Difference between pre post auto gearbox

[Guest]

As title .I haven't seen any posts about differences between the 2 boxes but when I tested keith's(my brother) gearbox ecu in my car it also would not drive in 1st gear as what keith's car is doing at the moment. Fine in tip though. This implies there must be a difference and it may be that we need to fit a pre facelift ecu to Keith's car. I'll have to pull my one out again to test this.
The gearbox in keith's car now is a prefacelift

Anybody running a facelift gearbox ecu in a prefacelift??

 

[bradc]

I do know that at some point the gearboxes received a one way clutch, the gearbox will have owc stamped on it. Perhaps it is related to that change? Can you remember seeing owc on it anywhere?

 

[Guest]

I do know that at some point the gearboxes received a one way clutch, the gearbox will have owc stamped on it. Perhaps it is related to that change? Can you remember seeing owc on it anywhere?

Off hand I can't remember Brad but I'll try my ecu in at the weekend to see if that eliminates the problem without checking solenoids again. If that is all that is wrong that will save a lot of work . I'll go and have a look to see if the box that came out has owc on it.

 

[Guest]

Swapped in my pre facelift ecu tonight and the gearbox is working in drive though the changes are rough though I expect they'll soon improve.
Therefore you need a matching ecu if you change between a box with or without OWC (one way clutch)

 

[snickells]

Go team! More fodder for the impending vr4-wiki.

 

[Guest]

Does anyone know for certain when the OWC was introduced, or where can can find the signifying marking on the housing?

 

[Guest]

OWC is stamped next to the oil filter and from around 99 onwards

 

[Guest]

Cheers, so next to the blanked off non-existent oil filter on facelifts.

The later boxes didn't have an external filter, as I found out after purchasing one from Mitsubishi and wondering where the heck I was supposed to fit it.

 

[Guest]

Yes but the facelift we have still has the external filter

 

[Guest]

The part numbe rfor the OWC box was available from 97 onwards but going by the threads on CVR4 it does seem to be from facelifts onwards

 

[Guest]

Yes but the facelift we have still has the external filter

Interesting, I wonder why. Actually, I also wonder why they removed it.

I'll have a peek at my transmission and see if I can get a decent photo of the marking.

 

[Guest]

I have one sitting here

 

[Guest]

Some more pics to help you determine if you have the OWC.

 

[godzilla]

I noticed when looking at mine tonight that i have an "OWC" stamped transmission, without a filter next to it and on my 04/98 PFL . Is this normal? In Peter's pic it shows an OWC & filter and in another it shows an un-filtered OWC, in a Facelift. I am confused (As usual)

Do we know what the function of the one way clutch is?

 

[Guest]

The OWC acts like a freewheel and helps take stress off the engine. I wonder if the change could account for the pre & post facelift auto power output difference?

 

[bradc]

I doubt it, that would only be when decelerating.

There is a difference in boost between pre and post facelift, that is the most likely cause of the power difference.

Some facelift auto's have a larger intake manifold and a matching 64mm throttle body compared to the normal 60mm throttle. I don't think this makes any extra power but probably helps with throttle response.

 

[xtech]

I know its a old thread bump but I Found this explanation of the OWC

When the transmission is in Drive and sitting still, the driveset is engaged via the underdrive clutch. The holding systems engaged are the Low-Reverse Brake and the One-Way clutch.

The OWC is only used for normal driving in first gear an almost doubles the load capacity of the 1st gear. The Low-Reverse Brake is also used to soften the engagement of first gear, the TCU is programmed to disengage the Low-Reverse Brake at low speed (roughly between 6 and 12mph typically) when first gear is fully in motion and it is no longer needed. When this happens, full power is delegated to the One-Way clutch for forward motion in First. So 1st gear is the -only- gear that uses the OWC
The most common cause of failure of the OWC is Neutral dropping the transmission (Revving high then dropping the shifter into gear) or dropping into Drive while still Reversing (not coming to a complete stop in reverse before shifting to drive), however they can fail during normal operation... it just isn't as common.

The OWC is just a ring with a series of 'dogs' that extend out when it rotates in one direction to lock it, in the other direction the dogs collapse. When in first gear, the assembly rotates in the direction that extends the dogs, locking the assembly to the housing. When the OWC is exposed to high shocks, engaging at high rpm or engaging while still in slow reverse motion (shifting R to D before fully stopped), these dogs eventually break off, allowing the assembly to freespin in the housing once the Low-Reverse Brake is released at 6-12mph.