In a message dated 10/23/00 5:44:31 AM Pacific Daylight Time,
> The only problems with just hauling off and changing the rear end are listed
> below. This is something I will be faced with very soon and am NOT looking
> forward to at all.
> 1) Lug Nut Pattern... good luck finding a modern 6 lug pattern.. so now you
> either get to carry two spare tires so you can change a front one, or..
> an adapter plate for the rear.
Any 60-72? Chevy/GMC pickup is 6-lug, and fairly common.
> 2) Braking system...good luck again trying to get your hucks brakes on the
> front to work with the modern rear. I hear a proportioning valve will be
> needed at least. I am not sure if this is a big deal or not.
I don't think (and it shouldn't matter anyways) that he has Huck Brakes on
the GMC of this vintage.
> 3) Welding Perches.. suggest being really good at welding since these are
> pretty crucial to be done by a professional or at least someone who knows
> what they are doing. Lots of load bearing on these welds.
I'd agree here, if you're an ameteur weldor, may want some help.
> 4) Drive Shaft.. You might get real lucky and find a driveshaft that is the
> proper length. Probably not, so there is the expense of a custom
I used a '62 GMC Dana 44 10 bolt in my '59 and the original driveshaft
length was right on...also the original U-joints were a perfect fit too. In
my '57 when I switch from the 10 bolt '55-59 GMC rear, I put in a 12 bolt
from a '63 or 64 GMC, and the driveshaft and U-joints were also a perfect
fit. The driveline wasn't original though...because we had a TH400 in it,
and I don't recall if we shortned the original, or found another to use.
> I am sure I have missed a few things as I am getting more and more nervous
> about doing this. My plan at this point is to use a 55 1st series rear end.
> Perches should already be fine, its 6 lug already, and there is a slight
> chance of putting either all bendix brakes on it, or all hucks depending on
> the difficulty of borrowing from the donor.
You've got a bit more difficault task with the AD trucks, than the TF
> ----- Original Message -----
> From: <Passnb4U@aol.com>
> To: <firstname.lastname@example.org>; <email@example.com>
> Sent: Monday, October 23, 2000 12:19 AM
> Subject: Re: [oletrucks] Differential Problem
> > In a message dated 10/22/00 9:15:59 PM Pacific Daylight Time,
> > firstname.lastname@example.org writes:
> > > I am contemplating building up the two outside sides of the axle shaft
> > > spacer with brass or weld to take up this extra slack? Any other
> > > suggestions?
> > The ends are hardened, welding the splined ends may have adverse
> > Are you really stuck on keeping the priginal rear in it? You mentioned
> > welding, so it'd seem you have the skills to find another later modeled
> > with a more friendly ratio, and relocate the spring perches.
> > You could look for another axle, or stock rear...should beable to find
> > frmo those who've made a swap...although the GMC probably will be a
> > find.
> > There were many different Rear's GMC used...in fact I pulled a 3.08
> > out of a '55-59 GMC 1/2 ton pickup and ran it for several years...I bent
> > axle...and get this, there were no C-clips...the axle bearings were
> > on the axle...similar to the 88128 bearing used in later model axles. So
> > not suprised the parts guys are giving you several different options.
> > Good luck.
> > Mike
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