Keyed shafts -vs- Shear pins

[simpleton7016]

I spent the day yesterday tearing apart my third Terra Tiger. This was the scarcer all yellow model and is probably the hull that is in the best condition. But man oh man was it a PIA to get the axels out. The sprockets were frozen solid to the axels, but I only found that out after spending WAY to much time trying to get the shear pins out. I ended up having to cut all six axels off....too bad to b/c they were all pretty straight minus the pointy sprockets.

As stated before, I am going to gob my parts with antiseize when I put it back together. I am going to have my machinst make all new axels for me with 5 bolt hubs welded right on the ends. But before I get to that phase, I wanted some opinions on if I should go with keyed shafts or shear pins? I spoke with Richard and he said his preference is the shear pins. I understand that they are designed to be the sacrificial part in the case of a catastrophic failue. But Allis Chalmers themselves upgraded from shear pins to keyed axels on their later model TT 18's. This tells me that maybe they were having problems with too many shear pins snapping?

I don't think this question is unique to Terra Tiger owners, but if I choose to go with shear pin axels, what riding event usually caused them to snap? Getting caught on a log and full idle? Quick changes of direction? And what kind of internal damage can I expect if I go with keyed avels instead and suffer a failure?

Sorry again for all the questions, but I want to do this right and make the best decisions in the planning stages. Right now I am leaning heavily toward keyed shafts just because the shear pins were such a PIA to remove.

Thanks in advance.

[evil8x8]

what riding event usually caused them to snap? Getting caught on a log and full idle? Quick changes of direction?

My 1985 Argo 8x8 uses shear pins. They can be a pain but if you know how to drive without breaking them they won't be a problem. The first year of so, that I had my Argo, I would break the shear pins all the time. I find that my pins break when I stop and gas it again while crossing big logs, rocks, or other obstacles where only one tire is on the obstacle. If you cross the obstacles in one smooth motion and don't have to stop and than gas it again, you usually won't break any pins. I made it through Ashtabula, the Ledges, Philipsburg, and several other rides this year without breaking a pin.

[Amphiman1]

tigers 4 meeeee

i've never seen a broken one in 30+ yrs,,, only bent axles Terra tigers will take quite a beating too
I do like the keyed axles in the front, easier to replace when u bend one.......

[farmtoybuilder]

Reason they went to Keyed axles and sprockets was to make removal easier! I agree with Amphiman. I've had them bend and come out of ones with worn axle and sprocket holes. One of TT10's we brought had tape and wire holding pins in. Axles with keys are easier to replace! Ones with hole is easier to make, less cost & machining. If your going to be running and playing hard with it! I would go with keyed axles and sprockets on front ones for sure. As they are ones that get bent more often

[LarryW]

I think the worse thing on a pin is when your in the water. quick go and quick stop, bang, bang, pop.

[simpleton7016]

Makes sense, thanks guys...I really mean it. Do certain axles tend to break more shear pins then others? Ie, do the middles take a greater beating than the others? Also, if I go with shear pins on the middle and rear axles, is it advisable to NOT coat the with antisieze?

[farmtoybuilder]

Antiseize is fine. Axle and sprocket holes need to be same size so pin or bolt fits TIGHT in them. If one them is loose it could allow pin or bolt to move which could lead to breaking pin or pin coming out.