Rear Differential Swap and Drive Shaft

[lpcoating]

My rear differential had been getting louder over the past several weeks so I decided it was time to swap with one of several spares. I had one that was very clean looking inside and out so that was my first pick. While removing the old, I discovered that my rear drive shaft had about 1/16" end play. I couldn't get it past the differential flange to be able to remove it from the truck without loosening the diff to get the required clearance. My A2 is a 1/4 cut, thus the truck is short and who ever put it back together did not shorten the drive shaft. So, I removed about 3/8" from the drive shaft and changed the diff. On test run the rear sounded a little better but then became loud (and funny sounding) under load. Back to the garage. Grabbed another diff. This one was purchased 2 years ago at Gilbert with a pile of parts that cost me $40. I drained the oil that was in it and it looked okay. Put it in the truck, added fresh oil and did a short test ride. Sounded 1000% better! Drove the truck 10 minutes down the highway at about 55 mph and had zero issues and no leaks! Must of done a good job with the drive shaft as I had no vibration at speed. Did a local parade in it (rained entire parade) and headed home later that night. Before the parade I hooked up one of my 416 trailers as my son and I were clearing out some rocks. My first time using one of the trailers. Was pretty handy!

Old diff:



First pick:













Guy

[rickf]

The first one died of color fright! Noise under load is usually a pinion bearing.

[acudanut]

Good looking weld. !!
On a Muscle car I would have taken to a shop, so they can cut and balance it. For a Mutt that never goes too fast, I would have done the same thing as you.
On a A2, it looks like you can use the rear Diff to power a PTO. !!

[rickf]

You can do the same with the front on an A1 or A2 as long as you are driving. And as far as fast, those rears have 4.88 gears so the shafts are screaming.

[acudanut]

Too bad my Mutts (62 @ 66) can't use the rear diff. to hook up a pto and spray for weeds.

[rickf]

https://www.tractorsupply.com/tsc/produ ... _vc=-10005
Mount in bed with a battery, quicker, easier and a lot less complicated! You can also get ones with booms.

[halftracknut]

I think I mentioned this some time back...but I changed 11 rear ends and never did get a quiet one...discovered it was tranny bearings.

[acudanut]

I think I mentioned this some time back...but I changed 11 rear ends and never did get a quiet one...discovered it was tranny bearings.

I guess I have had the opposite. It was the rear end.

[acudanut]

Double post.

[lpcoating]

I picked up (2) NOS differentials over the weekend along with some other goodies. The diff I changed out last Fall started to leak and I was going to change the seals but decided to install one of the NOS units. Also changed trans and front diff oil and greased the drivetrain.













Bonus pic - my sister in laws car. 1970



Guy

[m3a1]

A 'car family'.... Very nice. People who can appreciate good iron are usually good folk. Glad to hear you had such great success.

May the Fourth be with you....always...

Cheers,
TJ

[rickf]

Getting brave cutting and welding the shaft that far from the end. Hard to get it straight like that but you seem to have done it. Excellent work.

[m3a1]

When I lengthen my drive shaft I'm paying someone else to do it...chiefly as a matter of having someone else to blame if things go badly later on.


Cheers,
TJ