Ford 2000 Rod Bearing Limits

Hello,

I've got a 1970 Ford 2000 tractor that just developed a slight rod knock. Got the pan off and would like to plastic gauge the rod bearings in place before deciding what to do next. If it measures within the limits, I might just replace the bearings. If it doesn't measure within limits, I'd have to get a professional do a full overhaul.

Does anyone have the limit or acceptable range on the plastic gauge measurement for the rod bearings?

Any suggestions and advise is welcomed.

Thanks,
Rob

.002 - .004" is a pretty typical spec for most rod bearings, and main bearings as well for that matter. If the bearings and clearances look good, I would look further for the knock, such as the wrist pin bushings in the top of the rod. This should be pretty easy to detect once you pull the rod cap off. Simply grab the rod and move it up and down. If you feel any play, you have a worn pin bushing.

Thanks Bern!

Is there enough room in there so that I can push the piston up such that the rod clears the crank journal? Can't tell if it can go high enough so that the rod can swing to the side with the studs still in the rod. I'd like to get calipers around the journal to measure several points around the journal. And if I decide to replace the bearings, I'd like to be able to install them in the rod without having to work around the journal.

Thanks,
Rob

If the piston is at BDC when you take the cap off, then yes, you can push the piston up to get some working room. That said, most caliper jaws are not wide enough to spread around the journal, nor is your typical calipers considered accurate enough to measure something that closely.

Myself, I would visually inspect the bearing and then plastigauge it. If the clearances are all good, no need to measure the journal.

I went to look up the clearances in my I&T manual and only got confused so I scanned the whole page for you. Typical of Ford, make a bunch of parts, see which ones fit together and then color code them. Seems the site will not let me upload so I will try again later. I've had this happen before.

That whole red/blue thing does throw a lot of people off. They only do it with the standard sizes though.

I had to walk away from an Engine Job two weeks ago. Owner refused the time to properly measure all crankshaft Journals...?.
Be cognizant of the information / advice you receive, and who you receive it from..

Bob..Retired Power Engineer...

Still will not attach the picture.

(quoted from post at 14:55:21 08/23/19) Hello,

I've got a 1970 Ford 2000 tractor that just developed a slight rod knock. Got the pan off and would like to plastic gauge the rod bearings in place before deciding what to do next. If it measures within the limits, I might just replace the bearings. If it doesn't measure within limits, I'd have to get a professional do a full overhaul.

Does anyone have the limit or acceptable range on the plastic gauge measurement for the rod bearings?

Any suggestions and advise is welcomed.

Thanks,
Rob

Click to expand...

If you decide to use plastigage, keep in mind that the testing (squishing) is done dry, with no oil or assembly grease on the bearing journal being tested. After the smear is compared to the chart and recorded, then use your thumbnail to remove the smear from cap and journal, re-oil, re assemble and re-torque. Oil and grease takes up room and gives you a false reading.

And while we're on the subject, never use oil or grease on the back side of bearings. There is no movement on the back side and that extra thickness will throw off your torque down routine.

Tom

I've rebuilt more Basildon Fords than I dare try and count, and for all the times I ever measured one of those cranks, I never found one with any out of round or taper that first passed a visual inspection. Yes, technically it should be done, but when you're in a workshop environment, you have to know where you can take shortcuts.

In the scenario described above, if the plastigauge comes out OK, it will work just fine.

Good evening "Bern"
Quote:
I've got a 1970 Ford 2000 tractor that just developed a slight rod knock......

Bern...
Quote:
I've rebuilt more Basildon Fords than I dare try and count, and for all the times I ever measured one of those cranks, I never found one with any out of round or taper that first passed a visual inspection.

Now Bern...With all do respect,if it was my money...and given I WEAR GLASSES and the SKIN on my FINGERS are such that I can not beyond any doubt verify if as Journal is round and or Tapered.... I have always used an OUTSIDE MICROMETER to verify such information on a Journal.

Again Bern...(with all due respect)
If the last individual whom was wrenching on this machine had as good an eye and a touch as light as yours then the present day owner has nothing to be concerned with.

It JUST MAY be a GOOD IDEA to MEASURE the CRANKCSHAFT and install the correct sized bearing shells ...eg..the Engine OIL PRESSURE may see some improvement ???

What ever the out come and who's ever suggestions is followed I'm sure your suggestion with all your hands on experience with these engines make you quite qualified not to follow Standard Engineer procedures.

Respectfully...

Bob...

Hello Bob,

If the knock that is being described by the original poster is indeed being caused by a rod bearing, this would be detectable by either a visual inspection and/or plastigauge measurement. In addition, getting an accurate measurement of the journal with the crank in the engine would be difficult at best, especially for a novice. In fact, I would argue that a novice would likely make an inaccurate measurement in a situation like that and end up with a false conclusion of a journal that is out of spec. This is why plastigauge is preferable for most people who work on engines.

I completely understand the logic of your statements, and I would agree with you that these measurements *should* be done with a micrometer in a perfect world. However, there are two things in our imperfect world that argue against your recommendations: 1) most people aren't good enough with an outside mic to give repeatable results within .0005" or even .001", especially if they're standing on their head to do it, and 2) time constraints in most workshop environments make plastigauge the sensible choice.

Respectfully as well,

Bern

Thank you for your reply and explanation Bern....

Your points are truly validated points. As well, I'm sure your experience and input is certainly appreciated by "YT" members. I know I certainly appreciate your sharing of your experience..

Thank you...

Bob.....

Hi Bern,

Well, after replacing all 3 rod bearings, I still have a knock. I carefully measured all three with plastic gauge and they were slightly under the .003 measurement. The journals were very clean and had no scars or groves. I checked each piston pin bushing by feeling for play while I had the caps off the rods. They seemed very tight. The valves and push rods seem to be just fine. Each cylinder has close to 110 psi compression.

There is no noise when first starting the tractor. It takes a while for the noise to develop. It sounds like it's coming from the fuel pump area. I put a wood rod against the engine all over the place and listened to the other end. You can hear the knock all over, but it's loudest right around or right on the fuel pump.

I see the fuel pump has a short rod between the pump and the cam that works it. Is it possible the knock is coming from this? Is it possible the cam is worn or the rod? Maybe the fuel pump is "sticking" and causing slack in the rod and that is knocking? Any way to rule this out?

Thanks,
Rob

Well, after replacing all 3 rod bearings, I still have a knock. I carefully measured all three with plastic gauge and they were slightly under the .003 measurement. The journals were very clean and had no scars or groves. I checked each piston pin bushing by feeling for play while I had the caps off the rods. They seemed very tight. The valves and push rods seem to be just fine. Each cylinder has close to 110 psi compression.

There is no noise when first starting the tractor. It takes a while for the noise to develop. It sounds like it's coming from the fuel pump area. I put a wood rod against the engine all over the place and listened to the other end. You can hear the knock all over, but it's loudest right around or right on the fuel pump.

I see the fuel pump has a short rod between the pump and the cam that works it. Is it possible the knock is coming from this? Is it possible the cam is worn or the rod? Maybe the fuel pump is "sticking" and causing slack in the rod and that is knocking? Any way to rule this out?

May I ask....Engine oil psi at start up... and Engine oil psi once engine is up to operating temperature?..Thermostat setting Deg.

Thanks...

Bob...