• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Wanting knowledge on torque converters ? Curiousity stricken.

D6 Merv

Senior Member
Joined
May 10, 2007
Messages
653
Location
Coromandel Peninsula. New Zealand
Occupation
Self employed bulldozing contractor with a D6D D4E
Most allis,s had a push start pump, you had to manually engage the pump that would provide oil to feed the control valve and select 2nd rev [this was on HD11 and 6] this gave drive pressure.
All AC converters had a overrunning sprag clutch; this was bloody good as it gave downhill braking. When the output shaft speed exceeded engine speed the cams and rollers locked up giving direct drive and this was how you could push start them.
Downside was it all made for a plumbing nightmare, especially when combined with ACs ground speed governor, which was just a bloody hard way of doing what we all do with a decelerator. Most people deleted all the push start and ground speed hyds, made them a lot easier to fix. But still difficult compared to cats simple layout like a D6
Incidently the early cat twin disc diesel torque converters also had the overrunning clutch; but cat bought out a product bulliten stating to remove them in the early 60s after the single stage oil converters became there standard p/s trans.
 
Last edited:

Scrub Puller

Senior Member
Joined
Mar 29, 2009
Messages
3,481
Location
Gladstone Queensland Australia
Yair . . . D6 Merv. Good one mate! I have mentioned push starting the power shift Allis's on other forums and copped a few snide remarks. (Big grin)

It's a long time since I messed around with them and the details get a little fuzzy with the passing of the years.

As far as torque converters go I think some folks don't realise those early setups had a conventional over-centre clutch in front of the converter which drove into (in the Allis case) a simple two speed gearbox.

As you mention the early ones used diesel from the tank as torque transfer fluid the later ones ran oil in the converter and the clutch. The system worked well and I suppose was the reason Allis took so long to come out with a true power shift.

I did a few shifts on a D8 with a fuel converter and it was an absolute dog . . . it appeared that torque converters work better at 2100 than at what? . . . thirteen hundred or something behind the Cat engine in the D8.

It was a really strange sensation to see a couple of Allis's clattering along in light country pulling in second . . . foot on the decell to keep speed down and when the tracks stop feed it to her, no go? Slip her back into first on the rock back and up it again.

They seemed to progress in series of jerks but in truth it was very smooth.

Cheers.
 
Last edited:

Aussie John

Well-Known Member
Joined
Dec 26, 2009
Messages
99
Location
Toowoomba, Qld, Australia
Occupation
Maintenance Planner, mining equipment
Hey Scrub Puller, what was the model of the D8 that had the diesel converter fitted? Were these the early D8s that were built in Scotland? Remember doing a re-seal on one back in the early 70's when with the MOW at Twizel. Carbon face seals were used as rotating seals to feed the diesel into the converter. Not many have heard of these converters.
 

D6 Merv

Senior Member
Joined
May 10, 2007
Messages
653
Location
Coromandel Peninsula. New Zealand
Occupation
Self employed bulldozing contractor with a D6D D4E
would have been a early 68A D8H John, these had diesel converter to start with, then later changed like the American 46A.
We had quite a few of the early pom built D8s come to NZ. Remember doing a final drive on 68A22. would have to have been a fair chance it might have been a ex works one too.
 

Scrub Puller

Senior Member
Joined
Mar 29, 2009
Messages
3,481
Location
Gladstone Queensland Australia
Yair . . . Aussie John . There you go, D6Merv has confirmed it.

I thought they were 68A's but I am pretty poor at remembering numbers . . . the one I ran had a seven roller track frame which was considered a bit of a novelty at the time.

In the soft red country with the torque converter and (so they reckoned) the extra roller it was very unresponsive and didn't want to turn . . . completely different to the stick shift on the other end of the chain.

Cheers.
 

tctractors

Senior Member
Joined
Oct 9, 2007
Messages
2,383
Location
Worc U.K.
Well I must say I wish I had not brought up the sprag bearing thing it seems to have made all 6 cylinders fire up, the lock up bearing was used by Komatsu in plenty of their iron, anyhow now the Diesel Torque has been dusted off I would like to say (already pointed out) that there was a single plate toggle clutch between the engine and the torque, the clutch was only engaged at low engine speed then the throttle was given the "Beans" and all was good and moving, if the clutch was worked (engaged) at high engine speeds with or without load the single disc would spit the dummy out very quick, this would get a fool like me to strip things down resulting with the pilot getting the lick em' and stick em' "Red Card" off the Slasher (Muck shift Forman) as in the right hands the diesel torque was a fair item that worked well with a pilot that understood the beast, the fuel tank liked to be kept filled 2 times a shift, not that it was an alcoholic it just worked better with a full tank, to drive 1 of these beasts was if you did not keep your head trouble coming fast, if you were pushing muck over an edge or into a hole as the load came off the blade the tractor would quickly speed up trying to send itself over the edge, so it would be best to say learners keep clear of them, the carbon seal was a thing needing carefull and often maintaining, they had a drip pipe off them that you where supposed to count the drips off in a given time, we used to have milk bottles hanging to catch the drips, when we swapped them for gallon cans it needed replacing, I thought the Glasgow built tractors fitted with the Diesel Torque had something like 52A series? I have never seen 68A tractors fitted with this style of drive, thinking back on things they were right "Dogs" but thats what we had, the other day I was told that I am "Old School" what is all that about? I had a hate for the place.
tctractors

p.s. there is a few snaps of a D8H torque that I refurbished the other day in the shop talk thing.
 

Scrub Puller

Senior Member
Joined
Mar 29, 2009
Messages
3,481
Location
Gladstone Queensland Australia
Yair . . . tctractors. As always interesting comments but I must say your mention of "babying" the master-clutch is some what at odds with the way we ran them.

When pulling with two (or three) tractors inevitably they would stopped by a tree or trees and begin to spin their tracks . . . one machine often a bit in front of the other.

The idea then was to manoeuvre and get the machines pulling level and up it again (usually with a bit of a bump on the throttle to make sure you had all the "Beans") when they got stopped again (if you had visuals with the other operator) with a bit of body English you sort of rocked forward and, in time with each other, disengaged the clutch.

The tractors would rock back a little from the weight of the chain and the swaying of the tree. This was done three times and if the tree didn't come the tractors were backed up onto the little mounds of dirt kicked up by the tracks. The tree or stump was given three charges in this fashion, if it didn't come the inside tractor rattled back and pushed the tree or lifted the chain over the rock or stump.

It all sounds pretty brutal (and I suppose it was) but the weight of the chain seemed to cushion the shock to some extent. At no time though was there any thought of studying the clutch . . . I can assure you though the adjusting ring never had time to seize.

When the later series HD21's came out with the oil arse end, torque and clutch (for us) they were pretty trouble free in that department.

Cheers.
 
Last edited:

D6 Merv

Senior Member
Joined
May 10, 2007
Messages
653
Location
Coromandel Peninsula. New Zealand
Occupation
Self employed bulldozing contractor with a D6D D4E
Hi Tony
yes the 52A was the stick shift torque converter model with the dry master clutch. They are a very rare tractor; only about a hundred or so were made. And none made it down here.
the very first 68As #1 up to 82 had the diesel torque converter and early double gear torque divider. Was a few of these early ones made it to NZ
Hope your keeping well and enjoying your UK summer. Is just wet cold rain and mud down here at the bottom of the world :mad: Cheers Merv :drinkup
 

tctractors

Senior Member
Joined
Oct 9, 2007
Messages
2,383
Location
Worc U.K.
Hi Merv, the Sun is like a big fried egg in the sky here with some off the scale temps, 30c has popped up a few times this week about 25c is about all we Brits are good for before we start to "Winge" anyhow back to the Diesel Torque thing as possibly I have been stuffing my rag in the wrong hole some? the 52A's that I used to tamper with also had a big sister a 19A chariot, they were owned by a right old style land clearing contractor that wore a tight collar on the hottest day, I have never seen a 68A with the Diesel Torque and fancy drive divider, all I realy remember was they needed lots of spanner work if the wrong pilot copped the ride, I can recall converting an 18A with the air blown brakes to a wet case, I had all the tech' drawings of holes to drill and tap and a box of parts to install plus loads of bits to remove to effect the modification, plus a good few days cleaning out the main case of brake dust ( I wonder if its still in my lungs??) well I supose this is a bit off topic but I can recall the 52A's being following serial No's the owner never bought them new, they were bought off a gravel pit local to me some years before I was allowed near them.
tctractors
 

D6 Merv

Senior Member
Joined
May 10, 2007
Messages
653
Location
Coromandel Peninsula. New Zealand
Occupation
Self employed bulldozing contractor with a D6D D4E
source of all problems Tony; the wrong pilot in the seat; some people couldn't drive a duck to water.
Interesting about converting those dry bum girls to wet; have never heard of that conversion on D9Ds and Es. 19As were a popular pusher tractor over here.
30c is just nice for me; barefoot and shorts weather, and I drove dozers in that attire too when I can. Not much osh bulldust where I am. Although has changed a lot for the worse in last ten years.
cheers mate :drinkup
 
Top