Gearbox troubles

[SpaceYam]

Interesting, I didn't realise the T56 has synchro on reverse.

But, if it works to put it in another gear then into reverse, it's not really a big deal You'd have reason to worry if it wasn't going in at all.

 

[mouseno4]

I just go in to 1st then reverse in all my cars heard some **** about it slows the syncros down or some bs but it works for me. Also check the clutch master hows the fluid looking?.

Actually, for my very first service whilst the car is in my possession, i specifically asked the mechanic to replace ALL liquids (not fuel) within the car with what it is meant to have. This means coolant, oil, fluid, the works. All genuine and designed for the car. I considered it a ''clean slate'' for my car since i did not know what the previous owner had used - best to just remove it and replace it completely to start from scratch.

The T56 HAS SYNCROMESH on REVERSE GEAR

The reverse idler gear is in constant mesh with the counter gear extension and the reverse gear, splined to the
mainshaft. When reverse gear is engaged, the reverse synchromesh ring engages the reverse constant mesh gear,

Has the oil been replaced with a NON COMPLIANT heavy weight oil ???????

REVERSE LOCKOUT MECHANISM
The transmission is also fitted with a reverse
lockout solenoid assembly that prevents the
selection of reverse gear, above road speeds of 8
km/h. Above this speed, the Powertrain Control
Module (PCM), causes the solenoid plunger (1) to
block the movement of the spring loaded, reverse
lockout plunger (2) (See view ‘B, next).
When activated, the rear offset lever (3) is blocked
from rotating to the reverse selection

Yeah that makes little sense to me as its not something i can understand. But as i said in reply to the first quote, i replaced all liquids in the car with ones designed for the car. The proper oils, the proper coolant, the proper fluids, everything. Wanted to be sure all fluids were correct and proper. Right now, i KNOW the oil in the car is what the car is designed to have and that grants me great comfort knowing. Perhaps it does not mean much to you guys as you know a lot more than i do, but knowing as little as i do, i just use what i know is designed for the car as i cant go wrong with that regardless how much more it costs.

 

[CONROD]

Hi mouseno4,
there,s nothing wrong with asking if you don't know, its better than thinking you know and cause more damage.
That's a good start changing all fluids :beer chug:

Sorry the pictures didn't come down with the extracts of the reverse lockout solenoid, but that's more or less only to prevent you from selecting reverse above a predetermined speed.
When you stop, prior to selecting reverse, try slipping it in neutral, clutch out let it spin the cluster, push clutch back in, wait a couple of seconds, then try reverse.

Make positive moves, you should feel it push against the spring loaded detents.

When you are in reverse and moving the gear lever back out to say neutral, does it slip out with ease or can you feel it binding, should be able to move it in and out with the tip of ya fingers.

When you had all the fluids replaced did they actually flush both the clutch (master and slave) cylinder ?
Just draining and changing the fluid in the reservoir from up top using a syringe might look pretty but think about all the **** and moisture trapped down in the master cylinder and slave cylinder, ( out of sight, out of mind ) if they are not equipped with the right tool to get into that prick of a bleeder chances are they wont attempt it!! and mate that's all it might be, it could have a gutful of air caught up in the line, sure it might make its way to the top eventually, a slight drop in fluid level would indicate this together with some of the old black **** fluid making its way to the top.
When I had all my fluids flushed and replaced I got an extended bleeder put in at the same time ( only about $25 from memory)

Sorry for raving on, when you pull your floor mat back and stick your head up into the foot well ( under the dash) where your pedal box is can you feel or see any brake fluid ? :blah blah:


Cheers bud,
CONROD

 

[mouseno4]

Hi mouseno4,
there,s nothing wrong with asking if you don't know, its better than thinking you know and cause more damage.
That's a good start changing all fluids :beer chug:

Sorry the pictures didn't come down with the extracts of the reverse lockout solenoid, but that's more or less only to prevent you from selecting reverse above a predetermined speed.
When you stop, prior to selecting reverse, try slipping it in neutral, clutch out let it spin the cluster, push clutch back in, wait a couple of seconds, then try reverse.

Make positive moves, you should feel it push against the spring loaded detents.

When you are in reverse and moving the gear lever back out to say neutral, does it slip out with ease or can you feel it binding, should be able to move it in and out with the tip of ya fingers.

When you had all the fluids replaced did they actually flush both the clutch (master and slave) cylinder ?
Just draining and changing the fluid in the reservoir from up top using a syringe might look pretty but think about all the **** and moisture trapped down in the master cylinder and slave cylinder, ( out of sight, out of mind ) if they are not equipped with the right tool to get into that prick of a bleeder chances are they wont attempt it!! and mate that's all it might be, it could have a gutful of air caught up in the line, sure it might make its way to the top eventually, a slight drop in fluid level would indicate this together with some of the old black **** fluid making its way to the top.
When I had all my fluids flushed and replaced I got an extended bleeder put in at the same time ( only about $25 from memory)

Sorry for raving on, when you pull your floor mat back and stick your head up into the foot well ( under the dash) where your pedal box is can you feel or see any brake fluid ? :blah blah:


Cheers bud,
CONROD

Trying to translate that into something i can understand.

When reverse is engaged, i can disengage it with the tip of my pinky it is that easy. Not easy enough that it can slip out on its own or from a bump of my arm or hand of course. But easy enough that it feels no different than any other gear.

This ''flush'' i dont quite understand. The service was performed a few weeks ago by a local mechanic so there is no point going and asking him whether he ''flushed'' the liquid out or not. Besides, i refuse to go back to him after what he pulled. But that is a story for another time though so i wont get into that.

I will have a look in the car under the dash on the drivers side to check for any liquids. The car didnt come with mats so there is no need to remove them! (incidentally, the mechanic mentioned a very small oil leak at the bottom of the engine - which i can confirm with my own eyes on the left side of the engine - not enough to worry about, but enough to soak up with a towel - likely the leak is what is mentioned here:http://www.phoenixmechanical.com.au/pages/vx_commodore_engine.html)

Back on topic - The reason i ask this is because my parents own an Astra that every so often has a complete and full block out of the gears - all of them. Inexplicably, i go from whatever gear i am currently in and attempt to enter the next and something completely blocks the gear shift preventing ANY gear from being engaged. I have to release the clutch in neutral completely before going back to flat-to-the-floor to make another attempt. All the while the car is losing speed. The second attempt does go in, but with some resistance. My car is not like this, but i would prefer it not get to this stage in the first place.

 

[RMartin]

I changed my own gearbox oil the other day the T56 has a separate filling hole for reverse gear. where the wire for the reverse light is, acts as the filling plug as well, careful how you take it off. takes approx..500mls..smooth as gear change..hope it helps

 

[Jxfwsf]

I changed my own gearbox oil the other day the T56 has a separate filling hole for reverse gear. where the wire for the reverse light is, acts as the filling plug as well, careful how you take it off. takes approx..500mls..smooth as gear change..hope it helps

There is no extra fill point........

1-1-3. APPROVED LUBRICANT. Most T56
transmission models use Dexron II automatic
transmission fluid. Refer to the vehicle owner’s manual or
service manual for lubricant specifications.

CAUTION
Do not mix different brands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T56
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.

1-1-4. CHECKING LUBRICANT LEVEL. Proceed as
follows:

NOTE
To check or drain the lubricant, the transmission
should be warm. This is best done shortly after
engine shutdown.
a. Wipe fill plug (2) and surrounding area clean.
b. Remove fill plug (2).
c. When transmission is full, lubricant will just drip out fill
plug opening.
d. Add approved lubricant if required.
e. Install fill plug (2) and torque to 20 lb. ft (27 N.m.)

http://www.gforcetransmissions.com/pdfs/t56manual.pdf

 

[BlackVXGTS]

From GM Service Techlines December 1999 on checking the transmission lubricant level. Note that if you were draining the whole transmission you would first remove the drain plug, drain the transmission, then replace the drain plug, take out the filler plug, fill to the correct level and then continue as in item (3) below:

2.2 CHECKING TRANSMISSION LUBRICANT LEVEL
Important: This transmission is classified as being a “Fill for Life” transmission and checking the lubricant level is not recommended.

The only time that fluid level checking would be appropriate, would be after correction of a fluid leak that did not require the transmission to be fully drained and/or removed from the vehicle.
1. Raise the vehicle front and rear and support on safety stands, ensuring that the vehicle is level. Refer to Section 0A GENERAL INFORMATION in Volume 1 of this Service Manual, for the location of jacking points.
2. Place a drain tray beneath transmission and remove transmission filler plug from left hand side of transmission case, using a 3/8” drive socket bar.
NOTE: Depending on the severity of the loss, fluid will probably flow from the filler plug hole, following removal.
3. Allow excess fluid to drain until flow stops. If required, top up fluid level until it does flow out.
4. Clean the threads of the filler plug, apply thread sealant such as Loctite 565 or equivalent (GM P/N 12346004), then reinstall filler plug, tightening to the correct torque specification. Do not apply Teflon thread tape to the plug threads.
TRANSMISSION FILLER PLUG 20 - 34 TORQUE SPECIFICATION Nm
5. Remove the back-up lamp switch.
6. Using commercially available fluid dispensing equipment, add a measured, 0.5 litres of the recommended lubricant to the transmission, via the back-up lamp switch threaded hole in the transmission case.
7. Reinstall the back-up lamp switch, then lower the vehicle to the ground.

 

[Jxfwsf]

So because it's "fill for life" and they don't check it, overfill for caution.....

Frequently Asked Questions (FAQs)

Q: Why use automatic transmission fluid in a manual gearbox?

A: Automatic transmission fluids provide the necessary protection and lubrication, while still allowing the synchronizer to function at its best.



Q: Why not use a synthetic fluid?

A: Some brands of synthetic fluid contain powerful detergents and additives that can prove harmful to your transmission's synchronizers. While many synthetic fluids perform very well, in most cases, we do not recommend their use. Furthermore, they may void your warranty. For peace of mind, remember that TREMEC conducts all of its OEM validation testing using conventional fluids without issue.



Q: Why not use gear oil in one of your transmissions?

A: A hypoid gear oil by design does not allow mechanical surfaces to make contact with one another. A synchronizer relies on friction (much like your car's brakes) to do its job. Thus, gear oil in a synchronized transmission can be a bad combination, potentially causing a variety of shift quality issues. Furthermore, many gear oils contain sulfur additives that can damage friction materials.