Brian,
I just finishing dismantling a old TR4 transmission for parts etc. The 3rd gear
both main and countershaft was toast. I was wondering what caused this trans to
self destruct. I think my answer was the same protruding roller bearing cage had
worked itself into the thrust washer and thus not giving enough "float" to
remove
the countershaft assembly. Since the case was already cracked, I decided to
smash
the case in order to extract the countershaft assembly. I am guessing this
caused
enough friction to cause the 3rd gear to self destruct. Only one cage had
drifted
out. This was the rear roller bearing assembly, the front seemed fine. Also the
gears on the countershaft seemed extremely tight, much different than a 3
transmission I just finished rebuilding. I am not sure on the history of this
transmission since it came as a package deal when I bought the car in 1979 but
your story leads me to believe that there is a design flaw somewhere or the cage
was just not assembled correctly. Could the dark gray gunk be aluminum shavings
from the thrust washer spinning against the trans case? I am guessing that
maybe a
new countershaft is in order here but I am no expert.
PS. The 1959 TR3A transmission I just finished rebuilding used the standard GL4
stuff and the oil was about the same color as new and this transmission had at
least 50K miles. Almost no sediment in the bottom.
Bob Labuz
1958 TR3A
1974 T140V
Brian Sanborn wrote:
> Tony Thanks,
>
> I took apart my rebuilt gearbox with 4000 miles on it yesterday in order to
> swap the mainshaft and install the OD I rebuilt. The only thing strange was
> the Redline synthetic oil was black and dirty already and there was a lot dark
> gray something in suspension... very fine... or maybe just dirt. The other
> thing was that the laygear would not drop and the back thrust washer would not
> come out. Really stubborn problem. I had to heat the case with a propane
> torch to get enough clearance to get the thrust washer out. What I found was
> that the roller bearing cage was protruding a little proud of the gear itself
> on both ends. The machine shop must have done this and I didn't notice. The
> ring of the bearing cage cut a groove in the thrust washer on both ends.
>
> Although... that still doesn't explain why the laygear would not drop even
> with a tap with a drift. The clearances were on spec when I installed the
> laygear.
>
> Should the oil be dirty after 4000 miles and two seasons? The gearbox was
> hospital clean when assembled. Any insight would be helpful.
>
> Brian Sanborn
> 62 TR4 CT16260L soon to be "O" - Groton, MA
>
> My TR4 Restoration Web Site
> http://www.net1plus.com/users/sanborn
> E-Mail: sanborn@net1plus.com
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