Broken fuel pump bolt hole in timing chain cover

[DFoley]

So I needed to replace the fuel pump on my '79 CJ7 AMC 304 V8. When removing the current pump the front-most bolt hole on the timing chain cover broke, see attached picture. So now what should I do? Replace the timing chain cover and while at it a whole lot of other stuff, water pump, timing chain, oil pump, etc. Or could I get a cover plate to hold enough to seal the opening and switch over to an electric fuel pump. I recently inherited this "hunting rig" jeep, so it's not in the best condition and a "little rough" to say the least. I didn't really want to spend a ton of $$$ on this jeep. Curious as to y'alls thoughts.

Thanks,
-Dan

 

[Sbasham1]

I've had dreams of an electric fuel pump that primes before I turn the starter over and doesn't have to take as long to start, however i'm just never going to go down that route cause I like this car staying stock.

I'd say if the pump and timing chain etc are currently working, no point in replacing them. Just fix whats broken and upgrade to an electric fuel pump.

 

[RiverandSand]

Looks like you have more issues than just a broken bolt, it's missing part of the side of the outter bolt hole. Its probably cracked in the area too, time for a new timing cover.
You could try to drill out the broken bolt and then Heli-coil both holes, but it would be a challenge not to hog out broken bolt hole in process.

 

[TeamRush]

One option would be to find a good TIG welder and have the flange built back up with 'Gob' (filler) weld.
This is fairly cheap but the guy on the TIG will need to know what he's doing.
This isn't a job for an amateur...

Work down excess (it will look like bird ) and re-drill/tap the hole.

This is a cast aluminum piece, it will have to be VERY clean before you start welding, but it can be done (I've done it myself to restore threads that were removed by rust when bolts were removed, tabs broken off, etc.).

Rehabbing the cover saves about $300.
A replacement will cost about $300,
Factory covers that have been completely restored run about $300.
This means your break even point is $300.
Look into rehab before new, it could be much less than $300.

.

I did an article on rehab of the front cover, but I can't find the pictures right now, but I'll look.
It had pictures of how the home rebuilder can flatten the gasket surfaces, clearance the oil pump & water pump, restore bolt holes/remove broken bolts, and insert an oil pump cavity insert to fix gouged out oil pump cavity walls.

Getting the oil pump cavity to fit the impellers is the hardest part of rehab, it takes an off-set mill to do, but even gouges in the oil pump cavity can be fixed.
That would involve an experienced machinist, which is why you don't hear about it from the average AMC/Jeep sites.
There is a push in sleeve that smooths the oil pump cavity, you have to oversize the bore(s) and you get one shot at installing the sleeve (like getting pistons in without breaking rings) but when it's done correctly, the oil pump cavity is better (tighter) than new.

Since this isn't your issue, it's just for FYI for anyone reading.

 

[hagar]

I'd try and fix it.
Pull it off, maybe have some one weld it up.
Then re-drill and re-tap the hole.
The China re=pop timing covers are junk and come with problems.
I'd try to fix yours.
Like somebody above mentioned, I'd just fix what's wrong.

 

[DFoley]

RiverandSand...I guess I should have been a bit more clear. I got the bolt out, but in doing so broke the flange as pictured. Thanks for you input.

 

[DFoley]

Sbasham1...I guess I don't really know how well the oil pump, timing chain, or anything else are really functioning. I just inherited this jeep and owned it a total of 2 weeks. It has been sitting idle for ~3-4 years. As long as I dribble gas or starting fluid in the carb it starts right up and sound OK, but I couldn't keep it running because the fuel pump was not working. So I have not yet been able to drive it around. I took the fuel pump off to replace it, breaking the bolthole, and now I'm in the predicament I'm currently in.

In all likelihood there are many things that need to be repaired/replaced on this jeep. But I was hoping to be able to pick away at them as time and $$$ becomes available, but in the mean time still be able to lightly drive it around my small ranch.

 

[Patrick]

Could you not make room for a hex nut behind the mounting flange?

 

[007]

You've been given good advice by everyone... The problem with replacing the timing cover is that it becomes Pandora's Box and thus the expenses just snowball. Not that the stuff might not need done, but it's like remodeling a kitchen or bathroom. One place to start and nowhere to finish.

Just because that piece is missing, you might still be able to thread a bolt back in there. Might not be enough for a fuel pump, but it would be enough for a block off plate. I ran an an electric fuel pump for a year or so and it was fine, just put a regulator on that sends the excess back via the return line. The MC2100's like 5-7lbs of pressure if I remember correctly.

If you want to keep the manual pump, then I'd be curious as to Patrick's question. If not, then put a bolt back in there before your TIG guy welds the missing piece and you might not have to do anything with the threads.