When I first got the Sigma and joined this (Previous) site I read a lot about how weak the Sigma gearbox's were. People were actaully breaking cluster gears by shutting the driver door to hard
So first on my list of many spares for the wagon was a spare gearbox. Anyway all these years later and my origonal gearbox is still performing faultlessly, so my reco is still just hanging around the shed
Now the reason for the post. The box has never had oil in it .Only the lube that it was assembled with . Almost to nerve racking to take the bottom cover and have a look. Anybody want to have a guess at what I will find.
Was recod in 2002 so I wasnt sure what to expect. I might stick some oil in it and spin it occasionally, becasuse is will probably sit for another 7 years before I need it
Dam Jap boxes, cant break em and they never wear out
NO There is such a thing as having sympathy for the machanicals. Anybody can break something. Doesnt take a lot of skill to break a diff or a gearbox. Even P platers can do it, so it doesnt need any special ability.
But to drive to the limit of the machanicals takes skill and knowledge. To push the machanicals to ten/tenths when you know eleven /tenths will break a component.
Now I am not saying I have this ability, but boy it felt good as I typed this reply.
karl_2ltgc wrote:
If you havnt broken a box it means several things
1. You dont have enough power
2. You dont have enough grip
Sigmaproject wrote:NO There is such a thing as having sympathy for the machanicals. Anybody can break something. Doesnt take a lot of skill to break a diff or a gearbox. Even P platers can do it, so it doesnt need any special ability.
But to drive to the limit of the machanicals takes skill and knowledge. To push the machanicals to ten/tenths when you know eleven /tenths will break a component.
Now I am not saying I have this ability, but boy it felt good as I typed this reply.
strangly enough the only gear box that I had break anything was I sheared an output shaft
on a jap 5 speed 2 Lt box ( the box is now apart for a rebuild the 3rd gear sincro ring also broke ) that only happened because a diff broke while doing 7000 in second about to pull 3rd
on a hillclimb
my car has been a logbooked race car for 10 years this year and atm I have a boagwarner
5 speed in there its done an OLT day and 2 sprint meets and a few laps at my last circuit race
and you know karl I still haven't pulled the gear shift out
maybe I haven't got enough hp or the tyres dont have enough grip
karl_2ltgc wrote:
maybe I haven't got enough hp or the tyres dont have enough grip
Maybe you dont
Its more a +t thing i think though. I know glen has busted a few boxes but hes got a t66 or somethin with 220kw+.
The box in my car now is a MINT narrow block 5speed. Came out of a galant(was converted from 4 speed) so its spent most of its life behind a 2ltr, then the rest behind a 1600! Now its got 135rwkw.... But I am very sympathetic to it, hasnt done stuff all mile or even any track days yet though. I'm even a little worried about putting race rubber on it. Not just for the box but for the welded scorpian diff....
i believe its all down to clutch and drivers sympathy.
ive put my 2l jap box through about 30,000 km of punishment. 15k of that with 220kw, the only thing thats worn now is the input shaft bearing (whining a little) and the 2nd/3rd syncros need a little more love on each change than they used to.
as far as snapping stuff goes, and from my experience with glass subaru 5speeds, its mainly the clutch and driving style that will destroy teeth.
use a full face clutch and you should be alright, get a snappy puk or button clutch and expect to be shearing teeth as the shock load is MUCH higher when your being rough. ive got a 2400lb clutch with full face plate and its loved life so far. even the many many times ive clutched it off the launch controll (5500rpm) in 2nd or 3rd to start having fun ;) not a nice thing to the drivetrain when i think about it, but its fun
Billsy wrote:i believe its all down to clutch and drivers sympathy.
ive put my 2l jap box through about 30,000 km of punishment. 15k of that with 220kw, the only thing thats worn now is the input shaft bearing (whining a little) and the 2nd/3rd syncros need a little more love on each change than they used to.
and you know the input bearing is the same on the 2 Lt and the wide box including a starion
some thing I'm trying on my big shaft narrow box is using 2 synchronizer springs on each side of the hub instead of one
I'm hoping to put a bit more load on the synchro keys and in turn push the synchro rings a little harder onto there seats
I'll report on my results the gear box is reassembled like this
id be very interested to hear how it goes, this box is in need of some new syncros and bearings. if theres any worthwhile mods while its apart then ill do that aswell.
out of interest, how much bigger are the internals on the wide jap box? is it just the shafts or the gears aswell?
Billsy wrote:id be very interested to hear how it goes, this box is in need of some new syncros and bearings. if theres any worthwhile mods while its apart then ill do that aswell.
out of interest, how much bigger are the internals on the wide jap box? is it just the shafts or the gears aswell?
its the same - the same gears/synros/bearings everything
except the input has a smaller spline so has the out put and the spiget bearing between them is slitely smaller
. Almost to nerve racking to take the bottom cover and have a look. Anybody want to have a guess at what I will find. 
and alloy corrosion 
No insects or corrosion 
There is such a thing as having sympathy for the machanicals. Anybody can break something. Doesnt take a lot of skill to break a diff or a gearbox. Even P platers can do it, so it doesnt need any special ability. 
