Stripped Water Pump Bolt

This is how I feel right now:   

So, put the water pump on, and did not really pay attention to the bolts as they came out of the old pump.  Put the pump back on, and noticed, one bolt was, shall we say, not tightening up.  PULLED IT ALL OFF again!

Sure enough one of the BOLTS was stripped.  It had to be before and I did not notice it, because, I never torqued down on the bolts on reinstall.  

I threaded the bolt, and cleared the threads on the block.  I actually went and got a new bolt because it looked a bit chewed still.

Reinstall.

I could scream.  Cannot get the bolt to bite when it gets snug.

I renew my disdain for whoever rebuilt this motor.  

The bolt could not have been torqued down, and yet, did not leak from that spot.  But, I am not one to let something like this go.  It needs fixed.

So, I throw myself on the mercy of the court.  Suggestions?  I post pick of the offending bolt below.

What are my options here, and how do I do it?

First question, does it go into the block or just the timing cover? If just the timing cover if I remember correctly on the 335 series engines, it is a punched in portion that is threaded. You may be able to helicoil or other similar thread repair system that hole, but I would remove the timing cover so chips from the operation don't get into the oil pan. If it goes into the block, thread repair won't get chips into the oil pan if you are reasonably careful.

Several thoughts.  First, are you sure that is the right sized bolt?  No chance you have a smaller bolt where a larger one should go?

Second, when you cleaned out the threads in the block did it feel like the tap was loose?  Like the threads are bad in the block?

If it feels like the threads in the block are bad, and you are pretty sure you have the right sized bolt, then I think I'd pull the water pump back off and get an up-close look at the threads in the block.  And if they are bad then you'll have to come up with a plan.  One might be to put a Heli-coil in the block.

85lebaront2 wrote

First question, does it go into the block or just the timing cover? If just the timing cover if I remember correctly on the 335 series engines, it is a punched in portion that is threaded. You may be able to helicoil or other similar thread repair system that hole, but I would remove the timing cover so chips from the operation don't get into the oil pan. If it goes into the block, thread repair won't get chips into the oil pan if you are reasonably careful.

It LOOKS like it goes through the timing cover, and into the block.

It LOOKS like it is also one of those that has not a lot of real estate, and is open to the timing chain area behind it—that is, there is an open space.  I need to make sure with a schematic if anyone has one.  I will also try to find.  

There is only one bolt that goes into the timing cover only—the very top.  

Gary Lewis wrote

Several thoughts.  First, are you sure that is the right sized bolt?  No chance you have a smaller bolt where a larger one should go?

Second, when you cleaned out the threads in the block did it feel like the tap was loose?  Like the threads are bad in the block?

If it feels like the threads in the block are bad, and you are pretty sure you have the right sized bolt, then I think I'd pull the water pump back off and get an up-close look at the threads in the block.  And if they are bad then you'll have to come up with a plan.  One might be to put a Heli-coil in the block.

Hey Gary—ALL the bolts are 5/16 (½ inch wrench or sockets on the hex), except for the power steering pump bracket.  

BTW, Blue top went in today easy.  Will post in my thread.

I was hoping to avoid taking off the pulley and harmonic balancer…ugh.  The Divine has other plans for me on this project.  

Ordering the kit for the timing cover tonight.  UGH!

What in the world is a Heli coil?  I need to research this!  

Another thought—are there stud bolts that, say, might go one step higher, and then decrease to 5/16 for a nut?  That would only work if this is a through and through hole into the timing chain area, which I think it might be.

Glad the Bluetop went in well.  

Ok, so all of the bolts are 5/16" and, I assume, have good threads.  That being the case, it sounds like the threads in the block are the problem.

As for Heli-Coils, they are thread repair pieces.  You drill out the hole, tap it with a special tap, and then thread the coil in.

It's hard to tell really but that particular bolt looks big to me. When I did mine, I remember one particular bolt giving me all kinds of grief. Turned out, the bolt I was using was the wrong size. Don't remember which bolt hole that was though. I'd double check thread size and even try a smaller course thread bolt in there before pulling it.

If the bolt hole is stripped out in the timing chain cover, a heli-coil is indeed the way to go.

Good luck!  

Here is a 400 I found on the web. You might be able to guestimate where the bolt lives. To me it looks like it goes through the timing cover and into the block.

Cover the front of your engine with saran wrap before you start drilling. Additionally a magnet taped to the outside of a plastic bag can catch all the metal shavings.

caution! I just did this on my truck three weeks ago. replaced the water pump, timing chain and I also did the crank bearings. the timing cover is nothing more than a steel plate on this engine and the threaded hole was made by machine punching through then tapped. there is not much there when compared to the block and I notice immediately that this would require a different feel or torque then the bolts going to the block. the chain is right behind it. you cannot go very deep. and a helicoil is best if it has a back shoulder to set against. setting the depth so to speak. it would be very easy to thread it on through into the engine and have it fall into the pan. it would certainly be best done with the plate on a bench but thats not always an option, so be careful. certainly, remove the pump to continue.

If you're not comfortable with a Heli-Coil repair, you can always buy a new timing cover. They're reasonably priced imho.

https://www.summitracing.com/parts/sdm-pce265-1052?seid=srese1&gclid=Cj0KCQiAzeSdBhC4ARIsACj36uEhGcdSwihqnOIK257Lso9E-z09BENmB6RYUDqRR8AuABqAjlkTdXQaAhhrEALw_wcB

https://www.summitracing.com/parts/ses-5-65-04-201

Going by your picture, it certainly looks like one of the lower timing cover bolts.

I've used Keenserts for thread repair in the past and I really like these, but I have only used them in aluminum, not steel. A company I used to work for used them a lot on new aluminum parts as well.

From the link Cory posted it appears the bolt threads into the tin cover and not the block. (well inboard of the water inlet)
I also note the aftermarket one seems to have threaded inserts unlike what Mat says about the OEM.

Helicoils are not going to work in sheetmetal.
Replacement is unfortunately the only viable option in that case.

ArdWrknTrk wrote

From the link Cory posted it appears the bolt threads into the tin cover and not the block. (well inboard of the water inlet)
I also note the aftermarket one seems to have threaded inserts unlike what Mat says about the OEM.

Helicoils are not going to work in sheetmetal.
Replacement is unfortunately the only viable option in that case.

The ProComp one shows what is basically nuts welded on the backside. I guess one could do that easy enough for a repair also. Once it is removed you could use the water pump as a template, and weld a hex nut on the backside, as long as you made sure it didn't interfere with anything.

Yep. I used the term 'insert' because I didn't see any hex, but you certainly could weld a nut to the back side if the dimpled thread boss on the original isn't so big that a nut would fall through it when ground flush.
(I'd probably do both just for peace of mind)

There's often more than one way to get around a problem.  

Here is a stripped down 351 C block.  I have circled the hole—it clearly goes into the bock, and it would need to since it is one of TWO bolt around the bottom radiator hose intake.  The only bolt I know that ONLY goes into the timing cover and nothing else, is the top bolt.  

I believe it is like the one you see at the end of my arrow—note—there is a void behind it.  NONE of these bolts interfere with the timing chain as the void is to hte outside of the chain.  

I will confirm all this and make sure i send pics.  

At this point, Wednesday is my earliest to take care of all this—to get the harmonic balancer and timing cover off at least.  

Today got the intermediate shaft on! Will update all this on the thread. Having some trouble putting the pitman and drag link on as a unit…may need to disassemble more linkage to get it to work.


Update:  Because of various comments, i think the part I circled is the TOP of the bottom intake bolt—that goes into the block.  

So, I think I am one hole off and that the bottom intake bolt does indeed go through the cover ONLY.

AmericanSavage wrote

Here is a stripped down 351 C block.  I have circled the hole—it clearly goes into the bock, and it would need to since it is one of TWO bolt around the bottom radiator hose intake.  The only bolt I know that ONLY goes into the timing cover and nothing else, is the top bolt.  

But that's not the same bolt that you pointed to in your original picture, is it?

tcbaklash wrote

Here is a 400 I found on the web. You might be able to guestimate where the bolt lives. To me it looks like it goes through the timing cover and into the block.

Cover the front of your engine with saran wrap before you start drilling. Additionally a magnet taped to the outside of a plastic bag can catch all the metal shavings.

This matches with my brief look at the cover, and noticing there is a block behind that hole in particular.  

GREAT idea on saran wrap and magnets!

Ordered the 5/16-18 heli coil today.  

Some folks have suggested maybe there is a larger bolt in that one spot only.  I am inclined to say, not in my case.

Here is Gary’s Diagrams—note the 351C/M 400, and 460) are the same.  The part list notes that they are all 5/16-18 AS REQUIRED.  Which means they are all the same size for those two engines:
https://www.garysgaragemahal.com/water-pump-s--illustrations.html


I add:  I ran the tap through a couple of other holes, and it went smoothly, and had the same fit as the hole I am having tropuble with.  

Rembrant wrote

AmericanSavage wrote

Here is a stripped down 351 C block.  I have circled the hole—it clearly goes into the bock, and it would need to since it is one of TWO bolt around the bottom radiator hose intake.  The only bolt I know that ONLY goes into the timing cover and nothing else, is the top bolt.  

But that's not the same bolt that you pointed to in your original picture, is it?

UPDATE:  I matched the gasket between the cover and the block….that hole on the block rests ABOVE the intake and the hole I circled.  THAT throws me off a bit because I saw block behind that hole…or did I?  Certainly here is a block on the hole above the intake.  Pics coming.  

AmericanSavage wrote

Yes, it is.

Ahh, OK, my bad. I thought it was one of these two bottom bolts which look to be the ones that thread into the timing cover and not the block.

Those will definitely screw into only the timing cover, be it aluminum or steel. The only oddity I have run into, some of the Windsor engines have two thin head bolts the come in from the back holding the metal back plate on the water pump.

All water pump bolts are the same thread, just different lengths.
That's why I like to make an outline and keep them in place as they come out.

I also apply anerobic PST on all my waterpump and timing case bolts to keep the threads from ever corroding.
(Yes, I know your 335 engine only has a steel plate and not the problematic mag/alu case of Windsors and 385's like mine)