pt_Ranger_v8
Registered User
I convienently have the entire axle 
4.10 and 3.55 comparison.
- Thread starter Goofyexponent
- Start date
Diesel_brad
Dunce
yea, that is prety cheap to install gears.
i to just swaped the entire axle. was easier in my mind, since i could rebuilt the axle outside the truck, then throw it under.
i to just swaped the entire axle. was easier in my mind, since i could rebuilt the axle outside the truck, then throw it under.
I don't blame you...that's the primary reason I didn't switch to 3.55 gears in 2003 or '04. Was too poor to pay someone to do the swap and didn't trust myself to do it. With how things turned out, it's probably better in the long run...ended up with the Doug Nash unit instead...now I just need to get it installed
I think that what gears are best for you depends on your primary mission...if you're primary loaded light and doing a lot of freeway running, 3.54's will be better, but if you're running tires that are considerably bigger or you spend most of your time loaded down, 4.10's are best. My truck is so multipurpose that I'm pretty sure the OD unit will work best in my application...I spend quite a bit of time empty on the highway running between the Bay Area and the Los Angeles area, but I also routinely load the truck down (loading the truck and trailer up to 14K+ is not uncommon).
Probably doesn't mean much, but there's my $.02...
Goofyexponent
Mentally Unstable..
Pretty much right about a 500 RPM drop overall.
Although I SHOULD add this. I was running at 55MPH with the 4.10's and 65MPH with the 3.55's.
I GAINED about 2.5 MPG while running an extra 10MPH.
I am running about 1850 - 1900 RPM on the highway now.
pt_Ranger_v8
Registered User
How does it pull with the 3.55's? Have you hooked it up to any serious load yet?
Goofyexponent
Mentally Unstable..
does a 1976 tandem axle 26 foot camper loaded to the 9's with junk count?
No doubt that the4.10's would have done that job a little easier, but I didn't mind teh way my 3.55's did it.
I plan on dragging my new crew cab with my 3.55'd pickup the weekend of the 29th. Some steep hills and shallow, LONG grades.....I'll take some videos....or SOMEONE will shoot some. I will have a cab full of back seat drivers!!! lol
pt_Ranger_v8
Registered User
That is a beautiful thing!!
Thank you for the comparison!!
CSARebel916
WMO Burner
I wonder how much of a differance id see if I put 3:55s in my truck? I dont have a 5spd, I have an old crusty C-6 lol. I crank 2500-2600 at 60 mph and 3000-3100 at 70mph. I drive almost 75 miles round trip for work, and all but 3 miles is highway driving. Ive thought of putting 36's under my truck to offset the 4:10s. Any ideas?? Id be all over a 5spd if I could afford one
This isn't a direct comparison, but I had 3.54's in my old E-350 with a 6.9l and C6...she was a very happy highway cruiser; did 70 to 75 without breaking a sweat. I generally did about 14 mpg, but that was with wider tires...the previous owner (who had put the wide tires/rims on) told me that he averaged 17 mpg with the factory tires.I wonder how much of a differance id see if I put 3:55s in my truck? I dont have a 5spd, I have an old crusty C-6 lol. I crank 2500-2600 at 60 mph and 3000-3100 at 70mph. I drive almost 75 miles round trip for work, and all but 3 miles is highway driving. Ive thought of putting 36's under my truck to offset the 4:10s. Any ideas?? Id be all over a 5spd if I could afford one
My truck, by comparison, currently gets the best mileage at 55 even after the ZF swap (with 4.10's from the factory)...if I can keep her at 55 on the highway, I can squeeze up to 20 mpg out of her. OTOH, at 70 to 75, I'm still lucky to get 15 or MAYBE 16 mpg
...I'm hoping that the OD unit swap will get me closer to 20 mpg at 65 to 70. I wish I could ditch the lumber rack...
ghunt
Full Access Member
Well, I know that's not a bad price for a gear install (although, that was almost 3 years ago and I can't remember who quoted me that price), but $500 will buy a fair bit of fuel....y'know? And I'm not made of money.
Though with the way fuel prices are going...
Well, I still have my new IP and injectors waiting to go in very soon...as soon as I can get a chance to pop test all the injectors. Need to get my test setup all rigged up.
Though with the way fuel prices are going...
Well, I still have my new IP and injectors waiting to go in very soon...as soon as I can get a chance to pop test all the injectors. Need to get my test setup all rigged up.
funnyman06
Full Access Member
Warden, how did you deal with the noise at 70 MPH? If I'm crusing down the highway at 70 the engine is roaring so loud I dont think I could even have a conversation? Plus mine sounds like its screaming.
check your fan clutch. it sounds like it's frozen and you have a B17 under the hood all the time now.
funnyman06
Full Access Member
This isnt the fan clutch, ive heard that come on haha. F250 ready for lift off. But still, just engine noise is incredible inside my truck. I guess it must be the metal head liner and limited padding in the cab.
