I think I finally solved two problems with my TR6 that I've been chasing for
some time. There are some lessons learned in each that I thought I would
share with the List.
The first problem was the infamous TR6 rear end clunk. In my case, the clunk
occurred as the car changed pitch with changes in the road - not with throttle
on and off. I had previously changed out the rear half shafts, splines,
u-joints and hubs to no avail. In the end, the problem turned out to be a
badly worn passenger side front differential rubber bushing. You could only
see this when you dropped the diff and looked inside the bushing. This also
caused an incipient crack in the diff mount on the frame. I welded up the
crack, added TRF reinforcing plates, put in new rubber bushings and presto,
the clunk was gone. First lesson learned; do the inevitable: drop the diff
and look at the inside of the differential mounting bushings first if you have
a clunk in the rear end of your TR6.
The second problem was a squealing clutch throw out bearing - or at least
that's what I initially thought. I had put a new TOB in two years ago and was
more than dismayed when I recently started to get a squeal when I first
engaged the clutch. Hours spent on the web brought up all kinds of stories on
faulty new throw out bearings followed by all kinds of advice on possible
One of the articles on the web talked about the need to locate the gearbox
center relative to the flywheel center with two 3/8 dowels or shoulder bolts.
That article mentioned that most owners are unaware of the need to do this and
only use 5/16 bolts in all the holes of the bell housing. This would cause an
eccentric alignment between the two centers and all kinds of clutch problems.
I then pulled out my gearbox and found that the 2-year-old TOB was perfectly
fine, but I had used only 5/16 mounting bolts. I also found a badly worn
(actually, badly machined) flywheel bushing. I replaced the flywheel bushing,
used two shoulder bolts with 3/8 ground shoulders and 5/16 threads from
Fastenal in the locating holes, reassembled everything and the squeal is gone.
Second lesson learned: Everyone, make sure you use 3/8 shoulder bolts to
properly align the centers of your gearbox and flywheel. If you only use 5/16
bolts to mount your gearbox, you will get all kinds of clutch/TOB/bushing
problems because of their eccentric motion.
I hope some of this might help others on the List chasing the same problems.
It's starting to look like a very promising summer for my TR.
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