The International Cessna^® 170 Association

My C170B s.n. 26433 (jul 54) shows that a Scott 3200 tailwheel was an optional upgrade ordered when new.

My question is to ask what is the difference between a 3200 and a 3450 style tailwheel ? Are the internal mechanical parts the same for both tailwheels?


STOP


regards

The Scott 3450 uses a 10" wheel/tire and is not approved for the 170.

On Cessnas, the 3450 is typically used on the C-180, 185, and 188 with round tailwheel stingers instead of flat springs and are built heavier/stronger than the 3200. Some parts MAY interchange, I have never checked it out.

The 3450-23 is made to fit a leaf sping gear. it is PMAed for the Pawnee. I have one on my 170B. It had a 10" wheel but I recently went with a Gar yoke and a big fat wheel. Oh how smooth it is! Lance

Watkinsnv-
Glad to hear they ARE made with flat spring housings. It is a better tailwheel in my opinion than the 3200.

The Gar (now Alaska Tundra Tire) or Alaska Bushwheel wheel/tire combos are the best all-around tailwheel conversions for soft terrain. The XP 5.00-5 tailwheel is just too big. Plus, the XP-Mods website is off-line, maybe out of business?

Look up Alaska Tundra Tires. they bought Gar - Aero what they sell is cheeper not yet STC'd. Lance

I have a Scott 3224, I believe (not even close to the airplane at the moment to check the actual number) and it is a heavy duty version of the Scott 3200. I just rebuilt it. The basic difference is in the steering arm area, dust cover, fork and internal springs. They are a bit heftier. OK for 170B's and the leaf springs. The info can be found at the Alaskan Bushwheel information spot on Aircraft Spruce website or at http://store.akbushwheel.com/auto/zoomv ... copied=YES.

I am in the process of re-building my tailwheel assembly (scott 3200) on my 170A. I am confused by the number of springs found internally in the housing. I found 3 when I took it apart, but on the drawings it shows 5. Can anyone explain the correct number.

The springs help prevent shimmy. Use three or the minimum number that prevents shimmy, the less the better. More springs makes it harder to swivel the tailwheel when you want it to swivel.

If a tail ski is added, more than three springs may be required to keep it from shimmying. If the tailwheel touches while tail wheel deflection is applied as in cross-wind correction there is a tendency to shimmy due to increased inertia because of the ski.

The answer is 3 springs for a Cessna 170.

hilltop170 wrote:The springs are there to prevent shimmy. Use the minimum number that prevents shimmy, the less the better. More springs makes it harder to swivel the tailwheel when you want it to swivel.

While your logic is impeccable... the purpose of the springs is to provide pressure on the "clutch" or friction plates to provide a steering input/transfer to the wheel. They do not prevent shimmy. Shimmy is caused by unbalanced tires/wheels accompanied by improper caster angle.

Howdy,

I am probably one of the least "experienced" folks on the forums. What Bruce said about three springs is correct. Three not five. When I purchased my "A" model four years ago , my scott 3200 tail wheel did not want to "break out" and castor on one side.....Myself and a good friend/CFI/A&P dissassembled the tail wheel and discovered that some burrs had "raised" on the (I believe) clutch plate. A very light "filing" of this area fixed the problem...and a good application of the grease gun and all has been well since.....I would strong recomend a tie down ring on the tail wheel. You can search the forums for this item. Here is a can of worms....since adding a quart of MMO to the crankcase, prior to an oil change, recommended by another IA/AP, four years ago, I have not had to grease the tail wheel

Richard.......

Haydon wrote:... Here is a can of worms....since adding a quart of MMO to the crankcase, prior to an oil change, recommended by another IA/AP, four years ago, I have not had to grease the tail wheel
Richard.......

So, what are you saying, Richard? That the MMO has created such an oil leak/blow-by situation that the tailwheel remains lubricated?

The 3200 series uses one bearing and a bushing to support the weight of the tail. The 3400 series uses 2 bearings. The 3400 also has a locking option which I have never seen on a 3200. It's interesting to hear that there is a 3400 housing for a flat spring, I wasn't aware of that.