Tach drive in Acc case - Leave out during rebuild?

jrussl · Dec 6, 2020

I am in the process of doing a major to my O-320 and am questioning the necessity of some of the parts in the accessory case.

Since I have an electronic tach and no need for a vacuum pump, is there any reason to re-install the tach drive pin or the vacuum pump drive?

Thanks in advance

Jeff

Gordon Misch · Dec 6, 2020

I had to make the same decision. Left them in since somebody in the future might want those parts, and they do no harm.

wireweinie · Dec 6, 2020

Not sure about the tach drive but the vacuum pump drive gear and pad can be installed any time, if needed.

Web

cubpilot2 · Dec 6, 2020

Leave the tach drive shaft in as it passes through an oil seal in the accessory housing. Don’t know of reliable way to cap off the oil. To reinstall would require major disassembly of rear case.

Vacuum drive is easy to install at any time.

mike mcs repair · Dec 6, 2020

wireweinie said:
Not sure about the tach drive but the vacuum pump drive gear and pad can be installed any time, if needed.

Web

i think accessory case has to come off for that....

https://www.aircraftspruce.com/catalog/inpages/tachcap.php

sells a nice cap with a Oring...

cubpilot2 · Dec 6, 2020

mike mcs repair said:
i think accessory case has to come off for that....

https://www.aircraftspruce.com/catalog/inpages/tachcap.php

sells a nice cap with a Oring...

Nope. On most Lycomings the drive adapter slides right in. If removed the long studs are covered With bushings after an aluminum cover plate is installed.

wireweinie · Dec 6, 2020

mike mcs repair said:
i think accessory case has to come off for that....

https://www.aircraftspruce.com/catalog/inpages/tachcap.php

sells a nice cap with a Oring...

Wow. That's about the fancies cap I've seen so far!

Web

PerryB · Dec 7, 2020

Gordon Misch said:
I had to make the same decision. Left them in since somebody in the future might want those parts, and they do no harm.

I second that.

Steve Pierce · Dec 7, 2020

Tach drive yes, vacuum drive no for the reason's Ed posted is my educated opinion.

Tach drive in Acc case - Leave out during rebuild?

jrussl

Gordon Misch

wireweinie

cubpilot2

mike mcs repair

Registered User

cubpilot2

wireweinie

PerryB

Steve Pierce

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