CSOBeech - TCM Starter Adapter Mystery Revealed

Starter Adapter Mystery Revealed

Are you experiencing slow prop turning or slipping of your starter? Assuming that your battery, starter and electrical connections are all in good shape, you might be experiencing the beginnings of the dreaded TCM starter adapter failure!

Depending on your CSOB proficiency, this might not mean a >$1,000 overhauled part purchase plus the mechanic hours to R&R the component.

Under the supervision of an A&P or IA the removal of the starter adapter and replacement of the bearings, seals and large drive spring is not rocket science, but that's my editorial opinion.

The shaft and spring interface clearances are best left to be fitted by an aircraft engine machine shop or a place like Niagara Air Parts, especially if your shaft has been buggered up or experienced inordinate wear and the shaft requires buffing or turning down, you'll need an undersized spring.

See the exploded view of a TCM Starter Adapter Assembly HERE

See the mysterious Starter Adapter Spring and Shaft HERE

Doing your Own "Freshen Up" of your Starter Adapter?

Check out these Low Cost Identical Replacement Part Numbers for your TCM Starter Adapter at

Purvis Bearing Supply

Rear Seal: National 450588

Starter Shaft Bearing: Timken 204PP

Inner Shaft Bearing: Timken 203K

Where can you purchase the Main Spring?

My personal source for engine parts is Superior's Line of PMA'd Parts. Here are the spring part numbers offered by Superior.

Superior P/N
Description

   List Price

    SA539800
SPRING

   $195.46

    SA539800 M15
SPRING

   $243.00

Caution: These springs may fit your adapter and they may NOT! Check your engine parts catalog and cross reference the TCM part number to Superior's replacement parts HERE

Check Superior's Distributors for their retail selling prices.

The recent pirep from a Bonanza owner about Airpower pricing was excellent, in that they priced the Superior PMA'd lifters at about half the price of Aircraft Spruce and the PMA'd exhaust valve was half of what the cylinder shop quoted him!

See Superior's TCM Replacement Parts listings HERE

Caution: Over the years TCM used a few different starter adapter designs! Check your engine parts catalog to be sure you get the correct parts for your adapter.

Here are pictures of the Starter Adapter internals. Click thumbnail for a full size image.

Here is a picture of where the E-Series starter bolts to the back of the engine.

It is a completely different configuration from the current starter adapters used on the 470 and larger TCM engines. Good luck to you guys who care for these E-Series birds!

2740 North Sheridan Rd
Tulsa, Oklahoma 74115
(800)255-9924

It's been reported that Aircraft Accessories of Oklahoma has/does good E-Series starter overhauls.

A Beech Lister/owner of an N35 Bonanza has provided a pirep on Niagara's starter adapter repair kits and shaft and spring services:

Their fee to turn down the shaft to fit a new spring is reported to be $75 and a new spring is from $140 to $250 (personally, I'd call one of Superior's Distributors for a quote on the spring). Niagara could be a place to get your shaft machined to specs for your CSOB sourced spring.

Check out these Starter Adapter Overhaul Kits from Niagara as a possible one-stop shop:

Kit reported to be approximately $100

Here's what happens when the starter fails to DIS-engage!

Not a pretty story.

See more troubleshooting info from Niagara on starter adapters HERE

See Lew Gage's Starter Engaged Warning Light Article HERE

A55 Baron owner, Jon B. reports that a Sloan 855 light fixture from Allied Electronics works nicely.