Paul:
It could be that you don't have to do anything more - if the noise does not
re-appear and all else stays well, you've probably fixed it by readjusting
the belt.
Moss lists a different P/N for the BN4 / 6 belt than the later 3/8" belt - I
don't own a BN4, but the belt I use on my BT7 is a Gates 11A1120 (3/8" x
44"). The BN4 belt is probably slighty shorter or slightly longer - just
about any auto parts shop should be able to source an equivalent to your
belt - say an 1110 or 1130 length. You'll probably find that there is no
choice but to get a toothed belt - not good for concours, but they do work
better. Maybe a BN4 or BN6 owner looking in could provide you with what is
the correct length belt for your car.
Best bet if you think a replacement belt is in order would be to remove your
old belt and take it with you to the shop and have them match it on the
spot. There should be just enough room between the crankshft nut and the
frame cross-member for the belt to squeeze by - if that is not the case, you
may have engine mount problems (or worse, G** forbid!). If your belt is
old, it may be a good idea to replace it anyway as a preventive maintenance
measure. (keep the removed one in the boot as a spare).
Earl Kagna
Victoria, B.C.
BT7 tri-carb
BJ8
----- Original Message -----
From: "Paul Negus" <Paul.Negus@ipl.com>
Subject: Fan belt problem?
Hi listers
I've searched the archives but cannot find anything relating to this.
Could I ask for your help, please?
We were out enjoying the BN4 last week until there was a brief shrieking
noise from under the bonnet (hood) when changing up a gear, followed by
a distinct rubber burning smell. Slowing to 50mph cured the smell and I
kept the revs down for the rest of the drive. Coolant temperature did
not waver from 190 degrees so I suspected a generator bearing failure.
Back in the garage I checked things out. The water pump turns freely and
so does the generator, with no evidence of bearing failure in either. I
also put the battery on charge - the charger switched from 'charge'
after only 30 minutes, so the generator appears to be OK.
Cleaning the fan belt (a simple wipe with a rag - no evidence of oil or
carbon contamination but the front end of a Healey isn't the cleanest of
environments) and re-adjusting it has stopped the noise for now.
However, as the belt was tight before - about 0.75 inch sideways
movement on the belt between crank and water pump, plus you could turn
the radiator fan but not the generator by hand - I therefore concluded
that a new fan belt was required.
Now for my queries:
1. Anyone disagree with my conclusion?
2. How do you get the fan belt between the starter dog and the chassis
cross member? (Jack up under the sump?)
3. Any preferences for fan belts sourced in the UK? The existing one is
toothed and sold under the 'Unipart' label, which means it could have
been made by any manufacturer!
Any help will be greatfully received!
Regards
Paul
Longbridge BN4
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