T5 Shift Enhancers

[azzfox]

Hey all, finally got around to giving the VN a propper test drive after being converted to manual. It all runs sweet, but the gears are a bit hard to shift. Its mainly 1st and 2nd, then 3rd onwards is less noticeable.

It has fresh Penrite Dexron III but I remember hearing something about an additive people use along with the ATF. I tried a quick search but as you all know the search function is pretty useless lol.

It could be worn syncros (hope not), but its all gears so hoping its just a fluid issue. Its not a shift mechanism issue because it shifts smoothly with the clutch in and input shaft stopped.

Cheers.

[immortality]

the additive is lubrizol (629 i think)

[greenfoam]

How do you mean hard to shift, crunchy? or just needs a bit of power to move around ? the T5 isn't really a girly gearbox it needs a decent effort

[azzfox]

Just needs a bit of force to synchronize the gears, like the syncros dont have enough friction would be a good way to describe it. Might have to teach myself to double clutch . But no way is it crunchy, or makes any noises really - which is a good sign.

Ill have to give the additive a go anyway. Thanks immortality!

[azzfox]

LZ 7906 - Penrite Oil

Bingo!

Also, I read that pre-VR should use gear oil and that it works fine. But arent all BW T5's used in commodores the same? Apart from V6 and V8 differences of course. I know that my box is a WC, and that WC's apparently need an ATF. But also read that using an ATF will cause premature wear due to being alot thinner, but gear oil can also cause premature wear. Bah! So confusing!

Going to try this lubrizol anyway. Seems people think it makes a noticeable difference.

[Morton]

ATF is good for the synchros, and not fantastic for the WC needle bearings. Gear oil is fantastic for the bearings, and less good for the synchros.

Try gear oil with added lubrizol Both bases covered.

[azzfox]

Ah makes sense. But in the data sheet for that lubrizol it states its for 93-95 commodores, obviously VR. And not designed for use with gear oil. Dang lol. What could have been so different about the VR T5's?

May as well just give lubrizol a go seeing the box is full of fresh ATF, then on next oil change Ill give gear oil a go. If it doesnt work out then I know I can always fall back on ATF + lubrizol (if it works ).

Morton: What do you use exactly? And how do you find it works?

[delcowizzid]

is you clutch cable adjusted enough it may just need a little more pull amasing what an extra 1 or 2 mm will do.

[azzfox]

The clutch pedal sits just a tiny bit higher than the brake pedal. I first had it level with the brake pedal but it diddnt feel right. All I know now is that theres enough travel to completely release the clutch plate - when the cars idling on the spot and you press the clutch pedal in you can faintly hear the gearbox slow down, and then doesnt grind when selecting reverse.

Havnt been bothered to set it properly but it seems fine where it is at the moment, but the fork pivot ball height is set spot on and the fork isnt bent.

[delcowizzid]

how far from the floor does it start to grab when you let it out 1 cm or so.sometimes ATF is good when the syncros wear out it gets them closer to the tapers so they grab better a thicker oil holds them off the taper further and lets them spin more which helps line up the gears for a smooth change.what did the box have in it before hand did it smell like horrible gearoil or ATF.did you just stick 2 litres in or fill till it just starts running out the bung on the side of the box.

[azzfox]

Cant really say, maybe half way? I bought the box still full of gear oil. Possibly because the wreckers diddnt have the correct hex key to remove the drain plug. I dont blame them - I had to modify an old 10mm hex key. I filled the box until it started to run out the filler hole with the car level.

[delcowizzid]

if it had gear oil ide go back to gear oil the syncros are probably to close on the tapers not spinning enough.does it change down gears better than up.if the clutch is high ide adjust it down a bit and make sure it has freeplay at the top of its travel or you could wear the plate quick if its too tight

[azzfox]

It was slightly easier to downshift, no doubt because its not having to slow the input/lay shaft from a high RPM. Clutch pedal has free play, but it might be worth adjusting it properly with a tape measure even just to see how far off I was. Hmm now considering going back to gear oil.

[delcowizzid]

save the trans fluid and for minimum outlay it would be worth trying the gearbox oil instead if it doesnt work out you can allways put the ATF back in later

[azzfox]

True that! Cheers for the help.

[kniever]

in my bro's old vr on the 1st oil change we put gear oil and the box absolutely felt like shit so a few days later we changed it to atf and lubrizol and the difference was amazing, so much smoother and quieter to drive.

when i did my conversion i put atf and lubrizol and the box feels beautiful, nice easy shifts and it is quiet so i will never be changing to anything else. just put in lubrizol and you will love it but the hardest part is tracking it down, took a week to get a tube cos no one stocks it

[maldotcom2]

Hmm, never heard of using ATF in manuals. Might help with my crunching of 2nd gear when cold.

[Chirpstr]

So with the pre VR T5's ATF is ok instead of Gear Oil which is recommend?

[Morton]

Hmm, never heard of using ATF in manuals. Might help with my crunching of 2nd gear when cold.

It's almost essential, unless you use Castrol VMX 80 which is specifically designed for gearboxes that require ATF.

[greenfoam]

So with the pre VR T5's ATF is ok instead of Gear Oil which is recommend?

The T5 is supposed to use ATF

[maldotcom2]

From Haynes workshop manual:

VN, VP and early VR models = 75W/80 oil
Later VR and VS models = Dextron IID, IIE or III ATF with 150ml of lubrizol

From Gregories workshop manual (VS only):

Series 1 manual transmission:
Lubricant = dextron III and 150ml of lubrizol 7906

Series 2 manual transmission:
Lubricant = 75W - 85W gear oil

I think the series 1 VS was the T5 and series 2 was the getrag. There seems to be a bit of confusion here, If VN through to series 1 VS used the T5, does it require gear oil or ATF?

[azzfox]

Something obviously changed around the VR era. Because I have never ever seen a VN/P workshop manual suggest using an ATF. We have books at tafe of vehicle oil listings straight from the oil manufacturers and they also say to use gear oil for VN. Diddnt think to look at later models because I just assumed all commodore T5's were the same. My Gregorys manual for VP says to use "Shell gear oil XGO 75/90". But I may give Penrite gear oil 80 a shot.

MANUAL GEAR OIL 80 - Penrite Oil

Another quick thought - my box came from a VN S1, which had gear oil in it when I bought it, so it must be ok to use because there obviously wasnt a need to swap to something else.

[maldotcom2]

Seems Lubrizol 7906 is ridiculously hard to find. Most of the auto shops i visited hadn't heard of it. Only one had, and they last had it in stock 8 years ago. LOL! C'mon is there an alternative i'm not aware of?

[kniever]

i looked around a bit too for some and most said they couldnt get it, went to repco and they said they just sold thier last tube and refused to order some in so went autobarn and they were right onto it took them a week but they got it and they stocked up too for me for next time

[maldotcom2]

Got tired of chasing up the lubrizol so i just got G70 and chucked that in with the ATF. So much smoother than the gear oil, no more crunching 2nd. Happy chappy.