103" rocker box gasket leak

[hattitude]

 I just purchased a 2016 Low Rider to add to my garage. It's only got 12k miles and is cleaner than any I've looked at over the last 8 months of shopping.

I bought it sight unseen (first time for me), from a large Powersports dealer in MN, who's also a Yamaha dealer. They seem to sell a lot of used bikes of all makes, and ship a fair amount around the country..  Even the transport company I'm using said they go there frequently to pick up bikes.

Anyways, they gave a good price. It also has a 30 day / 1000 mile, 100% parts & labor, warranty. I didn't care much, since I was having it shipped.

To their credit, just before shipping a 100% paid for bike 2000 miles away, they did a pre-delivery inspection and found a rear cylinder rocker box gasket "weeping". They asked me to delay shipping so they could fix it...

I have owned 4 Twin Cams, on which I have done big bore kits, cams, and tensioner upgrades. I removed & replaced rocker box covers and bases maybe 10 times for various things. I have never had a rocker box gasket leak....   

When I did an internet search, I was amazed at the amount of info on twin cam rocker box gasket replacements. I got the impression from the search that rocker box gasket leaks happen quite a bit....

My two questions are:

Does this really happen that often?

If so, I read a lot about changing gaskets, some people a couple times, but nothing about what would be the cause....  Is there a consensus on what usually causes these repetitive leaks?

Is it the gaskets used?

Improper installation techniques (torque and/or torque pattern)...?

Is it an issue involving the parts themselves....?

Just trying to educate myself on this issue, in case the bike gets to me and has another rocker box leak....

Thanks for any insight you can offer on this issue...

[Rusticwater]

Don't have any info on your query, just wanted to say congrats on getting your Dyna with the 103 HO engine!

[Hossamania]

If I remember right, those that have chased rocker box weeps ended up finding that the covers were warped a bit, or at least have an uneven surface. Sanding them on sandpaper on top of a flat plane of glass took care of the problem.
That is, of my memory is correct.

[FLDavetrain]

Using James low rocker gaskets wout beading can cause issues. HD gaskets all the way

[hattitude]

Using James low rocker gaskets wout beading can cause issues. HD gaskets all the way

I have been using either HD gaskets, or recently I have purchased some Cyco gaskets. They have a silicone bead rocker gasket that seems to be just like the HD gasket, only it's a grey/green color not orange.

But thanks for that info... I have those Cyco gaskets on two of my twin cams now, with no issues, but if something should pop up... I'll immediately switch back to HD gaskets...

[hattitude]

If I remember right, those that have chased rocker box weeps ended up finding that the covers were warped a bit, or at least have an uneven surface. Sanding them on sandpaper on top of a flat plane of glass took care of the problem.
That is, of my memory is correct.

So it's possible to fix a warped cover with sandpaper? I would have thought the chromed metal wouldn't be that easy to fix....  I don't have access to a lot of machine shop stuff like some on this forum...

Good to know... I didn't see that in my research..

I'll be filing that in my memory banks... I hope I don't have to try that....

[Hossamania]

I may be misremembering, hopefully someone else that knows what they are doing chimes in to either confirm what I posted, or discount my advice as completely ridiculous.
Don't start sanding on those until a smarter man than I helps out.
I do remember HD OEM gaskets being the preferred.

[hattitude]

Don't have any info on your query, just wanted to say congrats on getting your Dyna with the 103 HO engine!

Thanks... I felt comfortable buying it sight unseen as they posted 32 pics from all angles and all perspectives... the only thing I haven't seen is a pic of the bottom of the bike..

They also posted a video walk around of the bike, along with it starting, and running..

I got pretty good at spotting issues in pics during my search. I would spot something, like one bike looked like it had scratches on a rear turn signal and same side grip end... sure enough it was dropped.. Nothing major, but many weren't worth what they were asking.. by a long shot...

I could find no such telltale signs of issues in the 32 pics on this bike.... but until I get my hands on it... I won't know for sure.  This waiting for shipping drill isn't fun...

[hattitude]

Don't have any info on your query, just wanted to say congrats on getting your Dyna with the 103 HO engine!

Thanks... I felt comfortable buying it sight unseen as they posted 32 pics from all angles and all perspectives... the only thing I haven't seen is a pic of the bottom of the bike..

They also posted a video walk around of the bike, along with it starting, and running..

I got pretty good at spotting issues in pics during my search. I would spot something, like one bike looked like it had scratches on a rear turn signal and same side grip end... sure enough it was dropped.. Nothing major, but many weren't worth what they were asking.. by a long shot...

I could find no such telltale signs of issues in the 32 pics on this bike.... but until I get my hands on it... I won't know for sure.  This waiting for shipping drill isn't fun...

The best part is I bought it for less than "average retail" price in Black Book Powersports... Arond here I wasn't able to find one that was within $1000 of that "average retail" price. It is clearly an above average example based on the others I've inspected in person...

[Fugawee]

Very Nice Looking Bike.  Good Luck with It!

I have bought and flipped a few Twin Cams of various Models the past few years.
They all needed some TLC before a For Sale Sign went on them.

Only a couple of times did I encounter leaking Rocker Box Gaskets.  One of them was the Rear Cylinder, and just by looking at it...You could see a small piece of the Gasket sticking out a little.  I don't think that the Gasket(s) were lined up correctly the last time it had been worked on.  Replaced the Front/Rear Gaskets and all was well.  No more leak.

The other one was just a simple matter of tightening all of the Rocker Cover Bolts.  Many were extremely loose for whatever reason.  Cleaned it all up...replaced/ tightened/torqued the Bolts, and Touchdown.

When I got rid of them, I told the New Owners about the leaks and what had been done.  I told them that should they start leaking again...to get a hold of Me.  Haven't heard a thing, and I bump into these Guys on occasion.

Just a thought...but did You by any chance check on HD, or here at HTT, or elsewhere for any Recall, Service Bulletins, etc?

I have used HD, James, and Cometic Gaskets without any problems.

[Rockout Rocker Products]

FWIW I only use MoCo rocker box gaskets, and have reused them many times without issue.... well worth the price. 

[RoadKingKohn]

I was just working on a 2015 103. It had a leak right above the rear exhaust port. Took it apart and I didn't have to put any effort into loosening the left rear head bolt. Hope to find out in a few weeks if it works. To much ice on the road now.

[hattitude]

Thanks for all the feeback...

Fugawee, I did a VIN check on it that showed no outstanding recalls....

I've owned 2 shovels heads, one EVO, and now 5 Twin Cams... Luckily I have done the most work and am very comfortable working on the Twin Cams.... If it should need some work, I'll be able to tackle most anything that would come up..  although I could have a question or two...   

Since I now own four bikes, having a bike on my lift for repairs and/or mods doesn't affect my ability to ride...  I have the attitude that I did the best research and inspection I could for 2000 miles away, made the decision to buy the bike, and now I just need to get it, inspect it, and see if it was truly a gem, or I missed something...   

I am just surprised I've never heard (or maybe just never Paid attention) to this leaky rocker box situation..

Since I'm just a garage mechanic and not a trained tech, I learn quite a bit from this site....   

[calif phil]

Great looking bike!  Sounds like you got a good deal.  I would have shipped it maybe ask them to send the rocker box gaskets and replaced them myself. 

[Fugawee]

It sounds like You dealt with a Decent Seller.
Good for Them that They noticed, and was willing to repair the issue...instead of getting the "Really? It was fine when it left here...don't know what to tell Ya".

Now with 4 Bikes, all You need is 3 more...and You've got one for every day of the week.
I own a few different HD's also.  Many times People will ask Me..."Which one is Your favorite?"
My answer to that is...the Harley.

[motorhogman]

The rear rocker box on my 2001 FLHT started weeping a bit after ... I forget.. LOL 18, 19  years maybe... 80,000 mi maybe..  Replaced with OEM No problem since.

[hattitude]

Great looking bike!  Sounds like you got a good deal.  I would have shipped it maybe ask them to send the rocker box gaskets and replaced them myself. 

when I changed the "available pick up date" on the contract to 2/8/23, I decided that was a drop dead date....

When he checks in with me about the progress this Tues, that is what I decided to tell him....

"If it can't be ready for pick-up by Wed, don't fix it... send it to me, and mail me the gaskets... I'll fix it myself..."

It could be fixed already... I'll find out Tues....

[les]

Does this really happen that often?

As suggested in post #3, if you use James gaskets it will happen more than often.

[06SG103T]

First Check bolt for proper torque. If no, tighten to torque and clean, ride and see.
If yes, then replace gasket. Check entire inside lower and upper for witness marks. Just in case something is hitting them. If so, remove material from rocker to clear whatever is hitting.
I also remember reading that sanding on flat surface can be done. Like Hossamania said.
If they are removed, I would check them for being flat.
I know allot of people just tighten by hand.
I always torque to specs. The engineers must know something. LOL

I had one getting hit inside on a build I did years ago. Change it three times after going just down the block. I do use HD gaskets. I know there is others out there, but HD gaskets should work, LOL

Enjoy the bike it looks very clean. Mosty stock it looks like. Good luck with it.

[No Cents]

  on my old 2008 Duracell I have had to replace the rear rocker box lid "twice" in the past 15 years since I bought the bike new. Never the front lid. I do use the HD rocker box gaskets. Apparently, both of the rocker box lids that I replaced warped over time from the heat from the rear cylinder and they started to leak. I first tried replacing just the gasket only...but the leak was still there. A new lid...and the leak stopped.

[hrdtail78]

There are tq specs and a pattern given in the book.  For most models some type of tq extension needs to be used to hit all of the rear ones properly.  IMO the proper tools and good maintenance practices help to insure leaks don't happen.

How common?  How common is book time vs actual hrs billed?  Too many variables.