VY Adventra LS1 - RWD manual conversion

[jimmyd17]

Hey guys,

I'm wanting to convert my AWD Adventra LS1 to rear wheel drive only. I would like to do a manual RWD conversion using a T56 box and run a conventional RWD commodore setup (getting rid of all the AWD stuff).

OR

I am considering keeping the 4L60E auto box, and converting the current transmission setup to RWD only. Does anyone know if it is possible to remove the AWD extension housing from the 4L60E (which accepts the transfer case), and simply bolt on a normal RWD extension housing? Is the output shaft the same?

I've searched everywhere and am struggling to come up with any definitive answers. Any help would be appreciated.

Cheers,
James


PS: For anyone wondering WHY i would want to do this....
A) because my LS1 has much more power than stock which caused my front diff to get a horrible clunk
B) I don't want just another broken diff or transfer case (expensive repairs)
C) because a normal commodore wagon doesn't have enough ground clearance for my needs, so no i'm not going to sell it and just buy an SS wagon or something
D) its not a propper 4WD anyway, so while the AWD is good, its not essential for my needs. RWD would be sufficient to get most places
E) better fuel consumption

[IJ.]

4L60 Output shafts are different 2wd V's AWD

[jimmyd17]

thanks IJ. thats the info i was after. :) Looks like a manual conversion might be a better option as i don't really fancy pulling the auto apart. either that or just replace the front diff and hope it holds up to ~600nm/~320kw.

[vy2ttr]

Talk to steve from mainlube. his awd adv was putting out massive power (530 awkws from memory), he had no trouble with transfer case, not sure about diff but.

[Gmfan]

Also maybe contact member called IJ? He converted a monaro to awd using donor parts from an adventra. There is a thread in the my ride section called 'project Y'.

[edelbrock1]

To convert to 2WD, it would be easier to just swap out the gearbox for a normal one. As there is a lot of work in changing the shafts in the gearbox to get rid of the AWD transfer case. So just pull the gearbox and put a 2WD one in.
But then this would require unpicking the AWD gearbox mounts and welding in the 2WD ones. As luck would have it, I have an unpicked one left over from the AWD conversion that was done on my Monaro.
Then you would have to remove the front diff and drive shafts. No sure in this, but that is probably an engine out job. I guess you could leave them there, but why lug around all that extra weight if your not using it.
Then there is the electrics, there is a massive amount of wiring to make the cross track work. I think that making the thing 2WD would trip it all right out as it would have no idea what was going on. It would still be trying to engage cross trac. It may all work no problem, but I have my doubts.

Would be so much easier to sell it and buy another wagon and raise it to the required height.

[IJ.]

Can't just bolt a 2wd Trans in as the LHS Crossmember mount doesn't exist in an AWD Chassis so would have to be fabricated and fitted, Front Axles and Diff are easily enough removed, you would need to pop the axles out of the front CV joints gutt them them bolt the Stubs back in as they keep the front wheel bearing assembly together.

I'm not sure the electronics are going to cause an issue as the front wheel speed can never exceed the rear so the CrossTrac system will neve kick in on the front.

Nothing insurmountable converting it to RWD.

I'm a bit confused that it's eating the front drive components as I have 2x Crosstrack cars one being much higher output than yours and no sign of Stress in the Transfer Case or Front Diff!

[XUV]

sounds like a headache to me ,
do a swap for a manual v8 wagon and get king springs or the like to do a set of raised front springs and bag the back

[jimmyd17]

IJ - thanks for the valuable info! i just crawled under the car and yes you are correct, the LHS crossmember mount is non-existent. looks like the shape of the floor is slightly different compared to a RWD chassis to accommodate the transfer case where the front shaft is. that looks like the biggest challenge of doing a RWD conversion.

that is interesting your transfer case and front diff are holding up okay. perhaps i'm just unlucky. only 72,000km on the clock. very shortly after i did the cam swap (mild cam for max low down torque) the driveline clunking started. i thought it was the transfer case, because the was a big clunking slop in the front shaft when i moved it by hand, but then i removed the front shaft and the clunk is in the front diff, not the transfer case. maybe its from launching the car too hard which i only did a couple of times. it produces crazy torque just off idle. 0-100 in under 5.5 secs. it could be the sudden stress of moving 2 tonnes off the line with lots of initial torque? what cam are you running, NA or FI?

maybe i'd be better off to just throw another diff at it and hope for the best, but i wasn't confident i wouldn't just destroy another diff hence wanting to go RWD.

edelbrock1 - thanks for your input there, much appreciated! :) yes i think engine out would be the way to go and change to a RWD sump. wouldn't want to drag around the extra weight. as for the crosstrac system, to my way of thinking i would imagine the TC would kick in on the rear wheels only, and the system shouldn't even realise there is no drive going to the front wheels, so it just wouldn't kick in on the front wheels. but you're probably right, there could be some unknown electrical pain in the butt problem to solve that i can't think of right now. it'd be too easy otherwise lol.

XUV - yes starting to sound like a headache to me too. i tend to like your thinking at the moment. haven't decided which way to go yet.

thanks again guys.

cheers,
James

[edelbrock1]

There are some guys out there running massive HP in these cars with both Turbo and blown systems. The front diff does not seem to give any troubles. The gearbox is the weak point in these cars. That is why it is a surprise that yours is playing up. Are you sure it is the diff and not the CV joints at the diff?

[Toddler78]

To add to the above Steve from mainlube has had massive power and torque from his adventurer without issue with the front end of the drive train ad that is also launching hard at the track the only issue he was having is with the actual trans itself which has now Ben swapped out to a truck version ( can't remember the actual model number off hand) I can't see you having issues with it NA.

[IJ.]

James, Floors are the same you'd either need to fabricate a mount or cut one out of a donor car at the wreckers, if you have a look at the Project Y thread you can see the mount you need that I removed from the Monaro when I did the opposite of what you're proposing, my faster car is 402Ci/FI, the front Diff has 70K Km's so close in age to yours.

My Adventra has 245K Km's and the front axles needed to be replaced recently as the inner Tripods were totally shagged along with the front CV on the front shaft but that's an age thing and not power as it's 100% stock.

As I said if you're serious about converting it there's not really anything stopping you, I'd be happy to give advice if needed.

[IJ.]

This one is MIA on your car.

http://www.ls1.com.au/forum/attachment.php?attachmentid=2135&d=1367985841

[Micks]

This one is MIA on your car.

http://www.ls1.com.au/forum/attachment.php?attachmentid=2135&d=1367985841

I hope you stick around Boyo..Cause in my book your better than Wally Lewis!

[jimmyd17]

that is interesting. maybe it is a CV joint then. i just felt the clunk when i turned the diff flange by hand. what happens when driving the car is it has a big jolt/clunk sometimes when coasting down from say 60km/h, or sometimes reapplying a small throttle % at low speed after coasting. it never clunks putting it in or out of gear when stationary.

just uploaded a quick video to youtube of me turning the diff flange by hand with the front shaft removed. i'm not sure if the video conveys this, but i could feel a clicking as i turned it clockwise just before it stops (the front wheels were on the ground).

http://www.youtube.com/watch?v=KhJRS5XjtRo&feature=youtu.be

James

[IJ.]

The Front Diff uses a Rear type gear set that runs Upside down, it's never going to feel smooth turning it by hand..

Just watched the Vid, looks about the same as my 2 cars and the Monaro I just completed, they seem to run a LOT of backlash, my "Clunk" in the Adventra was as mentioned the Tripod ends of the Axles, jack it up put it in neutral and see if the inner end of the axle has up/down play.

[jimmyd17]

ahh i see. i'll jack it up tomorrow and check the axle movement. thanks!

[chocco]

that is interesting. maybe it is a CV joint then. i just felt the clunk when i turned the diff flange by hand. what happens when driving the car is it has a big jolt/clunk sometimes when coasting down from say 60km/h, or sometimes reapplying a small throttle % at low speed after coasting. it never clunks putting it in or out of gear when stationary.

just uploaded a quick video to youtube of me turning the diff flange by hand with the front shaft removed. i'm not sure if the video conveys this, but i could feel a clicking as i turned it clockwise just before it stops (the front wheels were on the ground).

http://www.youtube.com/watch?v=KhJRS5XjtRo&feature=youtu.be


James


My clunking might be different to yours but,,,,,,,,

Mine does it as well, I got rid of most of it when I went to DEX 6, could be a coincedence, but is definetly better, would always do it on DEX3. Was also worse when once warmed up and not cold.

Coasting into roundabouts, in and out of corners, then hitting the throttle, doesnt worry me as its pretty much gone now. I have few roundabouts where I live so was always a good test.


Cheers

[jimmyd17]

hey chocco, ahhhh yours might be the same as mine. got me thinking. i think i serviced the auto and put dex3 at the same time i did the cam! i thought dex3 was the correct fluid for the 4L60E.... hmmmm.

[chocco]

hey chocco, ahhhh yours might be the same as mine. got me thinking. i think i serviced the auto and put dex3 at the same time i did the cam! i thought dex3 was the correct fluid for the 4L60E.... hmmmm.

It is the correct fluid at the time it was made, when they stopped making DEX3 its replacement was DEX6 which is backward compatible with DEX3 and in the USA where they continued to run the 4l60/65 they used DEX6 as standard after DEX3 was stopped.

I just use the AC Delco semi-synth not Castrol full synth, the auto loves it.

Cheers

[jimmyd17]

It is the correct fluid at the time it was made, when they stopped making DEX3 its replacement was DEX6 which is backward compatible with DEX3 and in the USA where they continued to run the 4l60/65 they used DEX6 as standard after DEX3 was stopped.

I just use the AC Delco semi-synth not Castrol full synth, the auto loves it.

Cheers

thanks for that. i might drop the fluid and try DEX6 and see if that makes and difference. still chasing my tail trying to get to the bottom of this driveline clunk. i've wondered if its transmission, tcc, transfer case, front diff, axles and still scratching my head. if its as simple as the auto fluid, then this RWD manual conversion might not happen which i have mixed feelings about. sad that i might not get a manual box which would be much nicer to drive, but happy if i don't have to pull another car to bits lol.

[chocco]

thanks for that. i might drop the fluid and try DEX6 and see if that makes and difference. still chasing my tail trying to get to the bottom of this driveline clunk. i've wondered if its transmission, tcc, transfer case, front diff, axles and still scratching my head. if its as simple as the auto fluid, then this RWD manual conversion might not happen which i have mixed feelings about. sad that i might not get a manual box which would be much nicer to drive, but happy if i don't have to pull another car to bits lol.

Check ur cv joints first as per IJ if they look good and you dont mind dropping ur fluid give it a go, worked for me.

[jimmyd17]

Check ur cv joints first as per IJ if they look good and you dont mind dropping ur fluid give it a go, worked for me.

cheers, will do

[jimmyd17]

The Front Diff uses a Rear type gear set that runs Upside down, it's never going to feel smooth turning it by hand..

Just watched the Vid, looks about the same as my 2 cars and the Monaro I just completed, they seem to run a LOT of backlash, my "Clunk" in the Adventra was as mentioned the Tripod ends of the Axles, jack it up put it in neutral and see if the inner end of the axle has up/down play.

IJ - the inner end of the passenger side driveshaft does seem to have some up/down movement. i'm not sure if that is normal or not. here is a vid of the movement.
http://www.youtube.com/watch?v=UdyrCfO6m4U&feature=youtu.be

[IJ.]

IJ - the inner end of the passenger side driveshaft does seem to have some up/down movement. i'm not sure if that is normal or not. here is a vid of the movement.
http://www.youtube.com/watch?v=UdyrCfO6m4U&feature=youtu.be
You're more looking for movement/clunking of the Axle to the Part that's moving in the Vid James, but having said that it's an excessive amount of movement in the stub, has the Diff got Oil in it?

[Blown 454 AWD]

Just ring me and I'll tell you what you want to know! 0412-644-244 day time

The last thing I'd be doing is making it 2WD, 4WD is what makes the Adventra is so unique

And none of you could break the AWD or the diffs with the power your capable of, we're easily over 1000 hp with no problems.

Cheers

Steve

[XUV]

And none of you could break the AWD or the diffs with the power your capable of, we're easily over 1000 hp with no problems.

Cheers

Steve
Good to know.

But, I think someone read that as a challenge and just bolted a bottle of NOS to the tonner's tray ;)

[jimmyd17]

You're more looking for movement/clunking of the Axle to the Part that's moving in the Vid James, but having said that it's an excessive amount of movement in the stub, has the Diff got Oil in it?

thanks IJ. there isn't much movement in actual the inner axle joint on either side. i just checked the diff oil and it is low. (had to stick my finger down an inch in the fill hole before i felt any oil). car was level. could that cause the driveline clunking?

[jimmyd17]

Just ring me and I'll tell you what you want to know! 0412-644-244 day time

The last thing I'd be doing is making it 2WD, 4WD is what makes the Adventra is so unique

And none of you could break the AWD or the diffs with the power your capable of, we're easily over 1000 hp with no problems.

Cheers

Steve


Thanks Steve. That is good to know that the AWD components are strong. I was making the incorrect assumption that the transfer case and diff were weak points behind a tickled LS1. I am now reconsidering leaving it alone if the transfer case and diff are up to the task. one of the reasons i want to do a manual RWD conversion, is freedom to put whatever rear diff ratio i want. i would like to go taller to a 3.07 LSD with a 6 speed to be able to cruise at ~1300rpm @ 100km/h in 6th to increase the range of the small fuel tank for long trips. unfortunately, i can't change the front diff ratio, so i'm stuck with 3.46:1.

[vy2ttr]

Hey Steve, Is your beast finally finished ? What power did it end up making ?
Cheers, Josh

[IJ.]

thanks IJ. there isn't much movement in actual the inner axle joint on either side. i just checked the diff oil and it is low. (had to stick my finger down an inch in the fill hole before i felt any oil). car was level. could that cause the driveline clunking?
It won't be helping James, dump the old Oil out and get some heavy synthetic in there, I run the Penrite Pro Gear 80W-140 in mine.

[jimmyd17]

It won't be helping James, dump the old Oil out and get some heavy synthetic in there, I run the Penrite Pro Gear 80W-140 in mine.

will do, i'll grab some tomorrow. i presume same oil for the rear diff while i'm at it?

[IJ.]

will do, i'll grab some tomorrow. i presume same oil for the rear diff while i'm at it?

Yep I run it both ends, I have a Harrop TrueTrac in the rear makes a HUGE difference to how well the CrossTrac system works! :)

[XUV]

will do, i'll grab some tomorrow. i presume same oil for the rear diff while i'm at it?

check ya transfer case too , as they hold fukall, 150ml and you can run the same diff oil

[jimmyd17]

check ya transfer case too , as they hold fukall, 150ml and you can run the same diff oil

i read somewhere that the transfer case requires the holden stuff only? not sure why. i found an unopened 2.5L container of penrite hypoid 80w90 in the shed that i forgot i had. i'm assuming that will do for front and rear diff seeing as i have it already. might not be enough though.

[XUV]

i read somewhere that the transfer case requires the holden stuff only? .

well , mainlube Steve said

Thanks for the inquiry

Diffs hold a little under 2 litres, I can top our 2 litre tins up to the top, this would ensure enough left over for the transfer.


Mainlube 154 75w140 x 2 litre tin is $......

( I can't believe that was 3 years ago, I will get around to doing the diffs and transfer case , one day steve, I should order the stuff before spring)

[jimmyd17]

Yep I run it both ends, I have a Harrop TrueTrac in the rear makes a HUGE difference to how well the CrossTrac system works! :)

The harrop truetrac sounds pretty awesome. is it straight forward to bolt the centre into the adventra diff?

[IJ.]

The harrop truetrac sounds pretty awesome. is it straight forward to bolt the centre into the adventra diff?
Takes some special tools but it's not Rocket Science, having said that I had mine done by an "Expert" and it whines it's brains out on trailing throttle so I have another here I'll do myself.. ;)

[Blown 454 AWD]

Sonny fitted the TrueTrac to my Adventra, absolutely perfect,

you have to know what you're doing here or you will get a whining diff.

Cheers

Steve

[IJ.]

Did my Diff guy a disservice, turns out it was pinion angle when I converted to IRS in the Tonner ;)