Monaro gearbox

[mfp4073]

Just a couple of quick questions on the T56 as fitted to Monaro's.
For those of you that have had them rebuilt, do they now shift from gear to gear smoother without balking or having that bloody awful (slight) crunching noise as the gears start to mesh? and can they be rebuilt to a tighter tolerance, so you can reduce the (PIA) huge amount of back lash from the output shaft?

Regards John

[007 VXR]

Some have had work done to improve it, hope to be fitting one in mine next year

Have you spoken to Roger at Monkfish?

[KMud]

mfp4073 said:

Just a couple of quick questions on the T56 as fitted to Monaro's.
For those of you that have had them rebuilt, do they now shift from gear to gear smoother without balking or having that bloody awful (slight) crunching noise as the gears start to mesh? and can they be rebuilt to a tighter tolerance, so you can reduce the (PIA) huge amount of back lash from the output shaft?

Regards John

Mine's not rebuilt, but it doesn't crunch (more of a mechanical 'thunk' as it's driven home, but then it is a heavy box). Have you experienced multiple t56s? What oil are you using?

A couple of days ago I did the 'anti venom mod', which if you haven't come across it is basically shimming the shifting detent. I've only fitted a single washer, but this removes most of the resistance you feel moving across the gate...you may well be right about perceiving lash, but it can be hard to isolate exactly what you're feeling...so cheap to try and I'm a fan of the new, less notchy, feel.

[mfp4073]

TBH, I'm hoping the gearbox will last a while yet, the car will be off the road in October. (I expect its past redemption anyway)
My ultimate plan is to get the gearbox built up to a... way better than new standard.
I want to be able to change gear without the usual cringe factor! i.e get rid of crunching noise and sort out the back lash. These two issues are spoiling the whole damn car.
Now obviously to get the job done right it's going to cost.....
Any ideas how much a professional rebuild would cost?
I did consider saving for a brand new box, but I suspect it will probably be just as crap as the original one anyway...unless they have improved the build quality of course?
Before I forget.
I have been using Royal Purple oil for a few years, and I have driven a couple of other Monaro's, but it was such along time ago I cannot remember the shift quality of the gearbox.

Regards john

[stevieturbo]

mfp4073 said:

Just a couple of quick questions on the T56 as fitted to Monaro's.
For those of you that have had them rebuilt, do they now shift from gear to gear smoother without balking or having that bloody awful (slight) crunching noise as the gears start to mesh? and can they be rebuilt to a tighter tolerance, so you can reduce the (PIA) huge amount of back lash from the output shaft?

Regards John

Oil can sometimes make a good difference.

Whether a rebuild will help, really depends how bad your current one is. There should never be any crunching regardless.

And if the problems are bad, they could be clutch related....so rebuilding the box to any spec wont fix the shifting problem.

And most lash you're feeling will be from the rear diff, not the box.

[mfp4073]

stevieturbo said:

Oil can sometimes make a good difference.

Whether a rebuild will help, really depends how bad your current one is. There should never be any crunching regardless.

And if the problems are bad, they could be clutch related....so rebuilding the box to any spec wont fix the shifting problem.

And most lash you're feeling will be from the rear diff, not the box.

I had the diff rebuilt last year and fitted a truetrac. The car had a large amount of back lash both before and after fitment. So I then checked the propshaft and that seems in order. If I turn the prop by hand, it clunks big time from the gearbox.
I sometimes wonder if the pilot bearing has worn and damaged the gearbox.

regards John

regards john

[mfp4073]

I forgot to mention I don't hammer the car, and I have never considered the clutch might be part of the problem? but you never Know. The clutch fluid is always clean.

regards john

[stevieturbo]

There isnt really anything in the box that can clunk as you describe, the gears are always in constant mesh so unless there was serious gear wear, there simply wont be any lash worth talking about, at least not enough to ever make loud noises.
And if gear wear was that bad, it'd be screaming its tits off.

If you're rotating the propshaft and feeling lash/clunks, it will be the diff. And fairly normal at that too.

what gear was it in, if any when you say you heard or felt this clunk/lash ?

[VinceM]

Whilst I am no expert here, I think it might be worth either trying another Monaro and/or asking another Monaro owner to drive yours to get a second opinion before paying out a load of cash for the 'box. Last thing you want is to pay out the money for no real 'perceived' improvement.

[V88Dicky]

You're welcome to drive mine John. After all, they're identical and rolled off the production line the same month

[raving]

Prob diff backlash & put factory oil in for a start

[mfp4073]

stevieturbo said:

There isnt really anything in the box that can clunk as you describe, the gears are always in constant mesh so unless there was serious gear wear, there simply wont be any lash worth talking about, at least not enough to ever make loud noises.
And if gear wear was that bad, it'd be screaming its tits off.

If you're rotating the propshaft and feeling lash/clunks, it will be the diff. And fairly normal at that too.

what gear was it in, if any when you say you heard or felt this clunk/lash ?

The clunk happens in all gears even reverse. The box itself is not particularly noisy and it is not a screamer!
I think it will be better to check out another Monaro before I start pulling the car to bit's!!!!!
I think I will take up your offer V88Dicky if thats OK.
Raving sorry to ask but what brand of oil would you suggest?

Thanks again John

[stevieturbo]

mfp4073 said:

The clunk happens in all gears even reverse. The box itself is not particularly noisy and it is not a screamer!
I think it will be better to check out another Monaro before I start pulling the car to bit's!!!!!
I think I will take up your offer V88Dicky if thats OK.
Raving sorry to ask but what brand of oil would you suggest?

Thanks again John

Nothing in the description sounds like a gearbox problem.

[V88Dicky]

mfp4073 said:

The clunk happens in all gears even reverse. The box itself is not particularly noisy and it is not a screamer!
I think it will be better to check out another Monaro before I start pulling the car to bit's!!!!!
I think I will take up your offer V88Dicky if thats OK.
Raving sorry to ask but what brand of oil would you suggest?

Thanks again John

No probs John

[anonymous-user]

I'd start by looking at the clutch. The slave cylinder doesn't move much on these so there's a risk that it's not fully disengaged and dirty/old fluid makes it worse. I have an LS9 clutch and slave in mine which has extra movement and I couldn't believe the difference it made when it was first fitted. No wrestling with the box and you can change gear with 2 fingers it's that light.

[mfp4073]

wormus said:

I'd start by looking at the clutch. The slave cylinder doesn't move much on these so there's a risk that it's not fully disengaged and dirty/old fluid makes it worse. I have an LS9 clutch and slave in mine which has extra movement and I couldn't believe the difference it made when it was first fitted. No wrestling with the box and you can change gear with 2 fingers it's that light.

Thanks Wormus,
I plan to fit the LS9 in the future as I'm still running the factory set up at the moment.

regards John

[anonymous-user]

mfp4073 said:

Thanks Wormus,
I plan to fit the LS9 in the future as I'm still running the factory set up at the moment.

regards John

Bear in mind the LS9 clutch is not a straight swap. It requires a bigger VXR8 bell housing and some fabrication to make the gear stick fit the transmission tunnel. Also needs a spacer on the back of the the engine and a different length input shaft. If your current clutch can handle the power, try replacing the clutch fluid, you may find it makes the world of difference.

[KMud]

LS1 to LS7 is a straight swap, and also a noticeable improvement (although new for old usually is!).

[mfp4073]

OK, so it looks like the LS7 clutch and all the extras that need doing at the same time, is a straight swap. That sounds like the way to go.

Thanks all John

[mfp4073]

I forgot about this old thread...I had a new clutch fitted, and the gearbox is now way better.
I must admit I would never had put the clutch at fault since I don't hammer the car,and it had less than 60000 on the clock. But it was worn and never came close to actually slipping.. so there you go!

Johm