Loosening Bolts

[MrFixit]

My KAMA 354C has treated me well for it's first 50 hours so I'm giving her a break while I do maintenance and fix the little things.

This one has me stumped! About every 4 hours the front left axle starts dripping oil. There are (6) 18mm bolts that connect the axle to the Gear/Wheel assembly. it seems after running about 4 hours those 6 bolts come about half a turn loose. I've tried BLUE Locktite and still happens. I tighten to them almost to the point of breakage or stripping threads, and they still come loose. I'm avoiding using RED Locktite until I'm sure it's a vibration problem and not a stressed metal problem

I don't think they are vibrating loose as the right side never comes loose. I'm avoiding using RED Locktite until I'm sure it's a vibration problem and not a stressed metal problem.

Is it possible there is something that is stressing the axle against the Gear/Wheel assembly to the point of loosening? Just guessing at the possibilities I can only come up with a slightly bent axle shaft that is causing inner wobble or the mating surfaces are not flat.

Any suggestions would be very much appreciated!

Tim

 

[greg_g]

If I'm reading the torque tables right, 18mm bolts should be torqued to a minimum 86 ft-lbs. If that doesn't resolve your issue, I suggest you swap the 6 right side bolts to the left side, and put the left side bolts on the right. If the properly torqued bolts loosen on the left side again, the problem would appear to be with the bolt holes. If the problem moves to the right side, it's likely a problem with the bolts.

//greg//

 

[MrFixit]

Hi Greg

The head of bolts use an 18mm wrench. I'm not sure if that means they are 18mm bolts. Should I torque them to 86 as suggested by your table?

Tim

 

[DwayneB]

I sure hope mine never does that. If the things greg suggested don't work I would try a slightly longer bolt with a good flat washer and lock washer before I tried the red locktite. I bet the 1st time it came loose it wallered out the holes a bit. If that's the case you could drill the hole and sleeve it so the bolt fits tight in the hole again. I bet the lock washers will hold it though. Those things are amazing.

 

[greg_g]

</font><font color="blue" class="small">( The head of bolts use an 18mm wrench. I'm not sure if that means they are 18mm bolts. Should I torque them to 86 as suggested by your table? )</font>

I'm glad you made that distinction before any bolts got broken. You need to determine the actual thread diameter, look at the head for any hardness markings, then consult a torque chart. This is a guess mind you - you should measure the diameter yourself - but it's probably a M10. And I'm also assuming it's soft steel (8.8 hardness). If so, 40 ft-lbs should be reasonably close.

Further to the lock washer post; there should be lock washers on all those bolts. If they're missing, that could be part of your problem as well. It wouldn't hurt also, to see if perhaps part of the gasket material is missing or damaged.

//greg//

 

[MrFixit]

There are Factory lockwashers installed . In my process of overtightening, one of the lockwashers spread open and needed replacement, may be a bit too wimpy. As an easy test I'll obtain new bolts/washers for this side and get them a bit longer and harder version if available. I'll clean out the oil soaked holes so the Locktite has a better chance of gripping. If that doesn't fix it then I'm probably going to remove the Gear/Wheel assembly and inspect. While inspecting I'll drill and tap out the holes and stuff some bigger bolts in there.

If that doesn't do it I'm lost!

 

[SPIKER]

I don't think I would want to drill & re-tap as you stated, but NEW bolts are a good idea. use some brake cleaner spraied into the tapped holes to remove any residue / oil in there doing ONE at a time, use GOOD lockwashers, those IMPORT ones are junk... they spread open eaier than a 2 bit ho on shore leave day... if they do that they are shot. I think 7/16 lockwashers may be close? try one and see. also better grade of bolts if you are replacing them, be sure to remove one & take with ya to store...

add some blue to the clean holes then tighten to 35~40 ft lbs torqueing evenly.

mark m

 

[DwayneB]

I looked at mine this weekend. Several spred out lock-washers. Looks like something I will need to keep an eye on. Keep us updated on your fix.

Dwayne

 

[DwayneB]

I looked at mine this weekend. Several spred out lock-washers. Looks like something I will need to keep an eye on. Keep us updated on your fix.

Dwayne

 

[bluechip]

Tim,
The bolts you are talking about actually carry part of the weight of the tractor. the wheel bearings are in there, the outter one is in the "cover" part and it carries most the weight, the inner bearing is in the main part of that housing, under the cover piece. the 2 parts of the housing are held together by the bolts you mention. As for a mechanical stress causing the bolts to work loose, you might lift the front end of the ground and rotate the wheel, it should turn freely without any binding as it goes around. Be sure you have a little bit of toe in on the front end alignment.