Rear end swap/install

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1968 Dart 270

1968 Dart 270

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Hi,the 7 1/4" rear in my dart went bad and I will be swapping in another 7 1/4" rear ro get it back on the road. A couple people told me they could do this job in 40 minutes (which seems very optimistic),and that one person can do it by themselves. I've never had a rear end break before so I've never swapped one. If anyone here has done it before and has any advice/tips I'd appreciate it. That way I'm prepared for what's ahead.
 
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Depending on the shape or condition of your fasteners, should be pretty straight forward. Will need to check on the condition of your brakes and bleed them at the end. Brake fluid and gear lube .
 
lolz on the 40 min. but you can totally do it by yourself.

spray down all your fasteners with whatever weapon of choice on the slick stuff a few days in advance. this includes the brake line fittings and e-brake stuff as well as the u-joint fasteners.

are you reusing your brakes or going with the brakes that are on the "new" rear end?

basically, you'll want to take everything loose, leave the springs attached at the front and support the axle, then pop the springs off at the rear and drop them down, then pull the assembly out the back. you can use a floor jack or a furniture dolly or whatever to support and move the unit.

if you're reusing your brakes, you can pop all of that apart before you pull the axle and just support it. then knock it all back on the new one and you won't even need to bleed your brakes. i don't recommend doing it this way, but it can be done.

if you've never done it, and you don't have power tools it's a solid half day job.
 
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It takes a while with one person and no lift..

I would plan on new rear leaf spring shackles bushings and bolts and front leaf spring bushings too. Possibly some new U bolts that go over the axle tube and into the shock plates, sometimes the old ones do not come off too easy and the threads get messed up. If the brake hoses are old, you should replace those too. Double check your u-joints, and shock absorbers too. Some differential lubricant, the Lucas 85/90 works nice. Might as well do the brake shoes and hardware while you’re at it..
 
I did a 7 1/4 to 8 3/4 by my self.

  1. Raise rear of vehicle till rear axle is at full droop
  2. Support the car body with jack stands just in front of the front spring mount.
  3. Place a jack under the center of the 7 1/4 and pump just enough to give it some support.
  4. Remove the lower shock mount nuts and pull the shocks off the studs
  5. Remove the tires
  6. Remove the rear drive shaft yoke bolts and push the drive shaft into the trans enough to get the rear u joint out of the yoke. Put some tape around the u joint caps to keep them from falling off.
  7. If you are going to fully remove the brake hardware and reuse it. Then carefully remove all the hardware, brake lines etc.
  8. Remove the parking brake cables, a small hose clamp put around the fingers on the inside of the backing plate makes the job super easy.
  9. You can do it as mentioned above by pulling the axles and unbolting all the parts and supporting them from the body.
  10. Remove the u bolts and lower the jack supporting the rear end.
  11. The rear is heavy but use physics to your advantage.
I stall in the reverse order.

Get a Factory Service Manual (mymopar.com) for torque specs.

I was able to get all but one u bolt off. The last one I had to cut. So plan ahead and buy replacements.

GO SLOW ON THE NUTS. They are a locking type and take more for e to remove than a standard nut, plus 50+ years of rust.

Check the temp of the nuts if they get hot stop and let them cool or they can weld to the bolts.

If you can wire brush the u bolt threads ahead of time.
 
#8- if you aren't going to reuse your cables and the replacement rear is already set up, then you can just pull the cables up line at the stirrup leaving everything intact.

#10- by nature the the rear is nose heavy and going to want to rotate down, so know that going into it.

after you zip off u bolt nuts (or cut off the u bolts) is when you're going to want to undo the springs at the shackle mounts. it'll be a little bit of a balancing act, but like dana says use physics to your advantage.
 
All go info above.

I second regularly spraying down all fasteners for three days!!

Much better if you can remove and replace the entire assembly...leaf springs and axle.
 
Thanks for all the input guys. I'll spray the bolts down with seafoam deep creep a few days in advance. That stuff works really good and is low odor.
 
Dana67Dart said:
I did a 7 1/4 to 8 3/4 by my self.

  1. Raise rear of vehicle till rear axle is at full droop
  2. Support the car body with jack stands just in front of the front spring mount.
  3. Place a jack under the center of the 7 1/4 and pump just enough to give it some support.
  4. Remove the lower shock mount nuts and pull the shocks off the studs
  5. Remove the tires
  6. Remove the rear drive shaft yoke bolts and push the drive shaft into the trans enough to get the rear u joint out of the yoke. Put some tape around the u joint caps to keep them from falling off.
  7. If you are going to fully remove the brake hardware and reuse it. Then carefully remove all the hardware, brake lines etc.
  8. Remove the parking brake cables, a small hose clamp put around the fingers on the inside of the backing plate makes the job super easy.
  9. You can do it as mentioned above by pulling the axles and unbolting all the parts and supporting them from the body.
  10. Remove the u bolts and lower the jack supporting the rear end.
  11. The rear is heavy but use physics to your advantage.
I stall in the reverse order.

Get a Factory Service Manual (mymopar.com) for torque specs.

I was able to get all but one u bolt off. The last one I had to cut. So plan ahead and buy replacements.

GO SLOW ON THE NUTS. They are a locking type and take more for e to remove than a standard nut, plus 50+ years of rust.

Check the temp of the nuts if they get hot stop and let them cool or they can weld to the bolts.

If you can wire brush the u bolt threads ahead of time.
Click to expand...
Thanks for the detailed,step by step info. Guess ill.buy some.u bolts just in case.
 
junkyardhero said:
lolz on the 40 min. but you can totally do it by yourself.

spray down all your fasteners with whatever weapon of choice on the slick stuff a few days in advance. this includes the brake line fittings and e-brake stuff as well as the u-joint fasteners.

are you reusing your brakes or going with the brakes that are on the "new" rear end?

basically, you'll want to take everything loose, leave the springs attached at the front and support the axle, then pop the springs off at the rear and drop them down, then pull the assembly out the back. you can use a floor jack or a furniture dolly or whatever to support and move the unit.

if you're reusing your brakes, you can pop all of that apart before you pull the axle and just support it. then knock it all back on the new one and you won't even need to bleed your brakes. i don't recommend doing it this way, but it can be done.

if you've never done it, and you don't have power tools it's a solid half day job.
Click to expand...
I thought that sounded unrealistic too. Maybe a racing pit crew could do it that fast,doubt the average Joe could.
 
Id like to suggest just buy new u bolts and nuts. Cut the old u bolts with a cut off wheel and be done with it. Don't bother trying to save any of that stuff as it's likely at least 1 will not be reusable. Don't cut the u bolt at the top because you may not be able to rotate the bolt out of your way. Cut at the shock plate.
 
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1968 Dart 270 said:
I thought that sounded unrealistic too. Maybe a racing pit crew could do it that fast,doubt the average Joe could.
Click to expand...

If you had a lift, air tools, and a transmission jack, and you didn’t give a **** about breaking anything, you could have it pulled in 40 mins.

Otherwise I’d figure a few hours to get it out and a few more to get the new one in and brakes bled/adjusted.

It took me two nights probably 7 hours total to swap complete rear assemblies from my 65 to my 67. That’s on the floor, jack stands and hand tools. I have done this many times, and both cars are low mile/low rust cars.

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IMG_7373.jpeg
 
junkyardhero said:
after you zip off u bolt nuts (or cut off the u bolts) is when you're going to want to undo the springs at the shackle mounts
Click to expand...
I did not do that and did not see a need to do it.

I just slid the rear to one side, lifted one end off the spring then slid it the other way and off the other side.
 
Dana67Dart said:
I did not do that and did not see a need to do it.

I just slid the rear to one side, lifted one end off the spring then slid it the other way and off the other side.
Click to expand...
i always found it easier to let the springs down and just ease it right on out the back rather than futz around with trying to jump it over the springs and lever it in/out from the side coming and going.

different strokes for different folks and all that.
 
Dana67Dart said:
Two less bolts to break, but I get it.
Click to expand...
what, you don't salt the garage floor, burn sage and say the incantation printed in the FSM to ward off broken bolts and stuck fasteners?

i thought everybody did that...

(technically it's four bolts, i pull it at the body mount. ain't no way i'm pulling apart shackles unless i absolutely have to, and even then they're getting new bushings)
 
66Valiant528 said:
Id like to suggest just buy new u bolts and nuts. Cut the old u bolts with a cut off wheel and be done with it. Don't bother trying to save any of that stuff as it's likely at least 1 will not be reusable. Don't cut the u bolt at the top because you may not be able to rotate the bolt out of your way. Cut at the shock plate.
Click to expand...
Where is the best place to buy the correct u bolt kit for our cars? (1968 Dart 270)
 
mancini, year one, espo you'll get the right parts
amazon or ebay, cheaper but unknown quality and fit
local rear-end or spring shop, probably cheap, likely good quality, but may need to cut to fit.
 
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