33" and axle and gearing question

[ChuckD]

I have the 5-speed manual and have been running 4.88's with 31's for the last few months (haven't gotten around to trimming the fenders for the 35's). I'm not sure how the gearing would work on an automatic, but IMO 4.88's and 31's are meant for each other - I'm not sure if I'll be able to tolerate 4.88's and 35's (I'm being serious, here!).

Do you start off in 5th gear, I agree off road that would work really well, but can you actually get to highway speeds. 4.88's and 35's should be pretty good, it would be like running 31's with 4.10. I thought that was just about perfect, start out in second gear and had passing power in OD.

 

[red87cherokee]

Do you start off in 5th gear, I agree off road that would work really well, but can you actually get to highway speeds. 4.88's and 35's should be pretty good, it would be like running 31's with 4.10. I thought that was just about perfect, start out in second gear and had passing power in OD.

I had originally planned on going to 4.10's, based on keeping my gearing approximately what it was when stock. The shop recommended 4.56 for 33's and 4.88's with 35's. After creating a conversion chart on Excel, I decided that 4.88's would be tolerable temporarily even with 31's. I was surprised at how nice the 4.88's are with 31's.

Here is the conversion chart I made (and used before correcting the speedometer).

__________________________
ACTUAL . . . . . . . . . . INDICATED
SPEED . . GEAR . . . RPM . . . . MPH

. 20 . . . . 2 . . . . . 2506 . . . . . 30
. 20 . . . . 3 . . . . . 1506 . . . . . 30
-
. 35 . . . . 3 . . . . . 2635 . . . . . 52
. 35 . . . . 4 . . . . . 1882 . . . . . 52
-
. 45 . . . . 4 . . . . . 2420 . . . . . 67
. 45 . . . . 5 . . . . . 1912 . . . . . 67
-
. 55 . . . . 4 . . . . . 2958 . . . . . 82
. 55 . . . . 5 . . . . . 2337 . . . . . 82
-
. 65 . . . . 5 . . . . . 2762 . . . . . 96
__________________________

As you can see, in 5th gear 65 MPH is only 2762 RPM. Basically, with the speedometer error I already had with the 31's, the 4.88's have had the apparent effect of increasing my indicated speed vs actual speed by about 50% in each gear.

I start off in 2nd gear, go quickly through 3rd gear, do all my around town driving in 4th gear, and use 5th gear at anything over 45 MPH. Works great. The gearing (vs engine torque/horsepower) for 2nd through 5th on the highway with 4.88's is better than the gearing in 1st through 4th on the highway with 3.07's (5th was nearly useless except at freeway speeds).

I actually wonder if I'm going to be disappointed with the 4.88's when I actually get the 35's installed.

EDIT

FWIW - The weather-guessers have indicated we could be seeing some snow and ice this week, so I installed my old studded snow tires (235/75R15's). Still not a problem, even at highway speeds - it has only had the effect of increasing the RPM's at highway speeds by about 150 turns. I cannot imagine running anything less than this gearing.

To quote the old Alka-Seltzer commercial "Try it, you'll like it."

 

[crazy4mopar]

Whoa, my head hurts!
I just placed a call to my local yard and they're searching for one now. What gears were in your axles, or did you have to regear? What about the front steering hooking up to the 44?

It came with 3:55's Still working on the steering as $ allows
I did put in a set of high alloy Moser axles and a spool

 

[sredish]

What do you think about that price? That price is also with whatever gears you request. Its totally new shafts and all the goodies.

I figure buy a junkyard axle, regear, and all, I'll be looking at no less. And I'm unsure of the condition of the axle.

They'll sell me a Ford 9" rear with either a 27 or 31 spline and a ls or open diff. I told them a 31 spline with open diff for $390 plus shipping