Gents -
I hate to bother you guys with this b/c it’s non-Jag, but I am at the
end of my rope trying to help my son. So, if you have any ideas, please
respond off List. It is about my son’s 1970 Corvette which has a Big
Block engine, a 454, in it. 4-spd transmission.
He has come to me in desparation after installing around 6 different
starters in his car over
the past 1 1/2 years. Two cracked their housings, right across the nose,
more or less near the two bolts that hold the starter to the block. I
didn’t get involved in those starters, but I am trying to help him and I
am not a Chevy guy and this seems like a unique problem. I would like
your read on the current starter, which is a freshly rebuilt unit from
Delco that he bought at the Chevy dealer.
My son’s complaint was that, after he installed it last week, he tried
it 10 or 15 times in the driveway and it worked fine. He went to the gas
station and upon attempting to fire the engine up, it “clashed” with the
ring gear. The clashing has been the recent problem and seemingly what
cracked the prior starter. He didn’t have time for it (he’s working 16
hours a day at work), so, he just took it back to my garage and parked
it – and took my car. (What else are Dad’s for?!) I told him I would
attempt to figure it out.
I figured maybe it needed shims, b/c he had no shims in it. So, last
night I took the starter out and put a .060 shim in - it was the
thickest shim in the pack that I got at the auto parts store. The others
were .020 and .040, which I did not use. After I bolted everything back
together, I disconnected the coil so it wouldn’t start, for starter
testing purposes. I cranked it for about 20 short bursts and
there was nothing unusual - it sounded OK to me at that point. But I
kept testing with short bursts and, after that, the battery seemed to
start running down, b/c the engine was cranking with diminished vigor.
Then, it made two strange sounds. First, it made a very low grating
sound when I would release the key - but, that was very subtle. The big
sound it made – remember the battery was running down low – was like
it was arriving at a spot on the flywheel that had very worn teeth or no
teeth, and the starter would make a grinding sound in mid-crank. That
is, the grinding was not upon engagement with the ring gear, but
occurred after engagement and some slight amount of normal cranking. It
sounded rather like a normal crank for 60 or 90 degrees of flywheel
rotation and, then, the grinding, like it had arrived at a bad spot.
Only thing is, the flywheel looks pretty good to me. I haven’t examined
every tooth, but I’ve looked at it when my son had the starter out a
couple of times and I looked at it last night and every tooth I can see
in there looks good.
Do Chevy’s do that when their batteries get low? That is, do you think
this grinding could be caused by the low batter situation? I charged the
battery up and it didn’t do the grinding anymore. Could the starter
drive be failing to hold the starter gear into the flywheel and that
possibly the grinding sound was the starter gear backing out of the ring
gear? I never had a starter on another car do that, however, but it is
conceivable to me that this could be it – just a low battery and
nothing at all wrong with the starter. Although that would not explain
why my son cracked two prior starter casings. To my knowledge he has
never shimmed it. But, he did get one starter to last around 6 months.
Thanks in advance.
Cheers.
Bjarn