Rear Diff Q's and advice

[groundbound64]

Hello All,

I got a couple of questions for you and need some advice.. I going to update for 64 c10 with disc brakes and convert to 5lug (5x5). The front is easy but it's the back.. My question is..

1: Should I use the factory OEM diff and install a new 5 lug conversion Axle kit ??? ( Brother's, Ecklers sell them )

or

2: Should I find another diff for it? I've heard alot of guys use 73-87 diff's ??? Just not sure if it's the same width..

What do you guys use it your own trucks???

Thanks
Jay

[Captainfab]

The '71-'87 differentials are 1.5" wider than the differential you currently have. If you go with the conversion axles, you will also have to change the side spider gears to 30 spline units to match the axles. This is assumiong that the differential is an original '64 12 bolt. The '63 and '64 12 bolts came with 17 spline axles and side spider gears. The '71 and '72 12 bolts will be mostly a direct bolt in swap, with the panhard bar needing a little tweeking. The '73-'87 differentials will require cutting and welding to work under your truck. The other thing to consider when looking at another differential, is the condition of the internals as compared to the one you have now. If the one you buy needs a complete rebuild, then you may be better off just rebuilding the one you have.

[luvbowties]

Originally Posted by groundbound64

Hello All,

I got a couple of questions for you and need some advice.. I going to update for 64 c10 with disc brakes and convert to 5lug (5x5). The front is easy but it's the back.. My question is..

1: Should I use the factory OEM diff and install a new 5 lug conversion Axle kit ??? ( Brother's, Ecklers sell them )

or

2: Should I find another diff for it? I've heard alot of guys use 73-87 diff's ??? Just not sure if it's the same width..

What do you guys use it your own trucks???

Thanks
Jay

An addition to Cap'n's good advice: If your differential is in good condition and you just need 5-lug axles, it should be significantly cheaper to remove your axles & have a machine shop re-drill them for five lugs. The end result should be the same as newer axles. Best to take along a 5-lug drum you're gonna use so they can turn the "centering flange" on your axles to fit the smaller bore in the new drum's center. This procedure is a must-do, as 6-lug drums have larger bores than 5-luggers.

In our area, a machine shop will do a pair for around $50...compare that to the cost of conversion axles. HTH & good luck.
sam

[rbar]

I narrowed mine about five years ago and paid $230 for new axles from either Moser or Currie, I'd have to look in my files to recall which. Probably higher now, but it was the correct splines and length for me.
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[Captainfab]

I would only consider having your original axles plugged and redrilled to 5x5 if the wheel/axle bearing surface is in very good condition. And of course providing the machine shop bill is a good bit less than a new set of axles. Around here I would guess to say that a machine shop would charge close to what a new set of axles would cost. Unless the 'know someone'.