5 sp trans rear seal leaking
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.
Use the proper tool
A.There are many tools designed for this application. I recommend an inexpensive one.
This is an example,
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.
Oct 09, 2009 |
1997 Nissan Pickup