First Gen Diff.

Is a 4wd rear axle the same width as the 2wds?

Reason: Trying to source a limited slip in a 2wd is scarce. 4wd diffs are everywhere and affordable.

Thanks.

For 72-93 trucks yes 2wd and 4wd are same width.

But, there were changes to lug patterns, diff side gears and c clips in the half tons.

3/4 and 1 ton stuff is a book worth of changes but complete assembly swaps have less headaches.

Also, 4wd did not include limited slip.

What are you working on?

It's a 2wd half-ton, '85. For some reason it has the 5.5 bp, I thought it should be 4.5?

D100 slant six 833od, so not sure what yoke it will have? Do the 9 1/4 and down all use the same u-joint/yoke?

The width is the same, you can do a straight swap if you find a 4wd with limited slip. I think the u-joint should be the same UNLESS you have an 8 1/4 in that truck. According to yukon gear it was available and would make sense in a slant 6 truck. If that's the case I am not sure if they are the same size but could be.

1985 was the first year that Dodge re-introduced larger bolt pattern on 2wd trucks. (It was phased out back in the early 1970's I believe.)

I've seen a number of the 2wd trucks with the 8 1/4 axle. The small axle seems less common on the 4x4 trucks.

Rock Auto is showing the same u-joint for 4wd as 2wd so, must be in the clear.

Good deal, should be an easy swap.

This is for D100/150 and W100/150

'72-'84 2wd are 4.5"
'72-'74 and '80-'93 4wd are 5.5"

'72-'74 are 8.75
'75-'93 are 8.375 or 9.25

there are way more limited slips showing up under 2 wheel drive trucks than 4x4 because the fleet orders would slip them in----the 4x4 limited slips generally were a customer order--way more rare in the real world found in a highly optioned truck....

Can a 8.75 limited slip from a pre-1993 D150
be easily transplanted into a 1995 2wd 1500,
or is it better to look for a
Dana 60 from a 1994-2001 Ram 2500?

I realize there is the tone wheel inside the diff on the 1994+ Rams

either can fit----will be easier finding the dana 60----even easier to find a 9.25....

I have a Dana 60 from my 1996 2500 2WD. It has no internals now as I lost a carrier bearing. I ended up buying a complete Dana 70 and out of a V10 truck in a junkyard, they seem to be MUCH easier to find then a 60. It was also a cheaper alternative then buying the bearing and new gears for the 60. The problem is the differences in the shock mounts, brakes, and lots of other changes from first gen to second gen. I have two Dana 70's for first gen trucks too.

IIRC, rear springs went from 2 1/2"x52" to 3"x60" in 1994? Even if you found an 8.75 (last used in 1974?) diff I think spring perches would be hurdle #1, then shock mounts and driveshaft, can't recall if it needs to be longer or shorter. There's nothing wrong with the 9.25", I'd keep it.

I just put a Yukon carrier in my 9.25 in my red truck after the motor swap I did. Seems pretty beefy I think it would be tough to hurt it. Should last awhile I think it will be ok.

Just a pet peeve, but an 85 isn't a first gen. First gen refers to the 88-93 Cummins trucks. I also feel the same way about the words Cummings, and naaws. Instead of nitrous. I know that this has nothing to do with the op, but come on.

To be honest with you Wyldebill, I don't know who came up with "First Gen" to label this era of truck.

You'd think a First Gen Ram/Dodge would be something from the early 30's.

Probably started by GM guys, that's who I hear it from. A lot of em around here drive Dodge trucks nowadays but are still Chevy guys at heart.

See an early '80s two wheel drive short bed and they say "Dude! You see that first gen back there?"


Me and any other Mopar guys I know call em '72-'93s.

It got started with the Cummins guys. The "first gen" Cummins was the 89-93 body with the VE pump.

2nd gen is 94-01(?) Body, 3rd gen is 02-08 etc

Prior to that it was just Dodge truck.