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HDJ80 Clutch Pedal Height Adjustment

Macc_70

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HDJ80 AWD 1997 4.2 24v 80k miles Front/Rear/Center lockers/cruise control
Hello,
New here so hope I'm posting in the correct place?
My 80 has developed a strong vibration (like a v strong rotational wobble if that makes sense) when taking up drive, almost undrivable if trying to go uphill from a stand.
I've checked and greased all UJ's and replaced all fluids re diffs/ gearbox/trans.
Gear changes are fine once on the move and clutch seems smooth to operate but i would say this has got progressively worse over time. I'm tempted to think it's not the clutch with such a low mileage and i poked a small inspection camera through the actuator lever aperture and can't see any oil contamination etc.
Replaced the slave a couple of years back and no issues then? I'm now checking clutch pedal adjustment, height, free play etc. Mine has no conventional booster but does have the spring assisted contraption which i understand is not adjustable.
Question: The clutch pedal does appear to be low (closer to the floor) vs the brake pedal, by circa 10mm. Adjustment Info/manuals talk of loosening the stopper bolt at the top of the pedal and checking master adjustment etc. The only bolt i can see is the switch that deactivates the cruise control if clutch is deployed. Photo attached. Is this the bolt i should be adjusting to address pedal height? I would have to disconnect the wiring from the switch in order to rotate it and then re-connect?
Any thoughts or things I've obviously missed welcome.
Cheers
80-clutchadj.jpg
 

frank rabbets

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Could be you've got rust on the flywheel/pressure plate if the car has not been used much. This happens to mine if stood for a while. What I do is give it 3,000 RPM then gently take off in 2nd gear. This polishes things up a bit then no judder.
 

Macc_70

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Thanks for that, I'll give it a go. Do you know if the clutch pedal can be adjusted by the clutch/cruise control switch/bolt as in the pic?
Getting in there with a spanner (14mm if i recall correctly) is a bit of a pain but doable but if it makes no difference to the pedal height then I'll leave it alone.
cheers
 

frank rabbets

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The Toyota workshop manual just shows a plain bolt for pedal height adjustment but you could see if unlocking the switch and turning it can adjust the height.

The manual states the correct height from top of pedal rubber to top of carpet/plastic pad is 168-178 mm.

I assume broken engine and or gearbox mountings could cause your judder.
 

Macc_70

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Thanks Frank, I've got my 80 up on stands just now - better access for the fluid changes and UJ's etc but once back down, I'll test the clutch in 2nd gear etc. Same re the bolt but it really is a tight getting in there and all done by touch / blind as i can't see the pedal cluster and get in with a 14mm at the same time.
Engine and gearbox mounts crossed my mind, my missus once drove off, turning the wheels to correctly position the 80 relative to the road.
This allowed me (standing on the pavement) to see right in to the offside wheel arch and noticed just how much the exhaust manifold downpipe was wobbling about. Presume the engine was too? Quite alarming really.
I've visually checked the mounts but think a more physical or rigorous approach is required. Any suggestions on how to do this? Prybars / levers. Although a very low mileage, the truck had been owned by a farmer so possibly put to work. Previous owner had the truck properly serviced though and has a comprehensive logbook/service history.
cheers
 

frank rabbets

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I would have to look at the exact design of the mounts to be able to recommend a test but yes long prybars are a starting point. Or try jacking the engine then gearbox up to see. 80 is not known for failed mountings. My money would be on polishing up the clutch plates.
 
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Macc_70

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Thanks again Frank, will be taking a look today so hopefully unearth something? Will post my findings.
cheers
 

Dave2000

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Was this a sudden occurrence or came on over time, do you use the 80 to pull a trailer?

If it happened suddenly then it could be one or more of the damper springs on the driven plate, or even one or more of the 'fingers' on the pressure plate but unlikely if the clutch was recent and a decent brand.

I would be looking more at engine mounts along with the gearbox support. Mine had just the tiniest of vibrations on pull away but I went with the mounts, sure enough the engine mounts whilst looking OK, had started to delaminate form the metal, impossible to tell unless removed, new mounts all round (very easy to do) and it was job done.

EDIT: Just a thought, a clutch change can 'finish off' an ageing engine mount so...........

Regards

Dave
 
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Macc_70

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Thanks Dave, much appreciated. It seems to have come on gradually. I haven't been towing anything but the previous owner was a farmer and there's a Witter tow bar fitted so it may have been used for 'farm work/towing' etc? Overall though, the motor's in great condition which fits with the very low mileage, service records etc. Interior and body are very clean, no dings or obvious repairs to panels etc.
I've tried poking about re the mounts with a pry bar but think I'm possibly not being aggressive enough as I don't notice any obvious wobble or delamination but as you say, it's difficult unless removed for a proper inspection. The gearbox mount looks fairly accessible but the engine mounts look more of an effort to get to. Any advice there would be much appreciated. Did you go Toyota replacement mounts or aftermarket?
Re the clutch, I did poke a small inspection camera through in to the housing through the actuator arm aperture to check for any oil or contamination etc but I find those things aren't that easy to position sometimes as they have such a narrow field of view. Should i be able to see the clutch manufacturer name from accessing the actuator aperture?
I'm presuming it's the original clutch at 80k but of course, there's no guarantee there. Once on the move, the gear changes are fine though.
I've had the up on jacks to replace diff/trans and g'box fluids (they needed doing anyway). I'll soon be putting it back on the road to try some of the tests Frank suggested.
One thing I have noticed is that the front springs are very rusty, would any kind of 'general sag' cause any undue stress on the drive train to aggravate the issue? A tad far fetched for a motor that's so robust but thought I'd throw it out there.
I did replace the slave a few years back, is there enough range of adjustment on the slave that would have such a dramatic effect?
Thanks again for your help and comments.

Regards,

Gordon
 

Dave2000

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No, springs don't have a bearing on the clutch engagement, probing the rubber mounts with a bar will not reveal anything as they are being compressed by hundreds of pounds of cast iron, farm work is hard on a tractor but they are designed for it, towing around on a farm with an 80 is OK but will tell over time. The dust and 'stuff' in the bell housing may well cover the brand name on the cover plate. From a maintenance point of view I would change the three mounts and see if that cures the problem, much cheaper and easier to do, having said that the mounts are almost certainly past it anyway so not a waste of money.

I got OE mounts from @chapel gate, no liberties taken with the price and quick to ship to me here in Spain. Assuming you do not have an engine lifting brace that sits on the inner wing gutters then go this route. Fitting is not that difficult, do the engine mounts first, leave the car on it's wheels and use a flat piece of wood, something like 3/4 inch ply? Do not use chipboard as it will crush between the jack and the sump and perhaps cause damage? Then with the wood between the trolley jack lifting pad take the weight of the engine under the sump. A couple of notes here, one loosen the mount nut/bolts first, Keep an eye on the jack wheels when jacking up, trolley jacks do not lift upwards without the wheels rolling forward, if your not careful and the wheel get stuck on a rough surface, you will find the lift pad of the jack and/wood will slide and perhaps come away from the sump. You can use and ordinary jack, but this is dangerous, given you are going to have your hands down there if the jack tips over and your hand or hands are in there..............

I think the mounts were not 'handed' but my memory is a little shot, check the part numbers. Again assuming you do not have a full car lift and gearbox jack, then again use the trolley jack, use a thin piece of wood, the lower edge where your jacking will 'dig' in help prevent and movement removal is obvious when your under there, a pair of clear grinding goggles will stop the farm mud getting in your eyes. A tip here, depending if you have a sylph like body like mine....cough......er then get hold of FOUR car ramps and place in the front of the front wheels AND the rear wheels, now drive up all four. Using low range helps you control the vehicles pace up the ramps without using a lot of revs on your possibly 'iffy' clutch, have someone guide you up as in low range you don't really want to go over the ramp 'stops', easy done in low range if you are not experienced with doing this kind of 'stuff', and of course keep an eye on the ramps if the slip, which they should do if your centre diff lock is working.

Hope that helps?

Regards

Dave
 
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frank rabbets

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The slave pushrod should be resting up against the piston inside the cylinder. However you must be able to push it away from the piston a tad to prove it is not stressing the clutch when your foot is off the pedal.
 
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