Stripped threads on VP stern drive drain.

bobkatfly · 02-17-2021, 08:01 AM

Good video. I can see that the counterbore tool has a shoulder stop to control the depth. Soon as I get some cooperating weather I'll take a look at everything. The kit for 3/8-16 Time-serts is about $80 at Amazon with inserts that are 1/2" long. Not sure if I need a shorter one but I'm pretty sure I can measure the housing to determine that.
Thanks everyone, great advice.

8gv · 02-17-2021, 09:20 AM

In the Time-Sert installation video the insertion tool looks like it may extend well into the gear case.

Will there be enough clearance inside for it to do the job or will the case need to be emptied of its internal parts first?

bobkatfly · 02-17-2021, 10:45 AM

Quote:

Originally Posted by 8gv

In the Time-Sert installation video the insertion tool looks like it may extend well into the gear case.

Will there be enough clearance inside for it to do the job or will the case need to be emptied of its internal parts first?

Dam I hope not but I think you only need to run the insertion tool just far enough to expand the threads on the end of the insert so the tool would only need to go slightly past the insert. Soon as I get decent weather I'll give an update.

AC2717 · 02-17-2021, 11:05 AM

wow great insight and video

MAXUM · 02-17-2021, 03:31 PM

Quote:

Originally Posted by bobkatfly

Good video. I can see that the counterbore tool has a shoulder stop to control the depth. Soon as I get some cooperating weather I'll take a look at everything. The kit for 3/8-16 Time-serts is about $80 at Amazon with inserts that are 1/2" long. Not sure if I need a shorter one but I'm pretty sure I can measure the housing to determine that.
Thanks everyone, great advice.

Feast your eyes on this!

http://timesert.com/html/drainplug2.html

https://www.amazon.com/Time-Sert-M14.../dp/B00I3N39MC

They have shorties specifically for drain plug repairs. The key thing for this to work is the bottom part of the insert has to have material to expand and lock into.

Of course you are now obligated to provide pics so everyone can see the final product if you do this.

XCR-700 · 02-17-2021, 05:02 PM

Not knowing your drive is it safe to assume you have a separate fill plug above?

XCR-700 · 02-17-2021, 06:01 PM

The best plan would be to not get anything in there if possible, metal shaving are sometimes really tough to flush out.

That said, if there is a separate fill plug you could use it to apply VERY low pressure air flow to the drive while you are drilling and tapping it to blow the shavings out and keep them out.

You would need to be very careful to not use much pressure and damage the seals.

bobkatfly · 02-17-2021, 07:30 PM

I really appreciate the input from everyone.

As far as the insert length, I'll determine that when I finally get out to work on it (have to do truck brakes first).
The drain plug is 3/8-16 and although 1/2" long inserts come with the kit, they have inserts as short as 5/16" for that thread and the length from under the plug head to end of threads is 5/16". A little longer on the insert should be okay.

There is a dipstick port on the top so I could pressurize it while drilling/tapping as well as testing. I will definitely pressure test after install but I think using grease on the drill bit and tap will be okay. I can also get a Q-tip in there with grease to pickup chips.

As far as re-tapping without using an insert, I did that initially but I don't like the way the plug feels threading in so pretty sure the insert is needed as well as a new plug. I'll re-evaluate when I start.

Maxum, I'll try to remember pics also.

jst_4_kiks · 02-21-2021, 09:41 AM

Unfortunately that happens alot with the drain plugs of Volvo Penta outdrive. The lower drain plug gets corrosion around it being stainless steel and aluminum. The proper way is to replace the bearing carrier and a new plug. Upon doing that the rolling torque has to be reset for proper gear lash & new seals for the carrier.

bobkatfly · 05-03-2021, 05:22 PM

So, after over-thinking this (sorry Dave), I decided on the following plan.
The threads in the housing are about 3/4" long.
The threads on the plug are about 3/16" long (3 threads on a 3/8-16 thread). A little skimpy in aluminum. I believe that lead to the problem in the first place.
I was going to go with the Time-sert but was worried about drilling a straight hole with the drive installed. If the housing had been removed it would have been a different story. Also, the Time-sert kit is $80 plus additional cost for stainless inserts.
What I've done is modify a 3/8 bolt with about 1/2" thread length and machine a neck and counterbore under the head similar to the original, then drill the end and shrink fit the magnet in. I was lucky enough to re-connect with an old machinist friend that did it for a nice dinner that I didn't even have to cook.
Attached are pics. You can see the old plug with magnet removed, a new plug that I bought and the new screw with the o-ring installed.
I'll be trying it out soon.

MAXUM · 05-04-2021, 02:00 PM

Quote:

Originally Posted by bobkatfly

So, after over-thinking this (sorry Dave), I decided on the following plan.
The threads in the housing are about 3/4" long.
The threads on the plug are about 3/16" long (3 threads on a 3/8-16 thread). A little skimpy in aluminum. I believe that lead to the problem in the first place.
I was going to go with the Time-sert but was worried about drilling a straight hole with the drive installed. If the housing had been removed it would have been a different story. Also, the Time-sert kit is $80 plus additional cost for stainless inserts.
What I've done is modify a 3/8 bolt with about 1/2" thread length and machine a neck and counterbore under the head similar to the original, then drill the end and shrink fit the magnet in. I was lucky enough to re-connect with an old machinist friend that did it for a nice dinner that I didn't even have to cook.
Attached are pics. You can see the old plug with magnet removed, a new plug that I bought and the new screw with the o-ring installed.
I'll be trying it out soon.

That's a nice compromise and nicely done. I would however consider putting a very small dab of BLUE locktite on that thread.

Can't beat the price either

Dave R · 05-05-2021, 05:51 AM

Quote:

Originally Posted by bobkatfly

So, after over-thinking this (sorry Dave), I decided on the following plan.
The threads in the housing are about 3/4" long.
The threads on the plug are about 3/16" long (3 threads on a 3/8-16 thread). A little skimpy in aluminum. I believe that lead to the problem in the first place.
I was going to go with the Time-sert but was worried about drilling a straight hole with the drive installed. If the housing had been removed it would have been a different story. Also, the Time-sert kit is $80 plus additional cost for stainless inserts.
What I've done is modify a 3/8 bolt with about 1/2" thread length and machine a neck and counterbore under the head similar to the original, then drill the end and shrink fit the magnet in. I was lucky enough to re-connect with an old machinist friend that did it for a nice dinner that I didn't even have to cook.
Attached are pics. You can see the old plug with magnet removed, a new plug that I bought and the new screw with the o-ring installed.
I'll be trying it out soon.

Nicely done!

GeoBarb11 · 05-20-2021, 08:16 PM

Quote:

Originally Posted by Dave R

Nicely done!

You may be able to find a replacement bearing carrier on ebay for cheap. I have seen them listed there in the past.

Sent from my iPhone using Winnipesaukee Forum mobile app

02-17-2021, 08:01 AM	#1
bobkatfly Senior Member Join Date: Aug 2015 Location: Center Tuftonboro Posts: 370 Thanks: 57 Thanked 54 Times in 48 Posts	Good video. I can see that the counterbore tool has a shoulder stop to control the depth. Soon as I get some cooperating weather I'll take a look at everything. The kit for 3/8-16 Time-serts is about $80 at Amazon with inserts that are 1/2" long. Not sure if I need a shorter one but I'm pretty sure I can measure the housing to determine that. Thanks everyone, great advice. __________________ Bob F Amherst till the big 66 comes (made it!) Winter Harbor/Mirror Lake till the big guy comes

02-17-2021, 11:05 AM	#4
AC2717 Senior Member Join Date: Apr 2007 Location: Maynard, MA & Paugus Bay Posts: 2,577 Thanks: 755 Thanked 355 Times in 267 Posts	wow great insight and video __________________ Capt. of the "No Worries"

02-17-2021, 07:30 PM	#8
bobkatfly Senior Member Join Date: Aug 2015 Location: Center Tuftonboro Posts: 370 Thanks: 57 Thanked 54 Times in 48 Posts	Good stuff evryone I really appreciate the input from everyone. As far as the insert length, I'll determine that when I finally get out to work on it (have to do truck brakes first). The drain plug is 3/8-16 and although 1/2" long inserts come with the kit, they have inserts as short as 5/16" for that thread and the length from under the plug head to end of threads is 5/16". A little longer on the insert should be okay. There is a dipstick port on the top so I could pressurize it while drilling/tapping as well as testing. I will definitely pressure test after install but I think using grease on the drill bit and tap will be okay. I can also get a Q-tip in there with grease to pickup chips. As far as re-tapping without using an insert, I did that initially but I don't like the way the plug feels threading in so pretty sure the insert is needed as well as a new plug. I'll re-evaluate when I start. Maxum, I'll try to remember pics also. __________________ Bob F Amherst till the big 66 comes (made it!) Winter Harbor/Mirror Lake till the big guy comes

02-21-2021, 09:41 AM	#9
jst_4_kiks Senior Member Join Date: Mar 2009 Location: Laconia NH Posts: 130 Thanks: 25 Thanked 15 Times in 11 Posts	Unfortunately that happens alot with the drain plugs of Volvo Penta outdrive. The lower drain plug gets corrosion around it being stainless steel and aluminum. The proper way is to replace the bearing carrier and a new plug. Upon doing that the rolling torque has to be reset for proper gear lash & new seals for the carrier. __________________ Marine Technician - Learning Something New Every Day PM with any questions about marine repair

05-03-2021, 05:22 PM	#10
bobkatfly Senior Member Join Date: Aug 2015 Location: Center Tuftonboro Posts: 370 Thanks: 57 Thanked 54 Times in 48 Posts	New direction So, after over-thinking this (sorry Dave), I decided on the following plan. The threads in the housing are about 3/4" long. The threads on the plug are about 3/16" long (3 threads on a 3/8-16 thread). A little skimpy in aluminum. I believe that lead to the problem in the first place. I was going to go with the Time-sert but was worried about drilling a straight hole with the drive installed. If the housing had been removed it would have been a different story. Also, the Time-sert kit is $80 plus additional cost for stainless inserts. What I've done is modify a 3/8 bolt with about 1/2" thread length and machine a neck and counterbore under the head similar to the original, then drill the end and shrink fit the magnet in. I was lucky enough to re-connect with an old machinist friend that did it for a nice dinner that I didn't even have to cook. Attached are pics. You can see the old plug with magnet removed, a new plug that I bought and the new screw with the o-ring installed. I'll be trying it out soon. Attached Images __________________ Bob F Amherst till the big 66 comes (made it!) Winter Harbor/Mirror Lake till the big guy comes

02-17-2021, 09:20 AM	#2
8gv Senior Member Join Date: Jan 2012 Posts: 2,108 Thanks: 64 Thanked 747 Times in 481 Posts	In the Time-Sert installation video the insertion tool looks like it may extend well into the gear case. Will there be enough clearance inside for it to do the job or will the case need to be emptied of its internal parts first?

The Following User Says Thank You to MAXUM For This Useful Post:
upthesaukee (02-17-2021)

02-17-2021, 05:02 PM	#6
XCR-700 Senior Member Join Date: Sep 2008 Location: MA Posts: 1,342 Thanks: 757 Thanked 538 Times in 313 Posts	Not knowing your drive is it safe to assume you have a separate fill plug above?

02-17-2021, 06:01 PM	#7
XCR-700 Senior Member Join Date: Sep 2008 Location: MA Posts: 1,342 Thanks: 757 Thanked 538 Times in 313 Posts	The best plan would be to not get anything in there if possible, metal shaving are sometimes really tough to flush out. That said, if there is a separate fill plug you could use it to apply VERY low pressure air flow to the drive while you are drilling and tapping it to blow the shavings out and keep them out. You would need to be very careful to not use much pressure and damage the seals.

The Following User Says Thank You to GeoBarb11 For This Useful Post:
bobkatfly (06-15-2021)