Stripped threads in Waterpump Bolt Holes

JimboDean · 08-08-2006, 12:42 PM

As I was installing my new waterpump today I found two bolt holes to be stripped. The bolt just keeps turning, not allowing me to tighten all the way.

I've heard about helicoil kits and I'm probably going to go that route with tapping and installing new threads.

Is this the best route for fixing a stripped bolt hole?

-Jameson

pozican · 08-08-2006, 01:28 PM

I used a helicoil on my A/C compressor, and it worked GREAT!

In fact, I actually found a helicoil that my dad bought in '85 and never used. Dunno if they are any different, but I have had no problems

ae1969 · 08-08-2006, 06:15 PM

Helicoil will work fine.

Its not fun with the engine installed.

B. Elliott · B. Elliott's Garage

Also, check out the Timesert thread repair kits. More pricey than a standard helicoil kit but more reliable.

Timeserts were the only ones we would use in my old machine shop.

rudidelange · 08-10-2006, 06:50 AM

Helicoil is not the best. There is an insert with an outer thread and an inner thread. The hole is drilled bigger and this "insert" is then screwed or bolted into the hole... its a type of hollow tube. The inside of the tube has already the correct thread. I am not sure if the Timesert, mentioned by B Elliot is the correct term.
All the best

Techno Duck · Techno Duck's Garage

Helicoil worked for me with some stripped bolt holes for an oil pump. However the big problem is clearance as you need to be able to fit a drill in there to enlarge the hole. Unless you have a 90 degree bend type drill you will probably have to take the radiator out. Its imperitive you drill straight on with the helicoils.

Also if you do decide to use the heli coil, make sure you are aware of the depth you are drilling into, meaning measure how deep the threads go and dont drill beyond that. You dont want to drill into a cylinder now

.

Its pretty incedible how soft the aluminum block really is.. great care must be taken!

Razorback1980 · Razorback1980's Garage

You do have to remember that the block wall where SOME of the water pump bolts go is only 1/4" thick which will make the bigger inserts more difficult to put in than the helicoil. I'll put a picture up tonight to show which ones. As Techno Duck already mentioned, the cooling chamber is behind there and beyond that is cylinder 1 but there is about 1/2" gap in between.

JimboDean · 08-10-2006, 11:41 AM

Quote:

Originally posted by Techno Duck
. Unless you have a 90 degree bend type drill you will probably have to take the radiator out. Its imperitive you drill straight on with the helicoils.

make sure you are aware of the depth you are drilling into, meaning measure how deep the threads go and dont drill beyond that. You dont want to drill into a cylinder now .

Its pretty incedible how soft the aluminum block really is.. great care must be taken!

Thanks for the advice. The radiator is already out, but it's still going to be close quarters.

I'll take extra caution when I drill the old threads. The last thing I want is a cross-drilled block. Thanks for the feedback.

-Jameson

B. Elliott · B. Elliott's Garage

Quote:

Originally posted by rudidelange
Helicoil is not the best. There is an insert with an outer thread and an inner thread. The hole is drilled bigger and this "insert" is then screwed or bolted into the hole... its a type of hollow tube. The inside of the tube has already the correct thread. I am not sure if the Timesert, mentioned by B Elliot is the correct term.
All the best

Timesert is one manufacturer of the inner/outer threaded inserts. Although, they do require quite a bit of room to install and i know there isn't a lot of room to work with around the water pump.

May have to just use a regular Helicoil because of the space limitation.

924Sman · 08-12-2006, 06:21 AM

Are the threads completely wiped out and or do you have any good threads in the bottom of the hole?

If you have just crossed threaded and have good threads in the bottom you can back tap it. What this does is start the new threads at the bottom good threads and as you back the tap out it cuts new ones or straightens out the marred threads.

A back tap is basically a "mandrill tap" meaning it is tapered and can be expanded enough to re cut threads. No inserts needed, no drilling. And no concern on bore depth in the block.

Consider ALUMINOY sp? as a filler then retap at the OE size. Won't be too hot to weld.

Dal

ELLSSUU · 08-19-2006, 11:51 AM

Jimbo,

Just did the Helicoil deal today on one waterpump bolt that was stripped. Def. very easy to do and easily torqued down with zero issues. As others have said watch how deep you go with the drill bit.

JimboDean · 08-25-2006, 12:05 PM

Quote:

Originally posted by ELLSSUU
Jimbo,

Just did the Helicoil deal today on one waterpump bolt that was stripped. Def. very easy to do and easily torqued down with zero issues. As others have said watch how deep you go with the drill bit.

What size of helicoil threads, tap, drill bit, etc did you use?

ELLSSUU · 01:04 PM

Quote:

Originally posted by JimboDean
What size of helicoil threads, tap, drill bit, etc did you use?

Carquest part number HC 5546-6; M6 x 1. Instructions called for a 1/4 inch drill bit. Tap and nice little installer comes in the kit although drill bit does not. Also, if you get the kit above and you don't have a hand tool for a tap & die kit I highly suggest picking one up (only about $5).

I believe that our WP bolt dimensions are the same from a turbo to a N/A but it'd be best to make sure.

ae1969 · 08-25-2006, 01:16 PM

Quote:

Originally posted by ELLSSUU
I believe that our WP bolt dimensions are the same from a turbo to a N/A but it'd be best to make sure.

Yup ... they are the same.