Who is towing with 3.73’s?

[Bertram65]

3. 73s with the six speed give roughly the same final ratio as the 4. 10s with the auto. If you get the auto with 3. 73s you will be doing 77MPH at 2100 RPM, vs around 70 with the six speed and 3. 73s or the auto with 4. 10s.

 

[jsimpson]

Towing 38' Wells cargo steel framed inverted fiver wit 03 305 automatic. No problems, but it does downshift sooner than I'd like. I'd LOVE to have some more control over downshift and lockup points!

 

[claymike]

On my 600 6 speed I am towing 21k gross, no problems at all. Out of the 9,000 miles I have on the truck 4,500 of them have been towing.

 

[Udaloy]

As far as the overdrive ratio goes, I know the '02 I had with the 47RE used . 069. If memory serves, I think I read somewhere that the 6-speed has something like . 075. I'm sure someone out there knows for sure.

 

[CajunDieselMan]

Wish I'd put 3. 73 on my truck. 4. 10 keeps it wound up a little too much. I added the 4. 10s when we were thinking of a bigger trailer (have a 10000# Sunnybrook now) My wife found a nice place to park our fiver so I hardly tow. ONLY complaint with my truck and it's my fault, really. No..... my wife found the place for our RV... . it's HER fault!

 

[FDrake]

I have the 04 with the 305/555 CTD. My truck weighs about 7500# and the 5th wheel combo weighs in at 19,640#. I get about 12. 5 MPG unless I am on a LOONG grade like the Baker to or from Vegas. I have the 3. 73 rearend on this truck and my last one. I had 3. 55 before that. In each case, when I needed a lower gear, I downshifted and had no trouble. It is great to have the taller gear when driving solo. This truck is an auto transmission. The 02 was a 6 speed stick with the 3. 73 gears. The 97 was an auto transmission with the 3. 55s.

 

[s.hale]

Just returned from a 12,000 mile trip to Alaska from Georgia with my new 04. 5 Quad Cab,Dually,long bed,4x4,48RE with 50 Gal. aux fuel tank (500 lbs). I was pulling a 37 foot 5er for a combined weight of 21,600 lbs.

On about 5 or 6 long steep mountain grades I wish I had the 4. 10 rear end to keep up the rpm's and stay out of 1st gear. In first I was turning 2500 rpm;s at 30mph. The lighter 5er's and other campers were still in 2nd and passing me which I didn't like.

Most of the driving was on grades that when I shifted out of OD at 62mph I could maintain 60mph at around 2400rpm.

I also found it difficult going from a standing start to highway speed as the engine and trans seemed to struggle. Maybe a 4. 10 would help this situation.

If you don't tow much with weights such as mine you probably won't have a problem. My problems were from a standing start and long steep mountain grades.

 

[claymike]

Like I stated earlier I tow 21k gross but I think the big difference is I have the 6 speed. Only one time have I needed to get as low as 4th gear on any grade.

 

[CFenton]

My trailer is about 7. 5k, so it is on the lighter side. I run about 18K rpm at 65 in OD. Steep grades with a head wind will knock me back to 3rd, but then it jumps to around 24k rpm and would seem to climb all day. I don't have gauges (yet), so I can't say much about EGT.

 

[y-knot]

There always seems to be a wall that separates the 3. 73 and 3. 54 guy's from the 4. 10 fellows. The guy's with the 3. 73 rear ends always say they tow with no problem, I just think they have never towed with a real gear like the 4. 10 or larger 4. 56 or even 5. 13 like in some trucks I have had.

This trucks are usually bought to tow something, so why not go with the best gear to do the job?? I know why, most only tow once or twice a year, the rest of the time they are getting grocery's or flowers from home depot. People that buy 3. 73's are penny pincher's they think they might loose a mile to the gallon or something like that. The trucks are much more lively and responsive with the taller gear, I think that the fun factor gets overlooked to often. The goofiest ones are the guy's that go with the small gear, knowing they are going to put larger tires on down the road. Then they wonder why there truck is sluggish and slow? I don't think the gear has as much of an effect on the fuel mileage as most seem to think. I suppose light loads or very light weight trailers would be Ok, but I have always liked to go with the largest gear the manufacturer offers. Most on this site don't keep their trucks but a couple years anyhow, or until the next newest thing pops up like the 600. Why not try a large gear truck? You might just like it enough to keep it around.

 

[EB]

y-knot

I believe you need to learn to put IMO when you make a statement like you did,



"I know why, most only tow once or twice a year, the rest of the time they are getting grocery's or flowers from home depot. People that buy 3. 73's are penny pincher's they think they might loose a mile to the gallon or something like that. "



I think I qualify as someone that tows more than once or twice a year, and I run 3. 73 gears. If I lived in a very hilly area I would probably run the 4. 10's but I don't. I go out loaded and most of the time come back empty or vice-versa. The 3. 73 gears work fine for me and as many miles as I run, every bit of fuel savings I can get helps.



I rolled over 143,000 miles coming back from Houston this afternoon and my trailer is sitting in front of my house with a 13. 5 ft high load on it. My truck will be 18 months old on the 14th of Aug. Last year 87% of my miles were towing.



If you have an opinion, state it, but don't make blanket statements. Everyones situation is different.

 

[klenger]

I had an 01. 5 with 4. 10's and now have an 04. 5 with 3. 73's. With the 600 ft-lb engine in the 04. 5, I have about 18% more engine torque than with the 505 ft-lbs on the 01. 5, but only suffer a 9% reduction in torque transfer to the rear wheels because of the 3. 73's vs the old 4. 10's.



In other words, if my 505 with 4. 10's was delivering 2070 ft-lbs to the rear axle, the 600 with the 3. 73's is delivering 2238 ft-lbs, so I'm still better off than I was before.

 

[KBennett]

3. 73's and 6-speed bone stock.

I pull a 5K camper and never lack for power. Going through the mountains I pass cars struggling up the hills.



My buddy has a V10 Ford and I passed him no problem going up hill in 5th and 3/4 throttle. He had his floored and has a 4K camper.

I will never own another non-turbo truck up here.

 

[sarj]

Originally posted by y-knot

There always seems to be a wall that separates the 3. 73 and 3. 54 guy's from the 4. 10 fellows. The guy's with the 3. 73 rear ends always say they tow with no problem, I just think they have never towed with a real gear like the 4. 10 or larger 4. 56 or even 5. 13 like in some trucks I have had.

I still have my '72 F250 w/ a 460 & a 4. 10 r. e. that's seen 250K pulling 9000 lbs from mexico to alaska and calif to maine... . I know exactly what it can do, and what it doesn't.

I got got 3. 73's to see what that does, and so far I got's no regrets... but you knew that ... . but I tow light now.

 

[NIsaacs]

Towing with 3.73's

I think the ultimate towing setup would be 3. 00's, and a direct ratio 6-spd. Most of the big trucks are moving away from the overdrive transmissions and using direct drives. They run cooler, last longer, and transmit more power. The only ones that spec the overdrives are the guys that want triple digit trucks,(100+ mph). Since our pickups run in high gear most of their life, it only stands to reason. I also like to run on the low side of the rpm band with the Cummins when I am towing, they seem to like the torque band more so than the horse power band. Like others have said, if you can't pull the hill in x-gear, go down one, thats what the trans. is for .





"IF IT AIN'T CUMMINS POWERED, IT AIN'T A TRUCK"





"NICK"

 

[klenger]

I've thought that a transfer case that provided final drive ratios of about 3. 54 and 4. 10 in 2WD or 4WD would be the ticket. You wouldn't need to be able to shift on the fly, just select hi or lo depending on if you are towing or not. I doubt that I will ever use the low range as it is set up now.

 

[jimnance]

Originally posted by onesloryd

Thanks for all of the replies.

I have been considering running 35” tires with the 4. 10’s and that would put it close to 3. 73’s with stock tires. When I tow (approx. 10K lbs. ) I usually have to go up a 6%-8% grade and was wondering if it would be better to put 4. 45 gears in with the taller tire.

Any additional input or experiences would be greatly appreciated.



Matt

Personally, I tried using the 315's and didn't care for them. They looked cool, but the ride was rougher and if anything the mileage went down.



I'm towing heavier than you, but I find the 3. 73 with 6 speed and standard diameter tire to be perfect. I definately would not recommend the 315's for towing a 10,000 lbs trailer. It can be done, but you'll suffer on the hills and poor fuel economy.



Just my thoughts having been there and done that.

 

[Bertram65]

I do not know how the ride could be rougher with the 315s. They are load range D, factory tires are E they also have a taller softer sidewall.

 

[onesloryd]

Thanks for all the great replies.

jimnance I would be towing with a 35" 13. 5 17" or 18". and 4. 10 gears which I think would be very close to a 3. 73 and stock tire.