NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

[David L.]

I have 3 NOS engine mounts and all 3 appear to be the type installed 1966-1968 Corvettes. The 3 NOS mounts are identical except for the numbers molded into the rubber.
Two of the NOS mounts have the following molded into the rubber part (see photo #2):
"3967767 GREEN"
"3886466 BLACK"
"M1 16 3796050"

These two mounts were probably made in 1969 as the 3886466 mounts were installed on 1966-1968 Corvettes and the 3967767 mount made its debut on the 1969 Corvette as per the assembly manual. According to Chevrolet Parts History GM # 3967767 was replaced with GM # 3980701 in Oct. 1969. GM # 3980701 was then removed from service on July 1970. My 1969 Corvette Parts Catalog (Oct. 1969) lists GM # 3980701 as the mount for the 1969 Corvette (possibly factory installed on late 1969's as the 1969 model year was longer then normal).

The other NOS mount has the following molded into the rubber part:
"3886466 2 14 E" with the "E" turned 90 degrees counterclockwise (see 4th photo).
I assume this mount was probably made in 1966, 1967, or 1968.

The 4th mount shown in my photo #3 on the right side is a Doan mount, # 2249, that I bought back in the 1980's. As stated on the Doan box this mount was "MADE IN U.S.A." and made by Anchor Industries, Inc. of Cleveland, Ohio. The 2249 Doan mount is very similar to my NOS GM mounts. The molded rubber on this mount seems a bit sloppy. I believe that the 2249 Doan mounts made these days are made on the other side of the Pacific.

Does anyone have any photos of original factory installed 3796050, 3886466, 3967767, or 3980701 mounts?

Dave

[Joe L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

I have 3 NOS engine mounts and all 3 appear to be the type installed 1966-1968 Corvettes. The 3 NOS mounts are identical except for the numbers molded into the rubber.
Two of the NOS mounts have the following molded into the rubber part (see photo #2):
"3967767 GREEN"
"3886466 BLACK"
"M1 16 3796050"

These two mounts were probably made in 1969 as the 3886466 mounts were installed on 1966-1968 Corvettes and the 3967767 mount made its debut on the 1969 Corvette as per the assembly manual. According to Chevrolet Parts History GM # 3967767 was replaced with GM # 3980701 in Oct. 1969. GM # 3980701 was then removed from service on July 1970. My 1969 Corvette Parts Catalog (Oct. 1969) lists GM # 3980701 as the mount for the 1969 Corvette (possibly factory installed on late 1969's as the 1969 model year was longer then normal).

The other NOS mount has the following molded into the rubber part:
"3886466 2 14 E" with the "E" turned 90 degrees counterclockwise (see 4th photo).
I assume this mount was probably made in 1966, 1967, or 1968.

The 4th mount shown in my photo #3 on the right side is a Doan mount, # 2249, that I bought back in the 1980's. As stated on the Doan box this mount was "MADE IN U.S.A." and made by Anchor Industries, Inc. of Cleveland, Ohio. The 2249 Doan mount is very similar to my NOS GM mounts. The molded rubber on this mount seems a bit sloppy. I believe that the 2249 Doan mounts made these days are made on the other side of the Pacific.

Does anyone have any photos of original factory installed 3796050, 3886466, 3967767, or 3980701 mounts?

Dave

Dave------


I have a few NOS GM #3886466 and they are identical to the ones you have. I have always wondered about the GM #3967767, not knowing if it was a locking or non-locking style mount. Now I know that it was virtually identical to the 3886466.

The GM #3980701 was a locking style mount. I have many NOS examples of this mount. I'm not sure, though, that these were ever actually used in PRODUCTION on a 1969. If they were, it was VERY late in the model year, maybe the last month, or so, in December, 1969.

[David L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Joe,

Do you have any ideas about the meaning of the "GREEN" and "BLACK" after the part number? Did the mounts on the assembly line have dabs of paint on them for easier identification?

My 1963 Chevrolet Parts Catalog lists GM # 3777409 as the mount for 58-63 Passenger cars and described as follows: "front, mark w/yellow paint". I have a used pair of 3777409 mounts and the only molded number is "3777409".

If the 3886466 and 3967767 mounts are the same why was there a part number change? Did they use a different type of rubber on the 1969 mount?

Dave

[Joe L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Joe,

Do you have any ideas about the meaning of the "GREEN" and "BLACK" after the part number? Did the mounts on the assembly line have dabs of paint on them for easier identification?

My 1963 Chevrolet Parts Catalog lists GM # 3777409 as the mount for 58-63 Passenger cars and described as follows: "front, mark w/yellow paint". I have a used pair of 3777409 mounts and the only molded number is "3777409".

If the 3886466 and 3967767 mounts are the same why was there a part number change? Did they use a different type of rubber on the 1969 mount?

Dave

Dave------


Motor mounts and transmission mounts often will have multiple part numbers embossed on the rubber portion of the mount with the name of a color following each part number. Then, a crayon "swipe" of one of the colors is made across the appropriate part number to identify which part number that particular mount is.

I've always assumed that this was done so that several different mounts that were very similar could be made from the same, basic mount. Obviously, the rubber portion of the mounts must be the same with differences in the other components (e.g. different size holes).

As far as the two 1969 mounts go, I figure there must have been some difference between the mounts even though it's not readily apparent. I suppose it's possible that there was some difference in the rubber but I know of no way to ascertain that other than to have the blueprints of the 2 mounts (which I do not have). More likely, though, I expect there was some difference in the way the rubber was bonded to the steel components.

[Terry M.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Joe & Dave,

I have always thought the different colors indicated differences in rubber compound to tune the mounts for a specific engine's harmonic characteristics. Different rubber compound could result in different durometer (hardness) readings, but there is no convenient way to determine this once the mount is fabricated. Thus the color mark to indicate the specific application.

[David L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Enclosed are two photos (#1 & #2) of an original used 3980701 locking style mount. The number "3980701" is on the side of the mount. The inside dimension is about 2 5/8".

Also enclosed are two photos (#3 & #4) of one of my original 1970 Camaro SS350 mounts. This is also the locking type. The inside dimension is about 2 7/16". The parts numbers are molded on the side of the mount as follows:
"3991271 BLACK"
"3988972 WHITE"
"3989488 LT. BLUE"
The mount listed in the 1970 Camaro AIM is GM # 3989488 which agrees with the last part number on the mount. The "early" 1970 mount was GM # 3964895 which was replaced with GM # 3989488 as of 2/27/70 as per the revision record. The 1969 Camaro used the 3964895 mount.

I can not find part numbers 3991271 and 3988972 in any of my many vintage Chevrolet parts catalogs, assembly manuals, or Chevrolet parts history manuals.

Dave

[John H.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Joe & Dave,

I have always thought the different colors indicated differences in rubber compound to tune the mounts for a specific engine's harmonic characteristics. Different rubber compound could result in different durometer (hardness) readings, but there is no convenient way to determine this once the mount is fabricated. Thus the color mark to indicate the specific application.

Terry -

That's correct - the different "color" codes resulted from different durometer of the rubber portion of the mount; mounts for differing applications could be made in the same mold with no additional tooling expense for "tuning" the NVH (noise/vibration/harshness) characteristics.

[David L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Terry -

That's correct - the different "color" codes resulted from different durometer of the rubber portion of the mount; mounts for differing applications could be made in the same mold with no additional tooling expense for "tuning" the NVH (noise/vibration/harshness) characteristics.

John,

My "3967767 GREEN/3886466 BLACK" NOS mounts shown in the very first post of this thread do not have any green paint on them but there is what appears to be flat black paint on the top part of each mount (see photo below). Does this mean that my NOS mounts are GM # 3886466?

Dave

[Terry M.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

John,

My "3967767 GREEN/3886466 BLACK" NOS mounts shown in the very first post of this thread do not have any green paint on them but there is what appears to be flat black paint on the top part of each mount (see photo below). Does this mean that my NOS mounts are GM # 3886466?

Dave

Dave, I would take it that means they are "3886466 BLACK."

[Joe L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Dave, I would take it that means they are "3886466 BLACK."

Terry------

"Black" usually means that there will be an absence of any other color mark "crayon swipe". So, if one finds a mount with no "crayon swipe" it's the part number associated with "black". Of course, this only works for NOS mounts since the "crayon swipe", if ever present, is often long-gone from used mounts.

[David L.]

Re: NOS 66-68 or 69 engine mounts, 3886466 and/or 3967767?

Terry------

"Black" usually means that there will be an absence of any other color mark "crayon swipe". So, if one finds a mount with no "crayon swipe" it's the part number associated with "black". Of course, this only works for NOS mounts since the "crayon swipe", if ever present, is often long-gone from used mounts.

Joe,

Here is a photo of a NOS GM motor mount that I got from the Nasty Z28 website that is exactly the same as my original 1970 Camaro SS350 motor mounts (GM # 3989488) except for the WHITE paint.
The molded part numbers are as follows:
"3991271 BLACK"
"3988972 WHITE"
"3989488 LT. BLUE"

Because of the WHITE paint I would say that the mount in the photo below is GM # 3988972. I just found part # 3988972 listed in the 1970 Chevelle AIM (UPC 6, sheet B7).

According to Chevrolet Parts History GM # 3964895 (69 Camaro) was replaced in Jan. 1971 (and on 2/27/70 in the AIM) with GM # 3989488 (70-71 Camaro) which was then replaced in Jan. 1973 with GM # 3990914.

GM # 3962740 (70 Z28) was replaced in Aug. 1971 with GM # 3962748 (70 Z28) which in June 1971(???) was replaced with GM # 3990918.

Dave