Sunday, February 12, 2012

twilight zone

Everyone with any Z vintage, albeit 24o, 26o, or 28o, inevitably has to deal with the dreaded spindle pin. I preformed this operation previously on my 28o z about 2 years ago, and if you go back through the un-worded entries from 2o1o you may see some pictures from that fateful weekend. I was able to remove one by hammering it out, and the other by sectioning it with a hacksaw into 3 pieces, separating the suspension column from the control arm, and then hammering each section out.

I was not so lucky with the 24o z.








The first pin came out just fine, so fine in fact it could probably be re-used. The threads on the ends of the hammering side are not even mushroomed as is normally the case after a harsh removal.  

Then came the 2nd side.




There are no pictures of the extremely frustrating period of trying to hammer out the pin and realizing that it wasn't going to happen. I then began hack-sawing the sections apart as I had before on my 28o. I should have known this was going to happen because when I re-installed the rear suspension from the 24o for the first time a few months ago, I noticed all the bushings had been replaced with fresh red polyurethane, except the spindle pin bushings on this side.

The previous owner, and now me, knew why.






After going through 2 hacksaw blades and 3o mins of my life, the pin was sectioned and the control arm fell away. It was good exercise if nothing else. The interesting part came after hammering out the sections from either side of the control arm.

The center section from the suspension column did not budge. This was a new development from previous experience.



I borrowed a 12 ton press from Giffin and went to town. The center section of the spindle pin didn't even think about moving. In fact, I think it actually got more stuck because it looked like the side I had hammered and now pressed may have mushroomed inside the suspension column a bit.

This may have just been my imagination.






When in doubt, go bigger.

I heard of a NAPA down the road that had a fabled machine shop "in the back" and brought the column, still assembled, to them. As I walked in carrying the coilover, brake caliper, rotor, and hub assembly in one hand, and a look on my face that I'm sure did not match most customers, I was directed to the back room. Upon crossing into this "back room" I instantly went back in time.

Two guys who were at least twice my age were running around running multiple machines that were at least twice their age. One gave me a funny look and humored me as I explained what I needed. After a few interpretive words between us, I started disassembling the caliper, removing it and the rotor. One of the men took the suspension column, still with the new coil and shock installed I may add, and walked over to the 2o ton press.  

Maybe I should have been more prepared before arriving in the twilight zone and spent more time disassembling. The second man mumbled something that was completely un-interpretable, walked away, and returned with the correct sized anvil and push pins. 



It didn't work.

After applying 2o tons of pressure DIRECTLY on the pin while supporting it on the od of the column from the other side, nothing happened. This perplexted the two men greatly, and the first one recommended I go up the road where they had "the biggest press in town." I thought this one was pretty big, compared to the spindle pin at least. I was just happy my suspension column, and coilover and shock, were still in one piece.

I apologize, but I don't have any pictures from the second shop, as even less happened there. The machinist looked at the suspension column and imedately said "no", that his 1oo ton press would simply crush the whole thing, and that I should drill it out or buy a new one.





I centered the bit as best I could in the side of the spindle pin which had gotten such a beating, and began to drill. Starting at the smallest bit, I worked my way up until I had drilled about 1/2 the diameter away. I didn't want to drill away the entire pin, or drill too much that I would be forced into this as I did not have a drill press or long enough bits to pass through the entire column. I left the exterior wall thick enough to support some pushing, but drilled as much as I could in the center to allow mushrooming inward.

It was a theory.







Victory!

The first positive pressing results were with an appropriately sized socket pushing on the thick outsides of the spindle pin. The poor socket then immediately bottomed out on the suspension column because after about 1/2 an inch it was too thick to push into the spindle pin hole. I bought a steel rod of the correct diameter, cutting it into various lengths, and used it to press the rest of the pin out.



Powerhouse.

3 comments:

  1. nice work, keep up the posts! good information

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  2. Cheers! I need some motivation after this weekend. I'm about 3oo pictures behind currently, but I'll post some teaser pic's (maybe even video) when things progress.

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  3. I'm so glad we survived that, I feared for my life with that press.

    ReplyDelete