Regear quick help please
Thread Starter
|
Tuned
Joined: Oct 2012
Posts: 409
Likes: 4
From: oregon
Regear quick help please
Alrighty, so I tow allot probably just as much as I am empty. I like to go a little faster than I probably should (60-65 mph in 55mph zones and 70-80 on the freeway) I tow my normal 16' tandom with my 4k crawler on it and my 40' gooseneck with two crawlers about 22k total. Now my question I blew my 3.73 rear end up (broke 3 ring gear teeth). I got a 4.30 front and rear end for free (was told they were 3.73) I'm on 35's going to 37's at some point after I buy a lift. My tow tune is 400hp so I have no problems with power, but I don't want my rpm's to go threw the roof at 70-80mph. Anyone running 4.30's with a zf6 that had 3.73's have any imput? I was really looking forward to the rpm drop going to the 37's with 3.73's but towing would kinda suck with that tall of gear.
Senior User
Joined: Jun 2018
Posts: 111
Likes: 2
Alrighty, so I tow allot probably just as much as I am empty. I like to go a little faster than I probably should (60-65 mph in 55mph zones and 70-80 on the freeway) I tow my normal 16' tandom with my 4k crawler on it and my 40' gooseneck with two crawlers about 22k total. Now my question I blew my 3.73 rear end up (broke 3 ring gear teeth). I got a 4.30 front and rear end for free (was told they were 3.73) I'm on 35's going to 37's at some point after I buy a lift. My tow tune is 400hp so I have no problems with power, but I don't want my rpm's to go threw the roof at 70-80mph. Anyone running 4.30's with a zf6 that had 3.73's have any imput? I was really looking forward to the rpm drop going to the 37's with 3.73's but towing would kinda suck with that tall of gear.
Laughing Gas
Joined: Oct 2016
Posts: 1,072
Likes: 91
From: DFW, Texas
My truck has 4:10's. From factory. When it wasDRW with stock tires I run those speeds when towing. When I changed it to SRW , I found a set of 4:30 differentials and thought that would be to much gear,so I kept looking till I found a rear differential that matched the front 4:10. I ended up putting 35's on the truck,and when towing I wish I would have went with the 4:30's with the taller tires
Senior User
Joined: Jun 2018
Posts: 111
Likes: 2
[QUOTE=akcooper9;18075397]What vehicle is the 4.30 coming out of stock?[/QUOTE
Yes it was a stock truck. There is a local junk yard that only deals in ford trucks. I have known him for over 30 years. He said he had just got a truck in and would check the ratio as he thought it might have 4:10's. The tag said 4:30 and he had not seen those gears from factory in all the years he had been parting trucks out,so he pulled the cover and counted the teeth. He said he did some checking and they could be ordered when the truck was new.
Yes it was a stock truck. There is a local junk yard that only deals in ford trucks. I have known him for over 30 years. He said he had just got a truck in and would check the ratio as he thought it might have 4:10's. The tag said 4:30 and he had not seen those gears from factory in all the years he had been parting trucks out,so he pulled the cover and counted the teeth. He said he did some checking and they could be ordered when the truck was new.
Thread Starter
|
Tuned
Joined: Oct 2012
Posts: 409
Likes: 4
From: oregon
Thank you for the replies, the axles came from a 450 I have the matching set i got gave to me. Has a rear sway bar too, so now I have sway bars front and rear.
Handy 1 thank you for that, I was wondering how bad the rpm's would jump seems like they don't do to bad being as you can carry those speeds too. There are allot of times I have wished I had a gear a little higher than my third but lower than my 4th when I am at 30k total gross going up some 7%grades 4th won't quite pull but third is wound out at 55-60. I just didn't want to loose my drive ability empty but I think I will love them towing. Also going to 37's in the near future will put me back at stock according to Dr. Google, so that sounds like it would be a good deal all the way around.
Handy 1 thank you for that, I was wondering how bad the rpm's would jump seems like they don't do to bad being as you can carry those speeds too. There are allot of times I have wished I had a gear a little higher than my third but lower than my 4th when I am at 30k total gross going up some 7%grades 4th won't quite pull but third is wound out at 55-60. I just didn't want to loose my drive ability empty but I think I will love them towing. Also going to 37's in the near future will put me back at stock according to Dr. Google, so that sounds like it would be a good deal all the way around.
Trending Topics
Fleet Mechanic
Joined: Jul 2010
Posts: 1,753
Likes: 34
From: Los Angeles, Ca.
My '99 F-350 4X4 CC SB V-10 had factory 4.30s. They might be as rare as finding a 350 SB, but they exist. It's possible it was a special order truck since I've not heard of another with that combo. I went to 5.13 with 37" tires which put it to about where a 4.10 and stock tires would be. Towing with the 4.30s and 37s sucked, but woulda probably been fine with a warmed up 7.3.
For OP, 4.10 with 37s would be about equivalent to the 3.73 with 35s you have now so your RPM will be a little higher with the 4.30 and 37s, guessing around 100-150 RPM. The little extra gear reduction will compensate for the new tires' extra rotational mass when accelerating.
For OP, 4.10 with 37s would be about equivalent to the 3.73 with 35s you have now so your RPM will be a little higher with the 4.30 and 37s, guessing around 100-150 RPM. The little extra gear reduction will compensate for the new tires' extra rotational mass when accelerating.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread Starter
|
Tuned
Joined: Oct 2012
Posts: 409
Likes: 4
From: oregon
My last powerstroke (00) and current (01) both had 3.73's the (00) was a auto on 37's and towed allot with it but not the loads I do with the (01) and never really had issues with the towing but with some of the loads iv towed with the current truck I could use some extra gearing, I just love the low rpm cruise that my last 7.3 had. Just thought I would see what everyone else had experienced with the 4.30's, my brother's obs (5speed) on 35's is wound tight at 70mph and I just don't want that, dont stockish rpm but another 3-400 on top of stock would be annoying as hell to drive everyday would up that much. For instance 2500rpm at 60-65 I don't think I would do, 2000rpm wouldn't be bad. Currently 1700rpm at 65 ish.
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,344
Likes: 5,941
From: Lake Hartwell, GA
My stock tire size and 3.73 gear ZF6 truck towed a 12K camper in 5th gear at 2000 RPM and got 12.5 MPG's measured over 1000 miles through mountains and plains.
Just trying to say that 2000 RPM is the happy place for me truck and is a good compromise between available power (versus lugging) and MPG's (versus wound too tight as you say). I would not feel comfortable towing heavy at 1700 RPM, but that is just me.
Just trying to say that 2000 RPM is the happy place for me truck and is a good compromise between available power (versus lugging) and MPG's (versus wound too tight as you say). I would not feel comfortable towing heavy at 1700 RPM, but that is just me.
Lead Driver
Joined: Sep 2010
Posts: 7,793
Likes: 50
Sous..what are you considering 5th gear? L,12345 or..1234(5)6...when i had 3.73 towing 11k, i couldnt keep in 6th on flatland without egt rising let alone there was nothingvin the tank when stomping on pedal..
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,344
Likes: 5,941
From: Lake Hartwell, GA
Brother Timmy, that is why I should not reply to forums shortly after waking up...
I refer to 5th as L, 12345, which is actually 5th if you do not count "low" as a normal forward gear.
5th gear is what I use 95% of the time when on the interstate or anything above say 55 MPH, even when towing heavy. My truck is happiest there and anything near 55 MPH should be 4th gear. Grades or long rolling inclines are usually 5th for a bit, then down to 4th or 3rd in some cases like in TN or CO mountains. All of that is/was loaded heavy, not unloaded.
I refer to 5th as L, 12345, which is actually 5th if you do not count "low" as a normal forward gear.
5th gear is what I use 95% of the time when on the interstate or anything above say 55 MPH, even when towing heavy. My truck is happiest there and anything near 55 MPH should be 4th gear. Grades or long rolling inclines are usually 5th for a bit, then down to 4th or 3rd in some cases like in TN or CO mountains. All of that is/was loaded heavy, not unloaded.
Hotshot
Joined: Mar 2014
Posts: 10,750
Likes: 1,065
From: Douglassville, PA
My stock tire size and 3.73 gear ZF6 truck towed a 12K camper in 5th gear at 2000 RPM and got 12.5 MPG's measured over 1000 miles through mountains and plains.
Just trying to say that 2000 RPM is the happy place for me truck and is a good compromise between available power (versus lugging) and MPG's (versus wound too tight as you say). I would not feel comfortable towing heavy at 1700 RPM, but that is just me.
Just trying to say that 2000 RPM is the happy place for me truck and is a good compromise between available power (versus lugging) and MPG's (versus wound too tight as you say). I would not feel comfortable towing heavy at 1700 RPM, but that is just me.
Logistics Pro
Joined: Dec 2010
Posts: 4,738
Likes: 15
From: Temperance, MI
Without reading any other comments and having done the homework while I was running 3:73s and 38s. 4:30 gears are as close to the same ratio you can get that equate to 3:73s after its all said and done. So 4:30s and run it!
