Is Summers Brothers full-floating enough to strengthen AMC 20?

[deru]

Hi Jeepers,

I just plugged Summers Brothers full floater kit into my AMC20 few days ago, replacing its stock 2-piece. The tube was reinforced too a decade ago, in both ends with 10mm thigh pipe as well as its flanges. I don't know how strong it is, but my feeling, it much stronger than Dana 44 . So how do you think?

(1) axle tube (reinforced):


(2) tube with spindle installed


(3) fitting the hub


(4) full floater installation done


(5) the truck ready

 

[Torxhead]

I was not aware the Summers made a full floater kit, I will have to research that out. I am sure you know that the AMC20 axle tubes are quite weak, so good luck with that. How strong the axle is has a lot to do with how you drive it. I am sure in your country, your CJ will get a lot of use to its capacity. Nice pics and welcome to the forum.

 

[Old Dog]

From the pics it doesn't look like you've welded the tubes to the pumpkin, if not I would to keep the tubes from turning.
When you say you reinforced the tubes do you mean you welded tubes inside the tubes?

 

[Petescj]

:ww: We seem to be getting more popular with the overseas folks lately. Love the AMC Logo on the hood.

 

[Sam5038]

Those blocks under the axle don't look very safe.

 

[mtnwhlr]

I guess I don't understand the need for a full floating axle in a jeep. My understanding for a full floating axle is to carry heavy loads so your axle doesn't have to carry it and move you down the road the housing is carrying the load and the axle just needs to move you down the road. This is why they only came in heavy duty trucks.

 

[Sam5038]

I guess I don't understand the need for a full floating axle in a jeep. My understanding for a full floating axle is to carry heavy loads so your axle doesn't have to carry it and move you down the road the housing is carrying the load and the axle just needs to move you down the road. This is why they only came in heavy duty trucks.

I have a full floater axle. My main use for it is to flat tow it. Unlock all four hubs and it's like towing a four wheel trailer.

 

[mtnwhlr]

I have a full floater axle. My main use for it is to flat tow it. Unlock all four hubs and it's like towing a four wheel trailer.

Ok I can see that as being useful but he didn't install hubs on his.

 

[BusaDave9]

I was not aware the Summers made a full floater kit,

I know they made a full floater kit in the '90s but I didn't think they were still available. Where'd you get it?
They are a much better design. Less likely to spin the hub on the axle shaft. The end of the axle shaft is as big and has as many splines as the inner end, at the differential. Axles rarely strip those splines. That 2 piece axle design with a the hub was a bad design.

Yes it would be better to have locking hubs. Now you would have to remove the axle hub cap to remove the axle shaft. You'd have to be careful not to loose oil. I'd look for locking hubs.

 

[deru]

Many thanks everybody

Reinforcement of the housing is only on both tube ends, not on the center. Connection of pumpkin and both tubes still its standard.

Regarding the shaft, its outer end is bigger and has more splines, i didn't count it. You can not invert it. It even bigger than spindle hole, so you wouldn't be able to insert it inverted.

I agree full floated axle is for heavily loaded vehicles, and Jeep is not the one. But, by installing it in my rig, i believe i can get its advantage, especially for bearing ages. As my area is a deep rural and mountain where most roads are very bad and dangerous, most of small vehicles there seems have to renew their rear wheel bearings every year. That because semi floated axle uses a single bearing and normally its rigidity is not adjustable. My Jeep was about 2 to 3 year, probably because it's bigger than usual cars. But, in fact, front bearings, which are double and adjustable, live much longer. The last replacement was in 1991.

Now i can expect the rear bearings much more durable, hopefully as durable as front.

Cheers

 

[Petescj]

Many thanks everybody

Reinforcement of the housing is only on both tube ends, not on the center. Connection of pumpkin and both tubes still its standard.


Now i can expect the rear bearings much more durable, hopefully as durable as front.

Cheers

Alot of us who take our Cjs off road here in the U.S. weld the tubes at the centersection in 4 or so spots. The AMC20 axles tubes are only pressed in. That was what Old Dog was referring to. How do those tires work in what looks to be some muddy terrain?

 

[deru]

Alot of us who take our Cjs off road here in the U.S. weld the tubes at the centersection in 4 or so spots. The AMC20 axles tubes are only pressed in. That was what Old Dog was referring to. How do those tires work in what looks to be some muddy terrain?

Huh... just pressed in??? Honestly i just know it. Thanks a lot. So i got to weld it ASAP

 

[Torxhead]

Huh... just pressed in??? Honestly i just know it. Thanks a lot. So i got to weld it ASAP

Good plan, I have seen the center section rotate on those "Pressed in" tubes. Do you have any pics of your CJ out in the jungle BTW?

 

[Sasquach]

Mine is factory welded in the typical spots just inboard the tube and housing loc. I think all are.

 

[Petescj]

Mine is factory welded in the typical spots just inboard the tube and housing loc. I think all are.

http://www.jeep-cj.com/forums/f2/amc-20-a-14231/?highlight=amc+tube+weld

 

[deru]

Good plan, I have seen the center section rotate on those "Pressed in" tubes. Do you have any pics of your CJ out in the jungle BTW?

Unfortunately not. Because it's nothing special for me, just routine work. Well, probably later. Right now is very wet season. The land is too muddy, so it's not a good idea to get down just to take a pic.

 

[deru]

http://www.jeep-cj.com/forums/f2/amc-20-a-14231/?highlight=amc+tube+weld

Crazy! isn't it? I thought the 2-pc axle was the only critical point. After read that, the tubes are severe too. Can't imagine why AMC made poor stuffs on the critical part of a legendary brand.

So my expectation wouldn't be achieved until one more step... welding the tube pits. Ridiculous

Is there any better alternative? By knowing that, i actually prefer to swap my AMC20 to something else. But i don't want to lose my SB full-floater, as i am very sure it is the best solution for bearings lifetime. Many thanks in advance.

 

[Petescj]

Crazy! isn't it? I thought the 2-pc axle was the only critical point. After read that, the tubes are severe too. Can't imagine why AMC made poor stuffs on the critical part of a legendary brand.

So my expectation wouldn't be achieved until one more step... welding the tube pits. Ridiculous

Is there any better alternative? By knowing that, i actually prefer to swap my AMC20 to something else. But i don't want to lose my SB full-floater, as i am very sure it is the best solution for bearings lifetime. Many thanks in advance.

You have to remember that alot of the Cjs that have had this happen are running 33-35 inch tires and have had higher horsepower/torque engine swaps alot of times. You dont want to ditch the AMC20 now , your almost there. 3-4 "stitch" welds on each tube and your done. Id do it to yours just for the better safe than sorry feeling in that environment

 

[Sasquach]

http://www.jeep-cj.com/forums/f2/amc-20-a-14231/?highlight=amc+tube+weld

I realize they are prone to twisting but to say they are only pressed in is not accurate. Unless I am mistaken the spot welding I mentioned for something else, Old dogs appears to be as if the welder waved the stick by the dimpled area that should have received a spot weld.

 

[Petescj]

I realize they are prone to twisting but to say they are only pressed in is not accurate. Unless I am mistaken the spot welding I mentioned for something else, Old dogs appears to be as if the welder waved the stick by the dimpled area that should have received a spot weld.

I know the J-truck tubes were fully welded , I could be mistaken the Cj ones might have a couple spots. I'll look at mine later. Either way Im welding mine to prevent it. A couple of 30 year old spot welds combined with 35 in tires ( in my case ) doesnt make sense.