NH T7.20 Kingpin snapping

[Bumble Bee]

Our T7.210 has snapped 2 front axle Kingpins in less than a year. The heaviest weight it carry on the front is a 3m ring press.
It is all shimmed up correctly and greased. There is not a great deal of metal where it has broken off.
Has any body got any ideas as to why this is happening?

 

[ACEngineering]

Our T7.210 has snapped 2 front axle Kingpins in less than a year. The heaviest weight it carry on the front is a 3m ring press.
It is all shimmed up correctly and greased. There is not a great deal of metal where it has broken off.
Has any body got any ideas as to why this is happening?

pin loose in the hole in casting i suspect. will never stop something like this shearing the plate or bolts if a pin is loose in a hole.

 

[Sharpy]

pin loose in the hole in casting i suspect. will never stop something like this shearing the plate or bolts if a pin is loose in a hole.

Sounds right, that's why those pins are a tight fit so the casting takes the side thrust.
Also that looks like the top pin so weight will have less of an effect.

 

[ACEngineering]

Sounds right, that's why those pins are a tight fit so the casting takes the side thrust.
Also that looks like the top pin so weight will have less of an effect.

unless of cause the bottom pin/bearing is worn and allowing the top pin to bottom out in the hole! that will load the plate but then it still wouldnt crack the plate/head would just shear the bolts off maybe. its got to be too loose in the casting/damaged hole so only fix is going to be a new swivel casting cause you would be mad to bore and sleeve that!

 

[Oliveau]

Had a slightly similar thing many years ago with my 2WD Case 2090 when a stub axle sheared off going down the road. The metal looked a bit odd so i took the offending bit to a metallurgist at Southampton Universirty, who took one look and said "That's classic metal fatigue." Bugger me, 3 weeks later the other side did exacty the same. I'd only had the tractor a month or so when the first one broke, and it had done just under 3000 hours. Happily the dealer stood by his warranty. Knowing where the tractor had come from we concluded that metal fatigue had been caused by the front wheels continually bouncing up and down during field work.

 

[Hay Maker]

Our T7.210 has snapped 2 front axle Kingpins in less than a year. The heaviest weight it carry on the front is a 3m ring press.
It is all shimmed up correctly and greased. There is not a great deal of metal where it has broken off.
Has any body got any ideas as to why this is happening?

Bolts definitely lose & bolt holes elongated, change all parts top & bottom. Make sure you locktite all fittings on reassembly & torque up to the required spec. Or bodge up & change tractor!

 

[Half Pipe]

Is that the pin with angle sensor in it?
If so it's not greasable. What's condition is bearing in?

 

[Bumble Bee]

Is that the pin with angle sensor in it?
If so it's not greasable. What's condition is bearing in?

Yes it is. That's how we realised it had snapped as the sensor stopped working.
The bearing is fine as we changed it last time the pin snapped.
Apparently is quiet a common problem according to NH mechanic.

 

[Bumble Bee]

Bolts definitely lose & bolt holes elongated, change all parts top & bottom. Make sure you locktite all fittings on reassembly & torque up to the required spec. Or bodge up & change tractor!

I think the bolts were tight.
All bearings were changed less than a year ago.
As soon as funds allow this tractor will be down the road.