Question re VL 6cyl 3.0ltr auto transmission

[burner1963]

Hi all!

I have an '86 VL Berlina, and am on my second gearbox (the car has done about 308,000km, with around 250,000km done at the time of replacing the first transmission).

When I hit around 80km/hr, and the overdrive is engaged, there is a 'rumble' in the transmission, and it is noticeable when I accelerate harder in 4th; it's NOT noticeable at all when I back off the accelerator slightly THEN engage 4th overdrive...

Transmission fluid seems good - clearish and pink, smells ok, not burnt, so I'm assuming that it's sort of ok for the time being. When I engage 4th on a level road, with no real load on the engine or transmission, it just glides along...

I read somewhere that these rumble symptoms are indicative of a possible overdrive clutch slipping (I guess that's a bad thing!). What I want to know, is how much longer I can use this transmission, and what my best options are out of 2nd hand, reconditioned ($1800 apparently!!), or get a new car (but I LOVE my VL!)

Any advice/comments?

Cheers

[jatsvl]

dissconnet the overdrive solenoid on the side of the trans then it will just be a 4spd with NO overdrive. and no more problem.

[burner1963]

But isn't the 4th gear the actual overdrive? I thought that if 4th gear (overdrive) WASN'T engaged, then what you ended up with was a 3spd...

[jatsvl]

the trans is a 4spd with a clutch inside the torque converter (overdrive) the clutch engages at about 70-80ks, when the clutch is stuffed it slips and shudders as you have described above, dissconect the clutch solenoid and you have 4 gears.

[burner1963]

the trans is a 4spd with a clutch inside the torque converter (overdrive) the clutch engages at about 70-80ks, when the clutch is stuffed it slips and shudders as you have described above, dissconect the clutch solenoid and you have 4 gears.

So if the gearbox already HAS 4spd, what does the torque converter clutch actually do? Does it engage a 5th gear?

[jatsvl]

NO, it is always referred to as a 4 spd overdrive unit. the clutch creates positive engagement at higher speeds to reduce fuel consumption.


QUOTE
" the torque converter has a lock up capability operated by a clutch within the converter, when the clutch is applied , the driven member of the torque converter is locked to the driving member creating POSITIVE engagement and when the clutch is released the normal characteristics of the torque converter are used to propel the vehicle, using oil as the driving medium."

first 4 gears drive the vehicle using transfluid,
overdrive locks the trans to the motor to drive the vehicle, you would notice when overdrive activates the revs of the motor drop 1000rpm (positive engagement)


BTW, the PWR button doesn't actually give you more POWER, it cancels out 4th and overdrive and is generally used when towing and/or steep hill climbs.

[burner1963]

Cool, mate - thanks for all the info! Guess I now know why I'm a musician, and not a mechanic...

If I DIDN'T press the power button (thereby NOT engaging overdrive), would that have the same result as disconnecting the torque converter solenoid? Or do I HAVE to disconnect it?

Lastly, when I do 100km/h and have NOT engaged overdrive, it revs at around 3000RPM, instead of around 1900RPM on overdrive. Putiing aside increased fuel consumption, will it damage the engine at all?

Cheers1

NO, it is always referred to as a 4 spd overdrive unit. the clutch creates positive engagement at higher speeds to reduce fuel consumption.


QUOTE
" the torque converter has a lock up capability operated by a clutch within the converter, when the clutch is applied , the driven member of the torque converter is locked to the driving member creating POSITIVE engagement and when the clutch is released the normal characteristics of the torque converter are used to propel the vehicle, using oil as the driving medium."

first 4 gears drive the vehicle using transfluid,
overdrive locks the trans to the motor to drive the vehicle, you would notice when overdrive activates the revs of the motor drop 1000rpm (positive engagement)


BTW, the PWR button doesn't actually give you more POWER, it cancels out 4th and overdrive and is generally used when towing and/or steep hill climbs.

[Panama]

you will be better off disconnecting the overdrive solenoid mate. if you just use the power button, all of the gearbox's shifts will be later and youll spend a lot more fuel. do a search. i think jatsvl posted a picture of which plug to disconnect.

[burner1963]

Thanks for your input! it may be my browser, but I can't see a picture of where the plug is that I have to disconnect... Do you have one?

Cheers

you will be better off disconnecting the overdrive solenoid mate. if you just use the power button, all of the gearbox's shifts will be later and youll spend a lot more fuel. do a search. i think jatsvl posted a picture of which plug to disconnect.

[Panama]

sorry mate i don't. but i think there might be one in the gregory's manual for vl's if you have that.

[jatsvl]

Lastly, when I do 100km/h and have NOT engaged overdrive, it revs at around 3000RPM, instead of around 1900RPM on overdrive. Putiing aside increased fuel consumption, will it damage the engine at all?

Cheers1

no damage will result just extra fuel consumption, and dissconnecting the overdrive allows you to have 4 gears, using the PWR only leaves you three gears and higher revs,

just dissconnect it don't remove it.

[burner1963]

Ok, let's see if I have this right...

From what I read here, it seems that by making sure the PWR button sticks OUT from the handle (and therefore NOT pushed in), I'm actually DISABLING the 4th gear, and that the gearbox is actually a 4spd anyway. But if I disconnect the torque converter solenoid, I'm preventing it from being restricted to 3 spd only. If I am experiencing an problem with the overdrive clutch (in the rumble that I feel in the car), does this disconnection 'cure' the problem by avoiding anything to do with the overdrive clutch?

Being totally inept with this sort of stuff, I'm probably saying some really dumb things... thanks for your patience!

Cheers

no damage will result just extra fuel consumption, and dissconnecting the overdrive allows you to have 4 gears, using the PWR only leaves you three gears and higher revs,

just dissconnect it don't remove it.

[Tree cutter]

The lock up clutch is in the torque converter that connects your engine to the transmission. When you unplug the wire to the lock up clutch it disables the lock up clutch so the torque converter works like an old school torque converter. You will still have all four gears in your trans. Overdrive is the front part of your trans which is fourth gear.

[jatsvl]

Ok, let's see if I have this right...

From what I read here, it seems that by making sure the PWR button sticks OUT from the handle (and therefore NOT pushed in), I'm actually DISABLING the 4th gear, and that the gearbox is actually a 4spd anyway. But if I disconnect the torque converter solenoid, I'm preventing it from being restricted to 3 spd only. If I am experiencing an problem with the overdrive clutch (in the rumble that I feel in the car), does this disconnection 'cure' the problem by avoiding anything to do with the overdrive clutch?
Cheers

YES! and you can still use the pwr if/when you need to.

[88-SERIES200]

hey man i think i have the same problem (although it may be related to one of my vl's other problems) around the same speed that you said when the box shifts up to 4th. as soon as it goes into overdrive (or 4th) theres a rough shudder like the back wheels have run over several small pot holes in a row. and other times it only goes thud once. if anyone knows what this could be that would be great..

[Panama]

that noise means that your gearbox's torque convertor lockup clutch is cactused.. it means buying a new torque convertor afaik and you're better sourcing a whole new box. (2nd hand is fine)

[88-SERIES200]

****in car.. takes up all my money. i have a rebuilt mf5 box in the shed. i think i might just do the conversion sooner rather than later. could it be axel tramp?

[jatsvl]

if it was the axle you would expect it to do it through all changes, generally if it happens at the overdrive shift would suggest it is the lock up clutch slipping.
if you have a manual to chuck in it what are you waiting for ? they are WAY BETTER.