Hi, is the third member replaceble for dana 60 .354 1968 from a 1979 dana 60 .354 from a f250. Thc

People do but you will not have a provision for the pinion snubber. I had Dr Diff build one for our '68 RR strip and some limited street use with a detroit locker in 2008, still going strong.

Do you mean just changing the gears from a ford truck back to a car?

All the Dana Corp. rear ends I've seen do not had a "third member" the ring gear comes out the rear on the carrier and the pinion gear gears comes out the rear after the carrier (center section that the axles slide into) is remove, they are independent of each other.
On the changing of the gears the Dana Corp made 3 or 4 different carriers for different ger ratios, the 3 series carrier works only on the 3:54, 3:73 and 4:10 ratio gears, the 4 series works on 4:56 up to 5:13, I think and the five series on the 5:57 and above gear ratios.
There may be some other brand carriers and spools that will work on different ratio other than I listed

I assume you mean the inside carrier with the ring gear and pinion. Like cab said, no drop out third member. No, they are different.
Side gears are 23 on the 68 Mopar and probably 30 or 35 on the Ford. Ford does not have the same cross shaft assembly. If your suregrip is bad, you have to buy a new one from DoctorDiff and use your old side gears and cross shaft assembly. I just did this job. You need to get someone that knows how to set up Dana gears. They are a bigger job.

Gear changing is a tricky job at best.

The pinion and carrier need ‘preload’ on the bearings.

This requires a ‘case stretcher’ for the Dana case, which is a hefty piece of kit.

I have build many third members and they is easy compared to a Dana...

“Case spreader” is the technical term. You use a dial indicator to spread it .015. It’s pretty unnerving to stretch a case that is not easily replaceable that does not belong to you. .020 is too
Much and might damage the case.

I don't use a case spreader, I have a set of set up bearings and use them to determine on the carrier to get zero preload on those bearings and when I'm done setting up the gearset I remove them and press on the new bearings and add between .010 and .015 shim to the carrier shim packs to get the preload correct. I do set the backlash up before installing the new carrier bearings also
I set the carrier on the case with the bearing races angle into the case and tap it gently into place with a rubber or plastic mallet
Works good so far ( going on 30 gear set changes now)

That is basically the same way my friend put the gear set in his Dana 60 out of a B Body in his Camaro. He did not use a spreader.

I did this before I bought the case spreader and the bearing puller that removes them with ease. It’s much easier now.

Wow I heard you could ‘mallet’ the bearings in, with preset preload, but prefer the stretcher myself.

Obviously you need to set the backlash and add shims approx 0.007 to each side.

I will give it a go and see how successful I am lol...

At Mopar dealer we used to use the case spreader and do bearings and gear replacements/service while the differential was still in the vehicle. Not just for the dana 60, several diffs it was required (per manual) for ring and bearing service. I never did one on the bench with the diff removed.
Copper

You can now buy the case spreader on eBay so reasonably, there is no reason not to use one.

I have read and reread this at least a dozen times and I am still scratching my head. Are you maybe a little confused on which part is the differential? I have done at least 1000 Dana 44, 60 and 70 r&p setups and you are absolutely not going to change a r&p and bearings without removing the differential from from the case.

I’ve heard the entire rear end assembly called a differential. I’m not sure what the proper term would be but I call the sure grip parts with the ring gear the carrier. In West Texas we fish in tanks, not farm ponds. That really throws off some people. Ha!

my dad uses a case spreader and the ford rotunda set up tools. the kit from ford does a lot of their rear axles. sometimes they are found on ebay. the tool sets the pinion depth at zero depending on what shim is needed. then if you change gears, you just have to add/subtract the difference of the plus/minus on your new gears. he also puts the shims behind the rear bearing race so he does not have to remove the bearing from the pinion. he also used dummy bearings for the carrier to set backlash.

Back in 1970 at the Dodge Shop we were told the 60 could only be spread maybe 3 times then a new housing. Told this by the Dodge rep and it was in the book too. I asked him why couldn’t you use the ‘spreader’ to pull it back once the case was empty? He just looked at me and shook his head while walking away.
I use a long crow bar to get them out then a big hammer to drive it back in, tighter shims on the back side of ring gear, pinion holds the other side tight. Use checker bearings and original Miller set up tools, inch pound TQ wrench to check preload. Piss poor design but cheaper than making adjusters like an S60, 8-1/4, 9-1/4 8-3/4, 9”

My current S/P car has a narrowed Dana 60 with Mark Williams 40 spline axles, two of his steel caps and it had one of his 40 spline aluminum spool with a set of Pro 5.86 gears when I got the car without a motor in it. I was told the rear gear ratio was either a 5:13 or 5:38 ratio, which with 16x33x15 tires should have worked fine with the 511 C.I. 400 E 85 stroker motor I put in it to race it.
I got it running in the summer of 2013 and ran it once at a 1/4 mile track and fund out my stroker motor had its tongue out at 7300 RPM around the 1000 ft timers
I check the gear ratio that winter and ended up finding out it had the 5:86 in it so I swap them out to a set of stock Dana 4:56 as I could not find a 40 spline 3 series 40 spline spool I wanted to put a set of 4:30 in it but I had to use the 4:56 gears and a Moser 40 spline steel spool as no one back then made a 40 spline 3 series spool
I use two short pry bars to pry on two ring gear bolts to remove the spool and ring gear and installed the 4:56 pinion using a Pro Parts pinion depth checking tool kit I had to add .003 spacer behind the rear pinion bearing race to get the pinion depth within the specs. on that gear, it has worked fine until the last race of this year when the rear bearing cage failed in the pits allowing all of the bearings to fall out and lock it up
I'm not sure what cause that but I will replace the bearing this winter and make sure none of the teeth on the ring gear and pinion gear are cracked or damaged and reuse that gear set if it checks out okay
Luckily, I was warming it up in the pits and was going less than 2 MPH pulling into tech when the cage failed after I had put it in neutral to stop in tech
I hate Murphy

I've done a DANA in a truck but it was a lot of 'huff-puff' working underneath!

If you can only 'spread the case' three times then that's a worry indeed...

Its not like a diesel head gasket with 'marks on' to show how many times its beeen done?

When you do an 8 3/4 diff, the preload is adjusted from one side and if the mesh changes you can adjust it back.

With a Dana the carrier preload is a bit 'hit and miss' with a guesstimate on side shims?

Sometimes they feel 'tight' when rotated and you lessen the load.
But they 'soften up' real quick in service and the preload goes away (with the fairies)...