Hi all, was looking for repair/maintenance info for this dozer, found a few other people in Aust/QLD posting here about it, so here I am too I have a workshop manual for this dozer (AD7 manual) - that manual shows a 'dry' master clutch. The 70ci has a 'wet' clutch, so as well as the obvious oily addition, the clutch plates, spider and throwout collar are a bit different. I got some exploded diagrams of this wet clutch, and can make sense of most of it. I'm not certain on adjusting the clutch spider though. The reason I've had to dismantle is the clutch jammed 'on'. part of problem was a circlip that sheared out of a groove so the hand-lever couldn't 'disengage' the spider, but it also seems that the spider might be over-engaging (over-centre? over-cam?) and therefore having a bit too much pressure on it for disengaging. So, I can adjust the plate it pushes on. Question is - do I turn this plate clockwise or anticlockwise? If I've interpreted the diagrams correctly, anti-clockwise screws plate 'out' so spider has less travel to engage the clutch? Any tips that save me simply experimenting are appreciated currently broken down on a hillside, so experimenting with whether I've made the clutch too loose or permanently jammed are a little nerve-wracking!
Hey Shane - sorry to hear you have broken down on the side of a hill - not fun I know! So just to check - You have a 70ci? I can't say for certain, but I'm pretty sure all 70c & 70ci (which covers AD7 also) are all dry master clutch. I have 3 & all of them are the same, the manuals I have (covering 70c / 70ci / AD7) all show dry with no mention of wet (even though the last one I bought the bloke thought it was a wet clutch & had been playing with some adjustments from the manual - when I got it home i could see why he thought it was wet - the drains in the bottom were blocked & it was all full of oil & water & the clutch had become fairly oily making release not so positive). I know there were some modifications which don't show in my manuals for later model 70ci & from what I have found lately the AT7 variants were slightly different also. The boys at South Burnett Tractor Parts are always helpful though. Jimbob
Hi Jimbob; Well, I'm not 100% on specs but when I've got other parts for it from SBT they've talked me through it and told me it was 70ci for everything from injector pump to final drive (yep, I 'adopted' something that needed a lot of TLC... fixing it on hillsides is almost second-nature now!) But I am 100% it's a wet clutch. doesn't have a dip-stick, oil filter and pump in there for no reason So... could be a later modification. Can enquire with SBT... probably be talking to them again for some bushes/bearings anyway, just felt bad asking them for 'free' advice before I had a go here! Thanks
Hi Shane Just checking - did you get sorted with your wet clutch situation? I met an old bloke in December that used to be an old dozer mechanic in the years that these machines were around - he tells me they used to modify 70ci / AD7 machines to be wet clutch by bunging up the drain holes the finding out what oil specs went in the later (BD7 I think) ones and fill to that same level - he said no need to change clutch plates or anything - he was a fair dinkum mechanic & knew all the gear & tips & tricks of the time & I think was working out of a cat dealership in rocky - would really like to hear if anyone else has heard of this to back it up a bit? Jimbob
Hi Jimbob, yes, got parts and a copy of the workshop manual pages for wet clutch, from South Burnett Tractors. now clutch is fine, but Dec workout has left old hyd pump practically knackered. ah well, I milked about 2 or three extra lives out of it, soon I guess will have to fit another, there's bound to be something lying around the shed...
Jimbob,Garrie here why would you want to make a dry clutch wet by running half submerged in oil? Some advantage ? I would have thought that would make the four section clutch plat slip for sure.
Yeah Garrie - I was wondering on the reasons why & what advantages too. I guess it might keep temperatures down & maybe wear rates, but the friction material would want to be oil friendly I reckon. That's why I was asking, hoping to find some more info on it. Maybe next time I speak with SBT I will ask? Jimbob
I agree but the friction material four our beasts are for a dry set up, you know how well brake pads work when therve been doused with brake fluid, useless,any way something no doubt will surface most likely, have you got any photos to post on your restoration yet ?