Non synchro reverse gears in various cars

anuragn · 27th October 2007, 13:20

I too face reverse gear problem in my Wagon-R, as frequently as getting heads on flipping a coin. And many Wagon-R users i know also face it.
Yes, best solution is to engage the 1st and then shift to reverse.

Venkatesh.C · 28th October 2007, 03:51

Quote:

Originally Posted by androdev

I doubt it.. as u know, synchro allows you to shift from one gear to any gear irrespective of the RPM match.. while in motion.. this would mean you will actually be able to shift from top-forward gear to reverse gear and go really fast in reverse :-) but as u are not expected to shift into reverse on the fly (while in motion).. the need for reverse synchro is negligible and a good place to cut costs.

reverse not slotting:
the reverse is a straight-cut gear (spline). meshing spline gears requires 'exact' alignment that's why sometimes reverse doesn't slot in unless u somehow change the gear alignments (inch forward in a forward gear, or coast)

While solutions are aplenty and wide, it would be interesting to know Why this happens. Androdev's answer is perhaps the best bet yet unless someone else has a different perspective.

im_srini · 29th October 2007, 11:06

Hi guys, I'm no expert, but as far as I know, reverse gear is implemented in two ways - one, is for an 'idler' gear which is physically moved between the mainshaft & the layshaft gears. Because the idler gear needs to be slotted in between two other gears, the reverse gears are straight cut (this is also why reverse is also noisier than other gears). If the gears involved in reverse are not aligned correctly, shifting into reverse is not possible. The most common solution is to shift to another gear, thus 'jiggling' the gears, & enabling easier shifting.

In the second method, the reverse idler gear is constantly in mesh between the mainshaft & layshaft gears. In this case, the mainshaft reverse gear would be spinning in the opposite direction of the rest of the gears due to the inclusion of the idler. Shifting into reverse is accomplished like in the forward gears - with the help of a collar. I'm not sure, but in a reverse implementation like this, shifting into reverse would be a problem when reverse is engaged without giving time for the collar gears time to spin to a stop... In a reverse implementation like this, wouldn't a synchro slow down the spinning collar gear, making the shift to reverse easier ?

sanchits · 30th October 2007, 22:51

guys, i own a civic, even civic has syncromesh forward gears and not the reverse gear. but, no problem in engaging reverse. most of the cars i've driven did'nt have a syncro reverse gear like accent, alto, 800. currently driving swift and civic. i've experienced problems in the gears only in swift and not in any other car. but the reverse gear problem in swift has become very frustating.

Firebird · 30th October 2007, 23:44

I have a query here, in Palio, there is a reverse gear lock. until u lift it, you will not find the location for reverse.

This I feel somehow works great. In last 1 yr I have not seen any problem in slotting reverse.
i know this is not rocket science. So is it something different.

27th October 2007, 13:20	#16
anuragn BHPian Join Date: May 2007 Location: Navi Mumbai Posts: 192 Thanked: 51 Times	I too face reverse gear problem in my Wagon-R, as frequently as getting heads on flipping a coin. And many Wagon-R users i know also face it. Yes, best solution is to engage the 1st and then shift to reverse.
	() Thanks

29th October 2007, 11:06	#18
im_srini BHPian Join Date: Sep 2006 Location: Portland Posts: 1,010 Thanked: 490 Times View My Garage	Hi guys, I'm no expert, but as far as I know, reverse gear is implemented in two ways - one, is for an 'idler' gear which is physically moved between the mainshaft & the layshaft gears. Because the idler gear needs to be slotted in between two other gears, the reverse gears are straight cut (this is also why reverse is also noisier than other gears). If the gears involved in reverse are not aligned correctly, shifting into reverse is not possible. The most common solution is to shift to another gear, thus 'jiggling' the gears, & enabling easier shifting. In the second method, the reverse idler gear is constantly in mesh between the mainshaft & layshaft gears. In this case, the mainshaft reverse gear would be spinning in the opposite direction of the rest of the gears due to the inclusion of the idler. Shifting into reverse is accomplished like in the forward gears - with the help of a collar. I'm not sure, but in a reverse implementation like this, shifting into reverse would be a problem when reverse is engaged without giving time for the collar gears time to spin to a stop... In a reverse implementation like this, wouldn't a synchro slow down the spinning collar gear, making the shift to reverse easier ?
	() Thanks

30th October 2007, 22:51	#19
sanchits BANNED Join Date: Jul 2006 Location: gurgaon/delhi Posts: 331 Thanked: Once	guys, i own a civic, even civic has syncromesh forward gears and not the reverse gear. but, no problem in engaging reverse. most of the cars i've driven did'nt have a syncro reverse gear like accent, alto, 800. currently driving swift and civic. i've experienced problems in the gears only in swift and not in any other car. but the reverse gear problem in swift has become very frustating.
	() Thanks

30th October 2007, 23:44	#20
Firebird BHPian Join Date: Jul 2005 Location: Mumbai / EC1M 3NH Posts: 470 Thanked: 65 Times View My Garage	I have a query here, in Palio, there is a reverse gear lock. until u lift it, you will not find the location for reverse. This I feel somehow works great. In last 1 yr I have not seen any problem in slotting reverse. i know this is not rocket science. So is it something different.
	() Thanks