Default 4 speed or 5 speed tranny? 

Old 02-29-2012, 07:03 PM   #1
CJcountryboy is offline
CJcountryboy
New Jeeper
Vehicle(s): Nothing yet, but not for long!
 
Join Date: Feb 2012
Location: south alabama
Age: 16
Posts: 27
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 0 CJcountryboy is on a distinguished road
I am looking to get my first cj soon, and I am unsure whether to get a 4 or 5 speed. Would a 4 speed run high RPM's on the highway or interstate? I will be mainly driving it to school and at the beach, but I will sometimes drive it on the interstate to our hunting camp. Thank you.

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote
Register as a Member and remove this add!

Vote for Jeep-CJ.com daily!
Vote for Jeep-CJ.com

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 09:25 PM   #2
BusaDave9 is offline
BusaDave9
Admin
Vehicle(s): 1979 Jeep CJ5 with 304 V8, T18 Transmission, Dana 20 Transfer case with TeraLow 3:1 gears, 4.88 axle gears, Detroit Locker up front and Ox Locker in back with 1 piece axle shafts, 36" SuperSwamper SX Tires, Shackle reversal, MileMarker Hydraulic winch, MSD 6A ignition.
 
BusaDave9's Avatar
 
Join Date: Jan 2010
Location: Durango, Crawlarado
Age: 53
Posts: 3,949
Images: 353
Thanks: 216
Thanked 970 Times in 651 Posts
Rep Power: 10 BusaDave9 will become famous soon enough
The only 5 speeds to come in CJs were the T5 from the '80s. These tranies were crap. Very light duty. Actually most manual transmissions from the '80s were crap. The T176 was one exception. If you get a CJ from the '80s ask if it is a T176 four speed.

If you get a CJ from the '70s they often came with good strong transmissions but a lot of them were 3 speeds.

The T18 was the best tranny to come in a CJ. They were from the '70s.

Overall what I am saying is it's more important to get a good strong transmission that a 5 speed.

For more info on CJ transmissions check out this link: Manual CJ Transmissions
__________________
Busa

Click here to see my '79 CJ5

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 10:53 PM   #3
CJcountryboy is offline
CJcountryboy
New Jeeper
Vehicle(s): Nothing yet, but not for long!
 
Join Date: Feb 2012
Location: south alabama
Age: 16
Posts: 27
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 0 CJcountryboy is on a distinguished road
So is a 4 speed ok for 65 mph speeds? Would that be pushing it, or is it more about gearing?

Last edited by CJcountryboy; 02-29-2012 at 11:11 PM..

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 11:22 PM   #4
BusaDave9 is offline
BusaDave9
Admin
Vehicle(s): 1979 Jeep CJ5 with 304 V8, T18 Transmission, Dana 20 Transfer case with TeraLow 3:1 gears, 4.88 axle gears, Detroit Locker up front and Ox Locker in back with 1 piece axle shafts, 36" SuperSwamper SX Tires, Shackle reversal, MileMarker Hydraulic winch, MSD 6A ignition.
 
BusaDave9's Avatar
 
Join Date: Jan 2010
Location: Durango, Crawlarado
Age: 53
Posts: 3,949
Images: 353
Thanks: 216
Thanked 970 Times in 651 Posts
Rep Power: 10 BusaDave9 will become famous soon enough
Quote:
Originally Posted by CJcountryboy View Post
So is a 4 speed ok for 65 mph speeds?
Yes

Quote:
Originally Posted by CJcountryboy View Post
is it more about gearing?
Yes, It all depends on the gearing of the axles.
All 3 and 4 speeds have a top gear with 1 to 1 ratio.
5 speeds have overdrive and for that reason will be running lower rpm on the highway IF the axle gearing is the same.
__________________
Busa

Click here to see my '79 CJ5

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 11:26 PM   #5
BusaDave9 is offline
BusaDave9
Admin
Vehicle(s): 1979 Jeep CJ5 with 304 V8, T18 Transmission, Dana 20 Transfer case with TeraLow 3:1 gears, 4.88 axle gears, Detroit Locker up front and Ox Locker in back with 1 piece axle shafts, 36" SuperSwamper SX Tires, Shackle reversal, MileMarker Hydraulic winch, MSD 6A ignition.
 
BusaDave9's Avatar
 
Join Date: Jan 2010
Location: Durango, Crawlarado
Age: 53
Posts: 3,949
Images: 353
Thanks: 216
Thanked 970 Times in 651 Posts
Rep Power: 10 BusaDave9 will become famous soon enough
When buying a used Jeep it is common for a PO to install bigger tires without regearing the axles. That has the affect of tall gearing.
When I bought my CJ5 a PO installed 35 inch tires without regearing. The CJ had a T18 with Granny low first. Normally you would start out in 2nd but with the bigger tires it would be best to start out in 1st and then 4th was like an overdrive. It all depends on the axle gears and tire size.
__________________
Busa

Click here to see my '79 CJ5

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 11:33 PM   #6
BusaDave9 is offline
BusaDave9
Admin
Vehicle(s): 1979 Jeep CJ5 with 304 V8, T18 Transmission, Dana 20 Transfer case with TeraLow 3:1 gears, 4.88 axle gears, Detroit Locker up front and Ox Locker in back with 1 piece axle shafts, 36" SuperSwamper SX Tires, Shackle reversal, MileMarker Hydraulic winch, MSD 6A ignition.
 
BusaDave9's Avatar
 
Join Date: Jan 2010
Location: Durango, Crawlarado
Age: 53
Posts: 3,949
Images: 353
Thanks: 216
Thanked 970 Times in 651 Posts
Rep Power: 10 BusaDave9 will become famous soon enough

You can use the above chart to see what rpm your engine would be at top gear at 65 mph. If you have a 5 speed the rpm will be lower yet.
Normally you would want to shoot for anything in the green but if you are buying a jeep just test drive it on the highway and see what rpm it is running.
__________________
Busa

Click here to see my '79 CJ5

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote

Default Re: 4 speed or 5 speed tranny? 

Old 02-29-2012, 11:39 PM   #7
Saddle Tramp is offline
Saddle Tramp
Old Time Jeeper
Vehicle(s): 1978 CJ5, AMC 401, CJ T18, Scout Dana 300, 2-1/2" Lift, Locked
 
Join Date: Jan 2010
Location: Vancouver, USA
Posts: 797
Thanks: 2
Thanked 134 Times in 124 Posts
Rep Power: 5 Saddle Tramp is on a distinguished road
Check this out. It shows RPM in relation to tire size and gearing in the pumpkins.

http://4lo.com/calc/geartable.php

 

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!Stumble this Post!
Reply With Quote
Reply

Bookmarks

Tags
speed, tranny


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Swapping out 3 speed for a 4 speed Rippy Drivetrain 9 01-22-2013 12:49 AM
Wht speed do you shift your 4 speed at? CjDan Drivetrain 4 06-26-2011 07:22 PM
3 speed tranny stuck in gear Tonyrod123 Drivetrain 5 10-10-2010 11:45 AM
60' F134 - Would switching Tranny to SM 420 Improve Top Speed? CiviJeep Drivetrain 17 04-17-2010 12:29 AM
3 speed tranny Swap? Hotrod Robby Drivetrain 1 03-28-2010 01:39 PM


Vote for Jeep-CJ.com