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Old 12-10-2010, 12:09 PM   #1
LBYRNES
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Default Optispark replacement - '93 LT-1

I had to replace the water pump in my '93 LT-1. Usually, a leaky water pump kills the Optispark so I was going to replace it with a new MSD Opti. However, the FSM says that I need to remove the balancer and hub. That requires me to lift the engine. I don't have the equipment to do that, so the question is:

Can I replace the Optispark without pulling the balancer and hub?

Thanks,

Larry...
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Old 12-10-2010, 12:27 PM   #2
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You'll need to pull the balancer, not th hub. Also, you don't have to lift the engine to pull either.
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Old 12-10-2010, 12:32 PM   #3
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You just need to pull the ballancer off.
Mark the hub and balancer, remove the three bolts.
From underneath with a blck of wood on the balancer whack it a few times.
Using the hub bolt rotate the crank 90*, whack again, repeat until the balancer comes off.
Clean the balancer and hub, put a little anti-sieze on the mating surfaces when you put it back on.

It is CRITICAL that the filled tooth on the opti matches the gap on the spline when you replace it. The opti should "pop" on and the bolts just hold it in place. DO NOT use the bolts to draw the opti on!

Where in Atlanta are you? I may have some time next Sat if you want some help.
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Old 12-10-2010, 05:26 PM   #4
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As others have mentioned, all you have to do is remove the ballancer in order to have enough clearance to slide out the optispark. You do NOT have to remove the engine.

I did a write-up about my recent optispark swap a few month's back on my '92 'Vette. It might come in handy for you, should you choose to do the swap yourself. Just follow the link in my signature. Hope that helps.

As for the MSD opti, the jury's still out on their long term reliability since there have been a lot of complaints of them failing after a few month's of use and even a few showing up D.O.A. Right inside the box.

Maybe it was just production issues on MSD's first few batch's of optisparks, but there have been numerous unhappy MSD owners...

I just purchased a GM factory replacement (not a cheap chinese-made ebay knock-off) when I replaced mine. I figured what the hell, the original lasted 17 years, so they can't be all that bad

It's the cheap ones that are causing everyone problems...

Last edited by LT1*C4; 12-10-2010 at 05:28 PM.
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Old 12-10-2010, 07:53 PM   #5
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Another consideration

The other side of the coin is if it is running really good and your happy, leave it alone till a problem develops. A lot of people have gone back to the original GM opti after having problems with other systems and optis.

It's your call and definitely a judgment thing, no right or wrong answer. Mileage is a factor but not a definite determination. Neither answer is a sure thing. Depends how much you want to play with the car now or later.

If you decide to do it now, there is definitely lots of help from the Forum.
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Old 12-10-2010, 09:26 PM   #6
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Quote:
Originally Posted by LT1*C4 View Post
As others have mentioned, all you have to do is remove the ballancer in order to have enough clearance to slide out the optispark. You do NOT have to remove the engine.

I did a write-up about my recent optispark swap a few month's back on my '92 'Vette. It might come in handy for you, should you choose to do the swap yourself. Just follow the link in my signature. Hope that helps.

As for the MSD opti, the jury's still out on their long term reliability since there have been a lot of complaints of them failing after a few month's of use and even a few showing up D.O.A. Right inside the box.

Maybe it was just production issues on MSD's first few batch's of optisparks, but there have been numerous unhappy MSD owners...

I just purchased a GM factory replacement (not a cheap chinese-made ebay knock-off) when I replaced mine. I figured what the hell, the original lasted 17 years, so they can't be all that bad

It's the cheap ones that are causing everyone problems...
Have an MSD opti with 8,000 miles and 2 years on my '94. Replaced a GM opti installed by a Chevy dealer that lasted 4,000 miles. Original opti went at 44,000. Both failed because the water pump seal leaked. The MSD is vented which is a nice feature.

Last edited by airplane50; 12-10-2010 at 09:29 PM.
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Old 12-11-2010, 10:41 AM   #7
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Everyone, THANK YOU!

As so many of you pointed out, the engine did not need to be lifted. The balancer came off with no trouble. I was so relieved by your answers that I went directly to the garage and worked until it was time to retire for the evening. I forgot to post this thank you before I started. As of this moment all I have to do is put the water pump back in. Everything else is done.

I used the MSD because (a) I paid $499 for it already, (b) the stock opti had gotten very wet.

Anyway, thanks everyone.

Larry...
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Old 12-11-2010, 01:08 PM   #8
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Put a $1 piece of hose over the weephole and you would not be needing this help.

Just get some high temp adhesive and glue a hose to the weep hole and you need not was $500 again.

This is in Tech Tips, which I guess I am the only one who reads it.
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Old 12-11-2010, 01:10 PM   #9
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Also, put sealant all around the opti and that will save your opti. Just don't drop the WP on the opti , that will ruin your day and your pocketbook.
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Old 12-11-2010, 02:08 PM   #10
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Is it the WP shaft or front plate (weephole) that usually leaks?
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Old 12-11-2010, 03:09 PM   #11
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Quote:
Originally Posted by rinosaur View Post
Is it the WP shaft or front plate (weephole) that usually leaks?
It's the weep hole. If it leaks, you will weep, too.
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Old 12-23-2010, 03:12 PM   #12
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If you haven't bought already we've got a unit with a better rep than MSD's for $114.99
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Old 12-23-2010, 03:25 PM   #13
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Quote:
Originally Posted by ChandlerMotorsports View Post
If you haven't bought already we've got a unit with a better rep than MSD's for $114.99
In what country are the parts made and the unit assembled?
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Old 12-23-2010, 07:44 PM   #14
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Quote:
Originally Posted by ChandlerMotorsports View Post
If you haven't bought already we've got a unit with a better rep than MSD's for $114.99
Details?

TIA,

Live well,

SJW
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Old 03-06-2011, 12:41 PM   #15
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I have had many problems with the optispark and have had to buy about 6. I would like to add that in addition to all the other problems given, there is often a problem with the coolant bleeder screws being left open. I last had my 93 distributor repaired at the dealer. About a year later I noticed a small coolant leak where the screw had not been tightened quite enough.Might want to check this as I think it is the source of many problems and not just the optispark getting water in it.
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Old 03-27-2011, 03:55 PM   #16
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Default Balancer position

Hi , Just changed the Optispark unit and realized I did not mark the position the balancer was when I removed it. Which position is the arrow on the pulley supposed to be ?
Thanks
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Old 03-27-2011, 04:25 PM   #17
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It only goes back on one way, the holes are slightly offset.
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Old 03-28-2011, 09:53 AM   #18
Flyinrio
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Default Balancer

Thanks for the reply. I did get it back on the way I believe it came off and it went right on. I assume after reading your post I have it on correctly.
Thank you!!
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Old 03-28-2011, 05:39 PM   #19
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Quote:
Originally Posted by Flyinrio View Post
Hi , Just changed the Optispark unit and realized I did not mark the position the balancer was when I removed it. Which position is the arrow on the pulley supposed to be ?
Thanks
It will only bolt on one way,the bolts are not equally spaced
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Old 03-28-2011, 05:39 PM
 
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