Stripped threads in front cam chain guide.....fixable?

[bennecc]

I noticed that I've got a pretty good oil leak from the lower bolt on the front cam chain guide. The leak seems to be coming out of the smaller bolt that fits into the other bolt. All the copper washers are in place. The threads on the guide inside feel stripped....it is definitely on the guide but there is no resistance when I turn the bolt.

The upper bolt is fine, so the cam chain guide should be stable, I would think.

I've never used one of those helicoil things. Would something like that be usable in this situation where the damaged threads aren't readily accessible? My other thought was to just epoxy the smaller inner bolt to the larger one and worry about it next time I have to tear into the engine. Not sure if that would hold up to the heat though.

The other option is to go ahead and replace the cam chain guide. Does that require pulling the motor?

 

[Travis]

Just to help others out, here's what he's talking about:

If you can helicoil a blind hold, it could probably be done. You might get metal shavings in the engine that would need to be flushed out.

The epoxy trick might work.

If you replace the cam chain guide, you will have to pull the engine.

Tapping the hole to one size larger might also work. You may have to drill the nut for clearance for a larger bolt.

 

[nj1639]

I have 2, count them- one, two- front cam chain guides that have the lower threaded reciever stripped. From the time of purchase to the time of install the warranty had run out. I've been running the stock one and it's time to be replaced. IF you're talking about the reciever threads on the guide itself I'll see if a helicoil repair can be done. I believe that I have the correct repair set for that thread. Give me a day or so.

 

[bennecc]

nj,

that would be great, thanks! I confess that I put this guide in and I stripped the receiver threads. I never have seen a torque spec for it. That being said, the guide is virtually brand new so if I can repair it then I'd like to give it a shot. I was thinking that the upper bolt will hold the guide in place, and taking the lower large bolt out will give me some extra room to work.

 

[JasperLP]

That cam chain guide is pulled against the inside, any shavings should be confined right there in the hole. A little grease on the bits and taps can help catch shavings.
Working through that little hole ought to qualify you for brain surgeon status.

 

[Travis]

On the cylinders I took the picture of, it's not pulled up tight to the inside; it's pulled up tight to the nut thing. When the nut is out, there is a little space for shavings to fall into the motor. But the grease trick you're talking about should still work.

 

[jayel]

you are threading into aluminum while a helicoil would work it would be pretty hard to get to the right depth, would need to accuratly measure depth to bottom of the blind hole and know thickness of the chain guide at that point to know lenght the heli-coil will need to be if you're trying to do it in motor

 

[nj1639]

Looks like the repair kit is the NAPA BALKAMP 770-3091. That's the M6x1.
The Helicoil replacement thread that I have is the M6x1x090mm length, part no. R1084-6.
The depth of the threaded reciever in the guide is about 1 1/2 mm and the repair thread is 1 mm (.090).
Probe the reciever thread for depth, mark the depth on the drill bit and the tap supplied, drill then tap. The tap won't thread all the way to the bottom of the reciever but that's fine. Insert the thread to where it's flush at the end of the reciever and then break off the little tab that allows you to thread the thread in....huh? You'll see.
Probably best to have the guide in hand for the repair. If you use grease while drilling and cuttling, you may be OK in situ. If you miss a little bit of alu.....I've found pieces in the side strainer. BUT, watch out for that little break away tab. You may be able to grab it with a magnetized screw driver.
Can supply pics if needed, give me another day or so.

 

[xjwmx]

I would take the cylinder off, have a welder put aluminum in the hole, and drill and tap it so that it was like new.

 

[MOFOKKER]

"I would take the cylinder off, have a welder put aluminum in the hole, and drill and tap it so that it was like new. "

If you are going to go to the trouble of pulling the cyl off you should just replace the guide with a new one. They only cost 30 bucks.

 

[xjwmx]

If you are going to go to the trouble of pulling the cyl off you should just replace the guide with a new one. They only cost 30 bucks.

I have to admit I'm still not sure what's stripped! I'd either buy a new one or fill it with aluminum and tap it The alternatives being discussed are sounding like last resort stuff when the opportunity's there to do it right with maybe less effort.

 

[nj1639]

IF...the replacement doesn't wind up doing the same thing. Maybe the 'aftermarket supplier' had a bad run and everything is cool now. As it now stands, I should have replacement guides to last me, say, 30,000 miles? 15 thousand a guide?
Wish someone would come up with a better alternative, a nylon wheel?

 

[chopitdropit]

Having used helicoils before for other projects, I would be extremely concerned about the tab you have to break off after install. Even if you avoided shavings, that thing could do some major damage.

 

[XSLeo]

Wouldn't welding the hole full burn the plastic parts off the aluminum parts. That would suck.
You are talking about a new part that stripped out, not an old part. Right?

 

[jayel]

the heli-coil repair will be stronger than a filled and redrill fix, and if you have it out of the motor you can forget about chips just clean them off before re-install

 

[Ksboy19]

So total noob question, what happens if you unscrew those two bolts without taking the cylinders off??

 

[nj1639]

The front cam guide will drop down, probably to where you'ld have to tear down to put it back.

 

[Badger550]

I'm digging up an old thread here but I have an issue with this as well. From reading up top I'm not sure what the OP has stripped but both of the threads that I have stripped are the actual threads that are in the engine. Anyone have experience with this? Can the threads in the cylinder jug be heli-coiled? Is the wall too thin?

 

[angus67]

he stripped the threads in the cam chain guide.(.............i think)

 

[Badger550]

Then a new cam guide is easy enough but the threads on my actual engine case are stripped. Any one ever deal with that? Really don't want to buy new cylinder jugs.