Chickenjohn
Morris Minor and Porsche 944 fan
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I also think big end bearings, or even a cracked crank. Hence vibration only under load!
- Thread starter the repair man
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the snooper
getting older by the day
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I have not read the full thread but does the car have traction control and an electronic diff ?
the repair man
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Hi all, sorry for the delay, it's been a bad day. Not much progress on car, picked up some welding gas ( volkszone offer is great ) came home, welder broke, then my dumbshit dog took itself for a 5 hour walk...starting to sound like a country song! Anyway.
Yes it has traction control, don't know about electronic diff, possible, it has electronic power steering.
Re crank, big end bearings?? Very unlikely, how would this manifest itself in only one wheel? It all has to pass through a common flywheel, clutch and gearbox. That makes no sense to me!
I am aware of the lateral play, but this play is in any direction you push it, albeit very very slight. I will post a pic now of the castellated bit. I read somewhere it is a retainer for a castellated nut.
Many thanks for everyone's input.
the repair man
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This is taken from in the wheel arch, looking into diff / gearbox, with the splined shaft / c.v housing fitted there is a tiny amount of play in all directions, it is equal in all directions, as though the shaft, or bearing it sits in has worn a few thou. I would guestimate the complete movement to be 1-2mm at the cv joint end, so marginal at the bearing end.
Edit, I stuck a crowbar into the bearing and gave it a good wiggle, all felt solid.
the repair man
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Any ideas where I could get the bearing I.D or driveshaft O.D so I can get a digital vernier on it and see which is worn?
the snooper
getting older by the day
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the play you mention will not be there when both shafts are are fitted
the repair man
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It is though, that's why I have removed the shaft, to pinpoint the play. I noticed it with both shafts on the car.
the snooper
getting older by the day
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I meant if the bearings are good, it could well be your diff bearings especially if one wheel turns much easier then the other under engine power, whilst the car is on stands
the repair man
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it tends to favour the n/s wheel when on stands, but they are both free and easy to turn. Yet it is n/s with play. I'm going to see if I can get the cv bearing housing, rather than complete shaft, as the bearing feels solid it's more likely to be wear on the shaft.
Then just the fact that the water wont circulate, despite there being no stat in it, and perfectly good water pump, oh and a new alternator as I dropped a bolt in it whilst it was running...oops oh and it had a new windscreen a few months ago!
Wish I'd never started on this car, its a financial waste of time now, but as I've put £500+ into it, I refuse to scrap it or give up. It's a mission now, and I do love it. Not many cars have character these days, this does, albeit a dual personality!
Then just the fact that the water wont circulate, despite there being no stat in it, and perfectly good water pump, oh and a new alternator as I dropped a bolt in it whilst it was running...oops oh and it had a new windscreen a few months ago!
Wish I'd never started on this car, its a financial waste of time now, but as I've put £500+ into it, I refuse to scrap it or give up. It's a mission now, and I do love it. Not many cars have character these days, this does, albeit a dual personality!
the snooper
getting older by the day
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have you had the water pump off ive known impellers to fall off the shafts
the repair man
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Yes, that when I broke the alternator! I flushed the heater matrix with a very heavy duty industrial descaler, ditto the rad, took the stat out completely in case it was sticking, tried it, pffft nothing, so stripped it again, got new aux belt, checked water pump, refit with new belt and....nuffin water on one side of engine tepid, other side pressurising..I'll find it lol
I had similar symptoms on a Skoda a few years back, it wasn't as consistent as you describe but the effect under load was as though the nearside front wheel was square.
It turned out to be a sticky caliper, the wheel would rotate fine with just a little drag. As it heated up it was grabbing and you'd swear the wheel was falling off.
It turned out to be a sticky caliper, the wheel would rotate fine with just a little drag. As it heated up it was grabbing and you'd swear the wheel was falling off.
normspanners
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Wow I dont recognize any of that photo ! how are you taking the shaft out, you say the cv joint is fitted, I cant see it, normally the shaft comes out of the gear box complete with inner pot joint.
normspanners
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normspanners
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sorry about some of the abbreviations I drop into 'mechanics speak' when I'm thinking and my fingers type it before I have thought about it.
A 'drive shaft' is usually the complete unit with both CV (constant velocity) joints attached to the shaft between the two ( the actual drive shaft) usually the outer is called the CV and the inner is the the inner cv or pot joint because the shaft plunges into the pot, it has slots for the bearings to move in and out , they sometimes have a spring in there to keep the actual shaft in the correct plane ( not aeroplane HA).
if the engine mounts have moved or the car has had a bump or possibly an incorrect shaft has been fitted they can bottom out on the inner joint causeing a vibration as the car is loaded / unloaded as the shaft travels up and down and goes through its suspension travel and subtends an arc and therefore becomes longer at its mid point and pluges the pot the most, then shorter and travels out of the pot joint as the car is even further loaded whilst at the same time rotating. The opposite of this can happen if the shaft is too short I have known a shaft pop out of the inner pot when the suspension droop has been affected by suspension mods, and the car has jumped on a rally stage coz the engine has gone up and the suspension down
maximizing the distance between the two cvs.
A 'drive shaft' is usually the complete unit with both CV (constant velocity) joints attached to the shaft between the two ( the actual drive shaft) usually the outer is called the CV and the inner is the the inner cv or pot joint because the shaft plunges into the pot, it has slots for the bearings to move in and out , they sometimes have a spring in there to keep the actual shaft in the correct plane ( not aeroplane HA).
if the engine mounts have moved or the car has had a bump or possibly an incorrect shaft has been fitted they can bottom out on the inner joint causeing a vibration as the car is loaded / unloaded as the shaft travels up and down and goes through its suspension travel and subtends an arc and therefore becomes longer at its mid point and pluges the pot the most, then shorter and travels out of the pot joint as the car is even further loaded whilst at the same time rotating. The opposite of this can happen if the shaft is too short I have known a shaft pop out of the inner pot when the suspension droop has been affected by suspension mods, and the car has jumped on a rally stage coz the engine has gone up and the suspension down
maximizing the distance between the two cvs.
if the vibration as been with you since the purchase of the car.
Old Dog
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bad vibes
First of all the thermostat, if you look at it from the side, there is a large washer shaped disc at the top which sits in the housing, is there a spring loaded disc at the bottom as well? If so that engine requires a thermostat fitted to allow water to circulate and the system will not work with out it. There might also be a air lock in the system, fill the system then with the engine running slacken off the hose from the thermostat to radiator at the radiator end to allow any air out. As for the vibe problem, a standard diff will always drive only one wheel and that wheel will be the easiest wheel to turn, that's what a diff is designed to do. The 40 to 60 speed is classic symptoms of a rotating mass imbalance(though it is difficult to define the cause with out driving the vehicle, it's a feel thing, the same as welding) have you change the wheel to another position? There will always be a little lift in a output shaft because the diff gears are floating. The point that a load in that side of the car improves the vibes points to the shaft(with a heavier load the shaft is straighter therefore the joints are more in line) but a heavy load will also damp out the vibes. The rubber block is a shaft damper. You did say that some work had improved the vibe, what was the work that was done?
First of all the thermostat, if you look at it from the side, there is a large washer shaped disc at the top which sits in the housing, is there a spring loaded disc at the bottom as well? If so that engine requires a thermostat fitted to allow water to circulate and the system will not work with out it. There might also be a air lock in the system, fill the system then with the engine running slacken off the hose from the thermostat to radiator at the radiator end to allow any air out. As for the vibe problem, a standard diff will always drive only one wheel and that wheel will be the easiest wheel to turn, that's what a diff is designed to do. The 40 to 60 speed is classic symptoms of a rotating mass imbalance(though it is difficult to define the cause with out driving the vehicle, it's a feel thing, the same as welding) have you change the wheel to another position? There will always be a little lift in a output shaft because the diff gears are floating. The point that a load in that side of the car improves the vibes points to the shaft(with a heavier load the shaft is straighter therefore the joints are more in line) but a heavy load will also damp out the vibes. The rubber block is a shaft damper. You did say that some work had improved the vibe, what was the work that was done?
the repair man
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God your an attentive and helpful bunch on here, I only hope my contributions help others the same!
Ok, in this pic, the far right ( cup ) as I now know it to be called is removed with the driveshaft. In my pic the entire unit is removed, however I have been putting only the cup back in to ensure any play I felt was at the cup entry, and not in the cv joint on the shaft ( make sense? )
What you see is just a pic of the exposed diff with the oil seal removed.
I know what you mean about a knock from a lateral movement, this feels more like the wheel isn't even bolted on!
Re the stat, I have removed it completely, because even tho in opened in a pan of boiling water, I suspected it may be sticking. I removed it to eliminate from the equation, so that I now know pumped water can definately pass that point in the system.
The rotating mass theory, I hadn't considered an overheating brake, a definite possibility as I haven't done anything to the calipers.
The underside hasn't seen any accident damage, unless Da Vinci himself repaired it.! However when just revving the engine, there is considerably more movement on the mounts on the n/s ( gearbox side ) but neither of the garages picked up on it, or suggested it was too much.
The wheel balancing made no difference, nor did wheel rotation or changing shafts & disks. I think the improvement ( it actually just moved it up the speed range from 40 to 60 ) was when I made a n/s shaft from the spare o/s shaft and fitted that ( they are the same half shaft )
Oh, the loading / unloading, it requires very little acceleration to do it, literaly just maintaining speed up a slight hill. Not enough to load / unload the suspension at all.
Many many thanks for all your thoughts and suggestions.
Next job, strip and rebuild calipers! ho hum
cecotto479
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You have tried it with a different wheel and tyre on? A slightly deformed tyre has had me baffled until I had a puncture, put the spare on and the vibration went away.
