Checking gear ratio
#1
Senior Member
Thread Starter
Join Date: Apr 2013
Location: Dawson Springs, KY
Posts: 780
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1985
Model: Cherokee
Engine: 2.5L
Checking gear ratio
I am trying to figure out what gear ratio I have but I am missing the tags on both the front and rear axles. It is an 85 with the 2.5 I4 so I know they are in the 3.73 to 4.56 range.
I know I can turn the drive shaft and compare revolutions versus one revolution of the wheel, but right now I have no jackstands and only one jack, so I can only lift one wheel at a time. What I am wondering is would that result in a figure that is off by 2x because of the spiders or would it be correct as measured? It has been too long since I did it before I have forgotten how it works out.
I know I can turn the drive shaft and compare revolutions versus one revolution of the wheel, but right now I have no jackstands and only one jack, so I can only lift one wheel at a time. What I am wondering is would that result in a figure that is off by 2x because of the spiders or would it be correct as measured? It has been too long since I did it before I have forgotten how it works out.
#2
CF Veteran
To be 100% sure you can remove the cover & check the numbers on the ring gear. The last 2 numbers are the ones you want. Divide the first number by the second number.
#5
Senior Member
Thread Starter
Join Date: Apr 2013
Location: Dawson Springs, KY
Posts: 780
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1985
Model: Cherokee
Engine: 2.5L
If I divide the two numbers I get 10.16 maybe this one is older and doesn't follow the standard profile. Checking the rotations of the drive shaft versus the rotation of the carrier it looks like it is a 3.73:1 which seems high for a 4 cylinder but I think it is possible behind the three speed auto.
#6
CF Veteran
They may have changed the placement of the numbers by year, manufacturer, or gear ratio.
41/11=3.72... (the first 2 numbers)
41/11=3.72... (the first 2 numbers)
#7
Senior Member
Thread Starter
Join Date: Apr 2013
Location: Dawson Springs, KY
Posts: 780
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1985
Model: Cherokee
Engine: 2.5L
Ahh that pretty much verifies what I counted. Just over 3.5 turns to 1
Thanks
It was strange when I started opening it up when compared to most D35 photos I have seen here. The fill plug was screw in metal not rubber and used Torx driver to remove as did the cover bolts. The cover bolts have little rubber tips on them which I have never seen before too. I pulled one off before I figured out what it was, thought at first it was some old silicon stuck to the end, but the piece just pushed back in so all was ok.
Thanks
It was strange when I started opening it up when compared to most D35 photos I have seen here. The fill plug was screw in metal not rubber and used Torx driver to remove as did the cover bolts. The cover bolts have little rubber tips on them which I have never seen before too. I pulled one off before I figured out what it was, thought at first it was some old silicon stuck to the end, but the piece just pushed back in so all was ok.
Thread
Thread Starter
Forum
Replies
Last Post
riderjay253
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
09-16-2015 11:31 AM
Trevordickya
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
09-04-2015 03:28 AM
Docruiz
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
0
09-02-2015 07:54 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)