Early 58 Generator Adjustment Brace

[Gene S.]

I'm restoring an early 58 built 11/6/57 and when I tried to install the fan belt, either the belt is too long or the generator adjustment brace is too short. The generator U-bracket is bolted directly to the exhaust manifold and the pulley is spaced forward about 1/4". I have balancer pulley 3742991 and water pump pulley 3713974. The V-belt is 3747873 but there's no number on the adjustment brace. It all lines up perfectly, but something's not right. Did the early 58s use a different brace or belt?
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[Leif A.]

Re: Early 58 Generator Adjustment Brace

Gene,

Let me start out by saying I know very little about the '58 generator and it's brace. What I can tell you is that you're doing an immaculate job with your restoration. I don't know if it could possibly be this simple but is there a chance you can loosen the bolt at the water pump end of the brace and allow the brace to cantilever down towards the generator. Then, after installing the generator bolt thru the brace, re-tighten the bolt at the water pump. Surely it can't be that simple. Just a thought.

[David L.]

Re: Early 58 Generator Adjustment Brace

Gene,

Your generator brace appears to be correct according to your photos but what is the length from the center of the bolt at the water pump to the center of the slot?
My 1963 Chevrolet Parts Catalog (Oct. 1962) lists brace # 3755556 for 58-59 Corvettes. There is a drawing of the brace and the bracket in N. Adam's 53-62 Corvette restoration book (page 247). The brace slot is 0.36" wide and 2.80" long (center to center) which would makes the maximum length of the slot 3.16" (0.18" + 2.80" + 0.18").
The 3750548 bracket is described as 6 5/8" O.L. and 1 7/8" high in the parts catalog. The drawing shows the overall length as 6.600/6.617" long, 4.55" center 15/32" dia. bolt hole to center 15/32" dia. bolt hole, maximum height 1.84" +/- 0.03", and 11/32" dia. end holes.

The 1st design 58 Corvette fan belt is listed as GM # 3759202 (3/8" - 55") and 2nd design 58 Corvette belt is 3754906 (3/8" - 55 3/8") as per my 63 parts catalog. I sold my 55,56,58,59,60,61, and 62 Chevrolet parts catalogs several years ago.

The 3747873 belt was replaced with the 3754906 belt in April 1960 as per Chev. parts history.

Dave

[Gene S.]

Re: Early 58 Generator Adjustment Brace

Leif,
The nut on the water pump is loose and when I pull the fan belt tight the end of the brace will rest on top of the generator. But the end of the brace doesn't reach the bolt on the generator.

[Thomas H.]

Re: Early 58 Generator Adjustment Brace

Gene,

This thread has a lot of good generator info in it. Rich put a lot of time into the pdf and it may shed some light onto your problem.

https://www.forums.ncrs.org/showthread.php?108653-1961-RPO-582-Fuel-Injection-Generator-Bracket&p=728087#post728087

Tom

[Gene S.]

Re: Early 58 Generator Adjustment Brace

Thanks for the help. I've clearly got the wrong brace. It should be 12.68". The early 58s used a 3770360 or a 3755556.
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[Richard M.]

Re: Early 58 Generator Adjustment Brace

Gene, A observation about your Generator......

What is the spacing from the center of the pulley shaft to the center of the mount bushings on the end frames? In your 3rd photo, it appears to me that your end frames are not Corvette but are Passenger car/Truck, which are 3 1/2" spaced. Corvette generator 1102043 is 3 1/4" spaced. If your brace is wrong, that is likely your major problem, but the extra height of the generator may cause you trouble when you later drop the body on the frame/engine assembly. More information regarding these spacings can be seen here, in the Addendum at the end of the document......

http://home.comcast.net/~richmz/site/?/page/Chevrolet_Generator_Rebuild_and_Restoration

Another important factor for body drop......Is your hood support on the Passenger side(mounted to the radiator support), or the Driver side(mounted to the left forward top surround gutter)?

Rich

[David L.]

Re: Early 58 Generator Adjustment Brace

Thanks for the help. I've clearly got the wrong brace. It should be 12.68". The early 58s used a 3770360 or a 3755556.
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Gene,

Here are 2 photos of some of my alternator & generator braces but I do not a 3755556 or 3770360 brace. I have a few that look similar but I believe they are from Chevrolet passenger cars and trucks and are slightly longer along with longer slots.

Dave

[Gene S.]

Re: Early 58 Generator Adjustment Brace

Rich,

Thanks for the tip. My generator does have the wrong end frames. This might be why the front of the hood seemed to be adjusted too high. My car has the hood support on the passenger side.

Gene

[Richard M.]

Re: Early 58 Generator Adjustment Brace

Rich,

Thanks for the tip. My generator does have the wrong end frames. This might be why the front of the hood seemed to be adjusted too high. My car has the hood support on the passenger side.

Gene

Gene, Things may get a bit tricky when everything is re-assembled. The hood support arm may interfere with the generator brace. I helped a acquaintance in California a while ago having those exact issues. Much time on the phone and emailing photos etc. In fact, that's one of the main reasons I wrote that document that Tom referred you to above, to help to clear up confusions about these generators, pulley alignment, etc. His is a early '58 also.

When you get the correct adjusting brace, it will be important to have the correct length drive belt as well. One of the issues with the support being on the right, is that the belt length will be a factor as to how far the generator will be positioned "outward". This meaning that if the belt is too long, it'll swing it too far out and could interfere with the hood support.

Because there were running changes in the 1958 generator designs, hood support, and associated hardware, it's difficult to nail down the exact configuration. The AIM is no help because all references to early cars don't exist. It only shows hardware for the later cars, where the hood support is on the Driver side.

You may have to revisit all of this generator fun again when the car is fully assembled.

Here is another document that will help. Fellow member Dan Holstein wrote this in the Fall 1991 Restorer about the early '58's. Attached. Dave Zuberer snapped it into a pdf from my quick scans.

Rich