Advertisement
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Home Who's Online Today's Posts HP Calculator CompD Gift Shop Mark Forums Read
Go Back   Competition Diesel.Com - Bringing The BEST Together > Tech Area- Dodge > Dodge Tech
Register Members List Timeslips EFI Live Library Invite Your Friends FAQ Calendar Mark Forums Read

Closed Thread
 
Thread Tools
Old 02-14-2018, 01:07 AM   #1
Smitty256
 
Smitty256's Avatar

Name: Smitty256
Title: Too Much Time
Status: Not Here
Join Date: May 2014
Location: Killen, Al
Member`s Gallery
Posts: 234
Questions on 47re and 48re

Ok guys I have 2 separate questions for 2 different trucks.

First question on on a 98 12v with a full billet full manual 47re. When I am driving this truck down the road it drives good under normal crushing power besides shifting 2-3 which I'm guessing is just a bind shift and the band needs adjusting. Now when you really get down in it and lock the converter it feels like it is slipping, this is a brand new billet triple disk converter with less than 10 miles on it and the trans. I do remember when I put the trans in, the converter was stamped 48re so I messaged the guy that built the trans and got the converter from and he said it would be fine and I'm beginning to think there is something going on with that. My main question is, is it ok to run a 48re converter in a 47re trans?

My other question is I have a 06 cummins with EFI, well the same guy above build this trans as well. The first time he built it it ran and shifted perfect. I broke the input in it and took it back to him and it ran and shifted perfect after that as well. So now the 3rd time the trans just quit pulling, I took it to him and he went threw it all and I had him put a billet input shaft and a triple disk converter. I got the truck back and it feels like every gear, besides lockup, is not pulling to its full potential. I'm not sure what is going on there. Low gear is sluggish but when the converter locks it throws your head back. Any suggestions for this?
__________________
95 12v Cummins in peices

98 12v Cummins under construction

06 Cummins dropped, EFI by Robert Ivey
 
Old 02-14-2018, 03:27 AM   #2
Big Blue24
 
Big Blue24's Avatar

Name: Big Blue24
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Jan 2008
Location: Cedar City, UT
Member`s Gallery
Posts: 6,310
47re transmissions are 100% compatible with 48re converters.

48re transmission are compatible with 47re converters however, there is a seal on the stator support of a 48re transmission that is designed to help seal the stator shaft to the inside of the torque converter; 47re converters are larger diameter in the region where this seal rides so the 48 seal no longer seals. This is not a major issue other than lowering the converter pressure a little similar to what a 47rh or 47re transmission normally sees. Many racing and hot street performance 48re transmissions are built and sent out the door with the stator seal missing on purpose. For good measure, when installing a 47re converter on a 48re transmission, most guys spend the 10 seconds to remove the stator seal so it doesn't have the possibility of popping free and potentially ending up somewhere else in the transmission.

To fix your 2-3 bind issue, you can make small improvement by loosening the band adjustment try 2.5 loosened from 72 inch pounds. For major improvement, you'll need to increase the 2nd servo release spring tension (double spring), change to a different style servo and/or lever ratio, or slow down the 3rd gear apply circuit (VB modification or restrictor orifice on 3rd apply passage).

To answer your second question, depending on the stall speed of your converter, it will never pull as hard unlocked as in lockup. If you have a higher than stock stall speed, like a 2400 V-10, you could be down as much as 200 HP unlocked vs locked on a 1000 HP truck. With a 1600 to 1800 stall converter, you'll still be down 50 to 75 HP unlocked vs locked on a 600 HP truck. By design, a torque converter is designed to slip when not in lockup, that's how it multiplies torque. If you get a super low stall/highly efficient torque converter, it will have much less loss unlocked vs locked, but it will also bog and cause the truck to act sluggish/increase turbo lag at low rpm conditions.
__________________
95' 2wd Junker Drag Truck
1502 HP Fuel-Only 12mm P7100 Pump
SXE 472 over GTX55 116mm
OEM 12v Block

Last edited by Big Blue24; 02-14-2018 at 03:29 AM.
 
Closed Thread

Thread Tools

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

Forum Jump


All times are GMT -5. The time now is 12:02 PM.

 


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2006 - 2024, CompetitionDiesel.com
all information found on this site is property of www.competitiondiesel.com