What is a David-Brown gearbox?

If you experts on this forum wouldn’t mind edumacating a young sprog like me, I’d like to learn what a David-Brown gearbox was. I’ve seen older blokes than me refer to D-B boxes on here and flickr and elsewhere, but I admit I have no experience with one. In my mind, David-Brown will always be associated with agricultural tractors and Aston Martin.

Last time i drove a David Brown box it was in (if i recall correctly) a Sed Ack 400 6 wheeler rolonoff.
I’d previously had one in a SedAck 400 Artic with a 250 ■■■■■■■ lump.

As i recall it was a simple 6 speed constant mesh box, but in most cases was back to front in the way you selected gears, with 1st being where you would expect 6th to be, over to you and back, and 6th where 1st should have been.
Once on the move you didn’t need to bother with the clutch just get the revs right for the next gear and it would slot in cleanly, you could do this with many constant mesh boxes.

Point of interest as you mentioned at one time David Brown owned Aston Martin, presumably when it was still based at Newport Pagnell.

The 400 6 wheeler had PTO for operating the Multilift hooklift gear, whoever fitted it managed to run it off 5th gear, hence it was so high geared you could load the body in about 15 seconds, course this put tremendous strain on the box and the casing split pouring all the oil out in a council yard, my mate tried his best to be gentle with it so much so that once the PTO actually stalled the engine which saw the Gardner XLC fire up running backwards.

Quite a number of different boxes were back to front as it were, Daf 2600 had a 12 speed ZF (95% sure it was ZF) splitter that was also back to front and that same box i also came across in a Daf 2800DKTD, but the gears might have been the right way round by then, memory isn’t what it once was.

Hi all if you look up David Brown Ltd on Wikipedia it will tell you the full history, if one knew how I would have attached it here but beyond my IT skills, Buzzer

Juddian:
Last time i drove a David Brown box it was in (if i recall correctly) a Sed Ack 400 6 wheeler rolonoff.
I’d previously had one in a SedAck 400 Artic with a 250 ■■■■■■■ lump.

As i recall it was a simple 6 speed constant mesh box, but in most cases was back to front in the way you selected gears, with 1st being where you would expect 6th to be, over to you and back, and 6th where 1st should have been.
Once on the move you didn’t need to bother with the clutch just get the revs right for the next gear and it would slot in cleanly, you could do this with many constant mesh boxes.

Point of interest as you mentioned at one time David Brown owned Aston Martin, presumably when it was still based at Newport Pagnell.

The 400 6 wheeler had PTO for operating the Multilift hooklift gear, whoever fitted it managed to run it off 5th gear, hence it was so high geared you could load the body in about 15 seconds, course this put tremendous strain on the box and the casing split pouring all the oil out in a council yard, my mate tried his best to be gentle with it so much so that once the PTO actually stalled the engine which saw the Gardner XLC fire up running backwards.

Quite a number of different boxes were back to front as it were, Daf 2600 had a 12 speed ZF (95% sure it was ZF) splitter that was also back to front and that same box i also came across in a Daf 2800DKTD, but the gears might have been the right way round by then, memory isn’t what it once was.

I’m reasonably sure (I think… :neutral_face: ) I’ve heard of 8-speed DB boxes in some wagons. I might be wrong (again).

Buzzer:
Hi all if you look up David Brown Ltd on Wikipedia it will tell you the full history, if one knew how I would have attached it here but beyond my IT skills, Buzzer

All you have to do is post the link :wink: : en.wikipedia.org/wiki/David_Brown_Ltd.

I’m more after the gearbox side of things: were they synchro or constant mesh? What were they like to live with? That sort of thing.

ParkRoyal2100:

Juddian:
Last time i drove a David Brown box it was in (if i recall correctly) a Sed Ack 400 6 wheeler rolonoff.
I’d previously had one in a SedAck 400 Artic with a 250 ■■■■■■■ lump.

As i recall it was a simple 6 speed constant mesh box, but in most cases was back to front in the way you selected gears, with 1st being where you would expect 6th to be, over to you and back, and 6th where 1st should have been.
Once on the move you didn’t need to bother with the clutch just get the revs right for the next gear and it would slot in cleanly, you could do this with many constant mesh boxes.

Point of interest as you mentioned at one time David Brown owned Aston Martin, presumably when it was still based at Newport Pagnell.

The 400 6 wheeler had PTO for operating the Multilift hooklift gear, whoever fitted it managed to run it off 5th gear, hence it was so high geared you could load the body in about 15 seconds, course this put tremendous strain on the box and the casing split pouring all the oil out in a council yard, my mate tried his best to be gentle with it so much so that once the PTO actually stalled the engine which saw the Gardner XLC fire up running backwards.

Quite a number of different boxes were back to front as it were, Daf 2600 had a 12 speed ZF (95% sure it was ZF) splitter that was also back to front and that same box i also came across in a Daf 2800DKTD, but the gears might have been the right way round by then, memory isn’t what it once was.

I’m reasonably sure (I think… :neutral_face: ) I’ve heard of 8-speed DB boxes in some wagons. I might be wrong (again).
[/quote]

You are correct, we had an early Sed-Ak 400 which came with a six speed DB box but it went back under warranty to be fitted with a DB eight speed 4 over 4 range change one. You had to be very precise with the changes as unlike a Fuller box you couldn’t ‘feed’ the gears into mesh, all our later Sed-Aks were fitted with Fullers. The gear positions were reversed simply because the Sed-Ak gear lever was in two sections so pushing the main lever forward for example moved the lower lever backwards.

Pete.

Thinking further back, might have driven A series ERFs with the DB 6 speed box too.

windrush:
You are correct, we had an early Sed-Ak 400 which came with a six speed DB box but it went back under warranty to be fitted with a DB eight speed 4 over 4 range change one. You had to be very precise with the changes as unlike a Fuller box you couldn’t ‘feed’ the gears into mesh, all our later Sed-Aks were fitted with Fullers. The gear positions were reversed simply because the Sed-Ak gear lever was in two sections so pushing the main lever forward for example moved the lower lever backwards.

Yep.
Sed-Atk wouldnt have holes in the cab floor, to avoid noise and draughts, so had a mutli-link arrangement around the front of the cab. OK as long as wear was adjusted up. At our place the ERFs had ■■■■■■■ and Fuller, and the S-A had Gardners and DB, both range-change boxes, but one was clockwise, one antclockwise. That was due to the linkage more than box design though Im pretty sure.
Previous to the 8-speed range-change boxes, we had 6-speed D_B boxes in Gardner and ■■■■■■■ Atkis. Both with and without 2-speed axles.
If I remember correctly, the 6-speed box was a crash box, and a slow change, but the 8-speed, was constant-mesh and D-B much the same to drive as a Fuller.
Different drivers might swear one was better than tother, but I couldnt see much difference, so long as the S-A linkage was maintained correctly. If worn you were fumbling around to find a cog, but that was the sloppy set-up not the box`s fault.

Had loads of 6sp Erfs ridiculously slow gear change in Gardners but worse I thought with the ■■■■■■■ .
Yes 1/4 same as normal then 5th was towards you n back then 6th away from you,it helped if you’d arms like an urangatan :laughing: I was following a mate of mine in my ERF n him in F86 ,we were both fully loaded,n we got stopped up a steady hill,we both got going again n he left me for dead. He was going for high range when he topped the hill I was stuck in 2nd just too slow a change to make 3rd. The 8sp? Had an Akky with one, for 3days, not for me, give me a Fuller or better still aFoden 12sp

We ran Erf lv,s with 5 speed plus 2 speed eatons in the Gardner rigids and 6 speed in the ■■■■■■■ Unit’s not many problems .Then we had an 8speed in a B series an absolute disaster after numerous problems it finally exploded going in to Hull.We ragged what was left of it out and fitted a Fuller.

There’s a fair bit on a the '60s gearbox thread I started fairly recently. Here’s the link:

trucknetuk.com/phpBB/viewto … n#p2807279

Ro

SoM had quite a few Guy’s with the straight 6 DB box,terrible things IIRC,had to wait what appeared to be ages between shifts,married with a ■■■■■■■ 220 it was a marriage made in hell!
What you gained with the engine you lost with the box.

David

5thwheel:
SoM had quite a few Guy’s with the straight 6 DB box,terrible things IIRC,had to wait what appeared to be ages between shifts,married with a ■■■■■■■ 220 it was a marriage made in hell!
What you gained with the engine you lost with the box.

David

Point of interest David ---- Are you positive the Big J’s used the DB box and not the Thorneycroft 6 speed I recall that the Invincibles used the DB 5:500 box but as always I could be wrong on both counts eh ! Cheers Dennis. :blush:

We ran some Big J,with the ■■■■■■■ in and they had Thornycroft boxes and they were virtually trouble free always maximum weight so l suspect you are probably right Dennis. But saying that a fleet like Smiths could have what they warned even an 8lxb. Duck !

History. :smiley: :smiley: :smiley: :smiley: - :smiley: :smiley: :smiley: :smiley:

Some time ago I drove an ERF with a 150 Gardner & six speed David Brown box, on some hills you just could not change up as you would have come to stop before the next gear would have slotted in,
but saying that the whole vehicle never let me down and always got you there & back eventually .

The old man bought a Sreg ERE B series 6wheeler 180 Gardner 6 speed DB box it was a load of crap I could never get on with it and there was a problem with the gearlever it would get stiff and a lot of force to move it The solution was to take a plate off on the side on the top of the gearbox right side i think and spray WD40 to free the stiffness This had to be done every 6 weeks or so

8LXBV8BRIAN:
History. :smiley: :smiley: :smiley: :smiley: - :smiley: :smiley: :smiley: :smiley:

Good to see you’re taking notice Brian, let’s have an opinion, you had to look after them!
That 8speed DB was your particular hobbyhorse :wink: :wink: :wink:
Ps. Hope to see you at the “do” next month. Regards Kev.

youtu.be/nuVGc9mJcrM

Apparently a DB 6sp overdrive box.

ParkRoyal2100:

Buzzer:
Hi all if you look up David Brown Ltd on Wikipedia it will tell you the full history, if one knew how I would have attached it here but beyond my IT skills, Buzzer

All you have to do is post the link :wink: : en.wikipedia.org/wiki/David_Brown_Ltd.

I’m more after the gearbox side of things: were they synchro or constant mesh? What were they like to live with? That sort of thing.

They certainly were not syncro, a DB6 speed box, 150 Gardner, in a newish Atki 8 wheeler took me (fully loaded with road salt) UP the 1:4 Sutton Bank in Nth Yorkshire. (very naughty in those days :wink: )
Personal opinion…they were a good robust box, well suited to the motors we had in the 60/70’s. A 150 Gardner and a 6 speed DB box was a good combination.