Change wishbone bushes

How to change wishbone bushes

This procedure details how to change the nearside upper and lower wishbone bushes on an S2 K-series Lotus Elise. The offside front is an identical procedure and most of the principles apply when changing the rear upper and lower wishbone bushes. The wishbones on the S1 Elise are very similar, so this procedure can also be used but some of the torque settings may be different.

Several types of wishbone bushes can be fitted to the Lotus Elise. In the OEM bush the central steel sleeve is bonded to the rubber so it does not pivot around it freely. The central sleeve in a nylatron or polyurethane bush rotates freely within the bush.

In this procedure I have fitted polyurethane bushes and have explained the different steps required for fitting all three types where appropriate.

Step 1. Remove the front under tray.

Step 2. Loosen the bolts on the front road wheel.

Step 3. Lift the car using the rear jacking point.

Step 4. Place a fixed support under the front jacking point and lower the jack.

Step 5. Remove the road wheel and then the brake pipe clamp.

Step 6. Remove the brake caliper.

Step 7. Remove the brake disc and cable tie the caliper out of the way. Ensure the brake pipe is not under any strain.

Step 8a. Remove the damper assembly.

Step 8b. Damper assembly removed.

Step 9. Remove the drop link from the lower wishbone.

Step 10. Remove the upper and lower ball joint nuts.

Step 11. Remove the upper and lower ball joints from the hub carrier. I prefer to use a fork splitter, but there is a high probability of damaging the ball joint dust covers. Some people prefer to use a scissor type splitter for this step.

Step 12. The ball joints are both split from the hub carrier. If you apply some lubricant to the ball joint dust covers when using a fork splitter it can prevent the dust cover from splitting.

Step 13. The retaining springs always come off the dust covers when using a fork splitter, but they are easy to put back on if lubricant has been used.

Step 14a. Remove the upper wishbone. There are four 1.5 mm thick spacer washers for both the front and the rear bushes. Make a note of where they are positioned as the number of spacer washers either side of the bush set the castor angle. The spacer washers must be reassembled in the same order as they came off. The same number of spacer washers must be placed either side of the rear bush as the front bush.

Step 14b. Remove the upper wishbone continued.

Step 15a. The upper wishbone has been removed.

Step 15b. The upper wishbone has been removed.

Step 15c. This photograph shows the upper wishbone off the car. Once again, remember that there are four 1.5 mm thick spacer washers for both the front and the rear bushes. Make a note of where they are positioned as the number of spacer washers either side of the bush set the castor angle. The spacer washers must be reassembled in the same order as they came off. The same number of spacer washers must be placed either side of the rear bush as the front bush.

One of the front bush (large diameter) spacer washers is a snubber washer that has rubber bonded onto one face. It is important to place this spacer washer in the correct position because it is there to prevent metal to metal contact when using OEM bushes. If you are fitting nylatron or polyurethane bushes you may find that you need to remove the rubber from the spacer washer in order to make them fit.

Step 16a. Remove the lower wishbone. If you are working on your own you will find that it is impossible to remove the rear lower wishbone bolt. To overcome this problem I cable tie a ring spanner to the lower wishbone so that I can remove the bolt from inside the footwell without an assistant.

Step 16b. If you are working on the nearside and you have a passenger foot rest you will need to remove it first and then you can access the wishbone bolt.

Step 16c. Lower wishbone removed from the car.

Step 17. Both wishbones have been removed from the car.

Step 18a. If you are removing a polyurethane bush you will need to tap out the stainless steel sleeve first. I use a slightly smaller diameter sleeve to tap out the sleeve. The same process can be applied if you are removing Nylatron bush sleeves. Do NOT do this if you are removing an OEM bush.

Step 18b. The polyurethane bush can be tapped out easily using a 7/8 inch socket. I have removed nylatron bushes by tapping out the bottom bush using a screwdriver through the centre hole from the top bush, but the bush is not reusable with this method as the screwdriver damages it. It is NOT possible to remove an OEM bush by using either of these methods.

Step 18c. I have added this photograph to show how an OEM bush can be removed from the wishbone. This photograph is an indication of how to remove an OEM bush as the bush shown is polyurethane and CANNOT be removed by this method. The top hat is much smaller on an OEM bush so the 7/8 inch socket on the left can break the top hat and push the bush through the wishbone easily. The 11/8 inch socket on the right will allow the bush to be pressed out of the wishbone by about 1 inch. The assembly will then need to be removed from the vice and reinserted as in step 18b. The 7/8 inch socket can be used to tap out the remainder of the bush.

The OEM bush is NOT reusable.

Step 19a. Different methods are used to press in the bushes depending upon if OEM, nylatron or polyurethane bushes are being used. In this procedure I have re-fitted polyurethane bushes which are reusable and can be inserted by hand. Nylatron bushes need to be fettled and pressed in to fit properly and OEM bushes also need to be pressed in.

Copper grease needs to be applied to the sleeves for nylatron and polyurethane bushes during assembly to ensure the sleeves rotate freely in the bushes. I have never fitted OEM bushes but pressing in should be able to be carried out using a heavy duty bench vice and suitable lubricant. Nylatron bushes can definitely be pressed in using a bench vice.

It is important that the bushes are inserted into the wishbones in the correct way. The drawing below shows the correct orientation to insert both OEM and polyurethane bushes into the front upper and lower wishbones. You will see that the top wishbone bushes are inserted from the outside and the lower wishbone bushes are inserted from the inside of the wishbone. The same orientation applies to the rear wishbones. Nylatron bushes are designed differently and two bushes are used for each joint, one bush inserted from either end.

Note:- I am not entirely happy with my polyurethane bush installation for the front upper wishbones and I am planning on making a modification by replacing the small diameter 1.5mm thickness spacer washers used on the top rear bush with the same diameter spacer washers used for the front top wishbone bush. I have found that the small diameter washers dig into the polyurethane bush when the car is driven like this:-

This is what I am planning to do:-

When the bushes have been fitted, the wishbones need to be re-attached to the car. The reassembly procedure is more or less the reverse of the disassembly procedure.

However:-

Be warned - it is very difficult to get the castor washers back in on the upper front wishbone assembly. A technique needs to be developed that is not easy to photograph nor explain and a great deal of patience is required to fit the assembly back together again. It is even more difficult if you are fitting nylatron bushes as you need to fettle them to ensure they do not bind when they are torque tightened. Some people superglue the castor washers together before re-assembly.

If you are fitting nylatron or polyurethane bushes then you can torque tighten all of the wishbone nuts without having to fully build the assembly.

If you are fitting OEM bushes then all of the components must be fitted loosely. The nuts cannot be torque tightened at this stage because the suspension needs to be loaded and sitting at normal ride height otherwise the bushes will try to rip themselves apart during use as they will be tightened at the wrong orientation.

Lotus recommend smearing grease on the wishbone bolt shanks before re-assembly when fitting OEM bushes and do not get any grease on the bolt threads. Lotus also recommend that some of the threads of the suspension bolts are applied with Permabond.

Step 19b. Torque tighten the upper wishbone nuts to 45NM after fitting the polyurethane bushes. Both front and rear are easily accessible. The same procedure applies for nylatron bushes, but you must loosely fit OEM bushes at this stage and assemble the suspension completely then load it to the normal ride height before torque tightening the wishbone bolts.

Step 20a. Refit the lower wishbone. If you are working on your own you will find that it is impossible to refit the rear lower wishbone bolt. To overcome this problem I cable tie a ring spanner to the lower wishbone so that I can torque tighten the bolt from inside the foot well without an assistant.

The front nut and bolt are easily accessible.

Step 20b. The rear lower wishbone bolt can be torque tightened to 45NM from inside the footwell.

Step 21. If you are working on the nearside you can replace the passenger foot rest.

Step 22. Torque tighten the drop link to 45NM.

Step 23. You can loosely fit the damper assembly at this stage. I find it easier to fit now rather than later because the hub carrier is not in the way. Ensure that you grease the top hat washers where they come into contact with the damper. The nuts cannot be torque tightened at this stage because the suspension needs to be loaded and sitting at normal ride height otherwise the damper bushes will try to rip themselves apart during use as they will be tightened at the wrong orientation.

Step 24. The hub assembly can now be refitted. The suspension needs to be loaded by placing a jack under the hub carrier and jacked to normal ride height. Both upper and lower ball joints can be torque tightened to 55NM although you will not be able to use a torque wrench on the lower ball joint nut if you only have a basic tool kit, in which case you will have to estimate the correct torque using a ring spanner.

Step 25. The damper assembly can now be torque tightened to 45NM and if you have fitted OEM wishbone bushes all of the wishbone bolts can be torque tightened to 45NM at this stage.

Step 26. Refit the brake disc. You may find that you will need to slacken off one of the brake pads if your disc has developed a lip. I use a clamp and an old steel rule on the face of the pad to spread the load.

Step 27. It is always a good idea to measure the thickness of your brake disc at regular intervals to ensure it is still within tolerance.

Step 28. Refit the brake caliper and torque tighten it to 45NM.

Step 29. Refit the brake pipe clamp.

Step 30. Refit the front under tray unless you are about to start on the other side of the car.

Step 31. Refit the road wheel and nip the wheel bolts up. Check to ensure there is no play in any of the suspension components by trying to rock the wheel from side to side by holding it at a quarter to three.

Step 32. Lower the car to the ground and torque up the road wheel bolts to 105NM. Press the brake pedal several times to get the pedal feel back.

Step 33. As this is major suspension work it is advisable to check and adjust the suspension geometry.