Reverse Gear?

Alkers

New driver hear (not a learning to drive question), just got a bit of bother with the car (03 Fiesta). We always park in the driveway by driving in forwards, hence having to reverse out (quiet road). When starting the car from cold and putting it into reverse there is an audible grind as the car finds the gear but other than that it is fine. During normal driving there is nothing wrong with the car at all.
Then tonight I was coming out of a car park when the car was warm and the car would not engage into reverse gear at all. I de-clutched and tried again several times but to no avail. After a couple of minutes, during which I put it into first briefly to see if it would move forwards (which it did), it eventually engaged reverse as per normal (no noise) and was fine again.
Any ideas as to what might be causing this? I've got my driving test on the 29th (currently driving legally on my 2nd provisional) so I don't want to have this problem getting into gear during the reverse around a corner or on the turnabout.
Thanks

crosstownk

Check for silly things like a floor mat restricting clutch pedal travel. Also make sure that the engine speed is at idle before engaging reverse. Selecting reverse is different to selecting forward gears in that reverse does tend to 'crash' to some extent due to no syncromesh.

littlejukka

It would be worth making a habit of reversing into your driveway and carpark spaces, then driving out. it's good practise for the test and will help your coordination, use of mirrors and general car control.

if reverse grinds during the test, don't panic. just let the engine down to idle and try again.

Potential-Monke

Mine does the same, won't go into reverse first. I always put mine into first and then into reverse and it works everytime then. It's getting annoying thorugh, cuz now i'm insured to drive any car and other peple are looking at me when i driver theirs as if i've two heads when i do the first/reverse thing out of habit...

mthd

my parents escort had this problem for ages, clutch cable just needed tightening

Alkers

Thanks for the replies, theres definitely nothing blocking the pedal anyway. The problem I had to day was starting the car from being parked but the car was warm and had been only switched off for less than five minutes.
It was definitely idle also, it was just a problem getting the car into gear. Once I had the gearstick in the correct position, letting the clutch up didn't cause the car to move at all.
It's not really that it grinds as such, more of a clunk as reverse is engaged. If this happens during the test it's no problem, I just don't know what I'll do if like today it takes a few minutes to get the car to actually go backwards!
Thanks mthd, I think I'll have to drop it into the garage tomorrow.

crosstownk

Most cars are little noisier when selecting reverse. Put the clutch pedal the whole way to the floor, wait a few seconds and then firmly put the lever into reverse.

JHMEG

Sounds like there's no syncromesh on reverse gear. Not uncommon, especially in a car of that size and age. You unknowingly performed the cure when it won't go into reverse: put it in a forward gear first (some work better than others, usually 2nd in my experience).

biko

littlejukka wrote: »

It would be worth making a habit of reversing into your driveway and carpark spaces, then driving out. it's good practise for the test and will help your coordination, use of mirrors and general car control.

Good advice right there. I do this a lot and it's a much safer way of exiting your driveway or a parking space.

APM

exact same problem with 06' focus. I found that putting it into 1st and then into reverse eliminates the grinding noise. Found it very embarrasing at first in carparks etc after I got the car

crosstownk

JHMEG wrote: »

Sounds like there's no syncromesh on reverse gear.

Is it possible to have synchromesh with reverse? It sounds unlikely given the introduction of the 'idler' gear - reverse is never in constant mesh. Remember also that reverse uses spur gears rather than bevel gears, so it is more likely that selecting reverse will cause an initial 'crash'.

JHMEG

crosstownk wrote: »

Is it possible to have synchromesh with reverse? It sounds unlikely given the introduction of the 'idler' gear - reverse is never in constant mesh. Remember also that reverse uses spur gears rather than bevel gears, so it is more likely that selecting reverse will cause an initial 'crash'.

I bow to your superior knowledge of gearboxes! Newer cars don't "crunch" going into reverse, or lock the driver out of reverse requiring selection of a forward gear first to unlock. I was told when this first appeared on mainstream cars (by a mechanic) that it was because there was syncromesh on reverse in newer cars.

crosstownk

I'm intrigued about synchromeshes for reverse - it is possible, but it seems like a lot of work and engineering just to get rid of a slight crunch. The difficulty with reverse is that it introduces an idler to 'reverse' the gearbox direction - so constant mesh is much more complicated - but not impossible.

Reverse
The previous discussion applies to the forward gears. The implementation of the reverse gear is usually different, implemented in the following way to reduce the cost of the transmission. Reverse is also a pair of gears: one gear on the countershaft and one on the output shaft. However, whereas all the forward gears are always meshed together, there is a gap between the reverse gears. Moreover, they are both attached to their shafts: neither one rotates freely about the shaft. What happens when reverse is selected is that a small gear, called an idler gear or reverse idler, is slid between them. The idler has teeth which mesh with both gears, and thus it couples these gears together and reverses the direction of rotation without changing the gear ratio.
Thus, in other words, when reverse gear is selected, in fact it is actual gear teeth that are being meshed, with no aid from a synchronization mechanism. For this reason, the output shaft must not be rotating when reverse is selected: the car must be stopped. In order that reverse can be selected without grinding even if the input shaft is spinning inertially, there may be a mechanism to stop the input shaft from spinning. The driver brings the vehicle to a stop, and selects reverse. As that selection is made, some mechanism in the transmission stops the input shaft. Both gears are stopped and the idler can be inserted between them. There is a clear description of such a mechanism in the Honda Civic 1996-1998 Service Manual, which refers to it as a "noise reduction system":
Whenever the clutch pedal is depressed to shift into reverse, the mainshaft continues to rotate because of its inertia. The resulting speed difference between mainshaft and reverse idler gear produces gear noise [grinding]. The reverse gear noise reduction system employs a cam plate which was added to the reverse shift holder. When shifting into reverse, the 5th/reverse shift piece, connected to the shift lever, rotates the cam plate. This causes the 5th synchro set to stop the rotating mainshaft. (13-4)
A reverse gear implemented this way makes a loud whining sound, which is not heard in the forward gears. The teeth on the forward gears of consumer automobiles are helically cut. When helical gears rotate, their teeth slide together, which results in quiet operation. In spite of all forward gears being always meshed, they do not make a sound that can be easily heard above the engine noise. By contrast, reverse gears are spur gears, meaning that they have straight teeth, in order to allow for the sliding engagement of the idler, which would not be possible with helical gears. The teeth of spur gears clatter together when the gears spin, generating a characteristic whine.
It is clear that the spur gear design of reverse gear represents some compromises—less robust, unsynchronized engagement and loud noise—which are acceptable due to the relatively small amount of driving that takes place in reverse. However, many modern transmissions now include a reverse gear synchronizer and helical gearing.

Source = http://en.wikipedia.org/wiki/Manual_transmission#Synchronized_transmission

So it looks like synchromesh is becoming more common with reverse in modern cars - but unlikely in a 2003 Fiesta.

zilog_jones

Is going into reverse while still moving forward really bad for the gearbox? I admit I did this a few times, and very bad noises occurred Also sometimes when reversing it seems to "slip out", i.e. there's a fcuking loud thud and it's suddenly in neutral again. Probably my fault...

Alkers

That's not what I did, I just went forward a small bit, stopped, then I was able to engage reverse properly. I'll post up here when I hear back from the garage anyways.

msg11

I have a fiesta, This sounds like a problem with your fluid. Try topping the fluid up.

As, if you engage the clutch try to put it in reverse and it fails to go in while making a loud noise (grinding), You peddle may not be engaging the clutch properly because of the low levels. I would ask recommend that you bleed the system.

MercMad

Yes you may need to have the system bled and topped up but can you try to start the car with you foot on the clutch. That should prevent the 'box from turning and make it easier to select reverse, though I have found that the lever will resist that last little bit until you lift the clutch a fraction !

barryfitz

Mine does the same, 95 corolla. Sometimes i have to engage first gear, move a couple of Centimetres, then engage reverse. Sometimes all i have to do is let the handbrake off, and the smallest bit of movement and then I can get it into reverse. Its just that the gear cogs arent properly aligned. no biggy.

meathstevie

Could be a bit of trouble with gear linkage that needs a bit of thightening or replacing..if it's that at all don't worry it's not all that expensive

TestTransmission

ive got a fiesta (01) with the same issue,no need to go into 1st and then reverse,just simply pump the clutch once or twice then engage reverse.

Alkers

Still haven't got time to go to the garage yet but I had another problem today.
After reversing, I could not get the car out of reverse. The gear stick was stuck in reverse position. I turned the car off, moved the gear stick, put it back in reverse and restarted the car and it was fine again.
Would this change anything?

crosstownk

Sounds like a clutch problem.

mthd

Simona1986 wrote: »

Still haven't got time to go to the garage yet but I had another problem today.
After reversing, I could not get the car out of reverse. The gear stick was stuck in reverse position. I turned the car off, moved the gear stick, put it back in reverse and restarted the car and it was fine again.
Would this change anything?

I still say clutch cable