Building a Track Car – Rear suspension on the Miata

The Miata project continues with more work on the rear suspension and drive train.  The axles have proven to be a real sore point.  They are held on to the hub with splines and these just did not want to let go.  The typical method for removal is to use an air chisel with a pointed end and hammer the axle out.  It did nothing but start to mushroom the end of the axle.  So next we tried the tool that is held on by two of the lugs and then a center bolt with a point on it is turned in to exert pressure on the axle.  More mushrooming.  We had already used plenty of PB Blaster and let it soak in.  We next tried heat.  It didn’t make any impression. 

The axles stuck in the rear spindles. The splash shields would be cut off later.

Mark has a press that is huge and can crank out over twenty tons of pressure.  The spindle casting was held in place and the press put into motion.  The casting started to flex and the axle didn’t move.  Hmmm.

We knew that with the big brake kit we would either cut the splash shields or just leave them off so we decided it was time to cut them free of the spindles.  Then we could get steel plates under the hub itself and press on the axle.  The press cranked away and at about 40,000 pounds of pressure the axle moved.  A couple more presses and it was out.  Now we knew what to do on the other side.

With the help of Performance Chassis in Cary we had new bearings, hubs, and seals waiting by to be installed.  First we had to get the old hubs, bearings and races out of the spindle. 

While the hub was fairly easy to press out the bearing races were another tough area.  They had to be hammered out, but care had to be taken not to score the inside surface of the hub.  That would have made it messy to press in the new bearing set.  After much careful hammering Mark had the races out and I worked on cleaning up the castings. 

Spindle with new bearings and hub installed.

After everything was ready I greased up the inside surfaces with dielectric grease.  I used it because it is not water soluble and I want that surface to be kept rust free in the future. 

Teh bearing assembly ready to be pressed in

The new bearing was positioned in the spindle and the press pushed it down far enough to ensure it was well in place.

Using an old outer race to press in the new one completely

Next an old outer race was used to push against the new bearing shoulder so it would be pressed in completely.

This clip sits behind the hub so now is the time to put it in and lock the bearing in place.

With the bearing set in place it was time to reinstall the large inner circlip to keep the bearing from moving.

The hub shaft has been greased and is ready to be pressed in.

Then the hub shaft was liberally coated with more dielectric grease in preparation for the hub being pressed into the bearing.

This old inner race will support the back of the new bearing so the new race won't be pushed out.

An old inside race was used to support the back side of the new inner bearing race as the new hub was pressed in.

The new hub is pressed in place

Then it was time for a new seal to go into the back side of the spindle.  The ball joint press kit I use has a ring that is prefect for the job.  It was placed on the metal ring of the seal and then a hammer drove the seal into place.

The new seal was next.

This was done to both sides.

This ring allowed the seal to be driven on without cutting the seal itself.

We ordered two rebuilt axles.  One was available and the other would be ready later next week.  Their splines would be liberally coated with anti-seize prior to assembly.

This kit is very useful

In the mean time the lower and upper control arms were cleaned and painted along with the bracing that was removed to get the rear differential out earlier in the project.

Cleaned, painted and ready for new bushings.

The control arms will get Energy bushings to replace the old stock rubber bushings.  The new bushings will be far stiffer and also rid the suspension of preload as the bushings will allow the arms to rotate freely.  Now the spring rate will all be within the actual springs (and the tires to a certain degree).

We will retain the stock rear sway bar and replace the bushings with Energy again along with the bushings on the bar’s end links.

After we get the rear suspension buttoned up it will be on to the front suspension.

This entry was posted in Automobiles, Car Stuff, Cars, Life and Cars, Modifying Cars, Racing, Road Racing, Sports Cars. Bookmark the permalink.

One Response to Building a Track Car – Rear suspension on the Miata

  1. markitude says:

    Great write up Jim! Those bearings were a real pain and I’m glad we got them done. I think your notes here will help others who wind up dealing with stubborn axles.

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