Need higher overdrive 13 or 18 speed - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by 5.9 rookie, this thread has received 10 replies and been viewed 2265 times.

 2Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 04-10-2016, 04:20 PM Thread Starter
Junior Member
 
Join Date: Nov 2010
Location: caddo mills, tx
Posts: 148
Points: 45,814
Thanks: 9
Thanked 14 Times in 12 Posts
Need higher overdrive 13 or 18 speed

This is in a new to me truck, from California. It's a 94 379 with a 425, 18 speed, with 411 on tall rubber. At 65 mph I'm tacking 1800rpm. I originally thought it was wrong. With an rto 18speed, I know believe this is correct. Which trans should I get to run 65 at 1600 rpm, the rtlo series? And I'm not opposed to running a 13 speed. And really don't want a double over. For some reason I can't get the road ranger road speed site to come up. Thanks Tony
5.9 rookie is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 04-10-2016, 04:45 PM
Senior Member
 
Join Date: Dec 2008
Location: tulsa ok
Posts: 1,138
Points: 48,478
Thanks: 28
Thanked 234 Times in 200 Posts
theakerstwo is offline  
post #3 of 11 (permalink) Old 04-10-2016, 07:04 PM Thread Starter
Junior Member
Threadstarter
 
Join Date: Nov 2010
Location: caddo mills, tx
Posts: 148
Points: 45,814
Thanks: 9
Thanked 14 Times in 12 Posts
Thanks theakerstwo, but the road speed calculator won't work for some reason. I did look at trans ratio chart tho. Correct me if I'm wrong but the last two gears ([email protected]) on an rtlo trans, would both be overdrive. .87 for 17th and .73 for 18th. This must have what my old truck had. And the rto is just overdrive in 18th .87. Would there be any problems switching from rto to rtlo ?
5.9 rookie is offline  
The Following User Says Thank You to 5.9 rookie For this addition to TDG:
therabbittree (01-08-2017)
post #4 of 11 (permalink) Old 04-10-2016, 08:50 PM
Senior Member
 
Join Date: Dec 2008
Posts: 502
Points: 48,813
Thanks: 74
Thanked 54 Times in 43 Posts
They are the same size. You will want the RTLO-16913A trans. Top two gears will be .86 and .73. If you don't have a cooler you will need to get one.
theakerstwo likes this.
Les2 is offline  
The Following User Says Thank You to Les2 For this addition to TDG:
5.9 rookie (04-10-2016)
post #5 of 11 (permalink) Old 04-20-2016, 03:57 PM Thread Starter
Junior Member
Threadstarter
 
Join Date: Nov 2010
Location: caddo mills, tx
Posts: 148
Points: 45,814
Thanks: 9
Thanked 14 Times in 12 Posts
Would the low gear and reverse, be the same on rto and rtlo 13 speed? I can't figure that one out on the fuller ratio chart. I had a guy tell me with the rtlo I could go up one rear end gear ratio. From 411 to 390 and still have same low as the 411 with the rto 13 speed. Many thanks
5.9 rookie is offline  
post #6 of 11 (permalink) Old 04-20-2016, 05:27 PM
Junior Member
 
Join Date: Apr 2016
Posts: 4
Points: 273
Thanks: 0
Thanked 0 Times in 0 Posts
Interesting machine Good luck with it.
saturnalley is offline  
post #7 of 11 (permalink) Old 04-21-2016, 03:18 AM
Senior Member
 
pichu2's Avatar
 
Join Date: Feb 2010
Posts: 489
Points: 70,647
Thanks: 199
Thanked 81 Times in 66 Posts
hey rocky The easiest way is to change the differential and you can get it in junker for $750 and another for $500 if you put the RTLO cost around $2000 just to get 0.5 more fast and 150 rpm less this is nothing , and you had another problem rtlo is 4 inches long and may you nned too chance the joke ,and need cut the mainshaft and center bearing the best way put a 3.73 is best , much better than 3.70 for a 425 and rto 152 or 15618 those boxes are strong
pichu2 is offline  
post #8 of 11 (permalink) Old 04-21-2016, 02:31 PM Thread Starter
Junior Member
Threadstarter
 
Join Date: Nov 2010
Location: caddo mills, tx
Posts: 148
Points: 45,814
Thanks: 9
Thanked 14 Times in 12 Posts
Thanks pichu, it's a different truck. I'm buying a glider kit truck. I wanted 411 with 13 speed. They had one on lot with 390 and rtlo 13 speed. The salesman said the low would be same because the new 13 speed was lower geared than old one. They finally agreed to switch them to 411 for me. It's gonna be a dump truck so I want 411s. Hopefully I can get this deal done today.
5.9 rookie is offline  
post #9 of 11 (permalink) Old 04-21-2016, 04:34 PM
Senior Member
 
pichu2's Avatar
 
Join Date: Feb 2010
Posts: 489
Points: 70,647
Thanks: 199
Thanked 81 Times in 66 Posts
hhmm !!!the saleman is simple a saleman he is wrong just for sale something !!!!!a 13 RTO or RTLO !!!!DONT had lower !!I think in your case it would be better one of 15 ,15715 because 15 has 5 lower or like doyou had 15618 !!!those trasmissions had 5 lower speed perfect for botton dump or 10wheelers if you put a 13 your strees your clutch any time when you want to go so slow behing the alfalt machine

Last edited by pichu2; 04-21-2016 at 04:41 PM.
pichu2 is offline  
post #10 of 11 (permalink) Old 05-04-2016, 05:56 PM
Junior Member
 
Mr. Haney's Avatar
 
Join Date: Apr 2009
Posts: 631
Points: 72,771
Thanks: 16
Thanked 449 Times in 211 Posts
Quote:
Originally Posted by 5.9 rookie View Post
Thanks pichu, it's a different truck. I'm buying a glider kit truck. I wanted 411 with 13 speed. They had one on lot with 390 and rtlo 13 speed. The salesman said the low would be same because the new 13 speed was lower geared than old one. They finally agreed to switch them to 411 for me. It's gonna be a dump truck so I want 411s. Hopefully I can get this deal done today.
First stay with the 3.90 and 11R24.5 tires. Use a RTLO18918B transmission. This will have a low gear ratio of 14.42:1 with the top gear being a 0.73:1 overdrive. The glider needs a modern electronic engine to communicate with the other computers in the truck properly

Now the real thing is you haven't stated what engine you're installing in the glider for your dump truck.

Most modern engines are designed to turn low RPM for fuel mileage. Yet have the power to pull gross weights of 80K Lbs easily. Unless you plan on going to very high gross weights, you don't need a 4.11 rear axle ratio. Even in off road conditions at 80K Lbs you don't need that gear ratio

Gear the truck for fuel mileage and the work being performed. Stop thinking about the old mechanical motors and the way they were designed to work versus how you want to set this truck up with a modern electronic engine.
dbennett48 likes this.
Mr. Haney is offline  
The Following User Says Thank You to Mr. Haney For this addition to TDG:
Oxbow12 (05-08-2016)
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Higher altitude jorr83 5.9L Cummins (2003-2007.5) 3 02-08-2011 03:18 AM
Does higher elevation create higher or lower cylinder pressure? WasGas General Ford Truck and Excursion 1 10-19-2010 02:51 AM
Higher rpms on 6.2? Hotrodx199 6.2L Diesel Engine 2 05-16-2010 03:44 AM
Higher EGT'S POWER STROKE 99 1994-2003 7.3L Power Stroke 2 06-14-2007 07:57 PM
2006 5500 2 speed/overdrive tbone5500 Medium and Heavy Duty 7 01-23-2007 03:34 PM

Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome