8 replies to this topic

[Mark McCallister]

Two Q's:

 

1) When I was tapping the new pilot bearing into the flywheel (already reinstalled on the crank), it went in about .5 - 1mm past flush with the front of the flywheel.  I was expecting it to stop when it was flush.  Is it OK there, or should I pull the flywheel back off and look at the back side, or should I keep tapping until it *stops*?

 

2) I have an old dead transmission that I have removed the tailshaft casing from, removed the snaprings from the input shaft, and would like to further disassemble the transmission, partially so I can look at its guts and partially so that I can get the input shaft out to use as a clutch alignment tool.  What's the next step in pulling it apart, do I need to use a gear puller to pull the input or output shaft out?  Hit the side with 10 lb. sledgehammer a la Gallagher?  Everything seems quite secure and there are no further screws, nuts, or bolts to take loose. 

 

Thanks as always!

[Qik Nip]

I've pondered the same question and generally settle for getting it flush. If the input shaft needs it to be deeper in the bore, it will move it there when the transmission is installed. As for using the input saft as the centering tool for the disc, the new disc will come with a nice plastic one. Barring that source, you might be able to get one from the parts store.

Rick

[Bench Racer]

 

Two Q's:
 
2) I have an old dead transmission that I have removed the tailshaft casing from, removed the snaprings from the input shaft, and would like to further disassemble the transmission, partially so I can look at its guts and partially so that I can get the input shaft out to use as a clutch alignment tool.  What's the next step in pulling it apart, do I need to use a gear puller to pull the input or output shaft out?  Hit the side with 10 lb. sledgehammer a la Gallagher?  Everything seems quite secure and there are no further screws, nuts, or bolts to take loose. 
 
Thanks as always!

Have not taken a Miata transmission apart. In past years I did split a RX7 manual transmission. Never had the special tools to remove the stuff from the "bearing housing". At the time I wanted to see the stuff that was causing the transmission to jump out of 4th gear. Broken syncro spring and syncro. At minimum a deep tublar socket is required almong with a loooong jaw bearing puller. If you have the factory shop manual you'll get a good idea of what it takes to do the job. My intent is to sometime over the next couple months to fab these two tools and get into taking a transmission apart for the same reasons as you, because I'm another curious cat. If you don't have a factory shop manual pm me your address and I'll send copies of the transmission section. I looked for a youtube video on the subject and found nothing.

[FTodaro]

Two Q's:
 
1) When I was tapping the new pilot bearing into the flywheel (already reinstalled on the crank), it went in about .5 - 1mm past flush with the front of the flywheel.  I was expecting it to stop when it was flush.  Is it OK there, or should I pull the flywheel back off and look at the back side, or should I keep tapping until it *stops*?
 
2) I have an old dead transmission that I have removed the tailshaft casing from, removed the snaprings from the input shaft, and would like to further disassemble the transmission, partially so I can look at its guts and partially so that I can get the input shaft out to use as a clutch alignment tool.  What's the next step in pulling it apart, do I need to use a gear puller to pull the input or output shaft out?  Hit the side with 10 lb. sledgehammer a la Gallagher?  Everything seems quite secure and there are no further screws, nuts, or bolts to take loose. 
 
Thanks as always!

Mark , I assume the 90 is the same as a 99. On a 99 the bearing should be flush with the flywheel. If its not in to far it should be ok but I would wait for DAve or Drago to chime in.

[SaulSpeedwell]

We just had a pilot bearing discussion somewhere else on here recently.  I like the flanged version of the bearing, and if you get the press fit right (i.e. sieze the flywheel) it will never blow up.

[Mark McCallister]

Thanks guys - I decided I was happy with the pilot bearing fit, and left it as is.  Will look for the flanged pilot bearing next go-round, thanks for the tip Mark B.  The other advantage of that solution is that it guarantees the pilot bearing will be in exactly the same plane as the flywheel, which I don't think I can really guarantee with the tapped-in fit.

 

The old transmission finally gave up its input shaft, which became a perfectly fitting clutch alignment tool, thanks to whoever suggested that here (I think it was Drago?).  Ironically, the 10 lb. sledgehammer did figure prominently in the task of separating the bellhousing and bashing various other bits loose.  I enjoyed that part.  I'm sure I will be finding chunks of broken gear teeth in odd corners of my garage for a while.    

[steveracer]

Where does one locate these flanged bearings?

 

I've not heard of them.

[Mark McCallister]

He said in another thread on transmission replacement - "(NAPA used to sell these by default, but you can get them from any bearing place too)"

[SaulSpeedwell]

I'm going to order another bunch of them, but if you figure out Bearing Company "X's" nomenclature, it gets easy.  When they flange (or snapring flange) a bearing, the fit tends to get looser because they realize you have the flange there.  Both benefit us - the flange to avoid "pushthrough", and the looser fit keeping the bearing from being crunchy after we press it in.

 

For example, this bearing is a 6202 in Koyo-speak ... and there are a ton of prefixes and suffixes for the fit, the seals and shields, whether it gets greased, whether it is flanged, etc.  Figuring out the nomenclature is "easy" - but figuring out which one is "off the shelf" and $15 instead of $76 is hard.  If you have a good local bearing wholesaler, work with him.  Else, work through someone who has already figured it out.  I'm not sure what NAPA sells these days.  If someone knows, let the rest of us know