Rear hub nut tightness questions. - Welcome to The Amphicar Lovers Digest / Forum

DavidC · #1 (**permalink**) 06-25-2008, 08:17 PM

We all know it has to be very tight but anyone guess a figure ? I seem to remember it needing to be well over 100lb/foot ?
Also anyone use a nylock instead of a split pin ? Hole for split pin always seems to line up for me in the wrong place and I don't want to go really really tight but then slackening it slightly for split pin to fit seems a bad idea as well. Maybe I just have to file the face of the nut ?
David C

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DrNoose · #2 (**permalink**) 06-25-2008, 09:55 PM

My driver side rear wheel nut had been loosening up on my everytime I
drove the car. I ended up cranking it down as tight as I possibly
could...including with a cheater bar! For now that seems to have solved
the problem.

Dan
'64 Das Boot

DavidC wrote:

Quote:

> We all know it has to be very tight but anyone guess a figure ? I seem
> to remember it needing to be well over 100lb/foot ?
> Also anyone use a nylock instead of a split pin ? Hole for split pin
> always seems to line up for me in the wrong place and I don't want to
> go really really tight but then slackening it slightly for split pin
> to fit seems a bad idea as well. Maybe I just have to file the face of
> the nut ?
> David C
>
>
>
>
>

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Brian Crombie · #3 (**permalink**) 06-25-2008, 11:06 PM

David and Dan,
I was taught to tighten the nut firmly then back it off to line up the castle nut slot to the cotter pin hole. Then spin the tire and if it is bound up at all, loosen the nut a bit more until it spins freely. Do this in small increments. It may take up to 3/4 of backing it off.
Dan, if you were to install a cotter pin, the nut won't back off. That's why the castle nuts have slots and the axel shaft has a hole through it. This is how I've been doing it for years on axels that have cotter pins and have had no problems.

Brian Crombie
Faribault, Mn.

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DrNoose · #4 (**permalink**) 06-26-2008, 12:12 AM

Brian,

Of course, I have installed the cotter pin. When that nut backs off, it
can take that cotter pin out. And it has. I have taken off the rubber
cap and found bits o' cotter pin in there. Since the axle is a press
fit, I am not sure I agree with the backing the nut off. But that is my
opinion.

Dan

Brian Crombie wrote:

Quote:

> David and Dan,
> I was taught to tighten the nut firmly then back it off to line up the
> castle nut slot to the cotter pin hole. Then spin the tire and if it
> is bound up at all, loosen the nut a bit more until it spins freely.
> Do this in small increments. It may take up to 3/4 of backing it off.
> Dan, if you were to install a cotter pin, the nut won't back off.
> That's why the castle nuts have slots and the axel shaft has a hole
> through it. This is how I've been doing it for years on axels that
> have cotter pins and have had no problems.
>
> Brian Crombie
> Faribault, Mn.
>
>

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Ron Green · #5 (**permalink**) 06-26-2008, 08:37 AM

I do not back the rear nut off only the front when adjusting the wheel bearings. I recently did some rear end work on my amphi and found that to pull the axle through you need to use the proper tool and really tighten the nut. Backing it off would only loosen things eventually. I used an air impact to tighten the nut which lined up the hole and allowed the wheel to spin freely.

My amphi now cruises at 65 MPH with no issues though I couldn't keep up with Tommy from Tampa last weekend who was at 70-75 MPH.

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CapnJohn · #6 (**permalink**) 06-26-2008, 09:36 AM

Quote:

Originally Posted by Ron Green

I do not back the rear nut off only the front when adjusting the wheel bearings. I recently did some rear end work on my amphi and found that to pull the axle through you need to use the proper tool and really tighten the nut. Backing it off would only loosen things eventually. I used an air impact to tighten the nut which lined up the hole and allowed the wheel to spin freely.

I have seen many an Amphi with scars from loosing a rear hub. It is VERY important to make sure that rear hub is TIGHT. The correct tool will pull the axle into position. DO NOT use the hub nut to do this. It won't be tight enough and you will be weakening the threads and at some point the nut can crack or just strip the threads. That would be very bad!

I try to use a new nut if there are any signs of wear. The rear hub should be tightened with an impact. I try to align the slots in the castellated nut by going to the next slot rather than backing off to install the cotter key. The front hubs need the pre-load set so you have to back it off a bit so you dont burn up your bearings. Be sure to recheck them after a few miles.

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Ron Green · #7 (**permalink**) 06-26-2008, 12:56 PM

Jeff Collins (in club roster) sells the special rear axle tool and also the pinch bolt (via the grease fitting) tool which allows you to align the grove to drop the pinch bolt in. Both are necessary when working on the rear ends. I have a mega wrench for the rear nut however the impact will still out tighten the wrench. Also allowing to sit overnight seems to help get that extra little bit to align the cotter pin.

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Midwest Amphicar · #8 (**permalink**) 06-27-2008, 01:35 PM

Dr. Noose, what probably happened to your car in the past is the hub slipped. Then by spinning it enlarged by a few thousands. The taper does not allow it to go further so it never gets tight enough. There are other solutions but cheapest is to use a bit of aluminum from a can, wrap axle area where hub contacts. The aluminum will fit via the force of installing hub. Realize there are different thicknesses between cans say Coors light compared to 7up. Rear hubs are around $400? Later Dave the Wave

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DrNoose · #9 (**permalink**) 06-27-2008, 09:26 PM

I will check it out!

thanks
Dan

Midwest Amphicar wrote:

Quote:

> Dr. Noose, what probably happened to your car in the past is the hub
> slipped. Then by spinning it enlarged by a few thousands. The taper
> does not allow it to go further so it never gets tight enough. There
> are other solutions but cheapest is to use a bit of aluminum from a
> can, wrap axle area where hub contacts. The aluminum will fit via the
> force of installing hub. Realize there are different thicknesses
> between cans say Coors light compared to 7up. Rear hubs are around
> $400? Later Dave the Wave
>
>

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GORDON IMPORTS INC.. The world's largest source of Amphicar parts and accessories. Visit our new website today.