Richard D,
To answer your question about being 2300RPM @ 70, yes that is in overdrive. I don't know how heavy your boat is but with 4.56 gears I don't think you will need to take it out of overdrive to tow! Now if you take it out of overdrive you will run 3000 RPM at 70. This truck really pulls in this configuration. I felt the same way about the possibility of going to 35's later but after driving it like this I don't think I ever will!!! I like the power right where its at... I was worried about the RPM's on the highway but after using a gear/RPM calculator I noticed that the RPM's where the same with my 33's and 4.56's as they would have been if Ford would have offered those 4.10'swith my stock 29.5" tires. The lowest they offered was 3.73's for my rig at the time.

 

Mr. Tude,
No problem and let me know when you get that programmer

 

Thanks THOR that was my concern is that I may have to high of an RPM's in the engine when on the Highway. I never tow in OD as it is not a good idea due to excessive heat build up in the tranny and the hunting for gears constantly. My boat is about 5500 "WET" but I don't do a lot of highway towing with it except for vaction time most towing is done in winding, hilly, terrain foothills of No. California. I will be going with 35's once the truck gets lifted because 33's just don't look right on a 6" lifted truck. Ford only offered the 3.55 when I got my truck.

Richard D.

WHILE YOUR HERE CHECK OUT MY GALLERY BOAT PICTURES THERE ALSO:
https://www.f150online.com/galleries....cfm?gnum=2479

 

Richard,
If you are serious about going to a 6inch lift and 35's then I HIGHLY recommend 4.56 gears or you will regret it later. The heat build up should not occur in your tranny if you tow in overdrive unless it hunts around alot which it should not do with the lower geared rearend. Now if you do go with 35's and 4.56gears you are only going to be running 2100 RPM at 70, which is where I used to run with my 3.73 gears and 245/75/16's.
After checking out your nice photo gallery I noticed you are in California, which when I lived there that ment highway speeds of 80 most of the time..so I can understand keeping those RPM's down when you are not towing also. here is a short RPM to gear comparison:
A) Ford 3.73 and 29.5" tires @70= 2100 in O.D / out of O.D. =2800
B) Ford 4.10 and 29.5" tires @70= 2300 in O.D / out of O.D. =3200

C)Yukon 4.56 and 33" tires @70= 2300 in O.D / out of O.D. =3200
D)Yukon 4.56 and 35" tires @70= 2100 in O.D / out of O.D. =2800

I looked at it this way. Then I decided that if those RPM's where too high for me on the freeway then I would take those 33's off and go have 35's put on to drop my RPM's back down. It's a heck of a lot cheaper to change tires than gears

 

Thanks THOR I know I will need those gears when I go to 35's and since I am currently running 33's I could actually use them now so it looks like I am going to be getting some 4.56's. You mention Yukon are those the brand of gears ? Or did you mean a Ch*** Yukon?
I know randy's ring and pinion sells Yukon gears but I have never heard of that brand do you have any info on them GOOD OR BAD?
I am also planning on putting as LS in the front diff more than likely Really does tick me off that you buy a "4x4" and the front differential is open essentailly making it a one wheel drive in the front.

Richard D.

 

Yea I had mine done at Randy's Ring and Pinion and they use there brand which is "Yukon" Absolutely no problems so far and no whine so I am happy. I did some research before hand and I never found any complaints.

 

I think those Yukon gears are made in America also which is my biggest concern the imported gears are junk from what i have heard and read. If you don't mind caould you tell me about what the cost was for the complete deal FR gears, install kit ,and the install?

Richard D.

 

Hey Richard,
Yea to have them do everything plus tax it was $2,000....painfull yes but well worth it. I decided to take the money for my suspension lift and do the body lift instead... I don't do much rock crawling so I opted for better performance and a cheaper means to accomplish the better look Once I figure out how to put a picture in the gallery I will post it in my Sig. Alot of people ask what suspension lift I have. They get this look of disbelief when I say it doesn't have one.

 

THOR,
Well I just got home from a short road trip and here are my numbers:

3.55LS 32.8" Tires @ 70mph OD off =2800rpm
3.55LS 32.8" Tires @ 70mph OD on =1975rpm possibly 2000rpm


So what can I expect when I switch to 4.56's? Also did you get any type of Locker or LS or is that price strictly for the gear swap front and rear plus install kit and labor?


Richard D.

 

Richard,
This is what you will have if you switch now:
C)Yukon 4.56 and 33" tires(32.8" actual) @70= 2300 in O.D / out of O.D. =3200

Are those stock size tires you are running now? The reason I am asking is because if not your speedo will be off. Regardless the numbers I gave above are Accurate.

No I didn't go with a locker in the front. I couldn't justify the extra cost for what I use it for and Randy's Ring and Pinion talked me out of it due to the characteristics of having it all locked up. (it drives like a tank) I use 4 wheel drive when required due to weather or on an occasional boat ramp. Unless you are doing alot of offroading I just couldn't see having it. I use the quads for that type of fun

 

THOR my truck came stock with 17" wheels and p265/70/17 Tires I switched to 16" wheels and am running a LT285/75/16 tire. I think I have to change a little gear in the transmission to bring the speedo back into line with the new gears as well as get a new Speed Sensopr Ring that mounts inside the diff cArrier nest to the ring gear I think. I am hoping that whoever I get the gears from can help me with all that info. So the 2k you spent was simply for front and rear R&P and master install kit then the installation? How much did they charge for the intstallation? and how much just for the gears?

Richard D.

 

Richard,

I would go with what Thor said about the locker in front. On dry pavement the wheels will have enough traction to force the clutches or locking mechanism to open and let the tires rotate at different speeds. But who uses 4x4 on dry pavement? On a slick surface they may not rotate at different speeds.
Did you ever back up with a LS on a slippery surface with both rear wheels spinning and try to turn? Went straight didn't you? That could happen with a locker/ LS in the front.

Regards

Jean Marc Chartier

 

My speedo actaully is not off even though i went with larger tire's than stock. I have verified it with GPS so I know for a fact it is on. I think I may end up going with 4.10's becasue as it stands now the Lift and 35's do not seem to be anywhere in my future. Then I will more than likely install TrueTrac LS in my front differential. Hell it's hard to turn the front tires currently on Dry pavement if I engage the 4 wheel drive. I engage my 4wheel drive at least once a onth just to get everything turing and under laod to keep it in good working order and make sure that when I do go offraod I am not suprised by it not working.

Richard D.

WHIEL YOUR HERE CHECK OUT MY GALLERY NEW PICS ADDED:
https://www.f150online.com/galleries....cfm?gnum=2479

 

Richard,
In addition to what JMC said keep in mind that if you use 4 wheel drive for icey roads in the winter time, you know the roads have ice patches, snowing and the wife or girl friend is driving so she puts it in 4 wheel drive, well she is going to have her hands full with the type of setup you are thinking about. I think the factory has the right steup for most people. But at anyrate have fun with your knew mods

 

That is a good point but I do not go to the snow hardy ever in fact it has probably been about 5 years since our last trip up, so that really isn't an issue and I am the one that drives the truck when ever wife and myself go somewhere together. And it's got nothing to do with her not being allowed to drive I just prefer to drive and she prefers I drive as well because I turn into a back seat driver when she drives like a little ol lady.

Richard