1967 coupe Vent Window Regulator analysis: original vs. 1977 GM service replacement

[Scott S.]

This was going to be a question about whether there was a difference between a presumed original vent window regulator and a 1977 GM service replacement. In the process of researching the question, it turns out that they are different from each other - but mine are also different from what the archives and back-issues of Corvette Restorer Magazine say they should be, at least with regard to the number of rings.

The car is a 1967 coupe. It has been in the family since 1976. It was in storage from about 1993 up to 2008 when we began the restoration.

The RH vent window regulator had the rivets drilled out and replaced with screws, so it had been worked on before, but it appears to be original. The shaft is 1 9/16" long (measured from the body of the regulator to the end of the shaft) and has two grooves or "rings" in the shaft. The housing has "3824304" and "FR" over "5" cast into it. There is also a "7" over "8" between the "FR" and the "3824304" cast into the housing, with "V" and "X" cast into the opposite side of the housing.

The LH vent window regulator that came off the car looked like it might be original at first glance, but there is a receipt in the history file showing that a service replacement vent window regulator was purchased on 9-19-77 (retail price $13.70, $10.28 with GM employee discount). I found the 1977 GM vent window regulator service replacement box in the garage attic a few weeks ago, and it had what appears to be the original 1967 LH vent window regulator inside (the replacement regulator had been installed on the car).

Both the presumed original (1967) LH and the replacement (1977) LH vent window regulators have two grooves or "rings" on the shaft, with "3824303 and "LF" cast into the housing. Both have only a "V" (no "X") on the opposite side of the housing. The only difference I noticed between the two LH vent window regulators is that the LH service replacement regulator shaft is longer, at 1 11/16", while the presumed original LH vent window regulator shaft length is 1 9/16" (the same length as the presumed original RH).

The difference in length was not immediately apparent to my untrained eye. I might not have noticed the difference at all, if I had not read about it in the archives here a while back.


Note: In the pictures, the vent window regulators with screws attached were the regulators on the car at the time of disassembly.

[Scott S.]

Re: 1967 coupe Vent Window Regulator analysis: original vs. 1977 GM service replaceme

The 1967 Assembly Manual (UPC 1 Doors, Sheet K4, Item 10) shows the coupe vent window regulator assembly is p/n 3824301 and 3824302. For convertibles, the AIM (UPC 1 Doors, Sheet K14, Item 7) shows the vent window regulator assembly is p/n 9704600 and 9704601.

The 1977 GM service replacement box is marked 9704601 (i.e., for a LH convertible), but the number cast into the housing is the same as the presumed LH original, 3824303.

In the archives, Joe Lucia explained the 7-digit casting numbers on the vent window regulator housings: "That number is not a part number for the assembly; it's a casting number for one of the components of the regulator and does not positively ID the unit." (11-10-04)



Picture 1: presumed original LH vent window regulator showing "V" only on this section of the housing

Picture 2: presumed original LH vent window regulator showing "3824303" and "LF" cast into housing

Picture 3: presumed original RH vent window regulator showing "V" and "X" cast into housing

Picture 4: presumed original RH vent window regulator showing "3824304" and "FR" over "5" (and "7" over "8")

[Scott S.]

Re: 1967 coupe Vent Window Regulator analysis: original vs. 1977 GM service replaceme

The back-issue articles in The Corvette Restorer Magazine say the original coupe shaft should have three grooves, and the convertible shaft should have two grooves:

"The original for the coupe is about 1-9/16" long when measured from the body of the regulator and has three grooves in the shaft. The convertible part has two grooves and measures 1-3/4". Therefore, there is about a 3/16" difference in length between the two parts." - 1966-1967 Corvette Vent Window Regulators, Bill Turner, Spring 1997

"The '65-67 coupe regulators have the shorter shaft and have three grooves (refer to photo*). The convertible regulators have the longer shaft with two grooves." - 1966-1967 Corvette Vent Window Regulators Revisited, Bill Turner, Spring 1998
[*photo on Restorer CD is too dark and too small to see details]


A chart from the same Spring 1998 Restorer article by Bill Turner shows (in part):

two grooves .......... 1965-67 convertible .......... 1-11/16"

three grooves .......... 1965-67 coupe .......... 1-9/16"


Mine are a mix of the above data, with the correct shaft length for the presumed originals, but ALL (including the 1977 service replacement) have only two grooves or "rings" on the shaft:

RH two grooves ..........presumed original 67 coupe .......... 1-9/16"
3824304 and "FR" (front right?) cast into housing. "V" and "X" cast into the opposite side of the RH vent window regulator housing.


LH two grooves ..........presumed original 67 coupe .......... 1-9/16"
3824303 and "LF" (left front?) cast into the housing. "V" only (no "X") cast into the opposite side of the LH vent window regulator housing.


LH two grooves ..........service replacement 9704601 .......... 1-11/16"
3824303 and "LF" cast into the housing. "V" only (no "X") cast into the opposite side of the LH vent window regulator housing.


The only difference I notice between the presumed original LH and the service replacement LH vent window regulators is that the service replacement shaft is longer (1 11/16") than the presumed original (1 9/16").


Picture 1: Presumed original RH (shaft seems just slightly bent, measures 1 17/32" or 1 18/32", effectively 1 9/16")

Picture 2: Presumed original LH - shaft measures 1 9/16"

Picture 3: Service replacement LH - shaft measures 1 21/32" or 1 22/32", effectively 1 11/16"

Picture 4: shows LH Service replacement casting number and "LF" for comparison to same section of presumed original LH in previous post

[Scott S.]

Re: 1967 coupe Vent Window Regulator analysis: original vs. 1977 GM service replaceme

I would like to rebuild the presumed original LH & RH vent window regulators, particularly considering they have the correct shaft-length for a coupe, which should result in a proper fit. The discrepancy over the number of "rings" or "grooves" between what I have and what the articles say has me wondering though.

Jimmy Gregg also had an article on rebuilding vent window regulators (Corvette Restorer, Fall 1997), and shows a chart with part numbers listed in the 1982 version of the parts book (group 10.661). The chart shows "2 rings" on the shaft for 9704600 & 9704601, which the Parts Book says is applicable to both coupe and convertible for 1965-1967, and shows a 1-3/4" shaft length.

For those with 1963-1965 Corvettes, the chart shows different part numbers for 1963-1964 coupes (3824605-6, 1-3/8" shaft length, 1 ring) and 1963-1965 convertibles (3824301-2, 1-5/8" shaft length, 3 rings). There is a notation next to each shaft-length number, mentioning that the evidence suggests there may be three different sets of regulators.

Does anyone have more recent information or research on this subject, since the Corvette Restorer articles were published in 1997 & 1998?