those infernal thrust washers

My TR6 engine has about 103K and as far as I know, the head & oil pan have never been off. I have 65 lbs oil pressure and good compression but bad valve guides so this winter, I'll take the head off & do the usual.But - I think my thrust washers must be original. I never checked them because nobody told me I should have.Assuming they have to be replaced, my question is this - should I replace the connecting rod bearings while the pan is off or am I looking for trouble? And - should I replace the main bearing cap bolts?

PD

Obviously, the first step is to check the end play. IMO chances are good that you don't have a problem.

If you do drop the pan to change the thrust washers, I would plan on changing the rod bearings unless you don't plan on driving the car much further. The inserts are cheap enough and bound to be at least somewhat worn by now; so changing them will likely extend the interval until you need to do a full rebuild.

Also IMO, I'd reuse the cap bolts unless they show signs of damage. The bolts should last forever in an otherwise stock engine.

Bad news. Crank seemed to move forward about 1/16". Dreading what I may see when the pan comes down. Wish me luck.

PD

Did you notice the idle speed decreasing somewhat when you fully depressed the clutch pedal ? If not, you may have been lucky. On the other hand...

The idle speed remains constant at 850. No clutch noises; clutch catches down low. I think it was rebuilt by a PO as was the front suspension, interior, crash pad & other goodies. Plenty of oil pressure & no knocks. I use only 93 octane and now throw in a can of additive. This car has been babied, at least by me. Never over 4K rpm, never out in the rain or in snow or ice.Gearbox is perfect, improved steering mounts, tube shocks, spin-on filter, rebuilt RR hub & spline, rebuilt RR suspension arm & bushing, new brake lines, new water pump, alternator, etc.As I said, it's begun smoking on the overrun due to worn valve guides.

PD

I did the TW two years ago with a little help from my friends..... had the car 14 years and decided it was time. I wrote the whole thing up so you may find some pictures that will help seeing as it's your first time.

And now the dreaded..... while you're in there words.... good time to pull the oil pump and clean it up. And you might even consider Marc Goldblatt's steel sealing block to replace the alloy one with the stripped threads!

The bearing discussion will range from....check them to see how they look to ..... no sense replacing them unless you have the crank checked.... and points in between. I checked mine and ran them by a few guys whose judgement I respect who said they looked brand new and to put them back in............ YMMV

Considering what you said about finding .06" crankshaft end float, PD, you are facing the task of replacing them.
The fact that your idle doesn't change when you depress the clutch, suggest that the crank is not floating far enough to grind itself away on the engine block.
So, if there is a bright side, that may be it.
Follow this post up with the measurements of what is left of the TW's thickness,if you would ?

OK - update. Dropped the pan & discovered a small piece of flat metallying in the sludge .I panicked. Cleaned up, it looks like a broken washer lock tab. At any rate, the thrust washers were still in place - thank God - and when they came out, the rear one was .087 and the front one was .092 - stock and almost no groove wear. The grooves in the rear washer had worn almost flat and there were a couple of small chips at either end so that one was probably on the way out.The bearing and cap were in good shape and were replaced. I cleaned the pan and oil screen and now to reassemble. I decided to leave well enough alone on the other bearings. Why the crank moved so much is a mystery.
This winter, I'll pull the head and have the guides replaced and put in hardened seats & maybe mill the head slightly.Looks like I dodged a bullet.

PD

double check end play before install of the pan. 0.004-0.008 is what's needed. oversizes are available if required.

I agree with Casey and now you can use a feeler gauge effectively between the rear TW and the crankshaft directly. See the picture 45.13 in Haynes Chapter 1.

It seemed right on. I'll have to check it again at the pulley when I get a few miles on it. The pan was full of sludge as you can imagine after 40 years. After thorough cleaning, I put new oil in although it was changed a month or so ago.I'll try to send a picture of the metal piece I found but I'm not optimistic.
I also sprayed some carb cleaner on both ends of the throttle shaft. The idle speed went down just a bit for about a second on the front carb but there was no change on the rear. Hopefully all the work is finished - except for the valve guides which will be done when the head is pulled this winter - and I can now start driving and enjoying the car. I was very lucky to have found a TR6 expert who did a lot of the heavy lifting and helped me complete these repairs. I'm getting too old and stiff to lay under a car anymore. I wish I had a lift...

While you have the head off, you should remove and mark the location of each push rod and check the cam followers (lifters). If they are pitted or worn badly, you will have to go further into it.