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- GM > GM Competition and Performance
Register Members List Timeslips EFI Live Library Invite Your Friends FAQ Calendar Mark Forums Read

GM Competition and Performance General GM Competiton and Performance

Reply
 
Thread Tools
Old 02-15-2017, 09:25 AM   #1
DIESEL_POWER

Name: DIESEL_POWER
Title: NGM Diesel
Status: Not Here
Join Date: Jul 2006
Member`s Gallery
Posts: 5,142
Built allison

Ok so I have a LML, and got a built trans, all is well except one thing, it goes into reverse rougher than it should. Almost like a soft slam into reverse. I was told by the builder it was normal, but it's so bad that the engine down pipe hits the fire wall on occasion because of this when out into reverse.

I put on over 40 k on it and changed to synthetic fluid and new filter, this seemed to help, but still pretty noticable.

Only thing that seems to help is leaving it in neutral for a few seconds before going into reverse.

Any ideas?
__________________
Proverbs 3:5-6 (KJV)
5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.
  Reply With Quote
Old 02-15-2017, 09:29 AM   #2
Chris Tobin
 
Chris Tobin's Avatar

Name: Chris Tobin
Title: Too Much Time
Status: Not Here
Join Date: Jun 2008
Location: Dayton, TN
Member`s Gallery
Posts: 2,370
Wade, I don't have suggestions for the trans issues, but if your engine is moving that much your factory motor mounts are probably shot. You need to install a set of the Merchant Automotive motor mounts which are also available from several other vendors in colors other than MA Orange...
__________________
Chris Tobin
Editor--Ultimate Diesel Builder's Guide

Freelance Editor and Photographer
Working with DIESEL WORLD, DIRT SPORTS, MUSCLE CAR POWER & STREET TRUCKS magazines
tobinemail@aol.com
I might be able to help get you in a mag.
Custom poster size photos available. PM or email for info.
  Reply With Quote
Old 02-15-2017, 10:44 AM   #3
sootie

Name: sootie
Title: .....like a BAWSS
Status: Not Here
Join Date: Jan 2013
Member`s Gallery
Posts: 154
could be too tight a stall on the converter? If it is really lugging the engine down at idle, it is a big change from drive to reverse.
  Reply With Quote
Old 02-15-2017, 11:12 AM   #4
IdahoRob
 
IdahoRob's Avatar

Name: IdahoRob
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Apr 2006
Member`s Gallery
Posts: 2,262
Wade, I've had a built tranny/converter in my LML for 35k miles and have never noticed that issue on my truck. I don't have an answer on what could be causing it, outside of a very aggressive converter. Do you have a stock TCM tune in it, or one modded for increased PSI?
__________________
Adrenaline Truck Performance

"Max'd Out" SoCal Engine, Randy's Trans, DDP 9.36@154 MPH SS legal trim.

Last edited by IdahoRob; 02-15-2017 at 11:13 AM.
  Reply With Quote
Old 02-15-2017, 12:44 PM   #5
DIESEL_POWER

Name: DIESEL_POWER
Title: NGM Diesel
Status: Not Here
Join Date: Jul 2006
Member`s Gallery
Posts: 5,142
The mounts are fine, it only jams in gear in reverse, no other gear or selection. Rob, yes the tcm was modified for extra rpm when towing using the exhaust brake, that's the way it was explained.
__________________
Proverbs 3:5-6 (KJV)
5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.
  Reply With Quote
Old 02-15-2017, 12:46 PM   #6
DIESEL_POWER

Name: DIESEL_POWER
Title: NGM Diesel
Status: Not Here
Join Date: Jul 2006
Member`s Gallery
Posts: 5,142
Had the tunes prior to the trans upgrade, since the trans upgrade this issue has been around.
__________________
Proverbs 3:5-6 (KJV)
5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.
  Reply With Quote
Old 02-15-2017, 12:47 PM   #7
DIESEL_POWER

Name: DIESEL_POWER
Title: NGM Diesel
Status: Not Here
Join Date: Jul 2006
Member`s Gallery
Posts: 5,142
Seems to me like a vb issue.
__________________
Proverbs 3:5-6 (KJV)
5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.
  Reply With Quote
Old 02-15-2017, 03:23 PM   #8
IdahoRob
 
IdahoRob's Avatar

Name: IdahoRob
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Apr 2006
Member`s Gallery
Posts: 2,262
For giggles, I'd throw the stock tcm tune in it. If you didn't do the tcm tune yourself, then it's unknown if line pressure was played with. Increased TCM controlled pressure coupled with VB mods when the tranny was done, may not be playing nice.
__________________
Adrenaline Truck Performance

"Max'd Out" SoCal Engine, Randy's Trans, DDP 9.36@154 MPH SS legal trim.
  Reply With Quote
Old 02-16-2017, 06:03 PM   #9
dieselpro55

Name: dieselpro55
Title: Green Behind the Ears
Status: Not Here
Join Date: Aug 2008
Member`s Gallery
Posts: 40
Maybe a mainline pressure shim with the spring would increase the pressure in the reverse...you could tune for a slightly lower idle and that would help some


Sent from my iPad using Tapatalk
  Reply With Quote
Old 02-16-2017, 07:51 PM   #10
DIESEL_POWER

Name: DIESEL_POWER
Title: NGM Diesel
Status: Not Here
Join Date: Jul 2006
Member`s Gallery
Posts: 5,142
I'll look into to the tcm Rob and let you know thanks
__________________
Proverbs 3:5-6 (KJV)
5 Trust in the Lord with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths.
  Reply With Quote
Reply

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 01:50 AM.

 


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright ©2006 - 2017, CompetitionDiesel.com
all information found on this site is property of www.competitiondiesel.com