1959 tach question

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Mar 22, 2009 | 03:59 PM

Treetopflyer

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From: Patuxent River MD

1959 tach question

The tach on my 59 goes to 7000 and red lines at 5000. I have been told that the tach drives on the generators were geared for specific tach gauges. My question is, do I need a specific mechanical drive on the generator for my tach gauge or will all 1959 Corvette generators work? Currently the tach gauge is not hooked up since I have a standard Delco generator that is lacking the shaft for the drive. I have found a generator, but before I buy it I want to make sure I am purchasing the right mechanical drive.

Mar 22, 2009 | 04:04 PM

62Jeff

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From: Conroe Texas

Quote:

Originally Posted by Treetopflyer

The tach on my 59 goes to 7000 and red lines at 5000. I have been told that the tach drives on the generators were geared for specific tach gauges.

Hmmm, I've never heard of that.

However it IS true that tachometers that were driven off the distributor (all 62's, and pre-62 Fuelies) have a different drive ratio than generator-driven tachs.

I'll be curious to see if anyone can substantiate what you've been told.

Jeff

Mar 22, 2009 | 04:10 PM

Frankie the Fink

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Army

Corvette Central lists the same drive and gears for '55 through '61 if that is what you are asking:

http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000050e~Z5 Z5Z5AAPCT~P129.95~~~~S2M00YL697242331107 35a~Z5Z5Z5~Z5Z5Z50000050x

Since this one kit works for all of those years and has a single gearing mechanism I would assume any generator from those years would drive the tach correctly and at the right ratio.

Mar 22, 2009 | 04:12 PM

JohnZ

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From: Washington Michigan

All the tach-drive generator gearboxes were the same - they were all 2:1 reduction (50%), so the cable ran at crankshaft rpm, assuming you have the correct crank and generator pulley diameters.

Mar 22, 2009 | 06:50 PM

Ironcross

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From: Taylor Michigan

I believe the power steering generator from the passenger cars is also the same with the same cable drive out of the rear housing.

Mar 22, 2009 | 07:57 PM

1snake

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Joined: Dec 2007

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From: Puget Sound

Quote:

Originally Posted by Ironcross

I believe the power steering generator from the passenger cars is also the same with the same cable drive out of the rear housing.

The only difference was with the tach. If generator driven, it registered cable speed, if distributor driven, it registered twice the cable speed.

Jim