Okay - bear with me here. I'm 74yo, with limited garage space, and very limited second person to help. So... I have to replace the inner lower A-arm bushings (Metalstik) and I have a rod knock in the 4.2L engine. I've been ignoring it for a while, but now I need to take care of it before I spin a bearing! I DO NOT have the facilities to be able to pull the engine - so that is not an option. So, here's my newly hatched plan. I will put the car up on jack stands on all four corners however high I need to drop the front sub-frame and remove it. And I'll work on it in a corner of the garage to do to it what I need to. Before lowering it, I will support the engine under the oil pan. Once the sub-frame is out, I will re-support the engine under the front engine mounting points. This will allow me to remove the oil pan for access to the connecting rod big ends. As the head has been off in the past 4 months (blown head gasket, so did a head job with all new block bolts, timing chain pressure pads, etc.) it should be a piece of cake for the top end. Of course the hood, radiator, condenser, etc. will all come off for easy front engine, etc. access. (been there done that more times than I can count). Once the head is off it, allows the pistons to come out. Then I can hone the cylinder walls and install new rings. Yes, I would ensure cylinder walls all okay (they were 4 months ago). And I would Plastic Gauge the journals with the new connecting rod bearings to assure all is well there (keeping my fingers crossed). I may also replace the timing chains now that the pan is off, and the front chain sprocket can come off. Couldn't do that job before. Then, all the engine goes back together.

On to the sub-frame - I've followed all the links on the Forum and watched all the YouTube Videos, so I'm confident there as to what to do.

So... all my invisible Gurus, those keeping me on the straight and narrow - I more than welcome your comments and suggestions.

Bill

 

Bill

That is quite an undertaking.

Threethoughts:

1. Support the engine from above. A pair of 2x4's from wing to wing. Cable chain or strap to the ears on the head. i think soewhere there is a steel device to do this.

2 A micrometer. Mic the journals before buying anything. For size and whether they bad one is flat or tapered. Visula might be a deal killer. Scoredor blue black!!!

3. Polixch trhe journals wit emery paper. Shoe shine style.

Good luck, you nreed it. Rod knoc are not a good thing.


Wayu back whem i had some adventures witjh rod knocks.

Carl

 

Thanks for the suggestions.

1. Yes, I could support the engine from above. But is there a reason why I can't support it from the rear of the oil pan from below? Then I don't have to build or buy anything. And when I take the head off, I lose the chain lift plates that I would be using when supporting from above. Yes I would have to ensure that when I lower the front SUB-frame I have to be careful it doesn't rock rearward and knock whatever I have supporting the engine up.

2. Yes I plan to mic out the rod crank journals both with a micrometer and Plastigauge. I don't plan on buying rod bearings until I see if they are std or oversize. Same with the rings.

3. Thank you for the shoeshine journal polishing suggestion. Will do. Not too much though.

Yes, I'm biting off a lot. But I Know I can do it. And have done it when I wore a younger man's clothes. But back then I didn't have guys and gals like you people for moral support and expert advice.

Bill

 

Time to sell that car and buy another one, frankly. You've told us little about the car, but what you've said so far indicates the whole engine/transmission needs to come out for an overhaul but you don't have the facilities to do it yourself. Replacing just the big-ends is not really going to get you very far, as the main bearings are likely totally worn out as well. Sorry if this isn't what you wanted to hear, but old cars do eventually need overhauling.

 

Bill,
The first time we overhauled the front suspension in 2015, husband cobbled together what we called a Levitation Device to support the engine on the pan rails because we didn't know of any other way to hold it up while support was removed from underneath.

However, it was *Frightening* to say the very least (I can't stress that enough as I'm not easily frightened), to be under that engine with such flimsy support as was possible under those circumstances. I could NOT in good conscience recommend such a Rube Goldberg setup for Anyone! In fact, it was so frightening, I Deliberately did NOT post any pictures of it for fear someone might try it and be injured.

I'm thinking I might take the front off the engine First so you know where your bolt holes are (surely something is bolted on the front, failing that, there's no reason it couldn't be supported from the side) that would be enough to suspend the engine from above. This also might allow you to drop the crank.

The Harbor Fright engine support bar isn't nearly as expensive as an injury or worse.

Just for the challenge, I might give it a go, but NOT without support from above.
Or, as Fraser suggests, you could cut your losses and sell the car.
(';')

 

The Harbor fright bar actually works pretty good if you weld the pivots so they can't tip. Still retains full adjustability.

Larry Louton

 

Top notch advise from both sides of the "fix it or get another one" aisle. If you go ahead with the "fix it" route, figure out why the rods are knocking. If the bearings are just worn out after 300,000mi of use, then so is every other moving part in the engine, but not all of them are of equal importance.

Carl's recommendation of using something like emery paper to shine the journals is spot-on. Back in the early days (Carl and I have similar early days) an abrasive called Crocus Cloth was available at any parts house or welding shop. This was a sheet of cloth with a very fine abrasive oxide coating and was used to polish fine machined surfaces. I have not been able to find a reliable source locally or online for many years. Most abrasives with Emery in the name are just too coarse (150 to 320grit) and should never be used on a crank journal. From what I can gather on the interweb, true crocus cloth is somewhere around 2000grit, I currently use Mylar sheets coated with abrasives measured in Microns. The two I use are 5micron=4000grit and .5micron=46,000grit. These are unnecessarily fine even for a neurotic like me (except that I finish-hone all of my woodworking blades/chisels on these sheets) , if you have a ding or nick in the journal that you can feel with your finger nail, something like crocus cloth is probably not the way to fix it.

Dave

 

Thank you, all great comments. But nobody has mentioned anything about my suggestion about supporting the engine from underneath? First at the rear of the oil pan. Then after the sub-frame is removed, from underneath supporting the front engine mounts. I may have to fabricate something for that. But I don't think it would be too complicated. It would then allow me full access to remove the oil pan? Has no one ever done that? Am I missing something? (Like my mind?)

 

Okay. Can't get to sleep thinking about this and went out in the garage and came to a conclusion. I made a couple of drawings of supports I would design to support ftom underneath using the engine mount brakets or their threaded holes in the block. And while it would work, it would be more expensive to have them made than a Harbor Freight engine support bar on top. So I'm sure that even with the head off I can utilize the block head studs with the HF bar, and still be able to get all the pistons out. You've convinced me...thank you.

So let me focus on another part of the job to my Support Team. Dropping the sub-frame to the ground - how much clearance do I need to get the sub-frame to clear the body to get it out?

And I guess it's obvious to all that I am moving forward with this. To quote Queen "I'm in love with my Car". No way am I giving up on it. I'm too stuborn for that.

 

Are you really sure you need to remove the pistons? If you have rod knock, why not just replace the bearings and that's all? You said that the walls were ok 4 months ago, is there any reason to suppose that has changed?

I ask because the crosshatch and specifically the angles the grooves intersect are critical to the amount of oil the engine will burn. It's very difficult to do by hand with the engine in the car, both to ensure you don't take off too much material and to get the angles correct and uniform. It's really easy to end up worse off than doing nothing.

If it was me, I'd support the engine from above, drop the subframe and the pan, Change bearings and put it back together.. Unless there is something else I'm missing about the engines condition? I think it would be very difficult to support the block adequately to remove both the subframe and the head at the same time and keep the engine in the car. I've done it on an E Type, but the engine isn't supported on a subframe there.

Timing chain are usually quite long lived, there is usually enough motion in the adjuster to take up and stretch. As an aside, the nut for the timing chain adjuster is Whitworth, I think 7/16 BSW from memory.


For the subframe, I can't give an exact number, but I'd drop it on a dolly and then pull it out from the side of the car. Then the spring towers come out the wheel wells and you don't have to raise the car as much.

 

Well, I just figured that if I'm going to all this trouble why not go the extra mile and do the rings. All the compressions are between 125-135. And the engine runs great. I really have no idea how many miles on the engine. Just know that it was swapped out by the PO snd he didnt know how many. It would be a lot less work to not have to pull apart the hot side, the cold side and the head certainly. I put new timing chain adjuster and new pads when I did the head a few months back. All went well with that job. You give me pause, and food for thought. Thanks.

Bill

 

Sounds like your compression is where it should be, I'd leave the rings. I'm assuming the engine isn't using oil and you're not leaving a trail of blue smoke?

It's not easy, but certainly easier to just change the rod bearings. While you are there, you could pull a main bearing and inspect them. The lowers will wear much more than the top bearing shells, so you could just replace the shells in the main bearing caps and leave the crankshaft and the upper shells in place.

 

Bill,
Jagboi64 has good advice regarding not removing the pistons if you're not using oil (1/2qt between changes would be acceptable to me). Once you take the pistons out of their bores, the rings will not reseal correctly. To reinstall the pistons, new rings should be used and the bores honed to break the glaze (45* cross-hatch). Honing will create metal filings to fall on the crank, even with the cylinders/hone oiled for lubrication. If you absolutely don't have to poke the bear with a sharp stick, don't do it.

Dave

 

Okay, I'm convinced. Not taking the top end apart and am supporting it at the top.

Are you saying that I can get all the main caps off. One at a time I presume? If I can, I don't see why I can't slide the block side of the mains also. By sliding in the new, pushing out the old?

You guys and gal are the best-est!

Bill

 

Okay, I'm convinced. Not taking the top end apart and am supporting it at the top.

Are you saying that I can get all the main caps off. One at a time I presume? If I can, I don't see why I can't slide the block side of the mains also. By sliding in the new, pushing out the old?

You guys and gal are the best-est!

Bill

 

Buy the Harbor fright tool and spend the creativity on replacing the rod bearings. Completely removing the shocks makes the subframe less tall. Have you found a spring tool yet while you do the lower control arm bushings?
Don't over think this but be safe.

Larry Louton

 

Bill, that's what most of my whole reply was about! Maybe I wasn't clear.
We did exactly that in 2015 and it was Way Beyond Frightening.
It wasn't complicated, merely DANGEROUS!
I would NOT recommend it as as the whole thing is far too unstable.
(';')

 

Yes to buying the HF support bar. Goos idea. I'll remove shocks. Yes Sanxhez was nice enough to give me a spring compressor he made. Safety first!

 

If the main bearing shells are indexed by a small tang at the part-line you should be able to roll the old ones out and the new ones in. I suggest making a short pin from aluminum rod (i.e. 1/4" dia.) that will fit into the oil hole in the crank, but have it stick up out of the hole just enough to push against the edge of bearing shell. Trim the end to the angle of the oil hole and rotate the crank by hand, in the same direction as the indexing tang, and the upper shell will rotate out nicely. The new shell is rolled in the same way, just in reverse. I'm assuming the XK engine has 7 main bearings, the upper shells might roll out a little easier if you loosen the 2 or 3 main caps, that stay in support of the crank, one turn to let the crank drop a few thousands.

Dave

P.S. When rolling in the new shells, start the flat end between the crank/saddle by hand. Make sure you are holding the shell against the journal in it's normal position as you push it around, rotating the crank as you're pushing on the shell usually helps. If and when you use the aluminum pin, make sure to keep the shell against the journal and do not let the pin slip under the end of the shell.

 

One at a time, yes. The problem with getting the block side out is the tangs that are on the bearings, that won't allow the bearing to slide around the crank. You won't be able to get at the rear main seal housing I think, as the bolts go in from the transmission side, so that limits how far you can lower the crank.

That being said, you might be able to push it out far enough to grab with pliers and then push the new one in, but you need to make sure that the new bearing tang is perfectly seated in the recess for it. As the crank rests on the lower side and the thrust from the rods is all on the lower side, I expect you'll find the upper shells are in much better condition than the lowers.