1969 3/4 ton breaking 4x4 hubs - need help

[firefighter*17]

Hi every one! First post here, I have a 1969 chevy pickup 3/4 ton 4x4 stock 350 with a 4 speed manual tranny. The pickup either breaks the 4x4 warn hub or loosens up the hub bolts or breaks the bolts. Anyone come across this before? I use the truck to plow snow and I don't chain up the tires. The first time it happened I put high grade bolts back in, thread lock and torqued them down. Half hour into first snow storm I hear popping sound get out and look all bolts are loose and some missing. I replace, retighten and thread lock. I get back to plowing and same thing happens accept the hub breaks. I'm lost on this one and could use your advise.

Thanks!

[Blazer1970]

Originally Posted by firefighter*17

Hi every one! First post here, I have a 1969 chevy pickup 3/4 ton 4x4 stock 350 with a 4 speed manual tranny. The pickup either breaks the 4x4 warn hub or loosens up the hub bolts or breaks the bolts. Anyone come across this before? I use the truck to plow snow and I don't chain up the tires. The first time it happened I put high grade bolts back in, thread lock and torqued them down. Half hour into first snow storm I hear popping sound get out and look all bolts are loose and some missing. I replace, retighten and thread lock. I get back to plowing and same thing happens accept the hub breaks. I'm lost on this one and could use your advise.

Thanks!

Those old external hubs commonly have that problem. It would be worst when you are using 4WD and doing a lot of backing up under power as you are when plowing. Some people have used studs instead of the bolts with some success. The real solution it to swap in a later mode front axle that has the (smaller) internal hubs - that will solve the problem permanently.

[pumpkin]

I would guess that you are missing a snap ring. The bolts that hold the cap on should have no pressure on them. The bolts are only to hold the cap on, and the most pressure they should see is from the spring. If a snap ring, or a thrust washer, or the inner bearing to support the stub axle are missing or damaged, when under power, the axle would move in and out breaking the little bolts.

[firefighter*17]

Originally Posted by pumpkin

I would guess that you are missing a snap ring. The bolts that hold the cap on should have no pressure on them. The bolts are only to hold the cap on, and the most pressure they should see is from the spring. If a snap ring, or a thrust washer, or the inner bearing to support the stub axle are missing or damaged, when under power, the axle would move in and out breaking the little bolts.

Let me clarify, the bolts that are breaking and coming loose are the 6 large bolts that hold the locking hub onto the axle. I sheared off 4 of the 6 bolts. The other 2 I assume worked their way out and feel out somewhere. I'm going to attach a picture of the hub if I can figure out the attachment process.

Thanks for your input!

[Blazer1970]

Originally Posted by pumpkin

I would guess that you are missing a snap ring. The bolts that hold the cap on should have no pressure on them. The bolts are only to hold the cap on, and the most pressure they should see is from the spring. If a snap ring, or a thrust washer, or the inner bearing to support the stub axle are missing or damaged, when under power, the axle would move in and out breaking the little bolts.

This is an external hub axle. The bolts that hold the lockouts to the bearing hubs also transfer the power to the front tires. That is why they back out and break. As I said, the solution is internal hubs where the torque is transferred with a slug from the external splines on the axle shaft to internal splines on the bearing hub.

[padresag]

have you checked your bearings?. bad brg will cause the drum to flop and pop goes the hub
ron

[firefighter*17]

Originally Posted by padresag

have you checked your bearings?. bad brg will cause the drum to flop and pop goes the hub
ron

Thanks Ron, no I have not checked the bearings I will check this weekend.

[firefighter*17]

Originally Posted by Blazer1970

This is an external hub axle. The bolts that hold the lockouts to the bearing hubs also transfer the power to the front tires. That is why they back out and break. As I said, the solution is internal hubs where the torque is transferred with a slug from the external splines on the axle shaft to internal splines on the bearing hub.

Thanks! Where should I look to purchase internal hubs?

[Blazer1970]

Originally Posted by firefighter*17

Thanks! Where should I look to purchase internal hubs?

The easiest way is to swap in an entire newer front axle assembly. In order to get an internal hub 8 lug axle, the most plentiful is a 10 bolt out of a '80 - '87 GM. A Dana 60 from a '77 - '91 K30 would be the ultimate axle if you can find one. I am assuming that you still have the drum brake front axle on the truck now, if so this swap also gets you front discs.

[msgross]

I would have this moved over to the 4x4 section (contact yukon Jack or Mudder) and maybe get more response...

Somethings not right inside the hub if you are breaking bolts like that. I would go for the hub rebuild (bearings, snap rings etc..) and fix what's broken. Is this on both sides or just one?

[firefighter*17]

Originally Posted by msgross

I would have this moved over to the 4x4 section (contact yukon Jack or Mudder) and maybe get more response...

Somethings not right inside the hub if you are breaking bolts like that. I would go for the hub rebuild (bearings, snap rings etc..) and fix what's broken. Is this on both sides or just one?

just the driver side has broke as of now. the passenger side will loosen up some of the time but has not broke a bolt or hub.

[LONGHAIR]

There are indeed "bend-tab" type washers for these hubs, but that only addersses the loosening issue. The breaking of the casting does not look normal though. I guess have something to do with the hub being loose, but loosening that quickly has to have an underlying problem.
Lool for:
Loose wheel bearings
Stiff axle joints
Bent spindle
Bad threads in the hub
etc...