DodgeTalk Forum banner

Status
Not open for further replies.
1 - 20 of 20 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
Finally took the plunge and joined the 4.56 club on Tuesday. :rck: Drove up to Ft Worth and let Jason of Texas Drive train do his majic. Install went well, quiet as can be. Acceleration noticably smoother and since I had to get back to Houston, was able to confirm that it has had less than 1 mile per gallon impact on my highway mileage. Sits about 300 rpm's higher at 70 mph.
Can't wait for the break in period to end to really test them out.

One disturbing thing though and it may be a coincedence. :huh: On the way back I noticed my cruise control was not functioning?? I wonder if having the rear end torn apart had any affect on the cruise. Does it pull it's speed info from the wheels or the speedometer? If any one out there can shed some light or help me figure this out I would appreciate it. I have a 2003 QC, 4.7L.
:help:
Thanks in advance
 

·
Registered
Joined
·
603 Posts
if you find out what happend let us know!
 

·
Banned
Joined
·
244 Posts
KASRAM said:
Finally took the plunge and joined the 4.56 club on Tuesday. :rck: Drove up to Ft Worth and let Jason of Texas Drive train do his majic. Install went well, quiet as can be. Acceleration noticably smoother and since I had to get back to Houston, was able to confirm that it has had less than 1 mile per gallon impact on my highway mileage. Sits about 300 rpm's higher at 70 mph.
Can't wait for the break in period to end to really test them out.

One disturbing thing though and it may be a coincedence. :huh: On the way back I noticed my cruise control was not functioning?? I wonder if having the rear end torn apart had any affect on the cruise. Does it pull it's speed info from the wheels or the speedometer? If any one out there can shed some light or help me figure this out I would appreciate it. I have a 2003 QC, 4.7L.
:help:
Thanks in advance
you know when your spedo says 70 your really going like 60 (you will have to check that) so that means you are 300 rpms higher at 60 not 70.
this is all assuming you didnt correct your spedo.
 

·
Banned
Joined
·
244 Posts
KYKillerKlown said:
I didn't think that the gears had anything to do with the speedo reading?
its just like adding bigger tires, except the opposite with a bigger gear.

with my tires now at 70mph im really going 83.
 

·
Registered
Joined
·
9,813 Posts
Your speedo is completely UN EFFECTED by a gear swap.... on our 3rd Gen Rams.

If your speedo was reading correctly with 3.55's then it will read EXACTLY the same with the 4.56's, 4.88's, 5.78... This is because the speed reading is NOT taken from the transmission tail housing like many transmissions in the past... the reading on our trucks is takin off the ring gear in the rear end housing... one revolution will ALWAYS be one revolution no matter the ratio. The only thing that will effect your speedo on our trucks would be tire hight.

The reason he gained 300 RPMs at 70MPH is because thats his .67 overdrive teamed up with the 4.56's equals a 3.05 overall gear ratio...

70MPH x 3.05 x 336 / Tire Hight = RPMs


As for the Cruze controle, have you been under your hood lately. Im willing to bet some how you somehow disconected the vacume line to your cruze controle... I did this once... took me a day to figure out. Look under your hood on the drivers side, you will see a vacume line around there in that area.....


SPEED SAFE, AIR RAM
 

·
Banned
Joined
·
244 Posts
AIR_RAM said:
Your speedo is completely UN EFFECTED by a gear swap.... on our 3rd Gen Rams.

If your speedo was reading correctly with 3.55's then it will read EXACTLY the same with the 4.56's, 4.88's, 5.78... This is because the speed reading is NOT taken from the transmission tail housing like many transmissions in the past... the reading on our trucks is takin off the ring gear in the rear end housing... one revolution will ALWAYS be one revolution no matter the ratio. The only thing that will effect your speedo on our trucks would be tire hight.

The reason he gained 300 RPMs at 70MPH is because thats his .67 overdrive teamed up with the 4.56's equals a 3.05 overall gear ratio...

70MPH x 3.05 x 336 / Tire Hight = RPMs


As for the Cruze controle, have you been under your hood lately. Im willing to bet some how you somehow disconected the vacume line to your cruze controle... I did this once... took me a day to figure out. Look under your hood on the drivers side, you will see a vacume line around there in that area.....


SPEED SAFE, AIR RAM
I stand corrected, this is the 1st time ive heard of a vehicles spedo not being affected by a gear swap. I am now going to go throw myself into traffic.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #8
Thanks Nick!,
I will check under the hood tomorrow and see if anything has come apart. I was afraid that the whell speed was measured by an electroic connection to either the differential or the wheels and somehow it got goofed up when the rear end was torn apart.
Will let everyone know what I find out tomorrow.

Dodge rules!
 

·
Registered
Joined
·
9,813 Posts
blok said:
I stand corrected, this is the 1st time ive heard of a vehicles spedo not being affected by a gear swap. I am now going to go throw myself into traffic.
:thatfunny:thatfunny

LOL... No need to do that bro. It was all new to us the first time we learnd of it also.

SPEED SAFE, AIR RAM
 

·
Banned
Joined
·
2,221 Posts
i kindof have the same problem but different.
when i put my 'drag radials' on and drive to the track my cruise control doesn't work.
when i change back to the 20s then it works again.
ive got an '03 Hemi Ram.
 

·
Where is my money tree?
Joined
·
793 Posts
The Cruise Control is very tempermental. The soon to be in-laws 03 CC kicks in and out all the time, and they are all stock all the time...

My CC was stupid too, being an 04, I can get superchips flashpaq, which corrected all my Cruise control isuues...maybe
 

·
Registered
Joined
·
11 Posts
Discussion Starter #12
Cruise problem identified

Quote:
Originally Posted by AIR_RAM
As for the Cruze controle, have you been under your hood lately. Im willing to bet some how you somehow disconected the vacume line to your cruze controle... I did this once... took me a day to figure out. Look under your hood on the drivers side, you will see a vacume line around there in that area.....

SPEED SAFE, AIR RAM

*************************
Looked under the hood today. Followed the vacuum line from the T-body to the solenoid, and when I got under the battery the line snaps like a dry twig. Apparently the plastic either was eaten away by corrosion from the battery or our Texas heat had gotten to it. Anyway, a new vacuum harness is ordered ($12) and all should be well by next week. :D
Thanks again Nick, as who knows what the dealer would have charged or replaced trying to fix this.
 

·
Registered
Joined
·
9,813 Posts
KASRAM said:
Quote:
Originally Posted by AIR_RAM
As for the Cruze controle, have you been under your hood lately. Im willing to bet some how you somehow disconected the vacume line to your cruze controle... I did this once... took me a day to figure out. Look under your hood on the drivers side, you will see a vacume line around there in that area.....

SPEED SAFE, AIR RAM

*************************
Looked under the hood today. Followed the vacuum line from the T-body to the solenoid, and when I got under the battery the line snaps like a dry twig. Apparently the plastic either was eaten away by corrosion from the battery or our Texas heat had gotten to it. Anyway, a new vacuum harness is ordered ($12) and all should be well by next week. :D
Thanks again Nick, as who knows what the dealer would have charged or replaced trying to fix this.
Good deal bro, Im glad I was able to help.

SPEED SAFE, AIR RAM
 

·
Registered
Joined
·
161 Posts
the cruise control gets its information from the same place your speedo does. if your speedo is working, then it is not the rear end gear swap effecting your cruise control
 

·
Banned
Joined
·
2,221 Posts
pooperscooper said:
the cruise control gets its information from the same place your speedo does. if your speedo is working, then it is not the rear end gear swap effecting your cruise control

i still don't get why my cruise control won't work when i've got my drag radials on. when i put my 20s back on the cruise works again.
 

·
Registered
Joined
·
9,813 Posts
How tall are your tires? That is very strange...

SPEED SAFE, AIR RAM
 

·
Registered
Joined
·
98 Posts
My .02 - On my 04' if I'm over 80 mph, the cruise control cannot be set. If I set it at a speed below that it can then be incrementally increased with the ACCEL button. Your tire/gear combination may be telling the PCM that you're over 80 mph.
 

·
Registered
Joined
·
161 Posts
or, if you are under 35mph i dont think it will set. if your speedo says you are at that speed, that is how fast the pcm or ecu reads. there is no secondary sender.
 
1 - 20 of 20 Posts
Status
Not open for further replies.
Top