[TR] TR2/4A Rear Crank Seal installation

[Catpusher at aol.com]

TR2/4A Rear Crank Seal installation by: Hardy  Prentice
I spent many months researching this during 25 years of  racing my TR3 at
the National level. I have also built quite a number of TR2/4A  race and
street motors. I have been a TR owner since 1961
Making the  factory seal work is not difficult with a factory TR2/4A crank.

The factory  TR4 manual images are a useful addition the TR2/3 ones,
but both  factory manuals have the same CRITICAL Error.
The  alignment tool drawing in both factory manuals needs to be changed to
2.818"  where the tool fits inside the seal.  The rest of the drawings in
the TR2/3 & TR4/A factory manuals will  work. The tool seal and bearing
surfaces must be concentric. The handle is not  necessary, and thick walled
tubing
can be used to save cost and weight.
I was given a tool made to the workshop manual(s) sizes,  and the motor
that I
rebuilt using it leaked oil very badly running on the  dyno (no G forces
involved)!
Previously, I had used the back end of a crank with the  flywheel flange
sawed off, with used main brg. shells with thin paper (or  thread) inside to
fill the normal bearing clearance, and  .0025b to.003b feeler gauges
between
the  seal and threaded crank surface.
(If you  know the seal is working OK, feel free to reuse it as is,
resealing the  main brg cap sides to the block recess, and avoiding  any
damage to
the  seal.)
1. Use the  tool to check the seal's ID for size and roundness by holding
the seal ID to  the
2.818b surface of the tool.  Illumination behind the seal and tool  help.
2. Hand work  can usually make the seal fit the tool very well, or try
another seal.  (I made a jig from two rear main caps to  size the seals in a
lathe)
3. Install  the tool in the block and the rear main cap first and carefully
check  that the seal halves will fit in the block recess with the tool in
place, and  the rear brg. cap torqued.
There have  been seals made where the seal step OD was too big for the
block/cap  ID.  A problem here can be fixed by a hand  file or grinder applied
to the seal step OD.
If you omit this step, you can destroy the seal and not realize it until
too late.
4. Use a  small amount of silicone sealant between the seal and block where
the seal  flange is bolted to the back side of the  block/cap. (Go to the
next step Before the sealant sets.)
5.  By hand, press the seal halfs evenly  towards the centralizing tool,
then do not further move the seal halfs when you  tighten the seal set screws.
 Allow  time for it to set.
.  During  final assembly, also use a small amount of silicone sealant on
the seal split  line, but VERY thinly, so that it does NOT block the internal
threads of the  seal.
6 Do not  hurt the seal when you lay the crank in the block.
7.  follow the manual(s) carefully.  The rear main cap sealing felt needs
to  be
soaked in  something like aviation permatex, short pieces at a time, and
then be driven  into the recess on each side.  A B<b  hex (Allen wrench) key
works well as a driver.
8.  The tool can be used to align a seal with the crank in
place...Interested?