Some may recall about a year and a half ago I was asking if anyone knew
of a problem that could cause a vibration on the road when operating
only in overdrive. Well in preparation for another road trip in June,
yesterday I spent a pleasant afternoon pulling the tranny out of the
BN1 to see if I could get to the bottom of the problem.
A few months ago I changed the oil and when I did I got a lot of
brass/bronze filings so I suspected the worst, and yet the OD never
failed and was (other than the shudder) as or more reliable than the
rest of the car. When I drained the oil this time it was quite clean
with only a little residual metal.
I am happy to say that the interior of the OD was extremely clean
(Approximately 12,000 miles on Castrol 20W-50) and the mechanical
condition is very good with a few exceptions;
- The recess in the bottom of the annulus (under the one way clutch)
appears to be worn in a dished shape, probably from a PO building it
without the necessary bronze washer. The washer I put in it has the
back side worn in the same pattern, probably the source of the metal
in the oil. I have replaced the annulus with one I had for a spare and
I'm replacing the washer.
- The pinion/sun gear had so much end float that the bronze washer
broke and the fragment,(about a quarter of the washer) was able to
slide into the clearance.I have a spare washer, but will have to order
the proper thickness steel washer to get the clearance in range. I
think this happened because I assumed that the internal parts were
original to the unit when I built it and didn't check the clearances. I
see now that the gear train has been changed as it has a 28% instead
of the original 32% planetary set.
- I replaced both of the bearings in the tail-shaft housing and the
seal. I am going to replace the bearing in the actuating clutch. I
don't trust anything in the direct line of power transmission and I
don't want to have to do this again for a while.
- The cost so far appears to be about $140, mostly for new bearings.
I haven't figured in they cost of chiropractic yet because I'm not sure
my medical plan covers it and besides it would be silly to get it fixed
now and just have to redo it after the tranny goes back in.
I have been running with my centrifugal switch jumped out for the last
two years and have just recently decided to check its operation. It
seems to work, but is nowhere near its designed set points coming in at
about 20 MPH and dropping out at about 5 MPH. Can anyone tell me how
these are supposed to be adjusted? There are two screws on the switch,
but I don't know which adjusts what etc.
Other things I am going to check or install while she is off the road:
- Balance the drive-shaft and check the U-joints.
- Balance the rear brake drums.
- Seal the transmission tunnel using Dynamat and Tac-mat.
- Reset throttle linkage to assure full opening.
- Reset OD throttle switch.
- Replace leaky oil sensor hose.
- anything else I find wrong or think of.
Off to Glenwood June 11-13.
Bill Lawrence
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