Hello, My 1988 JCB 1700B TLB doesn't seem to have a rear differential lock like my 1969 Ford 4500 TLB does. The Ford 4500 TLB has a manual heel pedal that I can step on and lock both wheels in so the tractor doesn't spin. I didn't know if this JCB should have some kind of lock or not. There is nothing mechanical. I didn't know if it was supposed to have some kind of button, switch, something electrical, something that I can lock the rear tires in to keep from spinning in loose material. There is/are several wires and other things that aren't hooked up on this machine. For instance it has the fuel pedal for my rt foot, then the Rt & Left Brake pedals, then another pedal over to my left for my left foot to engage. This last pedal does nothing at all,.... apparently several things are disconnected from this pedal. There have been several things disconnected here & there before I bought it back in 2019. But it digs and loads awesome! Just is helpless when loaded on soft material on a slope! James
I can't speak for your 1700B, but I once owned a 1400B [same year] and there was no diff lock. Mine was 4 wheel drive and if I recall correctly the rear diff was some kind of limited slip.
My 1700B is 2 wheel drive. Limited Slip is also kinda what I've been told around here locally in Central Oregon. There is absolutely hardly any JCB machines in this area, probably within 100 miles any direction, a few but not many. Last year a local equipment mechanic that has worked on a few JCBs told me to go to parts store and get some limited slip additive & put in. But I'm still trying to figure out what oil I need to use for this rear end because I want to drain and flush it. I never have since I bought it in 2019. I also am not very familiar with Limited Slip on anything, even cars, trucks, etc, etc. Just really have driven a vehicle with it.
I wonder if the mystery pedal was a transmission disconnect so you could increase engine speed without moving when in gear? I think some machines use a push button for this function. Some wheel loaders have a pedal operated trans. disconnect.
I changed the diff oil once or twice when I owned mine and I used the JCB oil simply because it removed any guesswork.
To OP: I've got a 1550-B, no diff lock on it. As per above quote: If you have (what might be viewed as a) 'clutch pedal' in front of you, (trying to recall it's formal name)..... ahh. I think that's called an inching clutch. As you approach maybe a dump truck, want to slow down BUT raise RPM's to power bucket higher, that will do something to the transmission. Mine has never worked so I don't know if it's a temporary neutral or something.... my machine also has a button on the loader handle that I presume (but don't know) does the same thing. Why might you need a diff lock? I've owned my 1550b and been in some S.T.U.C.K. situations..... never had an issue getting out.... just use the backhoe to extend and push yourself forward or, in my case.... I was stuck down to the rear axels in muck as I was dredging part of the (lowered water) lake bed.... between the outriggers and hoe, was able to finally crab it out of there however, I think it took me 2-4 days to figure out a game plan. I might add.....I've never done that since!
On your machine the pedal to the left of the brake pedals is the declutch pedal. If it's working it disegages the transmission to make shifting the transmission gears smooth and is also useful when loading trucks etc. It allows you to halt your speed so you can raise your bucket high enough to clear the box sides and so on.
Yes I think you guys are right, the pedal must be a disconnect switch and there is a button on the loader knob, but everything is unhooked/disconnected. As far as being able to dig or push myself out that is in fact possible with the loader bucket or rear hoe. What I'm talking about is like when I have a big loader bucket full easing down a slight incline, dump the loader, then try to back up. Try to ease back but the machine is very heavy. It'll try to slightly start kinda rocking sideways and one or other rear tire try's to dig in. This and other situations is where rear differential lock would be very handy, like my 1969 Ford 4500 has a rear wheel lock pedal. I'm going to explore more about maybe Limited Slip rear end on this 1700B. I found a 2015 post titled : JCB differential oil for wet brakes? where jcb jeff and [B]hookedondiesel[/B] and others were talking the correct oil to use for wet brakes, etc. Also I'm wondering about maybe some additive to add for Limited Slip. HeavyEquipmentForums
I never used any additives. Just the OEM oil. It also contains an additive that stops the brakes from chattering when they are applied.
I am going to ask the stupid question,,, do the rear tires have any type of weight in/on them== liquid or plate weights??
Whelp, stupid answer. I guess you could look. These older machines are like HD bikes. They are like a box of chocolates, you never know what you’re going to get.
Have you ever consulted an owners/operators manual? would probably take out all the guesswork.
If I'm following you correctly, you are suggesting that you are backing up in incline so the hoe is on the upside (?) Do you have room to turn around? I'd presume you'd have better performance if you went forward up the hill verses backwards? Seems to me that would shift more of the weight to the rear and net better traction to climb. If that's your only choice can you achieve a bit of (what I'll loosely call) wheel lock by using the turning brakes to slow the spinning tire and better distribute the power to both? I'm on hilly terrain (east Tennessee) so I'm always having to fight these types of situations. I'll take having the machine over not having it...... but, 4 wheel drive would certainly make life a bit nicer!! Folks on flat lands don't know how nice they might have it!
That deal with dumping a load on a downhill and backing up outta a hole is always a pain. My different lock is disengaged for a reason, I would definitely break something if it wasn’t. My Kubota still has it connected but it’s hydrostatic drive.
No my 1700B does not have any extra added weights, liquid or metal. It's just a very heavy machine. My machine just seems to start rocking and slipping/spinning one or other wheel on slight incline, backing up, going forward or reverse going around sideways, or going forward up a slight incline. Especially if the material underneath is loose or gravel. And I'm not giving LOTS of throttle, just usually trying to gently keep going. I'm going to try to call the JCB Dealer in Portland, Oregon tomorrow, or when I can. I'm still wondering about the Limited Slip Rear-End.
Might have a big block and a 3500 stall converter. lol
No front weights? Mine has two (iron?) plates. I'm guessing combined maybe 500 pounds? (they're tagged in KG's as I recall) I think it might have been an option on those machines, SUBSTANTIAL difference between using them and not. Anyway, years ago, was doing something on side (sloped) yard. Had rained a bit so was slick. Found myself sliding down entire width of yard with zero ability to stop other than dropping bucket. Turns out, the weights which hang under the front of the machine, had fallen off. There was maybe eight inches of all thread hanging below them, one of the threaded rods had been missing (for years) and the other finally let go. The front of the machine was bouncy as heII when those weights came off. Ended up at a machine shop and had a threaded "wedge" created to slip into the pocket that holds it..... and later on, those stripped out. Finally, with a machinest friend, drew the attached. They've been solid since. This holds the nut in place (the slot just fits the nut) Look between front tires, you might have an angled piece of steel on the right & left. Been years since I've done this but as I recall, the angled holder I had made (picture attached) slid between the piece of steel and the chassis.... then the threaded rod screwed into the nut that I had locktighted onto the end. I also put another nut between the two weights so one nut held the upper weight and the second/bottom nut held the bottom weight on. I think you said your rear wheels (?) were the ones sliding? None the less.... if you don't have front weights, it is a substantial improvement in keeping the nose in place and less bouncy. I have no idea how easy it might be to find some fronts for something like this. Also, mine has the implement (what I call balloon) tires and those are useless for side traction.
Actually my 1988 1700B 2 wheel drive without an Extend-a-Hoe has iron weights up front around behind the grill. Parts manual says weight weighs approx 300# plus. Near as I been able to internet search this 1700B weighs 16,210# if not more. I can get a loader scoop of damp dirt, raise it up, & go back & forth packing the heck out of the ground...... like when I was packing my shop pad where I'm building my shop. But that's level ground. Example of when I'm having trouble is when on a slight to medium slope, dump a load, then try to back up if ground still has soft fill that isn't packed. I been filling & dumping lots of rock, dirt, gravel, general fill over a bluff and filling in stuff. This 1700B looses traction easily, backing up, going sideways turning around, or driving uphill. Just wish it had differential lock like my Ford 4500 has. My old 1969 Ford 4500 TLB weighs about 10,500# or more. But it will climb a tree!!!!
It is a little odd it doesn't have diff. lock.