68 fury rear leak

[Furydude]

I found my 68 a few years ago and right after life interviened and I shelved it. It is a nice car but a bit of a leaker. Dif, trans, and engine all have some type of leak. Plus the brakes just plain ol suck. I am off the COVID couch and working on the car.

First up is the rear. I could not tell if its the pinion seal or the carrier/case. I am hoping the pinion seal. It has a 742 case and it seems I can drop the drive shaft, remove the yoke, pinion seal, and pop in a new one. Then snug it all back to factor torqe specs. While I am there I will replace the u joint and disassemble the brakes and put in new brake stuff.

Any suggestions? Or hints.

The brake lines look sketchy. Orginal. I think i'll replace them all the way up to the front. Get the rear brakes all spanky new. Any suggestions on where I can get pre bent lines? Or maybe its easier to pull the old and bend new ones using the old ones as a template. I have never done this but think i can get a bender and flare tool and figure it out.

Appreciate any feedback. Thx, Tom

 

[Davea Lux]

The pinion seal replacement on a 742 case is straight forward. Remove the yoke and pop out the old seal, then carefully install the new seal, oil it up first, and replace the yoke. Be sure that the yoke is properly torqued on the reinstall.
If your pinion seal is leaking, the case behind the yoke will usually be wet with oil around the area where the seal installs and oil will often be thrown up on the floor of the car above the pinion seal. If the 3rd member to case gasket is leaking, there will usually be oil residue around where 3rd member bolts to the housing. You will probably need to take some brake-kleen and a wire brush to the 3rd member to clean things up to locate the leak. If the car is not road worthy, it can be started with the rear wheels off the ground and the transmission in gear to see if any drips can be spotted once the unit is cleaned up. Do not go under the vehicle with the engine running and transmission engaged! If the axle seals are leaking, this would be a good time to pull the axles, replace the seals, inspect the bearings, repack/replace them as necessary. With the axles out, you can drop the 3rd member and replace the gasket, that way it is all fresh and nothing should leak oil.

www.inlinetube.com can supply pre-bent brake lines. Brake lines are double flared and need to be replaced with new double flared units so that they do not leak of blow out under a panic stop situation.

Dave

 

[413]

Maybe clean the rear with brake cleaner and then see where it’s leaking from. You might be doing the wrong repair.
You can buy straight 3/16” lines With both ends already flared and bend them by hand if you want it quick and know the flares are correct.

Many vendors sell premade lines:
Fine lines
inline tube

If you are going that far then remove the rear axle shafts to clean and repack the rear wheel bearings. They will last a long time if the get greased.

 

[crazyboutwagons]

I just had this done on my 68 Sport Suburban Wagon we pulled the axles and replaced the bearings and seals because we had to remove the center section to replace the housing gasket. Replaced the pinion seal and the u- joints. Now no more leaks. I bought the USA made pinion seal & housing gasket locally. I got the Timken axle bearings & seals and gaskets from DR.DIFF DRIVETRAIN COMPONETS @ 406-883-4772. i Bought NOS MOPAR U-JOINTS FROM EBAY can't remember seller but he was in California. Rearend no longer leaks and car drives so much better now no more vibrations.

 

[Furydude]

Thx for the replies. There was gear oil on the bottom of the case and also on the part of the case that support the pinion. It could be the seal and it leaked down to the bottom of the case. I cleaned it up real good. Hopefully I can see where its coming from. Probably should see if I need to add some more oil. What kind of oil goes in the rear? Never really done that.

 

[Davea Lux]

If it is an open rear end, not a sure grip, 85-90wt.

Dave

 

[Furydude]

If it is an open rear end, not a sure grip, 85-90wt.

Dave

I am a doofus and do not know if its a suregrip or not. I guess the best way is to put in neutral and spin one tire and see if the other spins. If they both spin i guess i need some friction modifer. Something like that?

 

[Davea Lux]

I am a doofus and do not know if its a suregrip or not. I guess the best way is to put in neutral and spin one tire and see if the other spins. If they both spind i guess i need some friction modifer. Something like that?

Yes, most auto parts sell it. If you jack up the rear and spin one wheel and the other side turns the same direction, it is a sure grip, other wise it is an open rear end. Most of the sure grip rears also have a round metal tag on one of the 3rd member bolts that identifies the unit as a sure grip.

Dave