rear axle lockup
Discussion
'01 chimera 450.
I left it in a garage while I went on holiday for 2 weeks. Came back yesterday and tried to reverse the car out of the garage. Moved about 1.5m before it stuck. Handbrake lever in down position but locked there, seemed like rear brakes locked on.
Called AA, who cut handbrake cable. Rear wheels still stuck, though handbrake lever now loose. Loosened brake caliper, rear wheel still locked. Engine runs with gearbox in neutral fine.
It's possible that a couple of planks touched the underside of the car while I was parking it but there was no noticable bump and this might be a red herring.
The car is now poking out the garage and immovable. Any ideas?
steve
I left it in a garage while I went on holiday for 2 weeks. Came back yesterday and tried to reverse the car out of the garage. Moved about 1.5m before it stuck. Handbrake lever in down position but locked there, seemed like rear brakes locked on.
Called AA, who cut handbrake cable. Rear wheels still stuck, though handbrake lever now loose. Loosened brake caliper, rear wheel still locked. Engine runs with gearbox in neutral fine.
It's possible that a couple of planks touched the underside of the car while I was parking it but there was no noticable bump and this might be a red herring.
The car is now poking out the garage and immovable. Any ideas?
steve
Strange, since the car moved at first this shows the brakes weren't stuck on and I'd be looking for other causes, but you say the handbrake handle was stuck too? This might imply that something had got caught up with the handbrake cable as the car rolled backwards? I assume you've ruled out something physically catching on the car, wrapped round any of the wheels, that sort of thing?
Does this mean you've been able to get the rear wheels off? If so you can prove whether or not it is anything to do with the brakes just by undoing one of the slides so the caliper lifts off (pivoting around the other slide), very easy to do if you have access and the right spanners. If the brakes are jamming on you won't be able to move the caliper.
The only other possibility I can think of is some one-in-a-million failure inside the transmission, causing it to lock solid. I guess if you rule out all the other possibilities you have to consider this one but really it doesn't sound at all likely to me. If it is a transmission problem you would find the car will move forward and back an inch or so just from the play in the CV joints, this would be a clue it is transmission related rather than brakes.
trip01 said:
Loosened brake caliper, rear wheel still locked.
Does this mean you've been able to get the rear wheels off? If so you can prove whether or not it is anything to do with the brakes just by undoing one of the slides so the caliper lifts off (pivoting around the other slide), very easy to do if you have access and the right spanners. If the brakes are jamming on you won't be able to move the caliper.
The only other possibility I can think of is some one-in-a-million failure inside the transmission, causing it to lock solid. I guess if you rule out all the other possibilities you have to consider this one but really it doesn't sound at all likely to me. If it is a transmission problem you would find the car will move forward and back an inch or so just from the play in the CV joints, this would be a clue it is transmission related rather than brakes.
trip01 said:
Engine runs with gearbox in neutral fine.
This would indicate that it's not a transmission fault. Presumably putting it in any gear and it won't move? Also with it in neutral you can't push the car?
Why do you think it's a rear brake problem (cutting the handbrake cable,etc)Could the front brakes have seized? Have you tried jacking it up and manually rotating each wheel?
Not necessarily the cause here but it really is bad leaving a car for any length of time with the hand brake engaged. Just leave it in gear.
If you engage the hand brake after a run where your brakes have been hot then they can literally glue together. If you leave the brake engaged in damp conditions or after a wet run for more than a few hours you stand a fare chance of them sticking. Brakes, by design, are oil free so the mechanical parts suffer for surface corrosion.
On flat or flatish parking you really don't need a hand brake, just put it in gear.
If you engage the hand brake after a run where your brakes have been hot then they can literally glue together. If you leave the brake engaged in damp conditions or after a wet run for more than a few hours you stand a fare chance of them sticking. Brakes, by design, are oil free so the mechanical parts suffer for surface corrosion.
On flat or flatish parking you really don't need a hand brake, just put it in gear.
If the car was put away wet and not used (rain or after washing car perhaps) the disc's will rust and sometimes the brake pads will literally stick to the surface.
You need to jack the wheels up in turn and see if the wheels can be made to turn or if pads are sticking. If no movement possible and sticking pads is suspected, remove the roadwheel and gently tap the pads with a softfaced hammer or a suitable piece of wood and hammer to free them. This should work.
You need to jack the wheels up in turn and see if the wheels can be made to turn or if pads are sticking. If no movement possible and sticking pads is suspected, remove the roadwheel and gently tap the pads with a softfaced hammer or a suitable piece of wood and hammer to free them. This should work.
I'd be tempted to just jack up each corner in turn, just far enough to see if you can turn the wheels by hand. That should identify the problem fairly quickly. If it's brakes one or more wheels won't turn at all(make sure it's out of gear). The rears should turn at least until the diff reaches it's locking point. If it's transmission then the fronts will turn and the rears will only turn taking up the play in the UJs.
If it is just brakes you could try the only thing that worked on my F355 (recommended by dealer). Start the engine, put the car into first(probably reverse for you or you may have bigger problems!!!!!!!!)and then just drop the clutch in an "I never learnt to drive" kind of way. This puts all the engine torque through the brakes and the car will lurch a foot or so as the engine stalls and the brakes release. This is a preferable method to cooking your clutch trying to be "sympathetic" to the mechanicals whilst unsticking the brakes. It also has the benefit that as soon as the brakes unstick you stop moving as opposed to spearing off into the nearest solid object. There will be a fairly sickening bang as the brakes release.
This all sounds horrible but is preferable to draging the car down the drive on a tow rope and onto a transporter.
Kevin
>> Edited by kevin secker on Monday 16th February 17:57
If it is just brakes you could try the only thing that worked on my F355 (recommended by dealer). Start the engine, put the car into first(probably reverse for you or you may have bigger problems!!!!!!!!)and then just drop the clutch in an "I never learnt to drive" kind of way. This puts all the engine torque through the brakes and the car will lurch a foot or so as the engine stalls and the brakes release. This is a preferable method to cooking your clutch trying to be "sympathetic" to the mechanicals whilst unsticking the brakes. It also has the benefit that as soon as the brakes unstick you stop moving as opposed to spearing off into the nearest solid object. There will be a fairly sickening bang as the brakes release.
This all sounds horrible but is preferable to draging the car down the drive on a tow rope and onto a transporter.
Kevin
>> Edited by kevin secker on Monday 16th February 17:57
greenv8s said:
Does this mean you've been able to get the rear wheels off? If so you can prove whether or not it is anything to do with the brakes just by undoing one of the slides so the caliper lifts off (pivoting around the other slide), very easy to do if you have access and the right spanners. If the brakes are jamming on you won't be able to move the caliper.
Yes, one rear wheel off, loosened the caliper, wheel still locked (ie. I couldnt turn the brake disc). The other wheel was on the ground and the gear box in neutral.
steve
I can't see why there's a feeling that the brakes have bonded to the disc - sure it can happen (I know what my pad's looked like after a similar moment of madness when I drove 10/10ths to the airport and clumsily pulled the handbrake on and left it for 2 weeks - there was a megabang when the bond let go but much of the pad surface went the way of all flesh at the same time - to dust).
But Steve said he reversed it about 1.5 meters - that's at least one complete rotation of the wheel. So it can't be a sticking brake pad. Or am I missing something?
But Steve said he reversed it about 1.5 meters - that's at least one complete rotation of the wheel. So it can't be a sticking brake pad. Or am I missing something?
trip01 said:
Yes, one rear wheel off, loosened the caliper, wheel still locked (ie. I couldnt turn the brake disc). The other wheel was on the ground and the gear box in neutral.
This is getting interesting. Just to be clear, what exactly do you mean by loosened the caliper? Did you take the caliper right off the upright, or release it enough to swing it up away from the disc, or something else? If the disc is not being clamped by the caliper then you will have enough play to feel just from the backlash in the transmission. So if you can't move the disc at all basically that means it *must* still be clamped by the caliper - that's assuming the little green men haven't been in there with the arc welder!
GreenV8S said:
Yes, one rear wheel off, loosened the caliper, wheel still locked (ie. I couldnt turn the brake disc). The other wheel was on the ground and the gear box in neutral.
This is getting interesting. Just to be clear, what exactly do you mean by loosened the caliper? Did you take the caliper right off the upright, or release it enough to swing it up away from the disc, or something else? If the disc is not being clamped by the caliper then you will have enough play to feel just from the backlash in the transmission. So if you can't move the disc at all basically that means it *must* still be clamped by the caliper - that's assuming the little green men haven't been in there with the arc welder!
Well I'm not exactly sure because the chap from the AA did it, but the caliper was still over the disk, but loose enough to wiggle slightly from side to side. He was convinced that the pads were not adhered to the disk.
The reason I thought brakes were the problem was that the handbrake lever was locked in the down position - locked as if the handbrake was fully on, but in the 'off' position. Cutting the cable released the lever but not the wheels.
A friend has suggested that the handbrake might not operate the rear disks, but a small drum which might be located away from the wheels (on the drive shaft for example) can anyone confirm or deny?
Thanks for all the suggestions, I'll certainly post when I discover what the problem was.
steve
trip01 said:
trip01 said:
Yes, one rear wheel off, loosened the caliper, wheel still locked (ie. I couldnt turn the brake disc). The other wheel was on the ground and the gear box in neutral.
This is getting interesting. Just to be clear, what exactly do you mean by loosened the caliper? Did you take the caliper right off the upright, or release it enough to swing it up away from the disc, or something else? If the disc is not being clamped by the caliper then you will have enough play to feel just from the backlash in the transmission. So if you can't move the disc at all basically that means it *must* still be clamped by the caliper - that's assuming the little green men haven't been in there with the arc welder!
Well I'm not exactly sure because the chap from the AA did it, but the caliper was still over the disk, but loose enough to wiggle slightly from side to side. He was convinced that the pads were not adhered to the disk.
The reason I thought brakes were the problem was that the handbrake lever was locked in the down position - locked as if the handbrake was fully on, but in the 'off' position. Cutting the cable released the lever but not the wheels.
A friend has suggested that the handbrake might not operate the rear disks, but a small drum which might be located away from the wheels (on the drive shaft for example) can anyone confirm or deny?
Thanks for all the suggestions, I'll certainly post when I discover what the problem was.
steve
Hand brake only operates on the rear discs - there are no drums.
Is there any movement at all, as per V8S, on the rear drive shafts? Yes the caliper is loose, but are the brake pads ??
Trev McM
I would remove the rear callipers by swinging them out of the way as if you were changing the pads so that they were now where near the disk. Remove the pads as well. Jack the rear of the car up and then see if you can turn the wheels. If you can then refitting the rear brakes should solve the problem. If not then the problem is with the transmission. The details are in the bible.
The handbrake does operate on the main pads and there is no seperate drum. There is a wear take up mechanism and it is possible that this has got jammed but I doubt it.
I am thinking that something has jammed the diff internally and locked it solid. If this is the case then you need to borrow a dolly of some kind to go under neath the car at the back to allow it to be moved. Some go under the wheels. I got one that goes on the suspension. Trolley jacks are not to be recommended as they can slip.
Steve
www.tvrbooks.co.uk
The handbrake does operate on the main pads and there is no seperate drum. There is a wear take up mechanism and it is possible that this has got jammed but I doubt it.
I am thinking that something has jammed the diff internally and locked it solid. If this is the case then you need to borrow a dolly of some kind to go under neath the car at the back to allow it to be moved. Some go under the wheels. I got one that goes on the suspension. Trolley jacks are not to be recommended as they can slip.
Steve
www.tvrbooks.co.uk
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