My car died! Not sure whats up......

[atalamark]

Well I bought a good 6mm socket with hex end today just to give myself the best shot at getting the crank pulley bolts off.

Nothing doing! They're all rounded out! Maybe I rounded them out yesterday trying to get them off, and maybe the PO did it, but whatever the case I can't get the 6mm or 7mm to allow me to get any kind of fit in the heads, which means I can't turn them at all, which means they won't come out.

So now I'm looking at this thing and wondering how the heck can they come off? Am I screwed? And why did they use allen heads anyway, if they were regular end bolts I would have had them off by now.

Well yet another roadblock in the way of doing something as seemingly simple as changing a belt.

what to do?

Mark E Kaylor

[83_maxima]

If they are really stripped out, you may be forced to remove the crank bolt, so you can remove the entire pulley and get it on the bench so you can get the bolts out.

Have you been using any PB blaster or another penetrant to help you get them out?

PB Blaster and/or heat will help to get them out. Sounds like you will need something.

[goglio704]

I wonder if the IP belt cover could be cut in such a way that it would be two piece. The only reason you have to take the socket head caps out is to get the Vbelt sheave off so you can get the IP belt cover off.

I agree with Ben about possibly pulling the whole assembly, but I see some real issues with that too. You'll need to use a puller to get the IP belt crank pulley off the crank. That will be tough with the Vbelt sheave in place and the IP belt cover on there too. If you could get two opposing bolts out, you could use those holes to attach a bar for the puller to act against.

Depending on the hardness of the socket head capscrews, it may be feasible to drill the heads off of them. One nice thing about socket heads is that they lend themselves well to drilling because you already have a centered recess to start in. The bad thing about socket head caps is that they are usually grade 12.9 and a real somebody to drill.

No easy answers in the above statements I realize.

[83_maxima]

As a last ditch effort to get them out before you try to pull the pulley off/drill the bolts, etc., etc. I would:

Soak the bolts with PB Blaster - several applications for a few days if they are really in there that tight. Next would be to make some room by removing the radiator (you've already got the belts off right?). If the 6mm hex is really rounded and tapping the socket in with a small hammer won't work, try a 7mm and really TAP it in with a larger hammer. If you can heat the individual bolts with a mini-torch (or equivalent) before trying to break them, even better.

You can usually get stuck bolts out one way or another. I've dealt with a few...

[goglio704]

I really hate to say it, but since you don't know for sure that the belt is your problem, I'd take the easy way out and cut the cover in order to get to the belt. If it is the belt and you get it running again, I'll sell you a replacement cover. If it isn't the belt, I'm guessing this car is headed for a new home?

[atalamark]

Well how hard is it exactly to get the crank bolt off? I mean if I can get that off then I can forget about removing the pulleys right? Just pull the whole hub off?

I'm sure its tight, and I think I remember reading somewhere on this site that you should use an air assisted tool to get off....

Is there any way a street mechanic like myself could get that thing off? I mean I have the correct socket to fit, w/ext, and a big old socket that I could find a long cheater bar for........of course, how to do it without turning the engine at the same time?

hmm........

I don't really have anything to use to cut the cover off, and yes , if the belt is there and moves with the engine being cranked this car will be finding a new home.......lets hope its not the case!! Just gotta figure out this situation......


Mark E Kaylor

[asavage]

Nothing doing! They're all rounded out!

ALL of them??? That's crazy.

So now I'm looking at this thing and wondering how the heck can they come off?

If you can get access to an air impact wrench, the crank bolt can be removed and the whole thing can come off, assuming you can get two of the six bolts out to use the puller. You can't pry at all on the damper, it will delaminate and you will be out a couple hundred bux to have it rebuilt.

You will not be able to remove the crank bolt without a powered impact wrench. The radiator must be removed (I hope you already have it out, as explained in the FAQ), and even then clearance to the condenser is very limited.

Offhand, I'm not thinking of any good, non-destructive approach to your situation.

Cutting off the cover won't help, because you cannot replace the belt with the cover on, and you will not be able to cut the entire cover off with the damper in place.

And why did they use allen heads anyway, if they were regular end bolts I would have had them off by now.

Un-uh. Socket head capscrews are a superiour choice for that design. HHCS (hex head capscrews) would have required a smaller bolt circle or a larger damper: design trade-offs.

Those bolts are hard -- I am very surprised that yours are rounded out. I have reefed on mine.

Well yet another roadblock in the way of doing something as seemingly simple as changing a belt.

It's a 5-year (60k) belt change interval. You should try changing the cam/IP belt on the '86 Toyota diesel I'm working on right now -- makes the Nissan look like child's play!

If you think this is hard, you haven't been working on modern cars. Wait until you get to change the timing chain on your 240D!

At least on the LD28 and OM617 you can see what you're up against. Changing the cam belt on a Concorde or the Chev. 3.1l DOHC . . . nasty.

==============

If you're certain that you are using the correct socket bit, and that the bolts are rounded out, I think I would consider a right-angle drill (I have one) and a handful of new, sharp 1/4" bits. This is a PITA for a couple of reasons: you do not want to damage the damper, so you need to drill only enough to be able to break each head off. Fortunately, you have a good leverage point for a big screwdriver to pry against: the inside of the damper. It's not a great angle to be drilling though, and a std drill will not fit in there. I happen to have a couple of right-angle drills, and at the shop we'd use an air-powered drill for this kind of thing. A Dremel probably wouldn't be effective here.

Once you break off the heads, the damper will more or less come right off -- it's a nice, tight fit but doesn't really require official "prying", just spray some lube all over it and work it back and forth and it comes off the front. If you pry with any real force, the outer ring comes off the rubber mounting and that's all she wrote: you have to have it rebuilt.

Also, you'll have to find replacement bolts in any event, and that's not going to be easy. In Portland, I'd try Winks, then Parkrose Hardware. Both of them have very decent threaded supplies. You will have to put socket head capscrews back in there, grade 10.9 or harder, and the thread pitch is finer than usual, IIRC. I have a spare set of these bolts, if you absolutely can't get them locally.

You in a world of hurt, boy.

[rlaggren]

Couple of thoughts. I don't own one of these cars yet, but I've done a bit of work on machines and have met reluctant socket heads b4. However, since i don't own the car, I don't know for sure what kind of work space you have, so read with salt.

Several times when I've had problems w/socket heads, it's been pilot error.

Error 1: the socket is not fully and completely clean, so the key won't go in much and thus has no real grip. Clean those sockets with spray cleaner and a small stiff brush; a very small flat screwdrive also works well at digging grime out. Buy a good 1-1/2" inspection mirror and a good light and examine your work to be sure.

Error 2: The hex key was rounded. I think the bolts are actually somewhat harder than the key so there is a reasonable chance the problem is actually the key; anyway, 3 or 4 times I've found that a new good quality key solved the problem. This is a case where dropping $20 on a Snap-On or Mac tool might be the right thing because you _really_ want to get those bolts out. There is a fair chance it won't work, BUT the alternative is so gross that you don't want to leave any stone unturned. While Chinese products (which are sold universally) have gotten better, metalurgy is one of their characteristic failings and in this case metalurgy seriously matters - so buying high end tool looks like the only way to go. Besides Snap-On and Mac there are a couple other old tool companys that's have sold top quality stuff for a hundred years but I can't just now recall their name - somebody else mabe?

Error 3: Use the right size. Corrolary: DONT use the wrong size - go back to the vendor and buy the right size. Also, if what _should_ fit doesn't seem to, try something else - like SAE sizes and see if they fit tight. And when you've got the right size, do what it takes to get a good clean straight grip on it with the ratchet. If that means pulling the radiator, that's the way to go.

Now, this is a terrible thing I'm about to mention, something that can turn strong stomachs, but......

I have many a time removed problem bolts, including socket heads, with a 6" pipe wrench. This won't work if the bolts are recessed into the sheave, only if they stand proud. 6" pipe wrenches are few and far between, but Rigid does sell one and they are what you want because, again, there is some fair chance the metalurgy in the jaws is good. The small wrench will fit into small spaces and get a grip on small bolts and, wonderfully, it grabs ROUND objects. It will also happily accept a 2' cheater bar.

Tthe recommendation to soak the bolts with penetrating fluid is certainly the right way to go.

The other way to encourage recalcitrant fasteners is heat. But since I don't know these vehicles, I'm not sure how close to the dampener rubber these bolts live. If they are real close, you'd have to apply the heat very judiciously indeed to avoid trashing the dampener. A small butane torch with a flame about the size of the sharpened end of a pencil would apply moderate heat with good control. An air-acetylene torch with a 1/8" "Turbo" tip would sizzle the spot, again with excellent control; but tool costs add up to about $100 and without some experience it's hard to appreciate just how hot these little devils get. A plain old heavy duty soldering gun will get the bolt fairly warm; but make sure you start with a CLEAN tip so you don't leave a piece of solder in the socket. I've always been able to get a threaded connection to give up by using heat but in this application, it would need to be used with care and caution.

"Heat" can also be applied in reverse sometimes. Air conditioner service suppliers sell cans of aerosol ice which can be used in A/C diagnosis. I've never used these and I'm not sure how to control the spray. You want to chill the bolt relative to its seat. If you do it too much, the metal can get brittle; but I'm not sure that is really a danger here. I think the metal should be fine down to about -20F and I doubt you could get the bolt down that low for more than a few seconds.

If all else fails drill the bolts and use an easy-out or cut/grind the heads off pull the part, then use a pipe wrench (or vise grips) on the stub. If it comes to this, it'd probably make sense to pull the grill and radiator for access.

I think you can get those bolts off and despite what it may feel like right now, it would probably be a lot easier than fighting w/the crank bolt and most certainly easier than trying to cut the timing cover in place - which would still require you to get the sheave off later. And if life is this hard, don't be afraid to clear the decks, pulling radiators and other stuff that prvents you from really applying yourself to the problem.

Best luck. Rufus

[goglio704]

Cutting off the cover won't help, because you cannot replace the belt with the cover on, and you will not be able to cut the entire cover off with the damper in place.

If you're saying he won't be able to salvage the cover I agree, but I can't see why it couldn't be cut. The section behind the sheave is multiple layers, but it is sheet metal after all. Maybe I'm overlooking something?

On a related topic, how many complications would there be if the timing belt was never covered? With the splash shield in place, it seems unlikely that a foreign object would make it into the belt. If it did though, the belt would die quick.

[asavage]

I don't think you can get a proper cutting tool behind the sheave to slice the portion of the belt cover enough to get it out.

On other cars, the cam belt covers are routinely left off -- think Subaru and old VW, where the covers are plastic and have molded-in nuts that folks break off. The covers are to keep things out of them, but the belts are just fine without the cover. However, in the LD28, I don't see a valid reason to leave it off. It's so simple to remove in normal circumstances, there's no advantage.

[atalamark]

Well maybe one day I'll learn how to do things right the first time.

So today was beautiful outside, and I had the day off. I went at these crank pulley bolts.

I followed alot of good advice here, alot of which I knew about but I tend to rush into things.......you know how it is sometimes.....

Anyway I soaked all the bolts in penetrant, got all the gunk out of the hex heads, bought a cheapo pen torch, and found a good long cheater bar.

With the heat I cracked every bolt on the first shot except for one........one has a head rounded out and won't grip......and a 7mm won't go.......

So I'm gonna have to drill the last sucker out, which isn't so bad afterall seeing as how yesterday I was expecting so much worse........

By the way, how will I know how far in to drill? Just drill out a bit and then try to pry off the head, then drill more?

thanks for all the help so far............you can't imagine the suspense here in waiting to get the IP belt cover off JUST TO SEE IF THE BELT IS FUNCTIONING>......well what alot I've learned so far!

Mark E Kaylor

[asavage]

I took a few pictures today. This is a delaminated harmonic balance from an '81 LD28 at the JY.

(click on any picture for larger)


Looking at this now, with it off, I see that only one sheave groove is mounted in rubber; the other is solid. You might get a little purchase behind the rear/solid one, but it should not be necessary, and a jaw-type puller definitely would break the sheave.

The area where those six bolts are is about 1-1/8" deep x 3.5" dia.

The overall depth of the socket head is within .010" of 5/16" (or 8mm). You may be able to use a piece of masking tape around your bit at that distance from the tip, and you'll be very close.




Another idea (if you can find one) is to use a left-handed drill bit. When you cut through, the head may come off, or the bolt may spin out.

As I suspected, that bolt has a 1.0mm thread pitch, which is not nearly as easy to find as the common 1.25mm pitch for the 8mm dia. I'll mail you one, if you want. Be certain to use aerosol brake cleaner or the like to remove all traces of your penetrant from the bolt threads and hub threads, before applying Loc-tite to them before assembly.


Here's the reason why I don't think the IP belt cover can be removed easily: no room to get behind the sheave and at the sheet metal.

[atalamark]

So I'm gonna see if Winks or someone has some 1/4" left handed bits....I bet they do, they ALWAYS seem to have what I'm looking for, and while I'm at it I'll see if they have any of the proper threaded bolts .....if not I would love to get one from you Al, I'll let ya know!

Oh and I couldn't find a friend with a right angle drill, and I don't want to shell out the $$ for a "not much space" drill which I saw today , but it seems if I pull the grill out I might have just enough room to get a regualar old drill in there? I'm mean thats what I'm gonna try first....certainly there won't be much room to work but I'm only getting one bolt out so I'm sure I can manage somehow......

thanks for the help!

Mark E Kaylor

[asavage]

I think the crank is too low to access via the grille area. You'd have to remove the A/C condensor of course, but since your compressor and hoses are gone, I assume that would present no problem in your case.

Winks should have left-handed bits. My hardware store up here doesn't, but surprisingly my FLAPS does

You might be able to rotate the crank so that bolt is at 6 o'clock, and use a small cold chisel on an edge of the socket head (ie hammer swinging down and in). Would require less room than a std. drill motor, and since you have the rad. out and don't care about nicking the condenser on the hammer's backswing, that might work.

[83_maxima]

Try an easy-out . PB Blaster and heat, like before, then tap in the easy-out and give it a try. They usually bite pretty good into a socket head bolt if it isn't too rounded.