Transmission front Sim question

[esprist]

While I was swapping a bell housings off a transmission (Datsun720(1981-83 720 Truck) to 280ZX type, I happend to lose a metal sim at front counter bearing.

It is located at front cover. I called Courtesy Nissan, they said that there are 4 different thickness, and are national back order(comes from Japan in 4 months!) Now my question is, do I really need it? Sim size could be different depending upon how far I press in the bearing into counter shaft.....

A transmission shop I know told me to use gasket maker rather than thick original gasket to compensate the thickiness......... I am looking for metal sim OD 6.2mm ID 5.4mm. (240Z-280Z ones are smaller in diameter) New or used.....

Anyone has experience or recommendation?

Esprist

[Arne]

The shim is needed to prevent the countershaft from walking forward and backwards under torque loads. The different thicknesses are to accommodate production differences. You want the shim to be a snug fit - it should take up all the play at the bearing, but not preload it. I'd fear that using a non-metal shim of some sort might cause problems eventually.

[esprist]

The shim is needed to prevent the countershaft from walking forward and backwards under torque loads. The different thicknesses are to accommodate production differences. You want the shim to be a snug fit - it should take up all the play at the bearing, but not preload it. I'd fear that using a non-metal shim of some sort might cause problems eventually.

Thank you for your quick response.　Well now the question is who might have the sim..

Esprist　6.2mm　OD　5.4mm　ID