Overualing 404/4630 ran into a snag.

Started tearing down the 14,000+houred 404 in our 76 4630.

Figured I'd take the head off first to get it sent out to the machine shop while I did the front cover and cleaned things up and re-assembled.

The valvetrain looked good, when I went to remove the head I had a broken head bolt that's been busted for awhile. it's broke off flush with the block deck and looks pretty rusty. I soaked it down with penetrating oil but I'm not sure how this will work out.

The cyl walls have no crosshatch left, but no visable scoring and a healthy ridge. pistons are all intact and have no cracks.

so far I don't see any cracks on the head except for at the hole where each nozzle protrudes there's about a 1/8-1/4 inch crack running back... no cracks anywhere else that I see right now. I'll know more when I get it completely buffed off.

I'm short the correct deep 15/16 socket to remove the nozzles, so I'll have to get that later, or have the machine shop do it.

I haven't got the radiator pulled or front cover off yet, but I'll try to get at that tomorrow.

My questions are-

How should I best go at this broken head bolt?
my instinct tells me to try and weld a nut on it, but I've never had one break off on the block deck before.

How do I "pin" this engine on TDC for valve adjustment purposes, and how do I correctly re-time the crank/cam/IP once the front cover is apart?

What are the specs for head bolt torque, and should the head bolts be replaced? what about valve lash specs?

Anything else I should be looking at before I order more parts?

I'll pull the lifters tomorrow to make sure the cam and lifters are good. didn't have time today.

Thanks!

DF
 
My first thought is your in over your head here...next "don't" weld a nut on the bolt,,drill it, you will not be "pulling" the lifters,, they go down out after the cam is removed, as for timing that will be done with the timing gears, which is a good way,, and "yes" replace the heard bolts,, you already see what can happen..and yes I will help you through it..
 
I would be scared, don't think I have ever heard Tim S be that direct. You will not want to order ANY parts until it is all apart cleaned up and head inspected by machine shop. You will also want the shop to boil, magnaflux and put the new sleeves in.

You are way ahead of worrying about putting things back together.

You will want to put the old lifters back in the same hole if you do not replace the cam. I use an egg carton and number them.
 
Hi Tim
Glad you got onto this and answered while I was trying to think about my reply and say what you did diplomatically. Was thinking along the same lines but didn't want to appear ignorant doing it, the way I would of said it .
With that 404 does he get into new style torque to yield bolt kits and gasket changes. I did that 466 JD and can't remember if it said 404 on the same sheet or not for bolts and stuff.
At least with your help he's got a good chance if he does whats told, it will run right and stay good for the life of the rest of it!.
You seem to be the guy that should work at our local dealership, Things would get done right the first time!.
Regards Robert
 
These are one of the nicest engines to work on, and done right they run like new, with that many hours on it the cam and oil pump should be replaced,, I have had head bolts like this before they are tough to get out and care needs to be taken so as not to damage the bolt Boss, I would pull the block and stand it on it's end to deal with the cam, magnetic follower holders are a AITA...it will also make the engine easer to work on..
 
You will probably end up replacing the cam as well. The cam gear drives the oil pump.they were known to wear,oil pump quits turning thus ruining your engine.
 
I guess I'm not sure how, but I must have come off as this is the first engine I've ever tore down in my initial post.

I'm used to rebuilding Cat engines, and can say I've never seen one break off at the block like this one has on this Deere.

I'm not certain why once the liners are pulled that I cant weld a flat washer and then a nut to this broken head bolt?...

Sure I can drill it out, I'd just rather not risk the chance of having to helicoil or keensert this block.

As for the lifters coming out of the bottom, I dont know if you're pulling my leg, or if you're serious, but it'd be the first engine I've ever seen that way. I didn't have time to go look at it once I had the head off, so I don't know.

I imagined that timing gears played a role in timing the engine as well.

I just was hoping for some advice from those that have done this a few times and to save myself the cost of needing to buy a shop manual. I may just buy one anyway...

As for ordering parts, the OH kit has been sitting in my shop for 2 weeks now waiting on me to have time to tear it down. This isn't a shop where we take our time tearing it down, playing phone tag with the customer figuring out what we want to do, then ordering parts, waiting 5 days, then assembling.

Where I started out overhauling engines You tore down and ordered parts the first day, cleaned and started assembly the second, and finished assembly, adjusted, tested, and painted the 3rd... Time is just as critical to me now as it was when I worked for someone else.

John Deere's are new to me, but the fundamentals of a diesel engine are the same...

As for head bolts, how was I to know that John Deere's head bolts were junk and all needed replaced? I thought maybe I was looking on a fluke deal here with the broken bolt because of the high engine hours involved.

I haven't been around torque to yield bolts since I had the heads off my 6.2 last. Is this common practice on Deere engines?

Like I said, I'm not unfamiliar or over my head with what I'm going to do here. It's simply that every manufacturer's engine is a different flavor, and this is one that I've not tasted before...
 
As far as the broken head bolt, don't attempt to drill it out unless you can find center perfectly and can drill perfectly straight,else you risk a compromised thread in the block. Weld a heavy flat washer, then a nut, the heat saturation should loosen the remains of the bolt.
 
So you do have engine knowledge,,good,,I have never O/Hed a cat engine so we are on even gound.But I have O/H'ed several dozen Deere engines. It seems that you are hoping for an in-frame O/H, it can still happen with magnetic follower holders ,but they are nasty to deal with. The cam should be changed, the oil pump drive wears on them.. I well be glad to help you with the things you are not sure of..
 
I have better luck drilling and caving it in, but yes you do need to be carful,, the last one i did like this it was very tight, I center drilled it and stepped up, then used a dremil with a rotary file and edged toward the threads, then warmed it some and it let go..
 
I got a nice set of reverse twist bits from Kimball Midwest a while back and they have worked well.
 
Hi I read your post the same as Tim it's just the way it's written and we read it.
I can tell you I've never worked on a motor that's new to me with out a decent manual. I wouldn't dream of doing it on a Cat or anything else, Why would you even think about it on a Deere. They love their thou of a Gnats whatsit tolerances just the same as Cat and other motor manufacturers do .
as for followers not coming out the top, you've never worked on some old Ford tractor /industrial diesels I guess. Simple fact is if the cam end of the follower is bigger than the stem it won't pull up through the hole in the block, unlike some automotive gas followers.
JD messed with head bolts in the last few years.

That 466 I did had an update from stock head bolts to torque to yield, the dealers mechanic messed it up installing them,by hydraulic locking the bolts in the block with too much oil on the bolts, the head torque was slack before the angle turn. plus they never told the guy about cracks between sleeves and 4 cracked pistons. the motor ran an hour or so after they fixed it. Re my comment about Tim should work for these guys here.
I just told the guy it was junk and not worth re building due to bad block, cost and value of a high houred 8430 with other issues to. I put it together to get it out of my shop. he wanted to chance it using it and blew it after 4 hours at full power. But atleast we knew why it puked this time!

from what you say if you get the manual you will have no problems what so ever with this motor.
I didn't have that injector socket, and couldn't find one deep enough locally ,so used some of my general shop skills and built my own, if you can't find one you can do the same if you need to.
Good luck with your project.
Regards Robert
 
Sounds like the head bolt broke due to vertical force instead of twisting off, so it may come out if you can turn it. You don't need the nozzle socket to remove the nozzles, but you will definitely need one to reinstall them. Look behind the crankcase vent tube where it goes through the rear block flange by the right hand frame rail, there's two plastic plugs. A big one and a little one. Take these out. The big one is for a turning tool and the little one is for a stop pin for TDC. The cam lifters do come out the bottom, so get 12 magnets to hold them up while you pull the cam. If it's the original cam, the oil pump drive gear teeth will be sharp enough to shave with. The rod and main bearings will also most likely be worn too. Check the crank journals for wear.
 
I may the cam, I'm not sure. The previous owner had it changed at around 7000 hours he told me because the 404s had a bit of a reputation for eating cams he told me.... I think that was earlier models though. so, I'm thinking that the oil pump drive gear/cam gear may not be too bad... I hope.

I've got some LH twist bits from snap on, but I don't think anything that big.

If I can get it centered well enough, I can most likely drill it strait enough to flake it off at the threads. I hope. Does JD make a helicoil kit for this engine, or will a helicoil hold when working with head bolts? maybe just have to go strait to keensert?

I thought about making my own socket for the nozzels too. I may do that today if I have time I think I'll send them out to get tested asap.
 
I'd say if you are going to pull the block then take it to someone with a milling machine and have them drill that broken bolt out.
A milling machine works wonders on broken off bolts !
 
You need a service manuel to be this far into the engine. The answers to most of your questions are there. I wouldn't be afraid of welding a nut on that head bolt, doing a washer first as somebody said might be good thing. I would plan on all new head bolts, there may be more close to fracturing.
 
A Napa and Craftman chrome deep well socket is fluted all the way and thin enough to work, when going back together I snug them then using a wrench to turn the body to get it clocked right and use a 15/16" wrench to tighten it on down while holding the body make sure the nozzle seat is clean, I have a seat hone and thread tap to clean the threads, lubing the nozzle nut helps with going back together. The newer style head bolts are improved and it's a must to use new ones, I would use new rod bolts too, along with having wrist pin bushings changed and rods re-sized. when I have the heads done I replace all the exhaust valves and springs.
 
Here are some things that will help you with this style engine.
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a172249.jpg

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a172251.jpg
 
(quoted from post at 21:06:00 10/21/14) Started tearing down the 14,000+houred 404 in our 76 4630.

Figured I'd take the head off first to get it sent out to the machine shop while I did the front cover and cleaned things up and re-assembled.

The valvetrain looked good, when I went to remove the head I had a broken head bolt that's been busted for awhile. it's broke off flush with the block deck and looks pretty rusty. I soaked it down with penetrating oil but I'm not sure how this will work out.

The cyl walls have no crosshatch left, but no visable scoring and a healthy ridge. pistons are all intact and have no cracks.

so far I don't see any cracks on the head except for at the hole where each nozzle protrudes there's about a 1/8-1/4 inch crack running back... no cracks anywhere else that I see right now. I'll know more when I get it completely buffed off.

I'm short the correct deep 15/16 socket to remove the nozzles, so I'll have to get that later, or have the machine shop do it.

I haven't got the radiator pulled or front cover off yet, but I'll try to get at that tomorrow.

My questions are-

How should I best go at this broken head bolt?
my instinct tells me to try and weld a nut on it, but I've never had one break off on the block deck before.

How do I "pin" this engine on TDC for valve adjustment purposes, and how do I correctly re-time the crank/cam/IP once the front cover is apart?

What are the specs for head bolt torque, and should the head bolts be replaced? what about valve lash specs?

Anything else I should be looking at before I order more parts?

I'll pull the lifters tomorrow to make sure the cam and lifters are good. didn't have time today.

Thanks!

DF

We can all appreciate trying to save time and money. However it's cheaper to do the job once instead of twice.
The engine is an unknown and may contain a few booby traps dating back to what ever initiated the 7000hr rebuild.
For the time, effort and cost to remove the block, take everything apart, hot tank , rifle brush and inspect. It's cheap insurance.
1-800-522-7448 for the service manual on CD or hard copy. As previously stated, do you want to use your best estimate on critical specs?
 
I would expect the cam and lifters are good, but the gear on the cam and matching one on oil pump are shot, that will take new cam.
 
*update*

Had a couple hours this afternoon and got the pan/pump/tubes off, and was able to pull the cylinder packs.

#1 rod bearing's got a pretty bad groove in it. the cranks got a ridge large enough I can catch my nail on it. Pulled the other 5 and expected to find the same thing but found that they were all in great shape.

On the downside, the oil pump drive gear and the cam gear have what looks to be fretting on the face of the gear teeth. as for wear, it doesn't look very bad. actually it doesn't look the the teeth are any more worn than the unworn part of the gear teeth. Damn what a backwards design. I'd expect this kind of a setup in a car or pickup, but not in a machine....maybe this was par for the course in the 70s?

I'm gonna figure out what to do with that pesky broken head bolt next.
 
You can up-date to a latter 4440 or 4640 engine with a crankshaft driven pump,,maybe even a latter 7720 combine engine, that would take care of a lot of your problems and get you back running...just a loose thought..
 
Here is a list of where you may be in parts, plus the head work needed,and my machine shop(which is the best and cheapest around here) has been charging $1500 for the head and rod work..(don't use these numbers with out confirming head and block casting #'s)
Total Price* Hold
Delete
RE524426 Engine Overhaul Kit - KIT, ENGINE OVERHAUL View/Update 1,730.00 USD 1,730.00 USD
R66452 Cap Screw - SCREW, CONNECTING ROD ADD 11.27 USD 135.24 USD
R88045 Cap Screw - CAP SCREW, HEX FLANGE HEAD View/Update 7.24 USD 50.68 USD
R88044 Cap Screw - CAP SCREW, HEX FLANGE HEAD View/Update 6.41 USD 51.28 USD
R88043 Cap Screw - CAP SCREW, HEX FLANGE HEAD View/Update 5.62 USD 28.10 USD
R88042 Cap Screw - CAP SCREW, HEX FLANGE HEAD View/Update 3.67 USD 22.02 USD
AR100385 Cam Kit - CAMSHAFT WITH CAM FOLLOWERS (PARTS) View/Update 551.55 USD 551.55 USD
SE500884 Oil Pump Reman - PUMP, ENGINE OIL ASSEMBLY View/Update 698.96 USD 698.96 USD
R42173 Bushing - BUSHING ADD 16.24 USD 97.44 USD
Parts are currently not in stock at this dealer.
Ordering preferences are on the "Availability" page. *Subtotal 3,365.27 USD
*Total 3,365.27 USD
 
This makes a $2500 7720 engine look very inviting,, and I would not worry about the inter-cooler...your head may be more because of the suspect cracks...
 
Thanks for all the leg work you've been doing Tim, it's appreciated!

I know what you're saying about going to the 466. just not sure if I want to do it. I looked over the cam and oil pump drive gear again tonight, and I'm not sure. the wear is definatly worse on the oil pump drive gear for sure. The lobes on the cam look great. no flaking, streaks, or anything else I can use to condemn it.

Don't know if the oil pump drive shaft is an optional part on the pump. I may get on deere's web page later and see if I can figure out how to run their parts lookup.

Right now I'm leaning towards replacing the oil pump, and throwing it all back together.

I got the pistons/liners out, and I was amazed to see that it didn't have so much as a broken piston ring.

No cavitation on the block or liners at all. The bearings were worn but not completely shot like some I've seen.

The only problem I really know I have is the head bolt (which I drilled a hole through tonight, and then filled with penetrating oil) the ridge I have on the #1 rod journal. I think I can buff that out, not sure what I'll use yet.

I'm actually sorry that I tore this engine down, I should've just re-sealed the front cover and ran it another 2-3 thousand hours.

I need to break open the intercooler and get that cleaned up and re-sealed as well (I removed it as one unit) Turbo is in great shape, couldn't believe it for running as hard as it has being "turned up" and from all the doom and gloom stories from some of the naysayers here.

I do need to re-adjust the aneroid to kick in a little sooner though, I'm seeing some signs of the rings getting pretty carboned up...

If I can find a place to post pictures, I'll try and take some pictures of the oil drive gear and see what you all think about it.

DF
 
We went through a 404 with 8000 hours because of broken rings, the crank, bearings, cam and lifters looked like new. The gear on the cam and oil pump were shot, the valves were recessed pretty bad. We put the performance kit in that raised the compression, really lit it up.
 
I threw the head and the bearing in there just because.

all the other bearings looked great, and I think I can polish this journal a little. every cylinder has a small crack above the nozzle, but the machine never used water or white smoked. I'm assuming this crack is just from long use?
 
Dumb question: When rebuilding a 14,000+ hour engine that will still be used for a lot more hours, why not have cam profile reground, updated, or at least measured for wear? Even though the lobes may all still look shinny, at 14,000 hours wouldn't they all be worn enough to hurt fuel efficiency and horsepower? How expensive is a cam regrind?

At $3+ per gallon diesel fuel, recovering an extra 0.1 gallon per hour or an extra two horsepower on the same fuel usage should pay off a $500 cam regrind in a little over 1500 hours.
 
For $450 for a new cam I would say change the cam for a new one, the oil pump gear will be worn too,,you can't re-grind that..
 

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