Front Subframe Removal

Jeff wrote,

So... Anyone here have experience replacing their oil pan? Hit a dip in highway and bottomed front suspension... cracked oil pan. Looks as though the front suspension comes off and things become accessible.

In the same breath... anyone got a good pan (sump) they wish to sell? Also any opinions on what else I should go ahead and do while suspension is off...

This process was carried out on a 1985 Series 3 Jaguar Vanden Plas with a 4.2 liter Federal Spec engine. The procedure is rather straightforward with no special tools required, only patience and some good music. A few cold ones don't hurt either.

1. Disconnect the battery. More on this later.
2. Start by raising the car up at least 16 inches, more room can only help (measure this from road wheel center to the floor). This is to facilitate the lowering of the subframe and rolling it out from under the car. Depending on the size of your floor jack you may need more or less height. Go high to be sure.
3. Remove the wheels.
4. Remove the tie-rod ends from the steering arm. `Plews' makes a nice Pitman-arm puller that will remove the tie-rod ends without damage. Good time to replace the tie-rod ends!
5. Unbolt the steering rack from the sub frame. There are two bolts, 1/2" heads, holding the rack on the driver's side and one bolt holding the rack on the passenger side. Make note of the shims that are found between the bushings and the subframe. I placed the rack on a jack stand to keep it from pulling on the steering column and from hanging down on the passenger side.
6. Remove the front shocks. This is pretty straightforward. On the top mounts there is a thin spring retaining nut and then another regular 9/16" nut holding the shock to the top of the inner fender. The passenger side (US) is easy. The driver's side requires that you move the radiator reservoir tank out of the way to gain access to the upper nuts of the shock. For this there is a small bracket on the front of the tank retained by two Phillips head screws. The rear of the tank is held by a slotted head screw. Kept the hoses connected and tilt the tank to one side to gain access to the nuts.
7. Remove the front calipers. The four-pot calipers on the `85 are bolted on with three 19MM bolts - 3/4" is close but not the best. If your car was previously serviced by a non-Jag service shop, it is likely the mechanics wire threaded through each bolt head will be missing. Mine had lock-washers and thread lock holding them in place. Also, be cognizant of the very thin shims found between the steering arm and the front spindle. Replace them in the same spot upon re-assembly. Note: I placed jack-stands in the wheel wells to rest the calipers on. You might want to wire the calipers to the stands as they can fall off rather easily. This will stretch the flex brake-line and the solid brake-line out nicely, not a good thing.
8. Spray a good dose of WD-40 or Liquid Wrench on the upper sway bar link nut and threads. Use a wire brush to clean up the threads before spinning the 9/16" nut off. The threads tend to flatten down on the swaybar link if there is too much rust. If this happens and you can't use a die to clean up the threads you should replace this link. They are hard to come by and cost about $20 a piece for a new one. So spend a few minutes prepping the joint.
9. There is a small clip that holds the power steering lines to the sub-frame on the driver's side (US) of the car. It is just visible between the sub frame and inner fender, directly behind the suspension assembly. The clip resembles a trash bag pull tie and in my case had deteriorated to the point it just snapped when an attempt was made to open it.
10. There are also four small Phillips head screws holding the power steering lines to the front of the sub-frame rail. Unscrew these screws to remove the line brackets from the subframe. Either bag the screws with a label or screw them back in after the hoses are removed - They are small enough to get lost in the crud that will fall down as the sub frame is dropped.
11. Remove the 9/16" nut on the passenger side (US) engine mount. This one is difficult to get to. First remove the air cleaner; easy. Next, remove the ignition amplifier which is mounted on the front end of the intake manifold. It is held with two 1/2" head bolts. To gain enough movement you might need to disconnect the two wires that lead to the coil. Make note of which wire goes where - white with black strip to Neg. side and all white to Pos. side. (This is the reason I disconnected the battery) Once the air cleaner and amplifier are out of the way you should be able to reach down to the nut holding the engine to the mount. A 9/16" spanner works best - I couldn't fit a socket down there. There will be a small lockwasher and a larger flat washer under the nut.
12. Remove the driver's side (US) engine mount nut. Same as step 11 only much easier to get to.
13. Connect an engine hoist to the front hook on the cylinder head and hoist just enough to create a little tension in the chain. I placed the crane to the side of the car at and angle, main crane assembly by the front door., then extended the boom. I wanted to keep the legs of the crane from interfering with the jack which will ultimately hold the subframe and rolled out. To further supplement the support I also used a jack stand with a block of wood to support the rear sump. Some people might just want to do this and disregard the crane. I don't recommend it because the weight of the engine will cause it to tip forward when the subframe is removed. If you have a device to support the engine from above, as described in the service manual, all the better.
14. Using a floor jack and a wide board, raise the jack so it is firmly pressing upward under the subframe. Try to get it in the center so it will remain balanced during lowering.
15. Remove the 9/16" nyloc nuts from both of the rear subframe mounts located just behind the wheel assembly and directly below the brake line union.. There will be a large flat washer under the nuts.
16. Remove the front subframe mounting bolts. These have 1 1/8" heads so check the toolbox before you begin. The head of the bolt faces outward. Place your socket on the head and an open end wrench on the nut. I did it this was because the radiator hoses are in the way if you try to place the socket on the nut. Once removed, drift the bolt out. There will be two flat washers on either side of the rubber bushings so pay attention to which one go where.
17. Carefully lower the floor jack and subframe. It tends to hang up on the steering rack and sway bar so watch out for these contact points. Roll it out toward the front of the car. Two people can lift it up onto some strong sawhorses for disassembly.
18. Installation is the reverse of above.

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