it's probably been asked a lot, but i didn't find it.

w/my 95, 160/400 right?, pullin a new 5th wheel(2002), aux tank, gen set and misc bs, i'm probably about 15k gcvw. w/the 3.55 and auto tranny my manual states 16 k max. on a recent 2500 mile trip i found we just don't have the power. on flat level stretches w/no wind i could hit 70 w/a full pedal. most of the time it was 60 ish w/almost a full pedal and 50 in 3rd on hills. in the smoky mountains i spent a LOT of time in 2nd at around 2200 rpms and 30 mph. o/a trip mpg was 11.77. on the frwy 12.66 was common even w/a lot of 3rd gear. i know theres lots that can be done to improve performance, at the expense of fuel economy if i hear right. been talkin to mike at hot rod diesels bout engine and tranny mods, but what about just goin to a 3.73 or 4.10? would either make much difference
if i'm drivin 65 at a higher rpm wouldn't i use the same or less fuel if it's pullin easier than my foot to the floor goin 65 now? also, i noticed that often, it didn't matter if my foot was 3/4 or to the floor, speed was the same, WU.

john

95 w/227,000, 42k mine, lots a replacement parts, kdp tabbed, KnN

 

Changing the gears is gearing not power [ mechanical advantage ] , with some thing like the 4:10s it help towing but less millage .
Since these trucks are detuned , bring back the power [ mostly just adjustments ] , but 1st a set of gages , 2nd trans/clutch [ your signature dose not say either way{ 160 HP means an auto} ] up grade to handle the power that you want to add .
With reasonable mods & driving you should be able to see 15+ MPGs towing .

 

I agree with John. The only question is how far you want to go in the power department. 1st gen trucks can be turned up a little with adjustments. You might try that first. If you are still not getting what you want the gear change will make a big difference with towing in the hills and I don't think your mileage will suffer much when you are towing. IMO 3.73s are not enough of a jump for the trouble - I'd go with 4.10s.

 

I am not up on power mods to the 12 valves (though I am told you guys can really get the power with a few cheap/free changes), but after going through the ordeal of getting new tires this month I want to point out that most trailer tires out there are not designed to run faster than 65 mph. I have seen that there are some exceptions if the load is less than the maximum load the tire is rated for, but if you have the originals on the trailer, it is probably a good idea to replace them anyway due to age, and not run over 65 regardless.

Now back to our regularly sched. towing power thread...

 

the setup I run does very well towing my excavator, 100 plate, 3gsk, afc forward, Banks turbo housing and wastegate, and thats about it, and I average 19mpg empty, and 15-16 towing. The 5spd helps alot when towing, I never have to drop gears unless traffic makes me. Are u still running a stock auto? A built auto would help alot. You can make 450hp and still get 18-19mpg, its all about how efficient ur setup is to burn the fuel and push air (right turbo, injectors etc). 4.10's really don't hurt milage to me, I don't run 75 though, I usually stay below 70 because rpms are to high for my liking up there. But 4.10's would help u keep speed on hills and getting going, I think u should do some power mods and or trans work first. Get a different air filter to, K&N's tend to get dirty or to oily and give poor air flow

 

i was really trying to avoid the power upgrades, then it would need some tranny work. was thinking the r&p changes would take the strain off the tranny, espescially w/ the 3.55, and help the towing. mine is an auto. whats another good air filter?
tires, too little depedable choices. our 1st 5ver was a 92 lance. no slide, even w/the builtin genset it only weighed 4400 lbs. i went thru a set of towmaster "E" tires, and an off brand set of E's due to blow outs. now, we did haul a**. 75 mph was common. discount tires web site states trailer tires speed rating is 65, yet some of the trailer tires the sell are rated much higher. was goin to put a set of goodyears, then talked w/some fulltimers hosting at a state park. he just rplaced a set of goodyears on a NEW rig due to blowouts. so i bought a set of dominator p235 75 r15 that had a load rating that equaled twice my rig weight and a 100 mph speed rating. no more trouble. my thor-29' 7500 lb 5ver-had 4 - 4year old carlisles when we bought it a month ago, and no spare. the front 2 were e's and the back 2 were d's. i bought a new carlisle e and used 1 of the d's as the spare. 500 miles in to our trip to the smokies the new E blew w/ nothing left but the bead and an inch of material. i had to buy a no name tire at the only place i could find it. the 4 year old tires made the whole 2500 mile trip w/out incident. when i replace these, i'll get an E truck tire.

off the main subject, but interesting


john

 

If you are setting up your truck to pull that load as your priority then the 4:10 gears would be a good choice. With your power level you are not going to get much with the 3:73s. With my '04 and the 305/555 and 3:73s, I have to run in third a lot in the hills when I get to around 15,000 gross. Don't be concerned about lower mileage with the 4:10 gears. That is not a problem in your case because you are not running around empty trying to get the max mileage, you're trying to get your load up the hill. The lower gearing will allow you to use OD sometimes, give you better throttle response and get moving easier from a stop. Proper gearing means proper for the job you're doing, not just higher is better.

More power would be very nice but be careful. Gauges are a must and that includes a tranny guage. You can't just add a bunch of power and go pulling in the mountains. My '93 had 160 HP and it would pull surprisingly well in the mountains, but the tranny would get hot and was definately the weak link. It would hold the power OK, just couldn't stay cool enough to live.

Keep the revs up. You'll get better throttle response and cooler EGTs with your RPM at 2,200 than at 1,600. Running the tranny in lockup more of the time (because of the lower gearing) will generate less heat.

Be patient. The CTD is a great pulling engine, but with a lot of weight you still have to slow down on hills.

John

 

I've read several times that the 3.54 can be changed to 3.92 and use the same carrier - 4.10 uses a different carrier. The guys that went to 3.92 rave about them. That's the ratio I always wished I had but never did it. That alone would make it tow like a different truck. I had a 97 - 215 and did a lot of mods to it. I was thrilled with the 3k gov. spring kit and wish I'd have done that first. The AFC kit helped, too. Then on your, (if the top end still needs help) I think I'd slide the plate forward a little before changing to a different one. You can help them a lot and still be safe. I can't tell you about the auto but I think there's some cheaper, easier mods that are a good idea no matter what, to make them hold up better. Craig

 

I'd leave it alone. Add some power. Not much, and hurt the tranny, but a small amount.