This is a multi-part message in MIME format.
Here's a note I wrote to Glenn, who asked for a summation of what I
learned about this job. Thought others might find it helpful too. I
forgot to mention that (of course) one should pull the plugs and loosen
the alternator to make it easier to turn the crank. A mechanic's
rollaround is also a helpful item, as you'll be getting back and forth
from under the car quite a bit during the job.
Date: Sat, 17 Jun 2000 03:25:12 -0400
From: "Martin A. Secrest" <firstname.lastname@example.org>
To: Glenn Rattmann <email@example.com>
Subject: Re: TR6: Bottom End Rebuild
Here's a synopsis of what I learned about this job by doing it and from others
on the list.
Pull the oil pan. In my case, it had lots of crap on it and some paint was
missing. I literally had to use a paint scraper to get the sludge off the
outside (and inside!) -- then lots of Simple Green and water.
Pull the big end bearing caps and mains. The bearings slide out if you push
w/your thumb against the side that doesn't have the locating tab. Make SURE
that you note the exactly how the caps came out, and which is which -- it's
critical for the engine's balance. (The bolts, on the other hand, don't much
To get the #1 main out, you'll also have to remove the metal bridge at the
front of the block. Note that it's also held in by three bolts from the front
of the engine that also secure the timing chain cover. As you do this, you'll
likely tear the bottom of the timing chain gasket. That's OK -- you can use
Form-A-Gasket to reseal it later. Hang on to the piece of the gasket that came
out w/the metal bridge. Note that the bridge also has two small wedge seals,
which you probably can reuse, again with some gasket sealer, but I put in new
ones. The wedge seals are made from heavy cardboard that's easy to shape, and
just stop the oil from leaking here.
To get the upper main shells out, use an appropriate prodding device that won't
scratch anything, pushing on the non-tabbed side. They'll slide around and
drop out, as will the Thrustwasers.
Look at the crank journals. Any significant scoring? If so, the crank has to
come out for grinding and you'll need oversize washers. If need be, use
Plastigage to check the amount of clearance between the caps and the crank.
But if the journals are pretty good, check them for roundness with a micrometer
-- make sure you're checking in the same part of each journal. Then, clean
them up using crocus cloth. Crocus cloth is similar to emery paper, and
available at most parts stores. ("Ask for it by name.") Cut it into strips
and rotate the crank. Take your time with this part of the job. I used two
strips per journal, polishing until the oil stains came off and the journal
Sometimes the hardest part of this whole job is the getting your butt back and
forth from under the car to push the fan blade from above to rotate the crank.
(You can turn it by hand from underneath, but it's not easy.) Also, once you
get the con rods free, push the pistons all the way up into their bore. This
should allow you to rotate the crank about a half turn in either direction.
When it comes time to fit the new shells into the con rods, pull the rods back
down to the bottom of their stroke to fit the shells and then reconnect the
rods to the crank. Use lots of clean oil on the new shells. The oil passages
on the crank can also be cleared out w/a pipe cleaner and some WD40, and then
blown out w/compressed air.
You should replace the oil pump. It's about a $115 dollar part. Prime the
new pump by squirting gear or engine oil into it liberally before installing
For the thrustwashers, most likely just replacing them with a set of standards
will not suffice. Also order a set of .005" washers, and mix and match them to
get the proper end float. You can test end float w/a feeler gauge and by using
a big screwdriver to wedge the crank back and forth. You're shooting for a
float of .004-.008 (mine ended up to be .010) -- insert the feeler between the
bearing and crank flange on whichever side is freed up. If you use a .005"
washer, fit it as the rearward one, which apparently takes more of the thrust.
Note that the oil grooves on the rear TW face the back of the car, and the
grooves on the forward TW face the front of the car.
Torque the main caps to 55 ft. lbs, and the big end caps to 40. Torque the oil
pan bolts to 16 and use a good sealer on the sump flange, having first scrubbed
off the old gasket from both mating surfaces. Also check that the crank moves
freely after all the new bearings are in. Then, before starting the engine,
crank it over for a few minutes to get everything lubed up nicely before the
motor kicks in. (When putting in a new spin-on oil filter, fill it up w/oil so
that it will take less time to prime when starting the car.) Then once you've
started the car, sit back and have a beer while the new shells bed in. And get
your kicks looking at your nice new oil pressure!
Feel free to ask questions once you get started, and good luck ...
Glenn Rattmann wrote:
> At 02:02 PM 05/22/2000 -0400, you wrote:
> >The car's in the air, the oil pan is off, and I'm about to undertake a
> >bottom end rebuild on my 72 TR6.
> >I'm intending to replace the bearings and mains, thrustwashers and
> >probably the oil pump. For those who have done this before, any pearls
> >of wisdom to toss my way?
> Hi Martin,
> I may be facing this myself soon so I am very interested in what you and
> others have to say, as it goes along. Please keep me informed if possible.
> I saw one reply by Randall but no others so far... if you are getting good
> stuff offline, please forward their comments to me or summarize for the
> list, if you have time.
> Good luck!
> Glenn Rattmann 74.5 TR6 X 2
> San Diego