64-67 transmission mount height
Does anybody have a known original 64-67 trany mount out that can be measured. Could probably be measured on the car. I have a 65 I'm finishing with all the original parts on the original trany. The mount rubber looks a bit dry rotted but not crushed so I ordered a new mount and pulled a number of GM originals I have. The original mount is 1.6" tall, other GM mounts are all 1.75" and replacement is 1.87" tall. GM 64-67 lists 3792133, 68 up as 3913498 w/ 4spd. and all current replacements so far are measuring 1.8 or taller. I can only speculate that the original GM 64-67 3792133 and maybe the 1963 3870182 are shorter than all mounts since than. I'm hoping maybe Joe Lucia could have some insight on this or if someone knows of a replacement around 1.6" high. Thanks for any help.
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Re: 64-67 transmission mount height
Mark------
I would not be too concerned about the minor difference in height. GM specified that the GM #3913498 and its successor, GM #22188495, the last available mount from GM, would SERVICE all 1963-81 Corvettes with manual transmission.In Appreciation of John Hinckley -
Re: 64-67 transmission mount height
Thanks Joe. It appears the original C2 trany mount was at least an 1/8" or more shorter than C3 and later replacements from GM. After market examples being 1/4"or more taller which are coming from overseas. The concern is lifting the shifter air cleaner ignition shielding and drive shaft higher than they should be. I'm fine with an 1/8" taller but more seems too much. I'm using a GM original mount in excellent shape on this 65 which is 1.75" tall. I'm glad I rechecked the original as the lower steel u plate has become unbonded from the rubber. What I'm seeing of many early GM mounts is that they are shorter than later ones. Do you have any early NOS trany mounts to measure? I've always used GM trany mounts but after seeing replacements from Corvette Central and Napa, I'll stay with GM.Comment
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Re: 64-67 transmission mount height
Mark------
I do not have NOS examples of the 1963 GM #3781950 or the 64-67 GM #3792133. However, I do have NOS examples of the 69-82 GM #3913498 which was also SERVICE for 1963-67 and the GM #22188495 which replaced the 3831498. The 3792133 was replaced by the 3913498 in July, 1974. As I mentioned previously, I would be 100% comfortable using a either the 3913498 or 22188495 in any 1963-67.
However, as far as the height difference you mention, I would offer this: comparing a used mount's height to a new mount's height is not an appropriate comparison especially when the new mount's height is in the area of 1/8" higher than the used. Regardless of whether the used mount's height appears uncompressed, I can absolutely assure you that it is compressed, especially if the difference is in the area of 1/8".
While I am not sure of the construction of the earlier mounts, the 3913498 is NOT a solid rubber mount. It may APPEAR like a solid rubber mount, but it is not. There is an internal "void" into which the upper portion of the mount can and does compress when the mount is installed in the car. I suspect that the earlier mounts were the same. However, even if they were solid rubber, I would still expect that 1/8" of permanent compression could easily occur over a 50 year period in service.In Appreciation of John HinckleyComment
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