I am new to the forum, but have found so much information that I am not sure if this is a good place to start. I found a 2001 Kenworth t2000, c-15 Caterpillar 550 HP, auto od,engine brake,air glide suspension,3.58 ratio,235"WD, 75" aerocab aerodyne sleeper, 24.5lp tires,aluminum outside wheels, V.I.T. interior 18 speed autoshift. Is this a good truck to start with ? I saw one on the photos page and thought it looked sharp. any information would be appreciated.

Well Bob, you've done your homework well as far as I can tell.
Seriously, I don't think you could want much more truck!
You've completely filled the wish list with that unit.
If you can afford it....your hunt is done.. https://www.truckhome.com/infopop/emo.../icon_wink.gif

Bob,

That's a good place to finish, not start. More HP and torque than you can imagine. good ratios. The only two thing's I personally don't like is the approx 13' 4" height, and the 18 speed.

18 speeds are for heavy hauling. I know you can click the autoshift up to 5th gear for starting off, but that still leaves a lot of gears to go through. You can shift an auto manually using the button, skip every other
gear. Skip shifting will help a lot. That's a lot of truck for anyone.

onezman

https://onezman.tripod.com/yourrvhaulercom

If I recall correctly, the 18 Autoshift will do its own skip shifting. I am pretty sure I saw that once when I downloaded the driver's manual for that tranny.
That's what I would have if I were to spec an OTR truck again for some reason.

bob, mase sanford, you've got my truck only i'm runnin' 3.08 . the tranny is the cat's meow or something. just great. if it's in good shape and the price is right go drive it. if you like it buy it. if you want to, call me at 540-672-4342. mase

Thanks for the information. I have a few more questions is this to much truck? I am going to use it for my 39" fithwheel will I have problems getting it to campgrounds? How much work will it take to remove one of the axels. What is considered high miles on these trucks? The asking price is 54,500 is that about right? There is some one on the photo page that has one posted, It looks sharp! vapoppa what would be a good time to call, I am in N.Y.

evenings------- 7:00 to 11:00, any day nearly.

In my opinion this would be a great truck to have, but I think you will find it too long and too tall. Also, that is a lot of power and a lot of gears for RV use. You might check with Larry about removing the axel, I think I read that this is not as easy with a Kenworth. I am sure if you could make it work it would be an awesome RV puller.

Sounds like an awesome truck!!

I've seen two Kenworth tractors with single rear axle - both had the forward axle removed leaving a long wheel base. Would be hard to remove the rear axle due to the way the brackets are used to mount the two axles. Larry might have more info on this subject.

I do not find the 13'2" height of my truck to be a problem -- heck, some 5th wheel RV's are that high, too!

I do like the shorter wheel base I have - makes it a LOT easier to get around turns, etc in RV parks - State Parks, etc.

To much HP? No such thing! You'll only use the power required anyhow. Shifting will be a learning experence - once you have your truck PRACTICE will take care of any problem.

Let us know of your progress with the Kenworth.

Don

Bob,

That KW would be a terriffic truck for OTR use, but I agree with RB7OD, it's too long and too tall for "practical" RV use. I don't know how much Rv towing Don has done, but I have been in lot's of RV parks you couldn't get into with a combination such as yours.

All parks have plenty of clearance for motorhomes, but they frequently don't have limbs cut back, or room to park a tow vehicle that size. In many parks you will be too long to maneuver when trying to back your 5er into a space.

Problems can probably be avoided in many cases, by calling ahead, but you won't be able to fit into a good percentage of parks.

I have never converted a KW. I THINK you will have to buy new single axle spring hangar brackets in order to accomplish this. That still leaves the height problem, but at least three guys have bought tall sleepers in the last 6 months. I don't know if any of them are full timing yet though.

Unless team driven, that KW shouldn't have more than 125K miles per year in service.

onezman

https://onezman.tripod.com/yourrvhaulercom

Ok the kenworth may not be a good idea for what I want to do I guess I will have to start looking for something else or stay with the truck that I have know. Thank You for all the info.

It may not be perfect, but if it is in good shape, I would not be afraid of it.
Too many gears? Phoeey. It's an autoshift. You will not care, as it does all the work.
Too much power? No such thing, just don't go ape stomping on the throttle.
Too tall? Maybe, as I have not been in many RV parks, but there are also other places to park. And with the big sleeper, you have more room to gut and modify, such as extra seating, fridge, microwave, etc.
Tandem? Well, I like them, but don't have anything to do with 5th wheels, so that may be an issue. Check with a KW dealer to see what kind of a PIA that is to deal with if you really need to.
I would be more concerned with the overall condition of the truck. You may find it better to get a good used truck and learn what works for you and what doesnt, then buy according to those lessons.

Thank you Doug for the info I did not think there was any thing as to much power. I only have three years till I retire and only want to do this one time. I appears that onezman has had good luck with the volvos, I just liked the look of the kenworth

Bob,

I know one guy who tows his Travel Supreme with a converted T2000. He really likes it. You just have to plan in advance what RV parks you can stay in.

Guys with pickups and MDTs never have enough HP, but believe me, 430 HP and 1,550 torque will keep you smiling. 550 HP is more than you can ever use in any RV situation and will wear out your drive tires much faster IMO.

onezman

https://onezman.tripod.com/yourrvhaulercom

Ummmmmmmmmm- how does more rear wheel horse power make your tires wear out quicker--- just askin' -- just askin'-- oh you can use all of the horse power on some of the hills that they have out in the rockies--- mase

....it's all that street racing against those posure cars....geof :&gthttps://www.truckhome.com/infopop/emo.../icon_wink.gif

Vapoppa

With 550 HP, Im guessing that motor probably has 1,750 foot pounds of torque. That kind of power will cause imperceptable wheel spin, even when towing.

I understand that OTR drivers who have 600 HP engines wear drive tires out twice as fast as normal in mountainous terrain. Even with 40K on the drive tires, they still get imperceptable wheelspin which wears tires out faster.

With 430 HP and 1550 torque, if a driver keeps the boost up, and has no curves or traffic problems, he can tow 20K at the trucks top speed up a 7% grade. Even doing that won't be working the engine hard enough to cause the engine fan to activate, or bring the pyrometer above a rather pedestrian 750 degrees.

There is simply no way to utilize that kind of power towing 20 K. Right now I have a 2000 Volvo which has a 500 HP Detroit with 1,650 torque. I won't get an opportunity to tow with it because the buyer is picking it up this Friday. I think it will tow 20 k up a 7% grade like it was towing a bicycle.

onezman

https://onezman.tripod.com/yourrvhaulercom

On the 18-speed....

I have a 10 speed autoshift. My opinion is that an 18 speed would have to many gears to move through. As Larry said, the purpose of those gears is to move heavy loads to speed - you will not be doing that. While it is true that "you" are not doing the shifting, you ARE waiting for all that shifting to happen to get up to speed. I find even my 10 speed takes longer than I want to pull up to road speed - if I manually shift (using the Hold) then I can circumvnet this. I can't imagine using an 18 speed.

Jack Mayer
1999 Volvo 610, 182" wb, ISM 400/1450
36' Newmar Kountry Star 5er

......I have been told that 18's are Owner/operator specs and that they are "old fashioned" and that newer vehicles are using less gears and more speed/torque form each gear....another words winding them out more?.....this is an opinion from a Freightliner salesman that I have a lot of respect for......geof

A 10 speed will get the job done 99% of the time for all OTR applications. 18 and 15 speed transmissions are becomming a thing of the past in the market place.

Generally, 18 speeds are only used for very heavy haul applications. These transmissions were popular when HP ranged from 250 to 350 with torque ranges from 1050 to 1250.

With the advent of higher HP higher torque engines, that many gears are entirely unnecessary.

For RV porposes, even a 10 speed is too much. The lower gears will almost never be used. For towing, 4th gear is sufficient for starting off. I use 5th gear starting off bobtail. The only time an RVer will use lower gears is for "creeping."


onezman

https://onezman.tripod.com/yourrvhaulercom

onezman, mase, first off i owe you an apology, i truly misspoke my self about the excess power issue-- i was thinking of my own rig which is carrying 21,500 on the rear axle, yep i know thats more than i'm sposed to but i'm giong to try to not put a tag under it for 2000 lbs.. hope you agree with my thought process on this. i put 15,000 on it this past summer and crossed the divide 4 times, and did a loop around colorado with no p'bms. take care. mase

Onezman said: A 10 speed will get the job done 99% of the time for all OTR applications. 18 and 15 speed transmissions are becomming a thing of the past in the market place.
Generally, 18 speeds are only used for very heavy haul applications. These transmissions were popular when HP ranged from 250 to 350 with torque ranges from 1050 to 1250.
With the advent of higher HP higher torque engines, that many gears are entirely unnecessary.
For RV porposes, even a 10 speed is too much. The lower gears will almost never be used. For towing, 4th gear is sufficient for starting off. I use 5th gear starting off bobtail. The only time an RVer will use lower gears is for "creeping."
**
Actually, there is a different basis. The 18s are pretty new, derived from the 13s in the early 90s, when the 3406B and Series 60 were changing the rules and did a decent job, with adequate torque and wider powerbands.

The 5 & 3/5 & 4 2 box transmissions are more like the situation you are describing - a response of the 60s to the lack of power, and at least as important, the narrow power bands, in the OTR trucks of the time. In the 70s, the folks who had the K series Cummins had to have such trannies because that was the only way to handle the torque of those large and heavy motors. Now Fuller and others make trannies that can handle a lot more, but a friend of mine saw a Fuller 10 blown up during a dyno testing and tuning session of a 6 cylinder Mack in the 70s.

For many purposes, a 10 is now adequate. However, for people hauling max loads (80K, not heavy haulers), the ability to split gears is of great value. The gap in a 10 speed is pretty big, and can make a hell of a mess on a grade. I ran out of the midwest, and a 10 is adequate there, with enough power. I would not have one for most purposes if I ran as far east as PA or West as Colorado; the ability to split the top gear on a pull is great. Depending on how much improvement there has been lately, I might reconsider that. A 10 was adequate for me running a V8 Mack in the late 80s, but it had far more torque than anything else around. I could run up grades at 65 that others could barely top at 30. (I had to jake going UP Jacob's ladder on the Mass. pike to keep down to the limit, and could get away with using the car lane on Sideling Hill in PA, running at 60+ when almost everyone else was at 20-25.) I see trucks having a hell of a time going up Vantage to Ryegrass (I90 W/B, from the Grant-Kittitas County line in Washington); often they are down to 40, which is inexecusable. I saw a heavy hauler from the Midwest, obviously underpowered, down to about 10 MPH.

Downshifting sucks fuel, and my time with a 9 speed and a 350 Mack (able to pull like a 400 Cummapart of the times) was not fun in some ways. The way to make speed and have decent fuel economy in a truck is to get a decent speed, like 62, set the cruise, and never slow down or downshift.

15s are not at all like 18s. 18s are good for heavy haulers due to the small spread on each shift, but it takes a lot of weight to make that important, and that's not our situation here. 18s, like 13s, are based on the 9 speed. In the 13, one simply can't split the bottom 5; in the 18, each gear can be split. A 15 is actually a 10, with a lower range below it, allowing for more multiplication at low speeds. (Besides, the max rating for a 15 is 1650 ft-lbs, which is a small motor in the OTR setting unless one never leaves the midwest.)

For an RV, it is almost certain that a 9 or 10 speed is ample, with one exception. The rule for picking a starting gear is that you use one that allows you to let out the clutch at idle (NO THROTTLE) - you have to get the clutch out and keep your foot off it, in fact have it flat on the floor next to the pedals! This should not be a problem with the relatively light weights involved. However, a nice low gear option (forward and reverse) would be great in a tight spot such as an RV park. The Mack trannies have it all over all the others in this issue; they have options for super low first and reverse gears. The Fuller 15 would be good on this issue, for that reason. Other than moving around in a tight spot, one need not use that creeper range, so it is really a 10 speed. Less shifting is a good thing for RV use, as it can be hard on the clutch if one is enough of a fumble bum to need it (although shifting is a LOT easier when one is closer to 80K than when light). This would be a good argument for an autoshift.

Today's powerplants have a LOT more torque, get better mileage, and broader powerbands. The first truck I really drove OTR, when a driver got sick, was typical of the old style. It was a '77 Freightliner, with a 400 Magnum small cam II and a 13 speed. The damned thing had no powerband. It ran like a scalded cat if you kept in the power band, and with 4.33 gears would easily pull 80+. However, it had to be kept perking like a 2 stroke racing motorcycle. The powerband was 1800-2100+, and at 1798, it fell on its face. Those days are over. The last of the N series Cummins (the same block as this motor) had a lot more power, a power band well over twice as wide, and was more tolerant of the drop in RPM.

What we have here is a guy looking at a used truck for his starter. It won't be perfect, but he (like me) does not know enough for sure to go order one and get specs right (I'm still not sure what I would spec for an engine/tranny combination; it depends on the feasibility of a driving front axle and who will make a truck with one). An 18 auto will skip gears as needed; it has a clutch (critical - a full automatic is a BAD idea because of the torque and heat involved, although a much smaller risk in an RV); and it is already there. For my money, the idea that an 18 would be silly to order in a new truck used for an RV, which is clearly correct, is not relevant here.

Doug...I had to read your post 4-5 times to understand it all....so much good info in so short of a post!....thank you geof

doug, thanks-- i'm glad to see your post. i've got an 18 auto shift eaton. i love the "split-ability" of my tranny. one of the hardest pulls i made last summer was out of bishop up to mammoth lakes. lots of the hills in the rockies made me glad to keep the rpms in the torque band as opposed to having to simply have to grind my way to the top.--- mase

I don't know about hauling 80K up a grade, but I know that hauling 20K up a grade does not require a single downshift if the driver has at least 400 HP and 1,450 torque. If the driver keeps the boost up, only traffic or curves will dictate a downshift.

I can't recall ever going below 8th gear using a 10 speed on any grade in any situation on an interstate highway.

https://onezman.tripod.com/yourrvhaulercom

I would say that is correct. I note for example that the 380/410 Mack delivers 1560 ft-lbs. That is probably more than enough, even with a tandem and building your Class 8 RV to the max (as I probably would, using it for more or less full timing). I strongly suspect that even the 310/330 would have enough torque for such a unit.

The 9 speed Mack with the low gears has only one disadvantage. If one drives over the entire country, cruising speed and speed limits can vary from 55 to 75. Gearing for one end means one is either racing or lugging at the other, or at least has that risk. While most motors are more tolerant than they were 20 years ago, they have a sweet spot where they give their best fuel economy for a given speed.

I did the math playing with the Roadranger road speed calculator some time back, and I concluded that the 13 speed could address that range best due to the small split (and since the 18 is fundamentally the same as to this issue, one could do it with that tranny, such as when buying a used truck, although I would find it hard to justify getting one if ordering new for RV use). With the figures I used, the difference in cruising speed at the same RPM was about 10 MPH or a little more. Set it for 58-60 in 8L and you have about 68-71 at the same RPM in 8H. Not bad, eh? And, if you don't need the extra flexibility of the 13, you don't have to split it, which means it's a 9 speed with an extra button.

In case anyone is thinking I am advocating for Mack over others, the answer is no. It can be a PIA to get a Mack worked on sometimes, and Mack parts tend to be more expensive. I am, however, looking at either a Mack or a Western Star, due to the ease of special odd orders for these makers. I think I want a driving front axle, depending on what I learn from a dealer, and that could be a controlling factor. The Mack website no longer mentions them.

These are of course, options based on my preferences. I hate to fly, need room for the dogs, might be functionally full timing, etc. What YOU need for YOUR life is a different issue, and in spite of my pontificating, I am not living your life. I used to run OTR, and generally hate automatic transmissions. I doubt that applies to most here. Some of these issues are personal preference - I prefer certain breeds of dogs, with certain attributes of size, hair length etc. That doesn't make Rotts or certain obscure Mastiff breeds right for you.

The issue at hand was the suitability of this used truck for this member. While it might not be the truck any of us would order, if it is a good condition used truck and he feels confident in that, the transmission would not be the reason I would pass on buying this truck.