DRIVESHAFT SEALS REPLACE

Chockblock front wheels to prevent truck rolling, and jack vehicle up and place a jackstand under frame to prevent vehicle falling. Remove driveshaft, seal is now visible to be pried out for new one to be lightly tapped into place with a rubber mallet or hammer, along with a wooden block, taking care to keep new seal straight while replacing. replace driveshaft and check fluid level, lower vehicle and remove chockblocks.

There are several seals for the differential. The pinion seal is towards the driveshaft. The rear cover is on the back of the differential.

The rear cover seal is a gasket and can be replaced by removing the rear cover and scraping off the old gasket. Some mechanics make their own gasket out of a liberal application of atv gasket compound. Other mechanics use a stamped gasket and may apply a small amount of cement to one side of the gasket to hold it to the cover.

The cover is bolted on by Torx head fittings.

The pinion seal is another matter. The driveshaft needs to come off. The flange needs to come away from the differential and the seal rides the shaft going into the differential. Some housings require a removal tool.

With either seal, you need to determine the type of differential you have. Limited -slip requires an additive to work in the standard lube. Some require only synthetic gear lube as well as the additive.

A cover gasket is not very hard to replace. The pinion seal can be more difficult. Price the repair.

Do not reuse the differential fluid.

The rear wheel drive cars can have their driveshafts removed by taking off the bolts where the driveshaft connects to the rear axle. The bolts may have Torx or Star type heads on them.

You would paint the ears of the joints to make sure the joints go back together in the same position as they started if you are seeking to change the U-joints. If you are doing this to change the rear trans seal on an automatic, be aware to check where the seal is installed.

Some seals are installed from the inside out on the tailshaft. Meaning the rear case of the trans must be separated from the main housing. Other more practical designs are accessible form the outside and do not require separation of the tailshaft.

I hope my solution is helpful and ask you to rate my solution.

I searched under 1997 lincoln continental and found this: Driveshaft and U-Joints
REMOVAL & INSTALLATION Town Car and Mark VII-VIII Fig. 1: The bolts retaining the rear driveshaft yoke-to-differential flange require a 12mm, 12 point wrench or socket to loosen them
Fig. 2: Remove the bolts retaining the rear driveshaft yoke-to-differential flange
Fig. 3: Separate the driveshaft from the axle flange and . . .
Fig. 4: . . . disengage the driveshaft from the transmission output shaft
Fig. 5: Insert a plug onto the splines of the transmission output shaft to prevent fluid from leaking out

1. Raise and safely support the vehicle.
2. Mark the position of the driveshaft yoke on the axle companion flange so they can be reassembled in the same way to maintain balance.
3. Remove the flange bolts and disconnect the driveshaft from the axle companion flange.
4. Allow the rear of the driveshaft to drop down slightly.
5. Pull the driveshaft and slip yoke rearward until the yoke just clears the transmission extension housing seal. Mark the position of the slip yoke in relation to the transmission output shaft, then remove the driveshaft.
6. Plug the transmission to prevent fluid leakage. To install:
   
7. Lubricate the yoke splines with suitable grease.
8. Remove the plug from the transmission and inspect the extension housing seal; replace if necessary.
9. Align the slip yoke and output shaft with the marks made at removal and install the yoke into the transmission extension housing. Be careful not to bottom the slip yoke hard against the transmission seal.
10. Rotate the axle flange, as necessary, to align the marks made during removal.
11. Install the driveshaft yoke to the axle flange. Install the bolts and tighten to 71–95 ft. lbs. (95–130 Nm).
12. Lower the vehicle.

Replacing the rear transmission seal involves removing the driveshaft for access.

Depending on the ground clearance of the vehicle, you may need to raise the rear of the car and support it on safety stands. Please make sure that the car is completely stable before continuing any work if you do need to raise it.

You will need some tools, mainly the correct sized wrenches or socket set to fit the bolts and nuts that must be removed. A large screwdriver will come in handy, a hammer, a marking tool, tape and if the transmission has fluid in it, you should have a container for catching any fluid that will leak out. You will of course need the correct seal for the back of the transmission and transmission fluid of the correct type to replace any that leaks out during this procedure.

The first step is to mark the location of the driveshaft in relation to the connection on the rear end. Using chalk or some type of marker, make a mark on the driveshaft and also the pinion yoke. This yoke is the part that the driveshaft universal joint is bolted too. Once that is done, you can start unbolting the caps or straps that are holding the universal joint to the rear end. With those connections out of the way, gently use the screwdriver to lever the driveshaft forward far enough for the universal to clear the pinion yoke. Now drop the back of the driveshaft down and using the tape, wrap a few runs around the universal joint and its caps. This will keep them from falling off and getting dirt in the caps which can damage the inner bearings.

Now you are ready to remove the driveshaft. While not very heavy, it can be a bit tough to handle while laying under a vehicle. Take your time and simply pull the driveshaft backwards until the front input shaft slides out of the transmission. With the container in place, any fluid that escapes should be caught. You can now lay the driveshaft to the side, but place a rag underneath the input shaft to minimize any dirt being picked up.

You can now remove the rear seal from the transmission. Normally using the screwdriver and being careful to only pry on the seal, you should be able to lever out the seal. You may need to work your way around the seal, levering it out a little bit at a time, but it will come out. With the seal out, wipe the seal area to remove any dirt, fluid, etc. I prefer to put a touch of sealant around the outside circumference of the seal (painted area), but it is not mandatory, just a little insurance. Using the hammer, carefully tap the seal back into place. Take your time and do not damage or bend the rubber seal area.

Now you can put the driveshaft back in, but here are a couple of tips. First, place the gear selector in neutral, this will help you line up the back of the driveshaft with the marks that you made during removal. Second, wipe the rubber of the seal with just a touch of transmission fluid to lubricate it.

Once you have the driveshaft input shaft back in the transmission, you will need to line up your marks on the driveshaft and rear pinion yoke. You should be able to rotate the driveshaft as needed, then remove the tape and push the driveshaft back in place. Replace the caps or straps, start the bolts, then put the gear selector back in park. Now you can tighten down the bolts or nuts as required.

Safely lower the car back to the ground, top up the transmission fluid as required and you are finished.

Please let me know if you have any additional questions concerning this issue.

The rear axle seals are leaking too,it's been my experience with Dodge 2500's,all 3 seals leaking is usually a indication that there are bearings going south!

Replace the seal. Also advise inspecting the front U-joint on the driveshaft. The front U-joint receives the most wear. Excessive wear on this joint will cause the transmission rear seal to fail.

To replace the seal:

USE safety equipment. You may not have, or wish to use a pair of mechanics gloves, but I HIGHLY advise donning a pair of safety goggles. It's relatively easy to get debris in your eyes when working in this situation.

1.Drain the transmission in a suitable container. I don't know how old the transmission gear oil is in your 1997 Nissan, but if you believe it to be the original gear oil, it's best to change it.

Check with your nearest Nissan dealer as to what gear oil is recommended. It may use a specific type that has additives in it.
There may have also been a change that came down with the gear oil, and the Nissan Parts Department will be aware of it.
(Maybe a change as to a better gear oil now, than when your 1997 Nissan was manufactured)

1 pound = 1/2 Quart
If your Nissan is two wheel drive, the capacity is 3.3 pounds

Based on two wheel drive and not four wheel.

2.Remove the driveshaft.

A.Start with the four bolts that connect the driveshaft, to the rear differential. Place all bolts that you remove in a suitable container. (Coffee can? Butter bowl? Magnetic parts tray?)

B.Disconnect the center bearing support

C.Place a suitable container under the end of the transmission housing, where the driveshaft enters. When you pull the driveshaft out, residual gear oil will drip out. Ease the driveshaft back.

Be aware that as the front yoke comes out of the transmission, that it will flop down if not supported.
(If you are holding the driveshaft with both hands, and one hand is not supporting the front yoke)

If you hand is in the wrong place you can get your hand/fingers pinched.

D.Now it's time to remove the seal.

You have to use care in order to Not scratch, or gouge, the outside seal area in the transmission housing, and to Not scratch the transmission main shaft.

There are several ways to remove the seal, and only one professional way.

Professional way:
Use the proper tool

A.There are many tools designed for this application. I recommend an inexpensive one.

This is an example,
http://www.sdaautomotivetools.com/servlet/the-3509/Seal-Puller/Detail

Your nearest auto parts store should have a tool similar to this. They make a design similar to this one, but it has a separate head from the shaft. I recommend the solid 1-piece design. Less apt to break.

As you can see the head of the seal puller has a curved edge. The thin pointed tip is inserted into the seal area, with the curved edge of the puller resting on the transmission housing. It's the same principle as using a crowbar.

The tip is just inserted past the rubber portion of the seal, and catches the metal ring of the seal. Do Not insert the tip beyond the metal ring of the seal. You can scratch the inside of the transmission housing, causing a leak when you insert the new seal.

The puller tool is rocked back with the tip pulling out of the metal ring. Most seals are tight. The metal ring will deform where the tip of the tool rests against it, as you use pressure to pull the seal out.

Pull the seal out a little in this area, then move over a little, and begin again. Keep working you way around, and the seal will come out.
You may be fortunate that the seal will pop out with no trouble!

Use a light, and inspect the seal area on the transmission housing. Clean the transmission tailstock area with a clean rag. Check that the area has no scratches, or gouges.
If a deep scratch or gouge is present your new seal will not seal around the outside metal ring.

If this is present when I do a seal replacement, I thoroughly clean the area, and smooth the scratches/gouges out. (I use the non-flammable type of brake cleaner in a spray can, and a clean rag )

Then I apply a thin coat of Permatex Black silicone adhesive sealant. This isn't an advertisement for Permatex. Use the sealant of your choice. I just know from experience, that Permatex Black will stick in this particular application.

Apply a thin coat to the outside area of the metal ring of the seal. Do Not wait too long to install the seal!

Install the seal:
The professional way is to use a seal installer tool. A round piece of pipe with a smooth edge, can be a substitute. The pipe has to have an opening large enough to go over that transmission's main shaft, and also be large enough to rest on the OUTSIDE edge of the metal ring, of the seal.

If the pipe isn't large enough, it will crush the inside edge of the metal ring. The edge of the pipe must be smooth, and flat also.

You can also insert the seal so that it starts to go in, then go around the Outside edge, with a small ball peen hammer. BE SURE to tap lightly, and Stay on the very outside edge! Takes a little finesse with this method. Keep the seal flat as you are installing it. DO NOT let it tip off to one side. (Do not let the seal come up on one side, with the other side dipped in)
You'll bend the seal.

Before you reinstall the driveshaft's front yoke, take your finger with a few drops of fresh transmission gear oil, and apply the gear oil on the rubber part of the seal. (IF the seal doesn't come pre-lubed. Some do, some don't)
If the driveshaft is inserted into a dry seal, the seal will tear.

NO - Here are the steps involved....

Raise the vehicle and support it on axle stands. Drain the lubricant from the transaxle.

1. Remove the front wheels and splash pan. Raise the tab on the wheel hub locknut, and then have someone apply the brakes as you loosen the nut.
2. Remove the tow nuts, bushings, and washers, then disconnect the stabilizer bar from the steering knuckle.
3. Remove the clinch bolts and nuts, then pry the lower control arm downward in order to separate the steering knuckle and lower ball joint. Be careful not to damage the ball joint dust cover.

On the left side:

1. Insert a lever (for automatic transaxles, you'll have to use a chisel) between the driveshaft and transaxle case (don't go in too for, or you will damage the seal). Tap the end of the pry bar or chisel lightly to pull the shaft out of the case just until it unlocks.

1. Remove the driveshaft locknut from the center of the brake rotor. Pull the front hub outward and toward the rear. Disconnect the driveshaft from the wheel hub. If necessary, use a puller. Then, pull the driveshaft straight out of the transaxle, supporting the joint on the transaxle side to prevent damage to the seal. Seal the transaxle opening with a clean rag.

On the right side:

1. Insert a lever between the joint shaft and driveshaft, then gently tap on the outer end of the lever to separate the two shafts.

1. Remove the driveshaft locknut, then pull the front hub outward and toward the rear. Disconnect the driveshaft from the front hub. If necessary, use a puller. Then, disconnect the driveshaft from the cross-shaft completely.
   
2. If it is necessary to remove the cross-shaft, remove the cross-shaft mounting bracket bolts, then remove the shaft and bracket as an assembly, being careful not to disturb the position of differential gears. Cover the opening in the differential case with a clean rag.

1. Installation is the reverse of removal, but note these points:

1. Check the transaxle oil seal for damage and replace it if necessary.
2. Replace the clips at the inner ends of the driveshaft or cross-shaft where they are locked into the differential gears in the transaxle.
3. Install the shafts into the transaxle carefully to avoid damage to the oil seal. Push the joint in on the differential side. Check the differential gears for alignment before attempting to install the shafts. If they are not aligned, turn them with your finger, as necessary.
4. After installation, pull the hub forward to make sure the driveshaft remains locked in the transaxle.
5. Install a new locknut onto the outer end of the driveshaft, adjusting wheel bearings as described in . Crimp the tabs over after they are aligned with the groove in the driveshaft.
6. Tighten the stabilizer bar link nut until 1 in. (25mm) of thread is exposed.
7. Torque the lower control arm-to-ball joint nut and bolt to 32-40 ft. lbs. (43-54 Nm).
8. Torque the control link for the lower arm and stabilizer bar to 9-13 ft. lbs. (12-18 Nm); except for the 1988-89 626s and MX-6s on which it should be 12-17 ft. lbs. (16-23 Nm).
9. Refill the differential with fresh fluid meeting proper specifications.

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Hello,you need to remove driveshaft to be able to get to the nut.Remove the nut (MAY BE VERY TIGHT) and pull the yoke or flange as you called it out & you can pop old seal out & new seal in.You may want to smear a tiny bit of grease or vasoline on outside of seal for easier installation & also on the rubber part of seal so itwon't get damaged when you re-install the yoke.Hope this helps.

Drive it home with a ball peen hammer.Just a note here,behind every leaking seal is a worn out bushing,so don't be surprised if replacing the seal doesn't stop the leak.Inside the tailshaft housing is a bushing that engages the driveshaft yoke.It should be a fairly tight fit when the yoke is installed and the driveshaft is bolted up.Grasp the driveshaft and yoke and wiggle it up and down,should be just a couple thousandths play.If excessive play,it needs a new bushing which entales removing the extension housing,driving out old bushing,and driving in new bushing which requires bushing drivers.But the seal,you just drive it in with a hammer.It will want to walk the opposite direction,so you have to press it down with your other hand while hitting it with the hammer.Also make sure the seal has some lube on it where it contacts the yoke.A dry seal will rip and leak.