I have a 10 bolt open ( presuming, because when i turn the passenger side tire one way the drivers side rotates the opposite way) that I am trying to figure the ratio I have without opening the diff. When I rotate the wheel 1 full turn the drive shaft rotates approxamently ( I marked the universal and wheel with chalk )11/4 times, if I go 2 turns on the wheel the shaft rotates approx 2 3/4 turns. Am I doing this correctly, What ratio do you figure this is.
Thanks Ron

 

Not sure how this is easier than popping off the cover?

Do you want to know what the gears are, or just want to monkey around a bit?

Pull the cover. You've already wasted more time than that would have taken had you gone directly to it and you still don't know what the gears are. Go directly to the source of the info and get the straight facts without ambiguity.

 

I was just trying to do it without having to replace the gear lube and resealing the diff cover. I am trying to stay away from doing it twice. I know, thats the cheapo and lazy way of doing it.

 

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

Ya I read that, infact I copied it for referance, thats were I got the idea about just turning the rear drum to calculate my ratio, The problem I have is 1 turn of the drum give's me 1 3/4 turns of the drive shaft. That does'nt sound right to me, but I checked it twice.

 

That's why, if you REALLY want to know what the ratio is, you look at the ratio, instead of monkeying around.

Changed the fluid lately? Ever? I thought not. Then it needs it anyway. Consider this as a sign from Above that it's time to catch up on the overdue routine maintenance.

I guess I'm pretty dumb; but I'm just not seeing how this is a problem. Everybody else, you know, all the smart people like you, seem to think it is though, so I guess it must be somehow. Now I know just about everbody is smarter than me, and I'm used to that (I've even got a wife and college-age kids, so I'm already good with the notion that I am absolutely the stupidest blob of protoplasm to ever splatter itself onto this planet); but I haven't been able to get anybody to clearly articulate why they don't want to do this. Would you mind helping out a very dumb guy and tell me how doing the right thing the right way is somehow .... Iunno .... I guess, not right? I'm really struggling with this and I'd like some help. Help me understand.

 

Got stock tire size?

Put it in 1:1 gear (3rd gear in autos, 4th gear in manuals).....Drive at 70 mph, then look at the tach.

2.73 = 2700 RPM
3.23 = 3200 RPM
3.73 = 3700 RPM

 

open diff you have to have two people turn the wheels at the same time one revolution, then you count the driveshaft turns

 

Why would you waste the time to sit around and spin the tires, and attempt to count the driveshaft revolutions, if you can just pop the diff cover off and look...?

 

I know the rear end will need service soon, I am leaking fluid around the pinion shaft at the yoke. So I am going to tear into it in a few weeks, I am driving the car now untill then and just wanted to know as much as I could with out opening it now, and then opening it again in a few weeks.

 

Ummmm.... OK ... it takes like 30 seconds to pop the cover off, if you're slow like me; you could prolly do it faster. Takes longer to jack the car up and monkey with drive shafts and counting (maybe you're faster than me, when I count I have to match it to my fingers, so w/e) than it does to do the actual WORK.

Plus, in the time you've spent here arguing about it, you could already be done.

Now I admit I'm pretty dumb, but I fail to see how this has "saved" any time.

And of course, later on, you can just catch your newly changed fluid when you "tear into it" in a couple of weeks, and re-use it; not like you'd be losing anything.

But I'm just the dumb guy, so maybe I'm missing something? (besides a brain) I still haven't heard how it's somehow "better" to do all this fiddling around with counting and all sorts of other WORK like that, all of which leads to WRONG ANSWERS, when it's quicker and easier to just LOOK AT THE PARTS. Not to mention more accurate and reliable.

The "tach" thing is no better than any of the other guessing methods; at least not with a stock tach since they almost always read wrong (too high).

 

Well I never meant to argue with anybody, just trying to explain my thought process, Give yourself some credit you really aren't that dumb, you have me convinced and I guess I will be removing the cover to get the correct info. This is why I love this site, 90% will give straight no B.S. answers. THANKS from lazy me.

 

With an open rear, raise up one rear tire and count your drive shaft turns per 2 revolutions of the tire. If you've done this and you get 2 3/4 (after 2 tire revolutions) then you should have 2.73s. It would be difficult to see the difference between 2.92 and 3.08s, but you will have a general idea.