Quick story.

I had an old Cherokee. It was a real POS. Broke the 3.55 D35. Installed a different 4.10 D35. Left the front at 3.55.

Planned to scrap it all anyways so I got out on the road, 4-hi and drove in a straight line as long as I could hard on the throttle. Right around 100 yards and 50 miles per hour the transfer case exploded all over the road.

It was lots of fun. You should try it some time.

 

Then what did you do?

 

haha sounds like the type of shenanigans you should have gotten on video

 

With the dana 30 there are actually 2 different ring an pinion combinations that were used to get the stock "3.54" gear ratio. Some use 39 ring gear teeth and 11 pinion teeth (3.545, also reffered to as 3.55) where the others use 46 ring gear teeth and 13 pinion teeth (3.538, reffered to as 3.54). But these axles are still interchangeable without issues.

 

Put it on a trailer, stripped what I wanted and hauled the rest to the scrap yard.

 

Hmm, I did not know that.

 

a few of you are looking way to much into this

 

Yup

 

Oh thank god! For a second I thought everyone was gonna have something constructive to say... You telling me I'm working to hard to try and understand something that interests me? Ha!

 

Yes. that's exactly what I'm saying.

Bottom line, .01 isn't enough to matter.

Several ratios up or down matters.

If you're in 4wd you're going to be on loose stuff anyway.

 

Well, ok, it seems its time to move on. I'm really sorry if I've dragged this on too long, but please know its only because I understand very little about the process and this is how I learn. I don't want my enthusiasm to discourage anyone, so again, sorry if I have..

 

its all good. its just different pinion/ring combos different company's/axles use to achieve the same(ish) ratio.

the small difference doesn't matter. he'll I know a lot of people running around with unevenly worn tires front and rear that ends up making more of a difference than that .01

 

Sorry, I guess that was worded akwardly. When you wrote spool I interpreted that as a locked axle differential. lol You knock my diagram... too bad I made one anyway :P Apologies for the tires, they must be bias ply or something.



Okay so normally the axle differential gears make up for the difference between inner and outer tires on a single axle. However, unless you have 4 wheel steering, the front axle (both front wheels combined) turns faster than the rear axle (both rear combined). You can visualize this by drawing new circles in the middle of the inner and outer tracks for both axles, which would represent an average. I would've done this myself but I couldn't find a dotted-line edge in Paintbrush (I'm at work) so it would've just looked confusing.

Indeedy the 231 is locked internally which makes this impossible without binding. You'd either need a 242 which can act as a differential, or a higher gear ratio in the front.

I think this should make sense now lol.

lol yes

 

No man! Just didn't make sense! And now that I see the diagram where the front axle makes a larger diameter turn, it's much clearer. Thank you!

 

I think the inside wheel would be going slower, but the outside wheel would be going faster, but I think the overall differential speed would be the same speed as the rear...

as in you could have a outside wheel speed of 2500 rpm, and a 2300 inside wheel speed making an average of 2400 rpm at the differential

unless I am misunderstanding the relationship here and the diff takes on the speed of either the outside or inside wheel

so which is correct