Stripped drain plug

[stokes]

So I was doing the 1k service on my '16 V7 Racer and stripped the drain plug on the transmission.I had the torque wrench set at 12nm since the manual only gave a torque value for the engine oil drain plug and figured it was the same for all 3.Years ago I had the same problem on my Harley and was able to get a replacement "kit" which included a tap and an oversized plug.Can somebody point me to such a "kit" for the Guzzi?Thanks in advance for any help here.

[blackcat]

Personally, I like a Timesert, but you can use a Helicoil for this application. I don't know the size of the drain plug but once you know that dimension,  just do a search for either of the above. With the Timesert the procedure is to drill out the existing hole, tap new threads, counter sink the opening and insert the new threads to work with the existing plug. The Helicoil is just drill, tap and insert the Helicoil.  Both Helicoil or Timesert cost about the same for the kit. I assume this is about a 13mm plug with a 1.25 thread pitch. If you live in Brooklyn, just stop at an AutoZone as they have one of those thread size/pitch tools where they sell nuts and bolts or maybe someone from the list will know this answer. 

Keep in mind that you will have to flush the transmission a few times to make sure you don't deposit any metal shavings in the transmission.

Next time, just wrench the plug tight with a new washer. I never use a torque wrench on oil, transmission or final drive drain plugs.

[troyhamilton]

its pretty easy to do. easy fix.

[Kev m]

So I was doing the 1k service on my '16 V7 Racer and stripped the drain plug on the transmission.I had the torque wrench set at 12nm since the manual only gave a torque value for the engine oil drain plug and figured it was the same for all 3.Years ago I had the same problem on my Harley and was able to get a replacement "kit" which included a tap and an oversized plug.Can somebody point me to such a "kit" for the Guzzi?Thanks in advance for any help here.

I'm a huge believer in torque wrenches. But I also believe in feel.

Just the fact that you have had this problem on another bike tells me that:

A. Your torque wrench is out of calibration.

and/or

B. You need to develop some feel.

and/or

C. You're doing something wrong.

Take a step back before giving yourself more headaches with this sort of thing. I think I'd start by having the wrench checked/calibrated and maybe until then just using your palm on the head of the ratchet for drain plugs and low torque applications.

[kirby1923]

So I was doing the 1k service on my '16 V7 Racer and stripped the drain plug on the transmission.I had the torque wrench set at 12nm since the manual only gave a torque value for the engine oil drain plug and figured it was the same for all 3.Years ago I had the same problem on my Harley and was able to get a replacement "kit" which included a tap and an oversized plug.Can somebody point me to such a "kit" for the Guzzi?Thanks in advance for any help here.

12nm is only 8 ft lbs, you should really pay attention to Why you striped it or might happen again.

Looks like you mixed up NM with KgM. 12 Kgm =86 ftlb,(1032 inlb) that a lot for a drain plug. conversion Kgm/.138=ftlb.
Easy to do on a torque wrench.

[not-fishing]

This is one of those "now I know" lessons.

I've also ran into manuals that have the wrong torque listed.  had to pull the timing cover off to remove busted bolts on an 04 Dodge Hemi I & my son kept snapping water pump bolts

After this you'll learn to get a "feel" for what the right torque is for a general bolt / screw size.

Mark

[guzzisteve]

Would this be on the 6 speed w/filter in the hole? That would be way different than the small drain plug on the 5 speed.

[pehayes]

Careful.  Italians like to use "transmission" for the bevel gear fina drive at the rear wheel.  Nomenclature often screws things up.

Also, this task of re-threading the hole is best done with parts removed and installed onto a drill press or mill so that you can assure the final installation is square to the face of the casting.  You probably didn't want to hear that.  If you want to do it in-situ, do everything you possibly can to insure squareness and rigidity before you start drilling and tapping.  A slight angular offset just means the gasket won't be sealed with equal pressure all around and you'll end with a persistent leak.

Patrick Hayes
Fremont CA

[stokes]

Ok,the manual says "transmission",its the final drive drain plug.10 yrs ago when I did it to my Harley,I didnt use torque wrenches.The "kit" I'm talking about had a tapered bit you used in a ratchet handle to cut the old threads out then the new plug which was tapered as well cut itself to fit into the bare hole that was reamed out in the first step.Cant remember where I got it.

[tris]

See if you can get a pilot nose tap for the job

http://m.ebay.co.uk/itm/V-Coil-12-mm-Helical-Wire-Thread-Insert-Pilot-Nose-Tap-for-M12-x-1-25-/310420659621

I only discovered these last week and thought how useful they were.

[Moto]

I also did the same thing to my Griso's transmission (gearbox, the thing with 6 speeds), the same way.

Looking into my accomplishment, I found that the Griso's plug seat was substantially shorter (less deep) than my T-3's, perhaps having led me to be a little careless in torquing. (I have crude depth measurements somewhere.)

I also strongly recommend Timesert. I raised the back of my bike with a jack while it was on my work stand, and did the job in situ. I had no trouble at all making the installation square with the surface, using some property of the Timesert that escapes my memory. It is a very well designed tool.

Follow the clear instructions that come with the Timesert and you have little chance of error or even contamination, I believe. I dilly dallied around for months in fear of goofing this up, but in the end it was an easy job, and one I regretting not having gotten to sooner. (Though my delay gave me an excuse to exercise my T-3 for a while, which was nice!)

Moto

[blackcat]

its the final drive drain plug.

Easier to address or just bring to a machine shop.

[guzzisteve]

Rear?  I would pull that apart, ring gear is right there, not much through clearance.

[blackcat]

Rear?  I would pull that apart, ring gear is right there, not much through clearance.

Well, that settles that.

[stokes]

Found something similar to the kit I used for the Harley.Just need to know the size of the plug.The manual I have doesnt show the size.Anybody know what size the plug is?

[guzzisteve]

Should be a 10X1 like the other oil drains in Guzzis.

[stokes]

Should be a 10X1 like the other oil drains in Guzzis.

Do you mean the other oil drains on the same bike?The engine oil and gearbox oil drains are much larger than the final drive,or transmission drain plug.

[Mike Tashjian]

You have the plug so the easiest way is to measure what you have.  Almost any auto store or hardware store will have a way to measure or compare what you have.  Then go from there.  If you are unfamiliar with these tools, seek help to do the job right the first time.  The torque wrench is a great tool and easy to use once you know how.  Mike

[KiwiKev]

Rear?  I would pull that apart, ring gear is right there, not much through clearance.

That pilot nosed tap wouldn't be much use in situ by the sounds of it  ?? Though I guess it would be easy enough to shove something up and see how much space there is to work with.

[guzzisteve]

Not your model but most others use that same magnet plug & rubber centered crush washer.
On the rear drive, trans, engine of most all the bigblocks in the last 10yrs

[sign216]

Also, this task of re-threading the hole is best done with parts removed and installed onto a drill press or mill so that you can assure the final installation is square to the face of the casting. 

Yes, happened to me, and as Patrick says, it's much easier to remove the pan or unit and do the helicoil/timesert on the bench.  Also, change the plug for an aftermarket aluminum alloy drainplug with a smaller head.  A smaller head means a smaller wrench, so you are less likely to over-torque it.  And since it's aluminum it'll be softer on the threads.

[tris]

That pilot nosed tap wouldn't be much use in situ by the sounds of it  ?? Though I guess it would be easy enough to shove something up and see how much space there is to work with.

The beauty of the pilot nose tap I thought was that since it follows the old thread it will be square - not cheap though

[KiwiKev]

The beauty of the pilot nose tap I thought was that since it follows the old thread it will be square - not cheap though

Agreed it looks like a good tool but it would protrude further into the casing than a standard tap I meant.


Sent from my iPhone using Tapatalk

[tris]

I understand your thoughts Kev and it may not be the tool for the job in this instance, but its one of those tools I've stashed away in my memory bank of "stuff that might come in useful" 

Personally, I'm not too thrilled drilling or tapping anything like this in situ.  I've done it but here's always that niggling thought in the back of your head that a bit of swarf might have escaped

[chuck peterson]

I'd start questioning my own abilities and seek professional help if this is a second time...really, I just know enough to be dangerous

Most trained mechanics I know are quite humble about you fking things up when you bring in the broken pieces....they've usually made the same mistake but twenty years ago. Mine just smiles and says, "yup, don't do that..."

I'd be absolutely horrified Id make it worse, like ruining an engine case

[Kev m]

Most trained mechanics I know are quite humble about you fking things up when you bring in the broken pieces....they've usually made the same mistake but twenty years ago. Mine just smiles and says, "yup, don't do that..."

That's called customer service, you should hear what they say when you leave.