Re-gearing
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
Are you guys that are running these gynormous tires doing anything to correct the speedo?...if not...the mpg's you are calculating will be way off regardless because the miles traveled per tank will be off due to the inaccurate speedo...a vicious cycle.
Now a re-gear does NOT affect the speedo because of where the speedo pick up sensor is located...but you would need a tuner to reprogram the PCM for tire size change...
Just thinking as I type.
Joe
Now a re-gear does NOT affect the speedo because of where the speedo pick up sensor is located...but you would need a tuner to reprogram the PCM for tire size change...
Just thinking as I type.
Joe
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
X2...couldn't agree more...very well said in a nice concise manner!
More Turbo
Joined: Nov 2011
Posts: 611
Likes: 4
From: Northern NV
This is all fine and dandy for you V-10 gas guzzlers, but what about us 6L PSD drivers?! 
With a measly 4500rpm redline we have far fewer revs to work with!
I've got the original 3.73 LSD in my 4x4 with 33.5" tires and am towing my car hauler. I don't plan to go any bigger on the tires but I'm thinking the 4.56 gears would be a better match and according to the FTE ratio calculator that will get me to an effective 4.28 ratio.
With a measly 4500rpm redline we have far fewer revs to work with!
I've got the original 3.73 LSD in my 4x4 with 33.5" tires and am towing my car hauler. I don't plan to go any bigger on the tires but I'm thinking the 4.56 gears would be a better match and according to the FTE ratio calculator that will get me to an effective 4.28 ratio.
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
LWW...you are 100% correct about 4.30's and V10...
As far as optimal gearing for the 6.oH and 7.3...I don't know...but I do know that some of the PSD's (6.4L I believe?) came factory stock with 4.88's!!!...
As far as optimal gearing for the 6.oH and 7.3...I don't know...but I do know that some of the PSD's (6.4L I believe?) came factory stock with 4.88's!!!...
Bleed Ford Blue
Joined: Apr 2009
Posts: 13,578
Likes: 157
From: Anchorage Alaska
i'm planning on going with 4:56s and a tru-trac in the rear when funds allow. after i may jump up to 285's. i dont really tow but i want neck snapping off the line power. so long as i can still hit 100 without running a crazy rpm i'll be happy.
Senior User
Joined: Feb 2011
Posts: 383
Likes: 1
y not go bigger lol!!
Posting Guru
Joined: Oct 2003
Posts: 1,198
Likes: 2
From: Tulsa, OK
This is all fine and dandy for you V-10 gas guzzlers, but what about us 6L PSD drivers?!
With a measly 4500rpm redline we have far fewer revs to work with!
I've got the original 3.73 LSD in my 4x4 with 33.5" tires and am towing my car hauler. I don't plan to go any bigger on the tires but I'm thinking the 4.56 gears would be a better match and according to the FTE ratio calculator that will get me to an effective 4.28 ratio.
With a measly 4500rpm redline we have far fewer revs to work with!
I've got the original 3.73 LSD in my 4x4 with 33.5" tires and am towing my car hauler. I don't plan to go any bigger on the tires but I'm thinking the 4.56 gears would be a better match and according to the FTE ratio calculator that will get me to an effective 4.28 ratio.
If we go to larger diameter tires, the RPM drops away from the ideal (2000 RPM) when towing at 68-70 mph in 5th gear. This problem keeps me from considering the factory 20" SD tires/wheels (34.1" diameter). A simple change to 4.10 gears would swing this -7.7% error to a +2.1% error--increasing the RPM ever slightly at 70 mph, once the 34.1" tires are installed.
Bleed Ford Blue
Joined: Apr 2009
Posts: 13,578
Likes: 157
From: Anchorage Alaska
no need or want to...i'm happy with how it looks with 2" of lift and 265/75s. only reason i would step up is if i had the 4:56's to bring the ratio up just a bit. plus i have issues right how finding parking garages i can fit into as-is.
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Senior User
Joined: Feb 2011
Posts: 383
Likes: 1
u should of got air bags lol j/p
Senior User
Joined: Dec 2002
Posts: 218
Likes: 1
From: Rancho Cucamonga USA
Michael
Posting Guru
Joined: Oct 2003
Posts: 1,198
Likes: 2
From: Tulsa, OK
I don't know how the rear axle is put together...is the LS separate from ring/pinion? My Ex has LS in rear axle and I would want to retain that. The 4.10s would be perfect to allow 20" tires on my Ex.
Sorry, I'm pretty ignorant of how these axles are put together and what will interchange.
Hotshot
Joined: May 2005
Posts: 13,484
Likes: 42
From: Stevens Point, WI
Is the rear axle w/limited slip? What sort of condition is the 4.10 truck? Are the fronts interchangeable or is the Dana 50 different from Dana 60(?) in the truck?
I don't know how the rear axle is put together...is the LS separate from ring/pinion? My Ex has LS in rear axle and I would want to retain that. The 4.10s would be perfect to allow 20" tires on my Ex.
Sorry, I'm pretty ignorant of how these axles are put together and what will interchange.
I don't know how the rear axle is put together...is the LS separate from ring/pinion? My Ex has LS in rear axle and I would want to retain that. The 4.10s would be perfect to allow 20" tires on my Ex.
Sorry, I'm pretty ignorant of how these axles are put together and what will interchange.
The 4:10 truck is from AZ and has 9*,*** miles on it. I haven't seen the truck in person yet but it sounds very nice and very well taken care of.
Yes the LSD is separate from the ring and pinion. I just know this is the standard sterling 10.5" rear end, I don't know what axles the ring and pinion are compatible with besides the 10.5".
Posting Guru
Joined: Oct 2003
Posts: 1,198
Likes: 2
From: Tulsa, OK
I tow at around 68 - 70 mph. Keeps me from getting run over on the interstates. I also have found that stock 3.73 axles with 265/75-16 tires keeps RPM at 2040 when running 70 mph. This seems to be a "sweet spot" for 6.0L.
When I try to tow at a lower speed, in theory to save fuel, I can't seem to get any better fuel economy by slowing down. What I think is that the transmission must downshift more often to get the engine back on the torque curve.
When I try to tow at a lower speed, in theory to save fuel, I can't seem to get any better fuel economy by slowing down. What I think is that the transmission must downshift more often to get the engine back on the torque curve.
Senior User
Joined: Feb 2011
Posts: 383
Likes: 1
by judgeing by your sig. trying to get mpg slowing down might help but then i would prob to work harder on any slight inclines i think u need is:
to devert the air up so u wont be dragging the air straight into your camper or what ever i am trying to say here.