VIKING3500

So I was putting in new water pump today and noticed the bottom bolt just spun. I assumed P/O stripped it since I haven't touched it until today. I tried putting a bit too much on the other three and one of them "popped" then spun. I stripped the threads in the block. The bolt came out ok but now I need to know how to rethread it since I havent done that before. Do I need to drill to the next size up or what? Is there a torque spec on those bolts?

Dan91

Water pump bolts torque are 17 ft pounds. Not much. As far as fixing them I'm not sure the best way to do it. Drilling and tapping to the next size would work fine I'm guessing. Or you could heli-coil it and keep the same size bolts.

VIKING3500

What is helicoil?

VIKING3500

Disregard. I looked it up. Which solution is better longevity-wise? Im guessing drill and tap but i appreciate the feedback.

lynskynbnd

If you pulled the threads out drill and tap won't work

I beleive the botom bolt goes into the aluminum timing cover. stronger to replace than helicoil. threads in the block can be helicioled.
http://www.helicoil.com.sg/
Get a kit from the parts store

PatriotGT

I'd go with the Heli-coil. I've used them several times with success. If you go with just retapping, make sure the bolt will fit thru the holes in the water pump and be careful
drilling either way. Wrap some tape around the bit to use as a stop.

lngliv3

Get a heli-coil it is by the best way to repair a damaged thread.... its simple to do you get the heli- coil kit it tells you what drill bit to use then you tap the hole with the supplied tap in the kit the thread the insert on the installing tool till its just below the surface then remove the tool insert a small screwdriver to break off the tab . Put some grease on the screwdriver to remove the lil piece and your all done...... DO NOT I MEAN DO NOT PUT LOCTITE ON THE THREAD INSERT BEFOR YOU INSERT IT... Its not needed nor is it recommened .....
I use heli-coil's at work on a regular basis. I have used them on everything from head bolt holes in a engine block on Cat engines (big trucks) to valve cover bolts to the valve cover base. Not to mention the cyl head to repair a broken exhaust manifold studs..... I would use them vs drilling to a bigger size and tapping to use a bigger bolt.... This is just my opinion .... I know what works and what dont..... good luck ....

5-90

A wire thread insert (Heli-Coil, Re-Coil) or a thread bushing (Tinesert, Keensert) will last you the longest hands down.

The primary difference? A wire thread insert is made from diamond-shaped wire (usually CRES,) and requires a special tap and mandrel to install.

A thread bushing has a standard thread on the inside and outside, and can be installed using regular taps & drills.

Which you use depends on how much "meat" is left at the threaded hole - a wire thread insert requires a good deal less than a threaded bushing. Both are difficult to remove if properly installed - a wire thread insert is wound oversize, and spring tension will hold it in place. A thread bushing usually has three or four "prongs" sticking out of the working side that get tapped into place, forming an interference fit to retain the bushing. Both repairs may be considered "permanent," and I've used both with excellent results.

As I recall, there's a good deal of material left in a lateral direction, but the casting is relatively thin there. It's easier to get a wire thread insert for thin sections - a kit typically includes the tap & drill required, installation mandrel, and thread inserts in three lengths (a Heli-Coil kit is spendy, but well worth it. Use the ones you need, put the rest in your toolbox. You'll probably need them again.)

A bushing should be installed flush and staked. A wire thread insert should be run about a half-turn past flush, to keep the wire from protruding (and when I say "flush," I mean it. You're dealing with a sealing surface here! It's safest to install pretty much anything in this case to slightly past flush, bushing or wire insert. Protrusion will wreck your sealing ability, but going past flush will not.

How good are these? Back when I was building maximum-effort engines, I made it a fixed policy that any threaded hole in aluminum and all critical holes in iron (cylinder head screws, main bearing cap screws) got Heli-Coil inserts installed. No exceptions. Not negotiable. Durability was a critical factor for me, and I wasn't going to skimp.

It added to the cost of the engine, but also made the difference between DNF and seeing the flag often enough to keep as policy.

VIKING3500

The wire thread inserts sounded good until i found this. Can i work around this? Broken ear off the bolt hole. Repairable? Bottom hole is stripped as well and should be repairable according to your guys' info.

5-90

Yech. Drill & tap for thread bushing (if you can,) use JB Weld or similar to build up the hole back to the surface - or close to it, if you don't have a steady hand with a grinding wheel.

You can also install the wire thread insert and carefully build up around it with JP or similar, just don't shove any in between the wire coils, or you'll really boned!

Yes, JB can be machined, ground, drilled, or tapped. If you check a welding supply house, you can find something called "Labmetal" or similar - which comes in bigger cans, but is even more useful than JB!

EDIT - looks like you still have some room behind - you can run the screw thread insert farther down, and use a longer screw to clamp. The sealing surface is still in good condition, right? You can get enough clamping force (especially since you don't need much) using exposed screw, but I'd use CRES or brass/bronze there (which I do anyhow. I don't like rust.) Ever see a high-pressure plumbing join with exposed screw shanks? They're out there, and there are plenty of them.

VIKING3500

Yes sealing surface is still viable.Project Sounds pretty reasonable to do. Probably should remove entire grill and rad for this one. Pisses me off cause i just wanted to get rid of the bearing squeal from the pump pulley. Impeller was a little rotten from sitting for years with p/o so its still worthwhile.

SpyderJeep

DUDE!!! You are screwed.... OUCH!!!
I have a broken bolt at the back most bolt for the exhaust manifold, I high temp RTV'd it like mad and it work well.

413maxwedge

Yes it will you dont need threads to tap a hole you need the next size drill bit that will clean up, and remove the old threads then a starter tap and a bottom end tap to thread it completly if it dead ends!!, but a helicoil for this repair is perferiable cause it's easier for most people to do.(threads should be in the block,the rest should be just a through bolt)

VIKING3500

Tore out grill, radiator and winch for better access. The bottom hole is fixed with the helicoil, easy fix.

The broken bolt ear on the right side is a pain. Makes since if you think about it but it's near impossible to start threading a hole that doesn't have a flat surface without fabbing up some sort of guide for the tap since you can't get the cutting force. Huge PITA. I ended up drilling out a bit more material and JB welding the threaded bushing into place. I've got my fingers crossed on that one.

VIKING3500

Painted bumper while jb weld cures