Hey,
Has someone experiance with the 15 speed box.
Is it true that this boxes only have a splitter in the low range and not in the high range ■■?
So in low will be 8 speeds and a crauwler, in high only 4 ■■?
Gr Eric,
Hi Eric,
There is some explanation of the different Fuller gearboxes on the Forum but, as usual, it’s easier to remember the information than to use the search function to find it. 
Unfortunately, the limit of my memory is to remember that things exist, while forgetting where they are and most of the other things about them.
From what I can remember, the 15 is made of a close-ratio 5 with a range-change, giving 10 more-or-less sequential gears. There is a also a splitter which gives approximately half a gear under(?). This works in high range only, I think, to give the lorry a more precise selection of ratio at its normal operating speed, while low range is for acceleration and climbing steep hills, of which there are few, so there is no particular need for the extra gears.
I cannot remember where the various bits are- I assume the more expensive, complicated 5 speed bit is put where the torque is lowest, next to the engine, then the 2-speed sections follow. If the range change is before the splitter, that would be a good reason for preventing the use of the splitter in low range- to limit the amount of torque it sees, so allowing it to do its job with smaller/lighter/cheaper parts. All of this stuff will need checking against the actual facts.
8 speeds plus crawler plus 4 would be a 13 speed, which is similar, but the 5 is wider-ratio, to give a lower starting gear, or crawler. The range-change has the same(?or similar) ratio step as that in the 10 (and 15) speed so bottom gear in high range ends up mixed in with the gears in low range. I remember reading peoples’ experiences of using those gears, even if they do not appear in the diagram on the stick. Again those memories are 99% lost.
Somewhere on here is an explanation describing it as a 5-over-5-over 5 range-change, with the bottom 5 being a set of deep crawlers for off-road use. There were probably variants! I’ll see if I can hunt some of this out. Cheers, Robert
Old and new diagrams. Robert
How to Shift a 15-Speed Transmission
By Kelvin Hayes, eHow Contributor
*• *
15 speed transmissions are primarily used on dump trucks and trucks that haul loads less than 100,000 pounds.
The shift pattern on a 15 speed transmission can be visualized like a three story building. On each level, you have five possible gears, defined as a “range.” The first floor is “deep lo” or deep reduction. The second floor is “low range” and the third is “hi range.” As you shift through the gears in each range, you’ll move to progressively taller gears, with less torque, but allowing for a higher top speed.
Blogger on Trucknet some time ago: I have a crusader now with a 15 speed (rto 915)10 on the stick and 5 extra low on the dash switch,you only need the clutch to pull away n stop,fast change,lovely,keep y i shifts etc.
Robert
robert1952:
How to Shift a 15-Speed Transmission
By Kelvin Hayes, eHow Contributor
*• *
15 speed transmissions are primarily used on dump trucks and trucks that haul loads less than 100,000 pounds.
The shift pattern on a 15 speed transmission can be visualized like a three story building. On each level, you have five possible gears, defined as a “range.” The first floor is “deep lo” or deep reduction. The second floor is “low range” and the third is “hi range.” As you shift through the gears in each range, you’ll move to progressively taller gears, with less torque, but allowing for a higher top speed.Blogger on Trucknet some time ago: I have a crusader now with a 15 speed (rto 915)10 on the stick and 5 extra low on the dash switch,you only need the clutch to pull away n stop,fast change,lovely,keep y i shifts etc.
Robert
Hmmm… according to this, it seems that there are two range-changes, or a three-speed range change, rather than a range and a splitter, as I originally thought.
Edit- this says the auxiliary 'box is a three-speed, but the diagrams show sticks with range-change and splitter controls:
roadranger.com/ecm/idcplg?Id … _TRDR-0700
Sorry I got into this now.
The PDF in your link does indeed show both range-change and splitter switches. This is appears to be a modern 'box, so I suspect that the older ones to be found on ERFs, Fodens, Scammells and Atkinsons may have simply been the five-over-five-over-fives described up the page. We need someone who used one to confirm! Robert
Reading these replies might go some way to explaining a gearbox in an ERF that we had second hand at Mothers Pride in 1975. It was an Eaton ENV 10-speed range change box (Eaton became subsumed into Fuller), and the bottom 5 ratios were very low. It would start from rest with a 40 ft trailer full of bread in 4th gear very comfortably. Originally the ERF had been new to Kaye Goodfellow on heavy plant haulage, and unusually for me I can even remember the registration number RNB 238J. It had a Gardner 180 engine. I always wondered about that gearbox because it was so unusual.
Hey, thank to all for the fast information.
I found this tabel and wanted to know more about.
It looked that it had only splitters in the low range.
We never had that here so far I know.
Thanks.
Eric,
About15+ years ago I used to drive a Scammell crusader heavy recovery truck with a V8 141 Scania and it had a 15 speed fuller in it.
The 1st 5 lower gears was a switch on the dash, you would flick the switch to move something super heavy and then go though the 1st 5 gears, the flick the switch back and then use the 2nd lower 5 gears, then once you had used them you would use the high range switch on the gear lever for the high 5.
Thanks Welly
Welly Bobby:
About15+ years ago I used to drive a Scammell crusader heavy recovery truck with a V8 141 Scania and it had a 15 speed fuller in it.
The 1st 5 lower gears was a switch on the dash, you would flick the switch to move something super heavy and then go though the 1st 5 gears, the flick the switch back and then use the 2nd lower 5 gears, then once you had used them you would use the high range switch on the gear lever for the high 5.
Thanks Welly
Thanks Welly,
It looks like it had two ranges or am I wrong aren’t I ■■?
And made for heavy duty work ■■?
Eric,
Well you could say they had 3 ranges. The very lower gears was classed at super low range gears.
I Did an 200t crane on a straight bars and needed all 15 gears, needed super low to even get the thing moving. Then after that using the 1st 5 gear, then used the low range before using high range.
That day the Scammell did all of 2 mile to the gallon.
Thanks Welly
Put this in google. Flickr millers of Longton you will see the Scammell look at the photo of the body sides, then look at the foden. That’s the same chassis we cut the Scammell front off and welded the Foden to it.
Thanks Welly
Welly Bobby:
Put this in google. Flickr millers of Longton you will see the Scammell look at the photo of the body sides, then look at the foden. That’s the same chassis we cut the Scammell front off and welded the Foden to it.
Thanks Welly
Thanks Welly,
Eric,