700r4 overdrive question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-03-2012, 05:55 PM
Registered User
 
Last photo:
Join Date: Oct 2010
Location: az
Posts: 204
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
700r4 overdrive question

Hey you trans/rear gears pros. I have a th350 and a little 283ci in my 56 chev. with 3.36 rearend. I want better overall gas mileage. I`m thinking about putting in a 700r4. About what speed does the overdrive kick in?
50 mph or? Most of my driving is around town near 40/50 mph. Would I be better to stay with the th350 and just change to higher rear gears such as
3.23 or? Comments welcome. Thanks

    Advertisement

Last edited by db flyer; 09-03-2012 at 05:57 PM. Reason: wrong word
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-03-2012, 10:56 PM
blwn31's Avatar
Registered User
 
Last photo:
Join Date: Mar 2011
Location: Placerville,CA
Posts: 170
Wiki Edits: 0

Thanks: 0
Thanked 13 Times in 13 Posts
With the 700, you can manually lock up the converter in any gear, if you wish. Many people will manually lock up in 3. But, you have to remember to unlock it when you are coming to a stop. Third gear is 1:1 like your TH350. Fourth is overdrive, then you have converter lock up. I have my car set up to lock up automatically when the trans shift into 4th. Most of the time the trans will lock the converter at about 45 mph under light throttle and about 60 mph under mild throttle.

Keith
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-04-2012, 08:43 AM
Registered User
 
Last photo:
Join Date: Oct 2010
Location: az
Posts: 204
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
Do all 700r4 have the lockup feature? Is this standard or is this a special torque converter feature? As you can tell, I know very little about this trans.
You mention that you have yours set to lockup at 4th gear shift, isnt that the overdrive gear [4th] ? I dont know much about converters either. As I mentioned before, I want the best all around gas mileage I can get around town. Thanks for any help.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-04-2012, 11:25 AM
blwn31's Avatar
Registered User
 
Last photo:
Join Date: Mar 2011
Location: Placerville,CA
Posts: 170
Wiki Edits: 0

Thanks: 0
Thanked 13 Times in 13 Posts
Yes, I believe all 700's have the lock up converter and, 4th gear is overdrive. Lock up is just that, drops the RPM about an additional 250 revs.
If you are just wanting the best mileage around town, and your speeds are under 45 MPH, I would say the TH350 that you have is the best bet. I don't know if I would change gears in the rear end. 3.23:1 is a pretty good gear.

Keith
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-04-2012, 01:14 PM
Registered User
 
Last photo:
Join Date: Oct 2010
Location: az
Posts: 204
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
Well, I drive about 65% in town, but even in town, my speeds average about 40/50 mph. I wonder if the 3.23 gears would be better than the 3.36 gears I currently run now. I have heard a couple guys on the forum say somthing like they have 3.08 gears. I dont know if I got the numbers right. Thanks
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-04-2012, 04:07 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
Before you run out and spend big bucks on a OD trans or swap rear gears ,, try this.
Install some rear tires on your car that are 10%or so taller in diameter than the present rear tires.
This will reduce the effective gear ratio and hiway cruising rpm.
Drive it around for a month or so and measure the real overall fuel mileage change.

Trying taller rear tires is easy and cheap and can be effective.

The th2004r is a real nice OD trans for your purpose.
The gear ratio spread is way better than a th700r4.

The real fun and bang for your buck deal with adding a OD trans (especially with a small motor)
is to combine it wiht a gear ratio swap like a 4.10.
Now your lil 283 really hauls when you rug it and cruises at low rpm in OD.
the .67:1 OD ratio of a th2004r tames down a 4.10 to a hiway cruiser friendly 2.74:1 gear

tames a 4.30 to a hiway cruiser friendly 2.88:1 cog.



Use the GM special high stall lock up converter that is from the 1987 Monte SS w 305HO and th2004R trans.
Just right for the 283 w a th 200r4 and 4.10's to 4.30's.

Now you will love your lil 283 '56 Goes like a bat out of hell from a light and cruises efficiently too.
It will be a whole different car.

Last edited by F-BIRD'88; 09-04-2012 at 04:25 PM.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 09-04-2012, 05:40 PM
Registered User
 
Last photo:
Join Date: Oct 2010
Location: az
Posts: 204
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
Thanks for your reply F-Bird`88. I would`nt mind trying a 10% taller tire, if it would help mpg overall some. Sure would save some money on trans. cost.
I think my current tires are 205 75 15. Wonder what ratio difference I would be looking at. Thanks
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
700r4 no overdrive reverse supercoop Transmission - Rearend 20 12-14-2008 11:16 AM
700r4 vs overdrive bostonrpm Transmission - Rearend 5 05-03-2008 06:16 PM
700R4 No Overdrive ranlom18 Transmission - Rearend 1 10-29-2007 06:36 PM
Overdrive in 700r4 av8r Transmission - Rearend 2 08-04-2007 07:59 PM
700r4 no overdrive wwhijr Transmission - Rearend 4 06-07-2005 04:52 PM


All times are GMT -6. The time now is 04:52 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.