L36 Motor Mount Shim

[Dale C.]

I have a 1968 L36 with C60. In the AIM page C60 - C2 item 10 there is a shim between motor and mounting bracket. Mine looks to be missing. I don't think its on the non A/C L36, see L36-A9. Why and how critical if not reinstalled after rebuild? It runs good now & A/C works fine. Also that idler pulley and bracket (3925592 item 5 in AIM, C60 - C2 / 68 only) is not there. Can't find a 68 replacement one, but there is a repo, different type on market for 69's and on. Is the function of an idler pulley only to change angle of belt contact on pully?
Thanks
Dale

[Jack H.]

Re: L36 Motor Mount Shim

The shim(s) were 'as required' items and not installed on every car. It depends on how well the original bracket matched up to a given A-6 compressor whether any shims were used and/or how many...

[Jay G.]

Re: L36 Motor Mount Shim

The shim(s) were 'as required' items and not installed on every car. It depends on how well the original bracket matched up to a given A-6 compressor whether any shims were used and/or how many...

Jack,

I believe that Dale was referring to the V shaped shim that goes between the block and motor mount.

Dale,

As far as I know they are not really required since I also have a '69 BB with A/C and everything appears to work fine without the shim. In the make believe world of perfect in the engineering department at GM I suspect someone determined that the additional weight of the A/C compressor caused the engine to sit a little different and that the fuel level in the carburetor wouldn't be exactly where it designed to be. In the real world, most cars don't sit exactly level anyway and everything works just fine so I wouldn't worry about it from a performance perspective however from a judging perspective they need to be there.

Regards,

Jay