I installed some 245/75-16 tires on Nismo rims and it of course through my speedometer off which I already expected.
Problem is, it's off by 10mph which is more than I expected and before it gets me in trouble with the local police I want to fix this problem.
I have "searched" before but the only threads were from back in 2008 and none came to a definite answer as to what was actually available and if it would fit or work on our trucks.
I called the local dealer and they seem to think that nothing was ever available for the 720. Someone else suggested the use of gears from the 280z...I don't know if they will work or not.
Please help me if you have any experience with this issue and can help, I'd appreciate it.
Just a side note on this.
You need to get a speedometer gear and shaft from a early '80's Z model and you have to get the bushing and O-ring for the Z model and not for the 720 pickup.
The shaft end, taper, etc. are all different, as noted above, and the new bushings are needed to properly seal the different shaft to prevent oil leaking out.
They are cheap enough to purchase so it is really not a big deal, just take note (or better yet take pictures) of how the seal sits inside the housing before removing it.
To get the old seal out I used a paint can opener like you get at Lowe's or Ace Hardware, they have a loop on one end for your finger to go through and on the other end it looks like a flat head screwdriver with a bent tip, you just stick it through the bushing and hook it on the back side and then pull it out, very simple.
Be sure to lubricate the O-ring and bushing before installing to reduce the chance of cutting them on a burr of metal and causing a leak.
Thanks for following up to your own discussion! I'm sorry I didn't have any definite answers so I kept my mouth shut. Although, the same transmissions were used in other vehicles, so it stands to reason there should be a multitude of other gears available. And some of these trucks had speedometer outputs on the transfer case instead of the transmission, so that opens up another whole set of possibilities... Although I'm not quite sure what the heck I got the transfer case with the speedometer output out of.
I thought I would follow up because it always drives me nuts when I am looking for certain information, think I have found what will lead me to an answer, and then the thread dies with no definitive answer.
My truck is a 4x4, so it does indeed run out of the transfer case but they appear to use the same gear setup and just run it from a different location.
I still have to test it for accuracy though.
Is this the large O ring between the pinion sleeve and the case? They are all the same from '62 Patrol into the 2000's, fit manual and automatic, and may be being used today. 32710-14600
The smaller seal in the end is 32709-14600.The 720 parts does not show this because it is sold as an assembly. To get one you need to buy the entire sleeve. But from any other year should fit.
The O-ring between the sleeve and the t-case is the same.
The internal seal, I assume, would have to be different to seal around the smaller shaft of the 280 pinion, unless the bevel on the shaft is the same?
Either way, if you have it apart it is a wise idea to replace it with a new one.