Author Topic: Starter bolts  (Read 1325 times)

Offline Cheyenne1010

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Starter bolts
« on: August 12, 2022, 03:20:29 PM »
I am a proud owner of a 1973 chevy Cheyenne longbed 5.7liter.the problem I'm having is the starter bolts are two different size.one is 3/8 diameter and the other is 1/2 diameter and when I purchase a starter the holes on the starter match up with the smaller diameter 3/8 bolt.thet last starter I bought I had to drill out the 3/8 diameter bolt hole to 1/2 diameter bolt hole.i have never see this before and if you have please explain what is going on and any suggestions on how to fix my issue will be greatly appreciated.

         Thanks guys
                  Robert

Offline Shifty

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Re: Starter bolts
« Reply #1 on: August 12, 2022, 03:34:00 PM »
It shouldn't be a 1/2....sounds like someone drilled/tapped your block at some point. 
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87 R30 3+3 Longbed (days of yore)

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Offline bd

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Re: Starter bolts
« Reply #2 on: August 12, 2022, 03:39:21 PM »
Someone may have stripped the threads out of the original 3/8" bolt hole then drilled and tapped for 1/2".

Can you post pics of the starter mounting surface of the block with the starter removed and pics of the starter showing the bolt hole layout?  Some starters use a straight across bolt hole configuration while others are offset or staggered.  Depending on how the block is drilled, you may be able to substitute an alternate style.

Rich
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In other words... if people learn by making mistakes, by now I should know just about everything!!!
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Offline Twosquarebodys

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Re: Starter bolts
« Reply #3 on: August 12, 2022, 06:11:58 PM »
Will a Heli-Coil work??
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Offline bd

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Re: Starter bolts
« Reply #4 on: August 12, 2022, 08:19:15 PM »
No.  The 1/2" bolt hole is already larger in diameter than the tap for the 3/8" Helicoil.  If the substitute starter suggestion posted previously isn't workable, contact Timesert to see whether they offer a solution.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

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Re: Starter bolts
« Reply #5 on: August 13, 2022, 10:03:11 AM »
No.  The 1/2" bolt hole is already larger in diameter than the tap for the 3/8" Helicoil.  If the substitute starter suggestion posted previously isn't workable, contact Timesert to see whether they offer a solution.

Did you mean the '1/2" bolt hole is larger than the drill size for a 3/8" Helicoil'?  ;D
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Offline bd

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Re: Starter bolts
« Reply #6 on: August 13, 2022, 02:23:53 PM »
JP, I meant exactly what I wrote.  A 3/8" Helicoil tap will fall through a 1/2" hole.   ;)

I don't believe an off-the-shelf 3/8" Timesert will work either, but they may offer a custom solution.

Of course, the easiest solution would be to use a starter with the alternate mounting configuration if the block is machined to accept it.

Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Shifty

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Re: Starter bolts
« Reply #7 on: August 13, 2022, 03:14:14 PM »
OP, is this the "thru-hole" in the block?  I've seen my share of longer bolts that just had a nut on them. 
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Online zieg85

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Offline Shifty

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Re: Starter bolts
« Reply #9 on: August 15, 2022, 09:13:19 AM »
Nice one Zeig!   8)
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Offline Stewart G Griffin

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Re: Starter bolts
« Reply #10 on: August 20, 2022, 08:11:35 AM »
Now is also a good time to verify that you have the front starter brace installed.  This sounds like a very precarious position to be in....