gearing and gen questios

just got an o1 tacoma. first is this a first or second gen, how does that work. what years. second. the truck was decked out when I got it, 35 inch tires and 6" db lift. but I dont think the gearing was ever changed. how would I know. is there a way I can count the rotations in nutrual to get the gear ratios?
and if it were stock 4.10, Im torn with 4.88/5.13. its an automatic, and Im gonna go down to 285/75/16 in a couple weeks., any one know what the rpms in overdrive would be at 65 with either of these? thanks!!

 

1995 was first year for the Tacoma. Sometimes called 1995.5 as it came out mid year. First gens also had changes in body/interior during the run. Your 2001 is a First gen.

Here is the sites tyre calc. Shows you the difference when changing tyre size, effect on speedo and gives RPM at 65 with various gear ratios.
http://www.tacomaworld.com/forum/tirecalc.php

 

Forgot to post. Here is a video on how to calculate your gear ratio that is pretty well done.

http://www.youtube.com/watch?v=i_Enyf67KTs

Hope it helps.

 

what I dont under stand is....is the other wheel moving too?..... I race RC short course trucks, and they have genuine spider gear diffs. but if only one wheel is spinning the the wheel would be moving twice as fast.....correct? so do I I lock up the other wheel? does it spin too?

 

no, rotation is constant, jack up the rear axle, mark the tire at six o`clock and the drvshft six o`clock,,, turn tire one revolution and count how many times the drvshft goes around, it will give you a good idea what the gear ratio is.

ie: 3 3/4 shaft rev's should be 3.73, 4 and a little is 4.10, 4 and a half is 4.56

get the jist??

 

I've been considering gear change options too. It is an oft discussed topic in the 1st gen section. 4.56 vs. 4.88s.

In a 1st gen auto, with 31" tires going 60 mph the rpms on overdrive are ~1900, the rpms in 3rd gear are ~2800

Based on some calculators I've used, with 33s going 60 mph:

4.10 4.56 4.88
1750 1950 2100 overdrive
2600 2900 3150 3rd gear

If these numbers are accurate, it looks like 4.56s are closer to stock ratios and might be better with 33s.

 

i did exactly that, and I got a little over two revs on the drive shaft........that dont seem right...even if it wer a stock 3.91. which is what the door sticker says

 

ok so it looks like .I got a 4.11,,,,,,after spinning both wheels,. but this is weird.....why would the pumpkin get hot after being on the interstate for 20 min? almost to hot to touch

 

They do get quite warm, especially when you have too large of wheels for the gear ratio, it means you're running with a higher torque on the driveshaft in order to sustain speed.

How about changing the fluid to a nice high quality synthetic? That should knock a few degrees off. Don't take it apart just to inspect it, better to look at the fluid first. If there are chunks of gear in the fluid, THEN you can start thinking about taking it apart to inspect.

Regarding spinning one vs both wheels: 4.11 turns of the input shaft = ONE turn of the ENTIRE output shaft (both wheels). If one wheel is held stationary, all of its revolutions will be transferred to the other side, so it will turn twice as much. Think of it as two turns of one half shaft = 1 turn of the full shaft.