What axle should I start looking for?

[BradyB]

I have my 1970 D100 2WD with the 727/383. I have no idea which rear axle I have, all the tags are gone. It looks like the "cheap one" with no removable pumpkin and no limited slip. My truck will do one-tire fires all-day. My passenger side seal has going bad again and the axle looks to be just about shot. I don't want to rebuild an open diff axle when something else might bolt up.

What would be a good swap that would give me a limited slip, the axle off a New Yorker perhaps? if I could find a junker and take the front brakes and rear axle I would be happy. Anything in Utah or Southern Idaho anyone is aware of?

[712edf]

Its a Chrysler 8 3/4", used in millions of cars & trucks until 1974. The limited slip diff offered by the factory was known as "Sure-grip".

Bucky

[soopernaut]

It looks like the "cheap one" with no removable pumpkin and no limited slip.

But it is removable. The whole center section comes out of the front. Another center with the gear ratio of your choice and a SureGrip can be installed into that axle housing.

[Rodger]

Brady

The "average" ( must used) ration in the 1970 D100's
( D = 2 Wheel Drive ) is the 3.55:1's . At your local
pick & pull they can be found in like era Dodge Van's.

The New Yorker ratio is 2.7 and your truck will perform
like an cat coughing up a hair ball if you load more than
a camping tent or pull more than a Lawn Mower Trailer.

An complete Bolt In Rear Axle is the 9 1/4 unit from 1972
or newer ( Dodge Truck's only ).

I would address your unit and repair it because it is cheaper
to repair than to replace.




Rodger & Gabby
COS

[Txas2step]

[quote="Rodger"]Brady

The New Yorker ratio is 2.7 and your truck will perform
like an cat coughing up a hair ball if you load more than
a camping tent or pull more than a Lawn Mower Trailer.

[soopernaut]

An complete Bolt In Rear Axle is the 9 1/4 unit from 1972
or newer ( Dodge Truck's only ).

The 8.75 was used through 74 in Dodge trucks.

[Outlaw]

so what gear do you guys recommend for having fun but still be able to drive on the highway some-what reasonably and haul a motorcycle or two in the bed? Where is a good place to buy the replacement centers with a new gear & Sure Grip?

[Johninky]

Pay attention to the brakeline size if you decide to swap rear axles. Many years ago I replaced the axle in my D200 with a much newer axle taken from a crewcab. Bolted right in except for the brakelines. The old Dodge used much larger diameter lines. I just replaced the wheel cylinders to make it work.

[Rodger]

Sir

In answer to your question for an newer unit start looking for an Five
Lug 9 1/4 from any 1972 and newer Dodge truck or Ram Charger. The
complete unit will bolt in. As already said you may need an size
adaptation to get the Brake Line on and a different Yoke/ U-Joint.

For trucks the 3.5:1 ratio is still the most sought after ratio.

If you find an Dodge Van with the same ratio and with Sure-Grip the
unit will bolt into the truck sized Axle Housing.

When I did this I scouted the pick & pull for an donor vehicle that had
no straw - no trailer hitch - and nothing else that looked as if the Rear
Axle could have been driven/ treated hard.




Rodger & Gabby
FltSgt@msn.com
COS

[Hobcobble]

so what gear do you guys recommend for having fun but still be able to drive on the highway some-what reasonably and haul a motorcycle or two in the bed? Where is a good place to buy the replacement centers with a new gear & Sure Grip?

3.55s
http://www.randysringandpinion.com
Randy's offers a 3.73 gear too. That would
be "pushing it" a bit with regards to highway rpms....
John

[Outlaw]

How can i tell if the axel has a sure grip without taking it apart? Does anyone know what year of Vans i can look for?

[JimE]

I know if it was on the truck, jack up both sides, start the engine and a suregrip will spin both the tires forward. Jim

[soopernaut]

Keep the current 8.75 axle you have. It is one of the best axles and used in Hemi cars. To check if you have a limited slip jack up the rear, both sides, and spin one tire. If the tire on the opposite side spins in the same direction you have a limited slip.

If you don't know the gear ratio you can also check that at the same time by marking the tire and driveshaft. Then spin the tire one revolution and count the number of times the driveshaft spins.

[Outlaw]

Thanks for the responses. looks like i'll end up keeping the axle I got and going from there. This means i get to save so cash!