FWD....
- Thread starter DanZac
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It didn't, and I was going to do a bit more digging to see if I was missing something obvious before I started asking questions and revealed my lack of knowledge in all its glory.
But you and the other forum knowledge fountains have already preempted my questions and saved me the trouble. (I still know nothing mind you).
Every day's a school day. I'm off down a google rabbit hole to learn about rear wheel drive differentials, just incase it ever comes in handy.
RIP
Kairo
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In a rear wheel drive car the diff also turns the rotation of the engine so it faces the wheels. It uses a pinion to do this, which creates massive forces and makes the teeth engagement complex. A front wheel drive car engine already turns on the correct plane so presumably it's a simpler configuration.It didn't, and I was going to do a bit more digging to see if I was missing something obvious before I started asking questions and revealed my lack of knowledge in all its glory.
But you and the other forum knowledge fountains have already preempted my questions and saved me the trouble. (I still know nothing mind you).
Every day's a school day. I'm off down a google rabbit hole to learn about rear wheel drive differentials, just incase it ever comes in handy.
And you're right, the knowledge ok this forum is extraordinary, a real gem. I regularly get help with cars, machining, electronics, DIY, and occasionally even history and social topics.
As long as it's a transverse engine - not all are. And some even had both layouts in the range!
dobbslc
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The French are good at this kind of madness...
Misterg
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To reduce noise and vibration, spiral bevel gears are used which are complicated enough. The fun really starts because, to keep the drive train low and avoid a big hump inside the car for the transmission tunnel, the axis of the pinion (and prop-shaft) is usually set below the axis of the back axle, so hypoid bevel gears are needed which have some sliding contact, rather than pure rolling contact, making setup critical if they aren't to wear out in short order.
Smallfry
HE's Spartacus.
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Just to clarify, Spiral bevel gears are on the same axis, whereas with hypoid bevel, the crownwheel and pinion are on a different axis, can be above or below.To reduce noise and vibration, spiral bevel gears are used which are complicated enough. The fun really starts because, to keep the drive train low and avoid a big hump inside the car for the transmission tunnel, the axis of the pinion (and prop-shaft) is usually set below the axis of the back axle, so hypoid bevel gears are needed which have some sliding contact, rather than pure rolling contact, making setup critical if they aren't to wear out in short order.
Spiral bevel will have smaller teeth and produces less friction than hypoid, hence the need for extreme pressure lubricants. Hypoid is also quieter apparently.
There, so information I learned forty odd years ago comes in handy at last
Smallfry
HE's Spartacus.
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Yes of course, but we do like going off at a tangent, and be fair, I didn't start the tangent !And totally irrelevant with a front wheel drive car
On a FWD transverse box like this, clearances are all set by machining of the gears and casing at the factory, so not adjustable, except possibly for endfloat.
Better ?
Thanks for all the input on this one guys, it's all much appreciated and if nothing else, I've learned some new stuff from the posts above.
Just to wrap this one up for the time being. As a quick fix, I've stuck a second hand gearbox in it to get it back on the road. It's £250 for a bearing set, and we managed to get a low mileage used gearbox for £350 delivered. So for the work involved it didn't need much thinking about.
Judging from the sparkly bits in the oil I drained out of the old box, I'd say it's not going to be a pretty sight inside. But when I get time I'll strip it down and have a look to see if it's worth rebuilding as a spare or flogging on.
Just to wrap this one up for the time being. As a quick fix, I've stuck a second hand gearbox in it to get it back on the road. It's £250 for a bearing set, and we managed to get a low mileage used gearbox for £350 delivered. So for the work involved it didn't need much thinking about.
Judging from the sparkly bits in the oil I drained out of the old box, I'd say it's not going to be a pretty sight inside. But when I get time I'll strip it down and have a look to see if it's worth rebuilding as a spare or flogging on.
Just to bring this one full circle in case anyone ever stumbles across the tread looking for similar problems.
Having replaced the gearbox with a second hand unit to get the car back on the road, I've spent the last few days stripping down the old gearbox and rebuilding it. There were a few knowledgeable folk here who said it wouldn't be the diff bearings when I originally asked the question, and they were spot on.
By the time it actually got to being unusable it sounded more like the input shaft bearings, and having stripped it down, that was indeed the case. However, the damage had already been done and from the amount of swarf floating around, and the way all the bearings felt (especially the differential ones) I elected to change all of the bearings, as much as a learning exercise for myself as anything else.
Please accept my bad manners linking to my blog, but if anyone's interested I've done a bit of a write up that may help someone out in the future on the process I used to get the bearings out, etc (https://pperratt.weebly.com/fiesta-st-gearbox-rebuild.html). And for those that aren't interested, there's a few random pictures below to wet your appetite.
The only problem I've got now is that I've got a perfectly serviceable gearbox, that hopefully I'm never going to need, cluttering up the workshop that I'm going to keep on falling over.
Having replaced the gearbox with a second hand unit to get the car back on the road, I've spent the last few days stripping down the old gearbox and rebuilding it. There were a few knowledgeable folk here who said it wouldn't be the diff bearings when I originally asked the question, and they were spot on.
By the time it actually got to being unusable it sounded more like the input shaft bearings, and having stripped it down, that was indeed the case. However, the damage had already been done and from the amount of swarf floating around, and the way all the bearings felt (especially the differential ones) I elected to change all of the bearings, as much as a learning exercise for myself as anything else.
Please accept my bad manners linking to my blog, but if anyone's interested I've done a bit of a write up that may help someone out in the future on the process I used to get the bearings out, etc (https://pperratt.weebly.com/fiesta-st-gearbox-rebuild.html). And for those that aren't interested, there's a few random pictures below to wet your appetite.
The only problem I've got now is that I've got a perfectly serviceable gearbox, that hopefully I'm never going to need, cluttering up the workshop that I'm going to keep on falling over.
