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endobear

02 7.3 regear thoughts

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I'm running 35" tires and pulling 13k to 15k with my 1 ton. SRW.

She's got just about everything done to her but bigger injectors and turbo. 130k miles.

She's still a dog on the mountain passes I pull and it seems like I'm always having to lift off the throttle to keep my EGTs under 1200. No boost leaks. 

Im thinking about a regear. 80 % of the miles I put on it are towing something.

4:30, 4:56 OR 4:88?

I would still like to be able to do 85 mph when im not towing. I'll sometimes through the dirt bike in the bed and hit Moab without my trailer.

Considered the gear benders underdrive but I'm not sure how much longer I'll have her.

 

Edited by endobear

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i broke 2 sets of 4:56's in my 7.3 when i had it.

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I just did this to my 6.7 Ford, and tow 22,000 and I run 37'' tires and Dune the truck every trip, 

I broke in the rear gear just like instructed, 1000 of under 55 mph and spirts of 30-45 minutes, took about a week in a half, and them did 3 trips of 100 miles, then changed the oil and did a trip of 100 miles towing my sand car, 

them it was broke in and towed my 5th at 22,000 at 80mph for about a year now 

I did a Yukon gear, 

I did a 4;56 with 35'' and hate it ---- went to a 37'' for better acceleration and highway towing, and it is a little better,   almost positive that truck came with a 3.55 rear end being a single wheel,  I would go to 4;30 and no lower, maybe even a 4;11, 

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Buy a newer truck with the 6.7 and never look back. Been there and done that with the 7.3

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I had the same truck.   I went with 4:56 gears with 37” tires.   It made a difference.   There are calculators on line that will show what the effective gear ratio is with the bigger tires.    I believe with 37s and 4:56 it was equivalent to a 3:73.    
   

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2 hours ago, J Alper said:

I just did this to my 6.7 Ford, and tow 22,000 and I run 37'' tires and Dune the truck every trip, 

I broke in the rear gear just like instructed, 1000 of under 55 mph and spirts of 30-45 minutes, took about a week in a half, and them did 3 trips of 100 miles, then changed the oil and did a trip of 100 miles towing my sand car, 

them it was broke in and towed my 5th at 22,000 at 80mph for about a year now 

I did a Yukon gear, 

I did a 4;56 with 35'' and hate it ---- went to a 37'' for better acceleration and highway towing, and it is a little better,   almost positive that truck came with a 3.55 rear end being a single wheel,  I would go to 4;30 and no lower, maybe even a 4;11, 

That whole break in procedure sounds like a pain in the ass. Of course I'll do it if means it will help make my rear end last though.

Im known to be extra hard on "rear ends".

I've had to put new rear ends in every van and truck I've owned over the last 30 years.  

Im positive I've got 3:73 gears.

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39 minutes ago, hondajimz said:

Buy a newer truck with the 6.7 and never look back. Been there and done that with the 7.3

New truck isn't happening until I build my new garage.  Won't fit in the one we have now and I can't stand the thought of a new truck sitting outside.

Ive been renting new trucks for the long tows the last 4 years but they jacked up the cost on me. Going to cost me double what it did last year.

Love/loved my 7.3.  I've had her since 03.

Will pass it on to my kid in a few years.

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Buy a newer truck with the 6.7 and never look back. Been there and done that with the 7.3 . The problem is the trans...you can't get good towing and 85mph without a gear vendors.

Why not the injector/turbo mods?  Better intercooler....gear vendors.....oops you could buy a 2014 and not have to do all that.

The new trucks are just better.

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2 hours ago, kofire said:

I had the same truck.   I went with 4:56 gears with 37” tires.   It made a difference.   There are calculators on line that will show what the effective gear ratio is with the bigger tires.    I believe with 37s and 4:56 it was equivalent to a 3:73.    
   

4;56 with 37'' is equal to a 4;30 gear on a dually ford my 4;56 is so low even with the 37'' cooper that it will get to 6 gear at 35 mph, it like driving a semi truck the gears are so short that the truck feels like it has less power because the ford holds at the max rpm for about 3-4 seconds before it shifts,  so it feel like a kid that can not drive a stick shift, 

I wish I did a 4;11 on 35'' tires

1 hour ago, endobear said:

That whole break in procedure sounds like a pain in the ass. Of course I'll do it if means it will help make my rear end last though.

Im known to be extra hard on "rear ends".

I've had to put new rear ends in every van and truck I've owned over the last 30 years.  

Im positive I've got 3:73 gears.

it does not help the rear end last, it will make the rear end work more than a day,   break in has to be done,

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With 35” tires I would do 4.30 if you plan on driving it on the freeway.

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My 1999 F350 dually w/37"  I went with  4:88 with a gear vender. Had Camping World install, they have a grandfather agreement that they are even cheaper than Gear Vender. Then you get the membership and save more.  Gear Vender was the hot set up, gives  you 1/2 gears and ad additional over drive.

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1 hour ago, J Alper said:

4;56 with 37'' is equal to a 4;30 gear on a dually ford my 4;56 is so low even with the 37'' cooper that it will get to 6 gear at 35 mph, it like driving a semi truck the gears are so short that the truck feels like it has less power because the ford holds at the max rpm for about 3-4 seconds before it shifts,  so it feel like a kid that can not drive a stick shift, 

I wish I did a 4;11 on 35'' tires

it does not help the rear end last, it will make the rear end work more than a day,   break in has to be done,

It wasn’t my experience with a 2002 7.3 which is almost identical to his.    If you plug in the numbers on any any chart with 4:56 and 37s.  It was within 10 rpm of 3:73 gears with stock tires.    I do know it put the 4 speed 4r100 back in a good range for climbing.  It could lock the torque converter in 3rd which was the perfect gear for climbing.   I’m not saying you’re wrong I’ve just done this whole thing with the almost exact same truck.  

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You have some sort of tuner or programmer I assume? Stock tunes are more than sluggish, usually Kicking out of overdrive on the pass keep it at 2500 rpm or above and keep your foot in it, should not need to re gear? may need to see John wood and add some trans mods or an engine tuner and your done!  My old 7.3 srw cc sb, would pull anything at 65 with stock gears and 37" tires just hard to keep egt below 1900 on long grades.

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14 minutes ago, 2turbofords said:

You have some sort of tuner or programmer I assume? Stock tunes are more than sluggish, usually Kicking out of overdrive on the pass keep it at 2500 rpm or above and keep your foot in it, should not need to re gear? may need to see John wood and add some trans mods or an engine tuner and your done!  My old 7.3 srw cc sb, would pull anything at 65 with stock gears and 37" tires just hard to keep egt below 1900 on long grades.

1900° EGTS?

I read somewhere that 1300 was the absolute highest you want and that should be done only for a few seconds. 

If I could go higher then that would be awesome!

I have a tuner but it seems that everytime I'm gonna tow my Edge CTS2 egt reading always gets stuck. I have to turn off the truck and it would work again. Needless to say I don't trust it and just use stock tune. 

I have a 2003 F250 7.3 CC short bed 4x4 with a 4 inch lift and 35 inch tires.

I tow a 38 foot triple axle Forest River 5er. Yes it's slow on hills but I'm not racing. I just keep the OD off the whole way.

Here is a picture of my set up. Inside is a 4 seat Chenowth Explorer with Honda V6.

I'm overloaded for what Ford recommends but my engine and tranny are good.  I think. lol.

20191201_104141.jpg

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Yes meant to say 1400 sorry, usually run around 1000 most time with a trailer. Is your egt sensor in the downpipe or in the manifold?  Better to see before the turbo temps with the sending unit in the manifold just before up pipe to turbo pedistal . Running big tunes I have seen 1500 temps before, and I sold the truck with 330,000 miles on the original motor and turbo, stock injectors also. 

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Call Tom Woods in Holtville and he'll tell you what to do to make it do what you want it to do.

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3 hours ago, kofire said:

It wasn’t my experience with a 2002 7.3 which is almost identical to his.    If you plug in the numbers on any any chart with 4:56 and 37s.  It was within 10 rpm of 3:73 gears with stock tires.    I do know it put the 4 speed 4r100 back in a good range for climbing.  It could lock the torque converter in 3rd which was the perfect gear for climbing.   I’m not saying you’re wrong I’ve just done this whole thing with the almost exact same truck.  

I not sure what math you are using but that is incorrect, also he wants to run 35'' tire so hopefully this should help you make a decision, I would still run a 4.11 to equal the f250/F350 factory or a 4.30  I think you will hate running even 75 mph is a pain,  this is same as my 37'' on 4;56,  and it feels like the mirage now is the same towing or not towing and as soon as you let off the throttle it goes down to 45-50mph that is the new sweet spot off throttle when before it coasted at 70mph 

2002 factory size tire 4x4 is a 235/85-16 pretty close to a 32'' tire, the chart below should help you  

tireandgear.jpg

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Anyone need  an almost new 4.56 R&P for a 11.5" GM diff?  Bought them from a board member for my 2500HD Dmax with 37's many years ago and never installed them.  just sitting on the shelf, sell them cheap.

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19 minutes ago, J Alper said:

I not sure what math you are using but that is incorrect, also he wants to run 35'' tire so hopefully this should help you make a decision, I would still run a 4.11 to equal the f250/F350 factory or a 4.30  I think you will hate running even 75 mph is a pain,  this is same as my 37'' on 4;56,  and it feels like the mirage now is the same towing or not towing and as soon as you let off the throttle it goes down to 45-50mph that is the new sweet spot off throttle when before it coasted at 70mph 

2002 factory size tire 4x4 is a 235/85-16 pretty close to a 32'' tire, the chart below should help you  

tireandgear.jpg

That one it looks like my number of ten rpm is off.   It looks like 65 rpm difference.   My truck had 31s and 3:73 to begin with.   They’re both in the green for balance and power.   
   65 rpm to is pretty darn close but ya it wasn’t the ten I said.    I’m not arguing with you I’m just giving him my experience.  I had the same exact truck with the same issues he has  Yes he’s asking about 35s.  I was referencing 37s.   
    Depending on what gear he wants to climb in he would  probably be best with 4:30s.   

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Punch it in here:

http://www.grimmjeeper.com/gears.html

To see where you land RPM wise.  4.30:1s would be cheaper (assuming you currently have a D50 front) because you can just swap in a set of V10 axles (common option was 4.30:1), which are fairly easily found under $1000 on Car-part.com for the pair (just find a vendor that has both and call them).  4.30:1 also appears to land you close to stock gearing (100rpm higher on the freeway with 4.30s).

2002 SRW F-350 could go either way (D50/D60) for front axle, but most common is supposedly a D50 up front.  

Edited by Rockwood

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keep it as-is, go slower until new garage is built, then buy a newer truck.......

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I have a 2000 7.3 with all the stuff done to it.   You can run the EGT @ 1200 all day and up to 1300 for minute or two.  You should never go higher that 1350.  I'm going to put a gear vendor in mine.  You can split every gear by 22% (under or overdrive) manually so you shouldn't need to change gears.  It essentially turns the 4R100 into a 6 speed with a double over drive.  The GV for the 4R100 is $3500, plus your have to shorten your rear drive shaft a little.  I went by a few weeks ago.  They are on Magnolia in El Cajon, CA.

~jw 

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33 minutes ago, jwest2sh said:

I have a 2000 7.3 with all the stuff done to it.   You can run the EGT @ 1200 all day and up to 1300 for minute or two.  You should never go higher that 1350.  I'm going to put a gear vendor in mine.  You can split every gear by 22% (under or overdrive) manually so you shouldn't need to change gears.  It essentially turns the 4R100 into a 6 speed with a double over drive.  The GV for the 4R100 is $3500, plus your have to shorten your rear drive shaft a little.  I went by a few weeks ago.  They are on Magnolia in El Cajon, CA.

~jw 

personally for the cost I like the gear vendor idea, if they made it for my 2012 would have done that in a heartbeat 

I will say my 6.7 I purchased 3 years old with 80k miles I put on another 80K hard towing foot to floor all the time, and has only need a small O ring for the Turbo drain back tube, I have replace one intake boost tube, that was $65 from the factory and one fuel pressure sensor was leaking, and that has been all 

I tow heavy with the 6.7 and I Dune the truck close to max RPM in the dunes, 

this has been a great truck,  

I have owned 7.3 the dreaded 6.0 and now the 6.7  

the only reason I would sell this truck is to get the newer model with the built in remote camera for the trailer,  but not worth the money due to the truck being paid for, 

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2 minutes ago, J Alper said:

personally for the cost I like the gear vendor idea, if they made it for my 2012 would have done that in a heartbeat 

I will say my 6.7 I purchased 3 years old with 80k miles I put on another 80K hard towing foot to floor all the time, and has only need a small O ring for the Turbo drain back tube, I have replace one intake boost tube, that was $65 from the factory and one fuel pressure sensor was leaking, and that has been all 

I tow heavy with the 6.7 and I Dune the truck close to max RPM in the dunes, 

this has been a great truck,  

I have owned 7.3 the dreaded 6.0 and now the 6.7  

the only reason I would sell this truck is to get the newer model with the built in remote camera for the trailer,  but not worth the money due to the truck being paid for, 

Agree 100%.  The 6.7 is much better suited for towing.  I just love the 7.3 rumble and I've always enjoyed driving older trucks and fixing them up.  I don't tow that often with mine and when I do it's about 8500#'s so the 7.3 works fine for me.  I just wish the new diesels weren't bogged down with all the smog crap and the issues that come with it.  I was going to sell mine and get into a newer F150.  Even had some good offers...but the new stuff is just boring to drive for me.   

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3 minutes ago, jwest2sh said:

Agree 100%.  The 6.7 is much better suited for towing.  I just love the 7.3 rumble and I've always enjoyed driving older trucks and fixing them up.  I don't tow that often with mine and when I do it's about 8500#'s so the 7.3 works fine for me.  I just wish the new diesels weren't bogged down with all the smog crap and the issues that come with it.  I was going to sell mine and get into a newer F150.  Even had some good offers...but the new stuff is just boring to drive for me.   

for me having a Ford / Chevy / and a Dodge in the Family, 

the 6.7 has no issues with all the smog components, really does not even know its there, and the deff fluid for me I only fill a couple times a year huge tank,  I like for trucks but never had good luck with the F150 for me always issues, still think Chevy has a amazing 1/2 Ton  the Jeep has been a solid vehicle, bad water pump and every Dodge V8 I have had to fix the ex-manifold bolt with small leak, I would consider a chevy 3/4 if they did not have the 1/2 ton front, only like to tow heavy with a straight axle, like a Semi or a Tow Truck  

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