How do I change the lower seal on the gearbox on a 98 Dodge ram 1500 4x4 5.9
Saturday, August 20th, 2011 AT 12:46 AM
Don't waste your time. Well, at least check it first, but a new seal usually won't solve a leak.
Have a helper work the steering wheel back and forth about 1/8 turn each way, about once or twice per second, then watch where the pitman shaft comes out of the gear box. If you look very closely, you'll see the shaft is moving sideways a barely perceptible amount before it starts to turn. I never autopsied one of those I changed years ago at the dealership, but I assume there's a bushing in there vs. The bearing they used to use, and that bushing gets hammered out. That lets the shaft move away from the seal. The permanent fix is a rebuilt gear box.
If you want to try to replace the seal, first you'll need a pitman arm puller and lots of muscles. Remove the large nut, install the puller, then hope you can get the arm off. Banging on it and some heat help while there's pressure pulling on it. Once it's off, there will be either a foam dust seal or a snap ring first, (I can't remember the order). Pull those parts out, then seems to me there's a second snap ring to remove.
Use something to measure how far up the seal lives so you're sure to pound the new one up far enough. To get the old one out, put a pail under the shaft, start the engine, then run the steering all the way one way or the other and put a little pressure on it. The pressurized fluid will blow the seal into the pail along with lots of fluid. If it refuses to come out that way, drill a small hole into the metal outer part of the seal, then run a self-tapping screw into it. That will give you something to tug on. It shouldn't come out real hard.
Put a little power steering fluid on the lip of the new seal, then stuff it in place and install the snap ring. The kit usually comes with a small packet of grease to put on next. That prevents corrosion from salt and water. Install the foam seal and any other parts I forgot about.
When you check the shaft for sideways play, you can check the ball and socket end of the track bar right away. It's mounted to the frame near the gear box. If you see any up and down movement between the ball and socket, that bar will let the front axle move sideways a little before the wheels start to turn. Both that and the steering gear box play are two very common causes of steering wander.