Tow rig gear ratio

[welndmn]

Math wize I think you are almost the same as me.
My Ford RV with V10 and 6 speed came with 4:56 from the factory, I am sure the tire size is the same as it's not like change happens in motorhome's.
I know the E4OD was 0.71, I think the 6 speeds are 0.69.

 

[Provience]

2016 is when they went to the 6spd in the motorhome chassis, it's also when they uprated from 5500 to 7500-8k lbs official towing capacity. Same engine and rear axles and frame

I didn't know they were common with 4.56 as well, that's pushing more to the 5.13 as well.

 

[welndmn]

2016 is when they went to the 6spd in the motorhome chassis, it's also when they uprated from 5500 to 7500-8k lbs official towing capacity. Same engine and rear axles and frame

I didn't know they were common with 4.56 as well, that's pushing more to the 5.13 as well.

I don't think Ford put an official tow rating on them, they always just said don't go over GCWR, but I know what you mean as the 8k rated receivers started showing up on the 2016s.

 

[Provience]

I don't think Ford put an official tow rating on them, they always just said don't go over GCWR, but I know what you mean as the 8k rated receivers started showing up on the 2016s.

I believe it was the coach builder ratings rather than ford. Since it is all advertising anyways, to me that means more the marketers were comfortable saying "anybody can tow this load with reasonable performance"

Changing the transmission to the deeper 1st gear gave that confidence to make the switch. 6k lbs dogs my motorhome worse than 5k lbs, if I can get reasonable performance with 7k lbs I'll be super happy.

 

[Rockwood]

My 5R110/V10 Class C came with 4.56 stock, and I sometimes wish it were shorter in 4th (same as your 3rd), but that's with the 6.8L V10 screamer, so probably right for a 460. When it drops to 3rd (same as your second), it can easily pull it, but max speed is 60mph if I mercilessly floor it to the limiter.

Currently tow between 5-7,000lbs with it (yeah yeah, overweight, tires scale correctly, so ). Seems to have adequate power even up the I8 grade headed into San Diego (6% with near-constant 25-50mph headwinds for 13-ish miles).

 

[GLTHFJ60]

04 F550, 6.0 powerstroke, zf-6 speed, 2wd. Came with 4.88s, but it's way too much rpm for the highway with the stock tire size of 225/70r19.5. I roll around at about 26k gross with my enclosed trailer.

Stock:

Changed to 4.30 gears. Kinda wish I went to 4.10, but not bad enough to buy another diff. This is after the gearset change. Yes, speedo is still accurate, verified with GPS.

I wish I had upped the tire size a bit when I bought new ones, but iiwii. I've put another 20k miles on it since I changed the diff, and the mpg increase has paid for the diff.

 

[CarterKraft]

I did a bunch of 6.7PSD 6R140 4.10 vs 6.7PSD 10R140 3.55 in the 6 month dually thread
Its not apples to apples but you can still "feel" the difference towing.
I think its a worthwhile compromise if the truck is driven unloaded most of the time.

On paper the change to 10 speed 3.55 was a decent MPG improvement, 2-3 MPG on the lie o meter.
Towing max GPM appears to be the same at 8-10 mpg.
The truck feels faster is not gear bound.

 

[YotaAtieToo]

2016 is when they went to the 6spd in the motorhome chassis, it's also when they uprated from 5500 to 7500-8k lbs official towing capacity. Same engine and rear axles and frame

I didn't know they were common with 4.56 as well, that's pushing more to the 5.13 as well.

5.13s would be the same as 3.54s with a c6 on the highway.

Have you considered 5.86s or 6.17s




Dumb side note, but I think a cool you tube video would be buying a cheap gasser tow rig, and swapping a few different gear ratios just to show people what the difference is. Would be fun to do a rig with a D70 just to do a final run with 7.17s

 

[tac1]

Dumb side note, but I think a cool you tube video would be buying a cheap gasser tow rig, and swapping a few different gear ratios just to show people what the difference is. Would be fun to do a rig with a D70 just to do a final run with 7.17s

I've been curious to do the same thing with my 09 2500 chevy 6.0/6l90/3.73 stock 265/75/r16s it actually pulls/accelerates pretty well for what it is up to speed towing 12k or so, hills but no real elevation, but trying to cruise 60-70 is miserable, it constantly jumps 3-4-5 gear if left in drive tow/haul, 6th is useless. Holding it in 4th is better but it seems to build heat in the trans in 4th for long periods of time, maybe convertor lock up related. My trailer are heavy empty ~4800 and 5000lbs

Took the same route yesterday with my beater 01 2500 chevy 6.0/nv4500/4.10 truck. 4th gear just under 3000rpm and set the cruise till I got there.

Anyone here geared a stock 6.0/6l90 truck to 4.88 or numerically higher?

 

[pennsylvaniaboy]

F250 cc converted to dually. D60/110, 4.88/truetracs. Stazworks, Deavers, bilsteins, hydro assist, shafts, etc.

Bought it with the idea of ditching the cray computer controlled 6.7, but things change. It’s fun for around town, even though it’s huge.


And it’s for sale.

we need pics of this

 

[CarterKraft]

Fun fact to add

2019 International CV (aka GM 6500)
225/70R19.5 tires 3.73 gears Allison 6 speed (not sure on ratios) and 6.6 Duramax.

Gross' 20k with a governed speed of 75mph.
Way too tall of a gear.
At normal take off acceleration for a 20k loaded truck it will "chuff" the turbo which I think is surge when it shifts to 2nd and 3rd.
I have to keep it in tow/haul to keep the shift rpms up.

 

[Rockwood]

I believe it was the coach builder ratings rather than ford. Since it is all advertising anyways, to me that means more the marketers were comfortable saying "anybody can tow this load with reasonable performance"

Changing the transmission to the deeper 1st gear gave that confidence to make the switch. 6k lbs dogs my motorhome worse than 5k lbs, if I can get reasonable performance with 7k lbs I'll be super happy.

I think with the tall 1st on the 4 speeds, shorter is better. My motorhome with the 5R110, 4.56s and tiny 225-75R16s felt peppier than my V10 Excursion with 4R100, 4.30s and metric 33s. Worst is reverse. Why in the hell did they make reverse capable of 60mph?

As long as it's not cruising much above 2500rpm, shorter is better.

 

[Provience]

I think with the tall 1st on the 4 speeds, shorter is better. My motorhome with the 5R110, 4.56s and tiny 225-75R16s felt peppier than my V10 Excursion with 4R100, 4.30s and metric 33s. Worst is reverse. Why in the hell did they make reverse capable of 60mph?

As long as it's not cruising much above 2500rpm, shorter is better.

Since the d70 has a stupid carrier swap at 4.10, I'll probably go too high first and then dial back later if need be. Going to keep the 4.10 and measure shims as well, I can always toss it back in [that's what we all say ] if need be.

If 5.13 is unbearable, 4.88 is only a couple hundred bucks away at that point

 

[YotaAtieToo]

I've been curious to do the same thing with my 09 2500 chevy 6.0/6l90/3.73 stock 265/75/r16s it actually pulls/accelerates pretty well for what it is up to speed towing 12k or so, hills but no real elevation, but trying to cruise 60-70 is miserable, it constantly jumps 3-4-5 gear if left in drive tow/haul, 6th is useless. Holding it in 4th is better but it seems to build heat in the trans in 4th for long periods of time, maybe convertor lock up related. My trailer are heavy empty ~4800 and 5000lbs

Took the same route yesterday with my beater 01 2500 chevy 6.0/nv4500/4.10 truck. 4th gear just under 3000rpm and set the cruise till I got there.

Anyone here geared a stock 6.0/6l90 truck to 4.88 or numerically higher?

4th gear is roughly 4.30 final

Even 5.38s, 6th would be taller than that

5.13s would make 5th gear about the same as your current 4th and 6th a little deeper than your current 5th

What's nice about the 6 speed is you can play with locking it into gears and a calculator to see what different ratios would be like.

Edit: I do wonder if some trans tuning might be a better start though.

Fun fact to add

2019 International CV (aka GM 6500)
225/70R19.5 tires 3.73 gears Allison 6 speed (not sure on ratios) and 6.6 Duramax.

Gross' 20k with a governed speed of 75mph.
Way too tall of a gear.
At normal take off acceleration for a 20k loaded truck it will "chuff" the turbo which I think is surge when it shifts to 2nd and 3rd.
I have to keep it in tow/haul to keep the shift rpms up.

Surprised they put 3.73s in those. Even with the 4:1 1st in the F550s, they often come with 4.88s. Makes getting 40k lbs moving a lot nicer.

 

[CarterKraft]

Surprised they put 3.73s in those. Even with the 4:1 1st in the F550s, they often come with 4.88s. Makes getting 40k lbs moving a lot nicer.

Best I can tell is it was a Covid get what you can get deal. IMO 3.73's in this size truck should not be a thing.
4.10/30 at minimum.

This thing turned less RPM @ 70 mph than my old F-350.

 

[Jeffh555]

7.3 Powerstroke, turbo but no intercooler (it's a van thing)
4R100
4.56 gears
37" Toyo R/Ts
Aerodynamics of a refrigerator
Gearing feels right, I don't think I'd want it any higher or lower.

 

[rockota]

we need pics of this

 

[Provience]

Added dana BOM identification pdf to first post and resources tab, because of course there are several versions of the D70

 

[YotaAtieToo]

Best I can tell is it was a Covid get what you can get deal. IMO 3.73's in this size truck should not be a thing.
4.10/30 at minimum.

This thing turned less RPM @ 70 mph than my old F-350.

Covid was after 2019

I guess it depends on the trans. If it's the same as the pickup, that's extra retarded since they only have a 3:1 1st and way tall 6th.


I guess my work ordered 2 of those new GM 5500s since they love gm for whatever reason. I may be one of 2 guys going to Wisconsin to drive them back. Curious how they compare to the F550s.

 

[Curbkrawler]

16 Ram 3500 CC DRW 4x4 6.7L w/ factory rear air suspension
4.10's
Aisin
235's (whatever stock)

Truck is bone stock. Plan on deleting eventually. Has 50k miles on it. No complaints really. I've only owned 3 trucks in my adult life. 02 3500 DRW 4x4 24V 5.9 w/NV5600 and 4.10's, a 14 3500 SRW 4x4 short bed w/ Aisin and 3.42's, and now the current 16. I was surprised the 14 with 3.42's got better mileage towing than my current 16 with 4.10's. I figured with the mechanical advantage the 4.10 equipped one would getter slightly better mileage towing and less while not but that really hasn't been the case. Truck and slide in camper I get about 12mpg. Truck, camper, and jeep on 18' bumper pull I get 10mpg east of Mississippi and 7-8 mpg out west. Pulling my 24' V-nose enclosed I get about 10.

 

[DMG]

What about warming up the motor a bit? Headers, a tune, get rid of the retarded cam timing gear set if it’s that old, cold air intake, etc?

 

[Provience]

What about warming up the motor a bit? Headers, a tune, get rid of the retarded cam timing gear set if it’s that old, cold air intake, etc?

For me, i'm trying to keep the speed density EFI, the issue is most prevalent starting on an incline with a load (5k lbs for the toad, goal is 7k lbs with the trailer) and it struggles. Sounds like the ignition is holding it back. It'll go, it just isn't too happy about it.

Looking into building power, it brought about the thought of what would it cost to make whatever amount more horsepower to meet whatever the stock power and new RPM would be through gear change.

The answer was, gears are cheap even if I need to buy a new carrier. added bonus is the reduction/leverage gain as well.

talked to my dad about it for a bit the other day as well. Plan is to start cheap, open up the intake, replace the old catalytic converter and muffler and change gears (i'm back to 4.88's ). Figure this will cost $500-850. timing set is already straight up.

see how that does for a trip or two and then decide on mild camshaft and headers, probably newer style larger valve iron heads. this would be $1200

anything more than that and i'd be looking at going to a carb and letting ECM handle timing/trans OR going to MAF system OR going full aftermarket fuel/ignition/trans control. That's all in the $3k range, though I could be into ~450hp pretty easy. I don't think i'm putting the miles on it to justify all that.

 

[DMG]

My last 460 truck was greatly improved with a msd box and some timing advance.

 

[skyhiranger]

Engine
Trans
Axle
Tire

2001 F350 4x4, CC, LB, dually
6.8 V10
4R100
4.30
Stock 235/85/16

Had an aftermarket cat on it when I bought it. Added a Y-pipe and Flowmaster Big Block muffler.
Running a SCT tuner with 5 star tunes. No noticeable improvement in towing over the stock tune (other than higher shift points).
Needs more tranny gears. The shift from OD to 3rd jumps the RPMs 900-1000 and I hate it. Then it is sometimes hard to get it to upshift back into OD, when I think it should.
Gets 7-8 MPG towing. Tow 8K-20K.

 

[Provience]

2001 F350 4x4, CC, LB, dually
6.8 V10
4R100
4.30
Stock 235/85/16

Had an aftermarket cat on it when I bought it. Added a Y-pipe and Flowmaster Big Block muffler.
Running a SCT tuner with 5 star tunes. No noticeable improvement in towing over the stock tune (other than higher shift points).
Needs more tranny gears. The shift from OD to 3rd jumps the RPMs 900-1000 and I hate it. Then it is sometimes hard to get it to upshift back into OD, when I think it should.
Gets 7-8 MPG towing. Tow 8K-20K.

I think the 6 speeds are really convenient from a power/size/useable RPM setup for gas motors. It's kind of funny that the e4od/4r100/zf5/zf6 all have essentially the same 1:1 to O/D drop

the 6L80/90/6R80/140 transmissions all lack the 1:1 ratio for a way smoother transition on the top end of things

 

[skyhiranger]

I think the 6 speeds are really convenient from a power/size/useable RPM setup for gas motors.

It looks like the 6R80 has ratios that would work really nice with my V10.

 

[Provience]

It looks like the 6R80 has ratios that would work really nice with my V10.

yeah, i just hate and don't understand why the 6r140 doesn't have the same level of aftermarket support. US Shift said they are shooting for the end of this year to have 140 programming for their Quick6 standalone.

that'd be sweet. it'll go a long way to keeping older trucks on the road ~$3-6k for a transmission swap for a huge improvement in driveability instead of ~20k for a whole new truck is a tempting option

 

[skyhiranger]

yeah, i just hate and don't understand why the 6r140 doesn't have the same level of aftermarket support. US Shift said they are shooting for the end of this year to have 140 programming for their Quick6 standalone.

that'd be sweet. it'll go a long way to keeping older trucks on the road ~$3-6k for a transmission swap for a huge improvement in driveability instead of ~20k for a whole new truck is a tempting option

100% agree.
The lack of gears is the one thing I don’t like about my truck.

What little I’ve read, the 140 is a considerably bigger tranny, so it is limited to what vehicles you can swap it into. So maybe that is why the aftermarket support is lacking?

 

[CarterKraft]

Covid was after 2019

I guess it depends on the trans. If it's the same as the pickup, that's extra retarded since they only have a 3:1 1st and way tall 6th.


I guess my work ordered 2 of those new GM 5500s since they love gm for whatever reason. I may be one of 2 guys going to Wisconsin to drive them back. Curious how they compare to the F550s.

I can't even begin to tell you what a mess they are... They have a front end vibration that will bounce the tire off the ground... New aluminum wheels, 3 sets of front tires, king shocks and still no resolution. We did get the max speed up to 65 mph instead of 60...

 

[Gbkeith]

I can't even begin to tell you what a mess they are... They have a front end vibration that will bounce the tire off the ground... New aluminum wheels, 3 sets of front tires, king shocks and still no resolution. We did get the max speed up to 65 mph instead of 60...

What is the bottom of that shock attached to?