280zx speedometer pinion gear swap

[ironhelix]

I have a late model 280zx 5speed and a 4:11 diff in my 240z and I'd like to correct the speedometer error (~10% high). A 20-tooth (red) pinion is needed but I'm having difficulty finding one. Courtesy only stocks up to the 19-tooth, which I now have. Any suggestions where to obtain one? Are there any other issues I should be aware of besides having to drain the trans first?

[grretc]

A place to buy:

http://www.nissanpartszone.com/parts/nissan-pinion-speedo~32703-78104.html

Source:

http://www.classiczcars.com/forums/attachment.php?attachmentid=1978&d=1051876395

I believe HS30-H provided the scanned photo of the part numbers while Leon found the site to purchase them. I have no personal experience buying from them, but I wouldn't hesitate to. They seem legit.

[Duffman]

If you are about 10% off, you may need the 21 tooth pinion gear, which has ~10% more teeth than the 19 tooth pinion gear. If so, will need the special housing that grretc reflects in his post for the larger pinion gear.

[LeonV]

A place to buy:

http://www.nissanpartszone.com/parts/nissan-pinion-speedo~32703-78104.html

Source:

http://www.classiczcars.com/forums/attachment.php?attachmentid=1978&d=1051876395

I believe HS30-H provided the scanned photo of the part numbers while Leon found the site to purchase them. I have no personal experience buying from them, but I wouldn't hesitate to. They seem legit.

You are correct! I got a 21T and it was something like $25 shipped.

[ironhelix]

Thanks for the help. The pinion and 2 new seals were $31 shipped. I'm still a little concerned about the pinion being a larger diameter. The engineer in me says the gears should bind. Is my concern unwarranted?

[olzed]

Your concern is unwarranted. The pinion shaft is slightly offset in the body allowing for different size pinions, by rotatong the whole body.

[ironhelix]

Just what I wanted to hear (see?). Thanks. Also looking forward to stopping the speedometer cable leak with the new seals.

[Duffman]

Ironhelix, I am hoping you bought the speedo sleeve assy. for 20 to 23 teeth pinion gears, part #32707-66300, otherwise will not fit in the smaller pinion gear housing and the gears will bind. Read what it says about the larger tooth gears in ggretc's post above; http://www.classiczcars.com/forums/attachment.php?attachmentid=1978&d=1051876395. The larger pinion gears will fit in the pinion gear housing for the smaller 19 tooth or less gears, but the teeth will not line up correctly in the tranny.

Edited April 24, 2012 by duffman

[ironhelix]

Thanks, I'm glad I asked. Looks like I have another part to order...