How to ensure top and bottom halves of thrust washer are aligned?

Beginning to put this 7MGE Toyota engine together, looking at the factory manual - the only instructions as far as installing the bearing caps, which includes the thrust washers on #4 is "install bearing caps", and then advises to check end play.

However, none of these caps have any way to precisely align them with the upper halves in the block - no alignment pins or the like. I see there's a small amount of side to side variance as to where they could potentially end up since the bolt doesn't completely fill the hole in the cap, which seems might not be so crucial with most of the caps, but on the #4 with the thrust washers, it would seem you'd want both halves to be precisely flush with each other to present a completely uniform surface to the thrust bearing area on the crank.

On an eyeball basis, where the #4 cap and thrust washers ends up seems to have little or no possibility for variance simply because of the snug fit with the thrust surface on the crank and looks like it's aligned with the upper half (i.e. the block half) on either side. Is this good enough?

Thanks.

Reply to
HiC
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The book should have a section on 'general' engine rebuilding where it mentions the need for grease and assembly lube.

If you put it together dry, it will get destroyed before it even warms up.

Bearings have a notched tab on the ones I have installed. This tab fits precisely into a notch in the journal cap. There is no 'play'.

The measurements required like end play are not something you can 'adjust'. If the end play is wrong, you simply need a different bearing with an over or under size cut on it. They make bearings with .001 or .002 etc. over and under.

Same for the gap between the bearing face and the crankshaft journals. This needs to be measured with plastigauge to see if the gap is right. If it isn't, then a different thickness bearing is needed.

Getting this correct is one reason folks let professionals rebuild their engines.

One other 'big' gotcha is the caps must go back onto the journal they came off of and be right side up, they are ground to fit when bolted together, then opened up for bearings. They will 'not' fit on any other so I really hope you numbered them or they have marks on them!

I helped one gent who came to me with way to many knocks in his engine. The stethoscope was telling me I was hearing 4 cylinders with rod 'knock' on a freshly rebuilt engine. Turned out the last 'rebuilder' played mix and match with the bearing caps, only 3 out of 7 were on in the right place and these suckers were even numbered 1 through 7!

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06
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HiC wrote:

Reply to
Mike Romain

Tighten the bolts on the #4 cap finger tight and snug them a little more (a few inch pounds) with a wrench. Then, using a a heavy shot-filled hammer or rubber mallet, smack the crankshaft briskly on the front snout; then go back and briskly smack the rear crank flange. Tighten the main cap bolts to the proper torque and then check the end play. Smacking the crank in both directions should align the thrust surfaces of the bearings.

Reply to
John Kunkel

With the engine "upside down", spin the two block-side thrust washers into position after coating them with oil or assembly lube. Use bearing grease on the two cap-side thrust washers to keep them attached to the bearing cap. They are not going to sit perfectly still but this is good enough. Just assemble the cap like you would the others. The thrust washers will rotate into correct position when they butt together. The bearing cap has notches and the cap-side washers have matching alignment tabs to keep them in the correct position.

Toyota MDT in MO

Reply to
Comboverfish

The scary part is they only make 7-cylinder engines for one use that I know of - radial engines for aircraft. And the repair field for those is very highly regulated - for a very good reason.

If any pro A&P mechanic was clueless enough to put the engine back together like that, I'd want his head on a pike and his Airframe & Powerplant License revoked and ripped into little tiny shreds. And all the licenses of the people above him or her, and the operating licenses of the FBO/shop he worked for.

(Insert 'The Sopranos' "I want him DEAD!" rant here by reference.)

And if this engine was a DIY Project by an "Experimental" airplane owner, I'd read him "The Riot Act" chapter and verse, and remind him that at 10,000 feet there is no such thing as 'pull over and let me check under the hood, it's making a funny noise...'

That engine comes apart in flight, you're in a Big Steaming Heap Of Trouble. Assume the Position: Put your head betweeen your legs and kiss your ass goodbye.

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Reply to
Bruce L. Bergman

I was assured this is a lubeless engine, no oil or other lubricants required.

I am of course kidding. Yes, all the bearings are being coated with assembly lube.

:-)

The bearings do, but the caps don't, at least not mine.

.nod, they're numbered and have arrows for orientation.

I assume you mean right side forward, not right side up. It would take a special variety of goober to attempt put bearing caps on upside down, not to mention some mighty long bolts.

Sounds like those guys are qualified to be mechanics in Florida.

Reply to
HiC

could have been a four cylinder with three main bearings, and he was counting the main caps as well. At least one of the main caps had to be right, because there's always one different (thrust bearing)

nate

Reply to
Nate Nagel

It was a Jeep 258 engine. The crank has 7 main bearings on it. I should have clarified that. The connecting rod bearings were numbered separately and also mixed up. The person had no idea what he was doing. The three he couldn't screw up were the first main, the third or thrust bearing and the rear one...

Mike

Reply to
Mike Romain

Okay - 7 main bearings, 6 connecting rod bearings makes more sense for a straight-six car engine. You just hung that '7' out there all by itself with no other descriptors, and the first thing that popped into my head was an "Oh Son of a (*****), You Didn't..."

If caught, the guy still deserves to be knee-capped for Gross Dumbth with "WTF Were You THINKING?!" Clusters, but if you are feeling charitable you can let him live to (hopefully) learn the lesson.

I'm a repair and maintenance electrician, and I have two or three of those AwShit moments a year. Last one was tracking down an open neutral to the subpanel and realizing that whoever wired this apartment bunched the neutrals (2 or 3 wires on one neutral bar screw) which is illegal - one wire per screw on the neutrals, but you can legally bunch the safety grounds.

They had #12 and #14 wires side by side under the same screw, and the #14 didn't get clamped tight enough...

And statistics say if they're done wrong in one unit and they had one company do all the work, without any evidence to the contrary you have to assume they're done wrong in all 500-plus units, and they all need to be checked. (At about a half-hour per unit just to get in and check, plus the clerical time for making tenant access requests and another half-hour to fix if needed.)

The owners of the complex are simply going to love the news... >_<

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Reply to
Bruce L. Bergman

He was pure sleaze 'fixing' the Jeep for a fast sell and unfortunately related to my friend so he couldn't quite be 'fixed' properly himself...

I am not even sure if the jerk was literate enough to read the numbers. Here in Ontario Canada, up until a couple years ago, reading is not a requirement to pass high school. Now they have to read at grade 10 level at least and only about 60% can do that according to the latest test reports to hit the newspapers...

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06
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Reply to
Mike Romain

To line up the thrust washers, snug the cap that incorporates them and beat on the ends of the crank with a soft hammer. Or a block of wood and hammer.

Reply to
Steve Austin

In a helicopter, maybe. In an aircraft, your description is a bit far- fetched. Engine failures in an aircraft are known to happen, which is why you have to practice engine-out procedures to get even a regular private pilot's license. My CFI pulled the engine on me more times than I can count and I'm still around to talk about it.

FYI - Engine failure in a FIXED WING airplane means that you are now flying a glider, not crashing down like a brick.

Chris

Reply to
Hal

I know that, but that's just removing power - I distinctly said "comes apart", as in rods physically parting company with the crank or the piston pins and ventilating the engine case, or other catastrophic engine failure. Oil all over the windscreen, or an engine fire...

A bit far-fetched yes, but well within the bounds of reason.

A good pilot can recover from some pretty bad disasters, but you have to keep it flying at the same time - and you'll need to change your underwear after you get back on the ground.

This all started from an assumption that when he mentioned 7 bearing caps he was talking about a 7-cylinder aircraft engine, and I do know there are fools that try to save a buck and cobble things together - and that's a REALLY bad idea on an aircraft. "Darwin Award" bad.

Sometimes all it takes is something as stupid as mounting a fuel tank selector valve where it can't be reached easily during flight, just ask John Denver - Oh wait, you can't...

Helicopters auto-rotate without power if you're on top of it. And as long as the "Jesus Nut" stays firmly attached and it keeps turning.

An airplane propeller is out there only to keep the pilot cool - when it stops turning, that's when the pilot starts sweating...

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Reply to
Bruce L. Bergman

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