkled some like salt.

The odd and most annoying is a new one is installed-when they fail. Wether the little edges don’t hold or it was seated too hard or not hard enough, idk. But I have seen it. A guy on the hummer forum bought a new optimizer, made it about 2,500 miles and had to have a new one replaced. It happens. In the fleet we had a truck throw one at about 4,000 miles. One of a couple thousand trucks- really really rare.

Remember that it was a different design in the 6.2? The sideways springs and all.
This is a cost savings move, nothing more. No one is holding a gun to your head and say you have to do it. The ROI may not make sense- I get that. But because I have seen more than 2 of these trucks over the years- I figure something is worth doing.

There’s 1 thing wrong they are doing when installing the plastic buttons. You just have to be there to see.

 

[Will L.]

There’s 1 thing wrong they are doing when installing the plastic buttons. You just have to be there to see.

Nah- I see it from here. What’s wrong is they are plastic.