O.T. Road Tractor (Semi) transmission synchronizers

My son went to truck driving school last summer and he was telling me the OTR tractor transmissions don't have synchronizers in them, because they wear out in about 100,000 miles and then the transmission would have to be rebuilt. It sounds kind of far fetched to me. How I wished the old IHC 706 had synchronizers like the JD 4020 did. That was the biggest improvement of green over red that I could see at the time, although it pulled another bottom.

They have synchronizers. Its called your left foot and right foot.

son is right they do not have them, i dont know about the very newest models like the auto stick, as ive not driven a truck that had one, but on the others you can double clutch or float the gears, its possible to float them up and down, but takes a very long time to learn to do it without raking the gears, i can do it as i started out with 2 sticks and thats the only way i was taught to drive a big truck, that was 30 years ago

No syncros on the heavy transmissions, maybe on some of the light/med duty manuals, but not the bigger ones, 9,10,13,15,18 speeds. Rev it up a bit to match the lower gear when downshifting, make sure you match it shifting up. Mystifies alot of people that have only driven synchronized transmissions.

Ross

He's right. Gotta have the wheels, transmission gears, and engine all spinning at the same RPM to select a gear. Takes a little practice and every truck is just a little bit different, but it's not that hard.

North American heavy transmissions are not synchronized, but the Europeans do build some. Its not a matter of how long they last. Mostly just American stubbornness. I took my license test in a Scania with a synchro 9 spd. I have also run several versions of Volvos.

Hello IA Roy,

He is right! There are sliding gears on the main shaft between gears. A fork goes into the center of gear. It slides between two gears and engages them one at the time. Because the main shaft is turning while the otbers speed gears are not.Pushing the
clutch down coming out of gear is needed to stops the main shaft from turning. This makes the sliding gear go into the next gear without clashing as it was not turning at the same speed of the main shaft.
There are three sliding gears on a Fuller trasmission for over the road trucks.
1 for First and reverse.
1 for Second and third.
1 for forth and fifth,

Guido.

I never use the left foot. After you do it for awhile, it is easier to shift not using the clutch. Course you have to step on it to start and stop.

its more like right foot right hand only time left foot is used is the start then it goes to sleep till you stop or back up

The only syncros are for the high/low range selector. Other than that you are the syncronizer. The syncros do wear out and they also reduce the fuel mileage ever so slightly (got more things spinning in the oil and more friction). If you sync the gears correctly your clutch wear will be minimum, just from the take off and when you need to kick it out of gear to downshift on a grade. When you drive a syncro trans most people don't worry about trying to match the engine to the transmission, causing extra clutch wear.

Yep, the Road Rangers shift just like your old tractor,do it right and it goes in gear, miss and you start all over again.

Yep , and i got quiet a few more years on ya . First big truck was a B61 Mack with a 711 and a five and four . Do you remember the CABLE shift Road Rangers ?? the four by fours . And the company i worked for we had the BIG truck , and Autocar that had a 380 hp. Cummins that had a six a five and four speed transmission Huge twin screw rears and sat on TRUE 24 inch rubber . It was a massive truck that pulled a big lowboy trailer for the really heavy loads . The mack i drove hauled anything from fifty five tons down. The A car would move the big shovel houses where we would remove the crawler section and boom and counter weight having the house up on cribbing and backing the trailer under the house and jack it down on to the trailer . Now moving thee big Manitowoc's and the big Lima's and some of the Bucyers shovel- Cranes took up to thirty truck loads to move and two weeks to put back together. Took all the trucks to make a move . Plum refused to drive the old White Mustangs . It was a major operation as power lines had to be ,oved or taken down along with phone lines. And NO BIG roads back then as we were just really getting started on building them. First 13 speed i drove was in a 69 Diamond Reo with a 318 , First truck i drove with a jake was a 73 I H 4200. If these KIDS and SO CALLED TRUCK DRIVERS of today had to get in one of them old trucks and run the old back roads that back then were the main roads with no P/S , No A/C , No air ride seat, no air ride , no air ride cab and at best if you were lucky a 36 inch fall in and fall out sleeper and around 250 Hp. and IF you were lucky maybe 318 to 335 Hp. for the big rigger owner operator they would quit in the first fifty miles . Us OLD guys were a tougher breed back then.

get you a two stick tranny for even more fun! pushed then horses down the road for over 20yrs. still drive once a yr during harvest. still don't shift with a clutch!!!!

Auto stick doesn't need them at all, the computer synchronizes them better than any driver could

Clutch only on takeoff from a dead stop, but not once she's motivated and moving. Slip it out of gear, rev it slightly, ease off and then gently ease it into the next gear when the RPMs match, and keep going. Treat her like a lady likes to be treated, nice and easy and you'll get a lot more partnership out of her. A little practice and you're..."Movin' On".

Mark

I think you will not pass a CDL test if you shift like that. Or so I have been told ?
But that is the way I was taught.

I went to work at a truck dealership in the parts dept. around 1995 ? I could not believe those trucks were still using such old designs. Farm tractors were WAY more advanced with wet clutches and power shift transmissions.
I guess the trucks stayed with what was cheap solid and worked.

And lighter which is most important.

Not buyin that you are tougher than anyone else.

I'll skip the toughness part of it, but you are not alone, I drove '68 AutoCar, 13 spd, 2 something cummins, maybe a 220, it was not a 290 thats for sure. Also drove a '72 AutoCar, 13 spd. 335 Cummins, both pulled lowbows, the '68 pulled one large enough to handle a D8K though, the '72 pulled a 50 or 60 ton Rogers, and I moved D8K's, later high track, 8N's which were new in those days, 235 hoes, 980 wheel loaders, 627 scrapers, 12G grader etc. Nothing but truck, you had to wear hearing protection in them, everything in them except the seat was steel.

I ran a '61 B61 Model Mack tandem dump with a 5x4, manual steering, 54K rears, definitely a mack engine, darned thing sounded like a rod was knocking to me at least until I got used to mack engines like that old naturally aspirated lunker.

Also ran those old Ford tandems, 850's with big gas engines, tandems with 5x4's, even an automatic, 318 detroit and Allison.


Thinking back, drove many 4spd/5spd with 2 speed rears, 7 speed (international tandem flatbed, 8 speed with low hole,('87 tri-axle freightliner dump w/315 cummins) 9 speed,('81 Mack R model tandem tractor) 10 speed, (international 4300 with 350 or 400 cummins big cam, first truck I drove with a 3 stage Jacobs engine brake, but also drove it without it before, engine was totally rebuilt and it was added, was on a '64 lowboy that was self contained, it had a wisconsin engine)13 speed (both AutoCar's '68, '72) 13 speed Ford (not Fuller Roadrangers in '77 & '78 Louisville L8000 or L9000 tandem dumps, 5 speed mack, R model, DM' RD's all tandems. Newest one I drove was a '00 Freightliner with a Detroit and 10 speed, that was a bit different than the old ones in regards to the RPM spread where you shift.

The old trucks were a learning curve, I had no formal training, learned from someone 20 years my senior who was a coast to coast owner operator, that ran in the early to mid 60's and up, he just happened to take a mediocre job like the rest of us had at the lumber yard to keep busy. He accompanied me to my NYS Class 1 road test, there was no CDL then.

Yes, most of these were raw truck, you were lucky to have AM/FM and a CB. In regards to shifting, besides the 5x4's, those other transmissions were not hard to learn if you were not a bonehead or had no sense for coordinating speed, engine rpm's with up and downshifting, to me it was common sense, you learned how to smoothly shift, how to approach and handle steep slopes. The R model tandem I drove with a flatbed trailer full of wet pressure treated lumber had no engine brake, you drove those slopes with respect to speed at the approach and to your brakes, by not overheating them, so that takes some experience, that and knowing you cannot get caught out of gear. I do recall the monkey on the back feeling with these heavy loads, there was always a little driver stress knowing whats behind you on a trailer. I really never cared for driving truck, but did so as necessary, full time for several years, then as assigned, all to make a paycheck, and still have my license and current medical card.

Started out driving these in the 60's,NH-195,NH 220 Cummins,and yes cable shifted RoadRanger,the T handle cable shifted the ranges,instead of an air button.Believe they were the RT610'S.There was also a Super 250 Cummins that came out,didn't last very long.

(quoted from post at 22:34:36 12/22/15) I never use the left foot. After you do it for awhile, it is easier to shift not using the clutch. Course you have to step on it to start and stop.

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Tin-fur! 8)

The old trucks with the weaker engines is where a fella learned to float the gears. If you double clutched each time you shifted it felt like you peddled the darn thing to your destination. With the strong engines they have now you don't need to shift as often on hills.

NEVER seen a big rig yet that had a sycro transmission. but have seen them with automatic's. What was real fun to drive was the old twin stick trucks and if you missed a gear you pretty much had to start all over again. I still have 3 truck here with twin sticks in them

Second summer I hauled ready mix concrete I got stuck in a '66 White 10-wheeler that had a 165 Cummins and 5+4 trans. Low in the aux. Was creeper range for crawling around job sites. 2nd, 3rd, &4th in aux. Was for splitting gears in the main on the road. Quite a letdown from the summer before driving a nearly new Diamond REO with Allison 5-SPD and 3-speed Brownie.

The old White was terribly underpowered, 165 HP in a truck that routinely grossed 50,000-52,000# many times a day. You used every gear when loaded, when empty you could skip a couple of the lower gears.

Well not sayen Jon that i am a bad arres but the NEW drivers today would never drive what we did . Those old trucks were not what these KIDs drive today. Us OLD guys got the job done . With what we had to work with. How many times have you pulled a hill at 7-maybe 15 MPH on a hot summer day with the drivers door open and standing on the fuel tank with your right foot glued to the floor because it was so hot in the cab . Or during the winter setting in there freezing and scrapping ICE off the inside of the windows all bundled up from head to toe . Same way with the old equipment on the old dozers you were lucky to have a sun shade over ya and in the winter side cretins or as some call them a heat houser and a winter fan . In 63 the owner bought a new Dozer for me to run and it was the first one in the company that it came with a cab , Rops with heat and A/C it was a D9G and the vary first power shift we got . It came in by rail as we had a rail siding at the main shop for moving equipment long distances faster then we could truck . Back in like 79 i was coming out of Chicago and about half way across In. some guy was asking if anybody knew where Ca-Dizz was Well he kept this up for about a half and hour or so when i finally asked him to just spell it and what state he was looking for this was . So he spelled it out and it was CADIZ , Cadiz Ohio Yep i know where it is whqat are you looking for in Cadiz , he tells me CONSOL. Main yard or maintenance, or what mine ?? Strip or Deep. He tells me main yard . Yep i know When i started to tell him how to get there he was getting really confused . So i told him that i would lead him wright to it . I was headed for Pittsburg and yea i could have stayed on the toll road there are about two dozen ways off the toll road to Pittsburg . The shortest distance to CAdiz off the pike is US 250 . A nice scenic drive shell we say But not what todays drivers want to be on . We got off the pike and i told him to stay close and i would not lead him astray Well i took him writh to main yard and he informed me that i was NUT and he refered to our fine hyways as GOAT paths.
I have hauled coal up out of that country for years and if he wanted to see GOAT PATHS i could show him more then he ever wanted to see . We don't have the big mountains of the west but our little humps and bumps will suck the horse power out of the baddest trucks fast to the point that you have to skip shift and even with big power there are hills that it is still 10-15 MPH up over them . The one long hill that i have hauled many loads of coal up over even with my own truck that would put more power to the ground then a turned up KTA 1150 Cummins was a forth gear climb with a wagon load on and that was hitting the bottom at 55 . Then came the day i hauled a 197+ thousand pound continouse miner DOWN that same hill . Lets just say my choice of third gear with a jake was NOT the best . As i could not hold it back and had to turn her loose for the last half of the hill . I have in my time on the raod hauled some really BIG loads , not as big as my one buddy does as he runs one of them 19-23 axle outfits now but i was the one thatt got him into truck driving and trained him on a coal bucket on these OLD goat paths . Also trained a dozen more drivers . When i needed to go back on the road i went to work for a compay that ran coal buckets and most of the upper office people are the same OLD guys that we all use to run together at one time or the other . Yea i had to got to there ORENTATION for two days along with thrity other guys . At the end of the second day I will call him by his old CB handle (Big Zek ) is assigning the new drivers to there TRAINERS that they will ride with for two weeks before they are assigned there own truck . Well when he was done with them he looks at me and said your going to driving GRAND PA's Truck and opens his desk drawer and hands me the key's to Grand Pa's truck > one of the new hires spouts off HOW COME HE GET'S HIS OWN TRUCK now and we all have to RIDE . Zek looks at him and said Well if he does not know how to operate a Coal Bucket there ain't nobody in this company that does because he is the master . Quite a complament from and old friend and fellow driver . I learned from and OLD guy and i rode with the OLD guy for two years as a flagman . Back in the OLD days when ya moved Oversized Over weight BIG loads there had to be a FLAGMAN in the cab . And Old John my boss was the grand master of training both on the trucks and also on the heavy equipment along with turning wrenches . Welding was learned from two of the best . Am i tougher don't know if i am tougher , I am a vetern , i am ex airborn ranger i have been shot once and hit with shrapnel three times and i was one of them shell we say Ground hog hunters that worked alone away from the rest . I have worked hard all my life except when i was a parts manger .

My boss with 250 tractors would fire us if we did that float thing.

We had tractors in fleet that you could shift like that and we others that it wouldn't work all like that.

Doesn't sound all that hard to me. I started farm chores when I statted kindergarten. Spent all summer starting with teen age years handling hay and straw, a thousand bales a day and 15,000 bales a year. Never even considered that we worked outside in the sun in hundred degree heat and 95% humidity. Plus we milked the cows and cared for them both before and after handling those bales. If we weren't moving hay we were shoveling manure out of pens or shoveling grain into or out of bins. And don't forget that after those 15,000 bales were in the barn we had to take them back out and break them up and fork them to the cows, only to have to fork it back up again after it went through and into the manure spreader. And as far as driving a truck up a hill I just don't see that as being as hard as sitting on an open station 65 hp tractor and heading into 350 acres with a 4-16s plow, only to follow that up with a 14' disc over the same ground twice. And we did all that without the benifit of a nice dry cab. And that was all before I was an adult. I just don't see that you could be any tougher than that, but I could he wrong.

Oh my god what story's you youngsters have to tell. Talking about starting out on B61's or a D100 Autocar ?? LOL I didn't see one response that they started out on a LJ Mack with a 672 Lanova and a duplex in it. After that I got moved up to a 260 W W Brockway with a 530 gas engine and a Contenal South Wind heater. warm going up hill and freeze going down hill. Left River Head L I for Huston and then on to Oakdale Ca. Then to Chacigo and then on to Syracuse NY .Was gone over 3 weeks. on the old roads. Retired off a new Mack Vision with all the toys what a way to live. Turn Oakdale Ca. in 10 days or less.

i didnt have to run a cable shift roadranger,, got lucky , maybe, i started out on a diamond reo with a 275 iron lung Cummings and a 5 plus 4 2 stick, the 4th was overdrive so it didnt get much use, the next was a white 4000 with a 290 Cummings and a 10 plus 4 that 4 speed was only used as a 3 too as 1st was a deep reduction, then had a mack r model with a duplex also 2 stick, got moved to a kenworth after that with a 350 cummins and a 13 speed range shift and the splitter air shifted, man! i thought id gone to heaven! then had a peterbilt with a 425 cat and a 15 speed, ran 2 of those back to back, what most dont realize is up to the mack those rigs had no power steering or a/c, the a/c didnt come untill the kenworth, all but the 2 peterbilts were spring suspension too no wonder i got back problems now,

One of my semis is an old Ford Pepsi truck. It's got a 3208 cat in it and an automatic. I really don't mind it at all. It has a short wheel base and is easy to put places with the flatbed or grain trailer. She will turn on a dime and give you change. It's no speed demon, though. During harvest when you leave the field you just put your foot down and let up when you get to the elevator. I think most Fords are junk - but they know how to build big stuff well. When I was driving school bus I would only buy buses on a Ford platform with a 4x2 or 5x2 transmission. I consider the L8000 medium duty - it's a good truck and always has been.

The other is a Freightshaker with an N14 plus Cummins and a 10 speed. It's an extremely easy truck to drive and only use the clutch when taking out. It takes 40 acres to turn around so it gets used less - that sleeper is something I could do without but it was on the truck I wanted.

Burn up in the summer and freeze all winter long driving a semi back in the day,full of airleaks,no insulation to speak of, and the damn heat in the summer.Ran cross country,spent weeks at a time in them.On my 69 CO4070A cabover,it had a 335 Cummins,very hot engine,big turbo,no after-intercooling.The cab sat down low on the engine on the A models,hotter than hell in there.I was a kid then driving wearing sneakers.My feet would get so hot after a long day,my soles of the shoes would get tacky and stones would stick to the bottoms of my shoes.Most trucks didn't have ac,and if it did,it was one of those worthless roof mounted units,that would blow a little luke warm breeze in your ear.Spent many a night tossing and turning in that sleeper.Lots of us used to run a hammock under the trailer frame and sleep there.I've even slept in the grass in rest areas before,just cause it was so friggin hot in the truck.Can't do that nowadays,you'd wake up dead!

Iron lung,was hoping someone would bring that up.Most truckers never saw a Cummins with a supercharger,they think they were all NA and turbos.

LOL I have driven big rigs for over 40 years.My last manual shifted truck was a 13spd double over I had a million five hundred thousand on it never rebuilt just seals.never double clutched it, never ground a gear didn't even think about shifting it was just like breathing. My last one an auto shift 10spd had syncros in it. rebuilt at 450000 miles sensors went out all the time had a million two on it.

A few years ago someone had sent me a You-Tube video about shifting the old trucks.
I did a little searching and son-of-a-gun, I was able to find it.
There are lots of other videos of shifting as well.

Enjoy!

https://www.youtube.com/watch?v=2mf6AUbjT-s

This discussion spiralled downhill from syncros to guys at a bar arguing who's pickup has the bigger testicles zip tied to there trailer hitch....but yes modern trucks have come a long way

If those are too new for ya, man you've been around LOL !! Trucks were just all truck until the late 60's into the 70's, when they started to get fancy. The friend who helped me learn, and accompanied me to the road test, had a few Marmons in his day, he really fancied those before I knew him. I can just remember the first time I saw one of those space cabs by Kenworth, and or some of the others when they started getting fancy sleepers etc.

I think you mentioned here before you were in Local #669 Teamsters ? I had mentioned that I was at one time, still have the card and dues receipts in an old ammo can, momentos of my past LOL !

You mentioned somewhere here that at one time you worked for Chemical Leaman Tank Lines. I worked with a fellow in the lumber yard in Troy by the name of Ray Cooper, who used to talk about his time with "Chemical" as he called it. Not sure how that worked out of the Albany NY area then as they were a NJ company, but he used to talk about "running for Chemical" often in conversation, that and Pyramid hauling food/supplies etc. Odd chance that you may have worked with him, figured I'd ask if by chance you knew him.

You are correct casecollectorsc, my little brother uses the clutch every time he shifts our 10spd road ranger grain semi,,he goes through a clutch every other year,,and not that many miles,,,he will not listen to us about not using it...it's much easier on evrything "not" to use the clutch on the road..

Jon, have you ever driven the Volvo I-Shift? If so how did you like it?

I've been driving one for almost 3 years now. As far as I'm concerned it's the best thing to happen to trucking dince airconditioning.

(quoted from post at 21:34:36 12/22/15) I never use the left foot. After you do it for awhile, it is easier to shift not using the clutch. Course you have to step on it to start and stop.

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Unless of course it is a duplex, then you start and stop as well, without the clutch. I drive a Mack sometimes that is so well synchronized that I don't even need to move the shift lever, LOL.

That is your opinion

Know that country pretty good also . Dad was from New Athens and Mom was from Cadiz area. My grandfathers old farm has the deep shaft mine on it. The air vents sit right behind where the old barn was. Haven't been down there in quite a few years.Got to see all the big shovels that worked the area also.

well back to scnchros. even some smaller trucks back then did not have a scynchro . in the transmission . I am thinking that there was a Clark five spped that did not have them and it was a CLASH box , Now don't hold me to it as it may have been a FULLER . i know that some of there five speeds did not . as that transmission was used in D and C pull Le turnino (Sp) never could spell that name . And also on 160 A C Pans shifting a CLASH BOX was learned early in life due to driving the old trucks that were used to haul taters from the fields to the storage buildings at my Uncles farm . Those old dodges and Cheve two tons were so whipped that i had no idea if they did or did not as you had to either double clutch or feel your way into the next gear up or down . I could shift and old three on the tree into first while on the move and never grind a gear. I doknow that the scynchro transmission that they do put in trucks like say a C60 Cheve or a F600-800 Ford you can not hammer on the gear shift and except it to keep them in . Never bothered me driving any of them old truck IMHOP the road ranger is the easiest to drive , never cared much for the spicers . Going from a twin stick to a signal gear shift with air shift on the high low split and air shift on the direct over drive or direct to under drive depending on the set up of the transmission made life easier . Then along comes the new higher H P engines with more torque made things great plus the interstates . With big power and the correct gearing in the rear ends and myself i like a 13 speed or the 18 speed Road Ranger as they shift nice and smooth have well thought out spacing of gearing add in the power under the hood and even with 90 grand setting on the deck once you get the load moving you may only have to shift a couple times in the main and ya may have to flip the button a couple times .

Billy I sent you a e mail I can't see where you got it. If not try to contact me again. I would like to talk with you sometime. We have some times in common.813 782 0352 home most mid after noon's. Thanks Jack

we had a bunch of them , not only in trucks but also in equipment The Cummins engine in the big A car had the biggest cummins at the time in it and it had the blower and a turbo and it was rated at 380 Hp.A couple Rubber tired dozers had the C 190 in them . Back in the late fiftys and early sixtys the big road power was 318 Detroits and 335 Cummins . For the most part it was 238 Detroits and 250 Cummins . Back then i lived in a two horse town that U S 224 and Oh . 46 224 runs from New Castle Pa to IN and ties into US 24 It was a major east west truck route . Copper Jarrett , Road way and Mid West Emery used it along with others Copper ran 238 Detroits in GMC Cracker Boxes Mid west Emery ran the 250 Cummins and Road way ran Macks The big gas burners were still running back then and you could tell each and every truck by the sound You could tell the I H 549 verses the 534 Ford or the GMC gasser same went with the diesels you could about bet on what carrier by the sound .