Speedometer Pinion Gear Installation Help

[Zed Head]

I went out and looked and mine look like they were molded on.  I've worked in some molding shops so am familiar.  The ends don't look like the MSA unit at all.  You can see where the plastic flowed over the end on mine.

[Patcon]

54 minutes ago, Zed Head said:

I went out and looked and mine look like they were molded on.  I've worked in some molding shops so am familiar.  The ends don't look like the MSA unit at all.  You can see where the plastic flowed over the end on mine.

Thanks Zed

I took a few whacks at the one I con't use but it didn't want to move so I left it f or now. If we have too much speedo error, I will have to try to source the correct one. I have heard many of these are NLA

[Zed Head]

Your best shot would be to dunk it in boiling for a few minutes to heat it up and to let it absorb water.  They're nylon and nylon sucks up a lot of moisture which makes it softer.  It will expand and be less likely to break.

But if it is molded on there is probably cross-hatching or grooves to keep it in place.

[Patcon]

24 minutes ago, Zed Head said:

Your best shot would be to dunk it in boiling for a few minutes to heat it up and to let it absorb water.  They're nylon and nylon sucks up a lot of moisture which makes it softer.  It will expand and be less likely to break.

But if it is molded on there is probably cross-hatching or grooves to keep it in place.

Thanks, I didn't know nylon would absorb water, fascinating. I may try that. The tranny it fit's is an odd 4 speed out of Cody's goon. Really short in length with a large flat cover on the bottom. Will probably never be used again, so if I ruin it, it's not a huge loss

[EuroDat]

I don't think you will get it off in any usable condition. They knurl the shaft (like Zed said) before they mold the plastic gear to it.

Well that was the old brocken one I had on the fs5w71c transmission. Can't see any reason why the earlier units would be any different.

Can you use the Z speedo adaptor? If the cable fits, would be the easiest option.

[Patcon]

2 hours ago, EuroDat said:

I don't think you will get it off in any usable condition. They knurl the shaft (like Zed said) before they mold the plastic gear to it.

Well that was the old brocken one I had on the fs5w71c transmission. Can't see any reason why the earlier units would be any different.

Can you use the Z speedo adaptor? If the cable fits, would be the easiest option.

I will try to take a picture of the 4 speed adapter. It is a good inch longer than the Z adapters. The speedo gear is correspondingly longer. One is a 16 tooth and one is a 17 tooth. I don't remember which is which. For now I have the Z adapter in the transmission. I need to get the driveshaft shorted and the the shifter up through the tunnel. Then we'll do a road test for proper operation

[zKars]

Two words.  GPS speedometer...

[Patcon]

22 minutes ago, zKars said:

Two words.  GPS speedometer...

On a different note, can I pull the engine and transmission as a unit out of a 510?

[zKars]

11 hours ago, Patcon said:

On a different note, can I pull the engine and transmission as a unit out of a 510?

But of course! It needs to come out at quite an angle, but it can be done. Bit tricky because of the steering link rod that gets stuck on the bell housing, but I done

Mind you, the experience convinced me to make my rad support removable...

[Patcon]

How did you finish the removable section?

[zKars]

I have to go take pictures of the finished product, but its just a small plate on each side that covers the gap. Spot welded to the center, two bolts into captured nuts on the outer part. You only need tensile strength here, that metal is so thin (that front bar that ties it into the lower valance is needed to keep the hood from bending the crap out of it), and your rad provides 95% of the strength in this area. 

Edited February 4, 2019 by zKars

[John B]

Hi, I need some help.  I switched tire size and needed to put back the 20 tooth red speedometer pinion gear that was accurate for the original sized tires.  I've done this before, but this time I decided to buy new inner and outer o-rings.  The outer was fine to replace, but I knew I was in trouble when I had a heck of a time removing the inner.  I should have left that alone!

Here's my problem.  I couldn't insert the inner o-ring no matter what I tried.  The inner o-ring is metal covered by a rubber material.  It is not flexible.  I thought it had to go down the sleeve to where, it seems, there is a indentation.  Maybe I'm wrong about the placement??  Maybe it just lays in there "loose"??

Then I bought a new pinion gear with sleeve for a 280ZX, but although almost identical, it was 3/32" (.24cm) smaller in diameter so I couldn't use it.

Questions:  1) How to insert the inner o-ring.  Which side is up (toward the sleeve threading.  2) Why was the new pinion smaller in diameter?  Could it be for a 4 speed automatic?  I have a 3 speed automatic.

Thanks for any help.  I'm feeling pretty dumb now.

Pictures show top down (from threaded end) the pinion sleeve and the small inner o-ring.