Venom: H6 Gen2 Liberty GX

Venom · Post by **Venom** » Sun Apr 26, 2015 9:58 am

Short answer, no. The cusco will come out, and either just go straight into a stock SF gearbox with the DCCD or I'll fit it all into an SG casing with the stronger gears. I see no point rebuilding the early gen gearset.

NachaLuva · Post by **NachaLuva** » Sun Apr 26, 2015 10:03 am

I would build an SG box, stronger gears, much nicer syncro, better all round!

YouTube · Post by **El_Freddo** » Sun Apr 26, 2015 2:03 pm

Well mate I hope this is a step in the right direction to resolving the jerking problem!

I'm looking forward to seeing you cruising with a smile on your dial rather than having a frown everything you look at it!

Cheers

Bennie

NachaLuva · Post by **NachaLuva** » Mon Apr 27, 2015 11:27 am

El_Freddo wrote: I'm looking forward to seeing you cruising with a smile on your dial rather than having a frown everything you look at it!

Turn that frown upside down! hahaha

vincentvega · Post by **vincentvega** » Mon Apr 27, 2015 4:43 pm

sounds like you may have pulled the box out for no reason? first gear whine is a factory feature of these early boxes. they all do it. especially when you give it a few revs.

my current rear diff is an early VLSD center thrown into a 3.9 open housing. Backlash is at the higher end of factory specs and i get a metallic clunk when on and off the throttle. it was especialy noticeable when i didnt have the center console in and had a hole in the floor. now i just crank the stereo and don't hear it

i can drive around the backlash but my wife finds it jerky. Yours must be worse by the sound of it.

vincentvega · Post by **vincentvega** » Mon Apr 27, 2015 4:46 pm

Just a thought - have you replaced your rear diff bushes with urethane or similar? the firmer bushes might be making the symptoms worse?

Venom · Post by **Venom** » Mon Apr 27, 2015 5:03 pm

Yes and yes VV, the urethane bushes did make it harsher and changed the feel which helped narrow it down to the diff itself. I have been 'driving around' the issue for many month, now at the point that is impossible. As i understamd it seems unlikely the pinion/crown wheel has worn that much. Maybe a failed diff bearing has loosened it all up?

First gear was definitely rooted, had a head turning howl.

pezimm · Post by **pezimm** » Mon Apr 27, 2015 8:04 pm

In order to narrow down the issue and eliminate the suspect offending component, couldn't you remove/disconnect your tail-shaft and lock your centre DCCD to do a test drive in FWD??

If the problem is gone, you'll know it's in that diff somehow... Many reasons for your backlash to be high besides worn crown-pinion. Maybe a shim dislodged, maybe it wasn't set up right to start with, tension nut loose, bearing collapse, list goes on.

It certainly sounds like you're getting to the bottom of it!

Pedro.

Venom · Post by **Venom** » Tue Apr 28, 2015 12:54 pm

SF forester gearbox in there at the moment, so DCCD is on the garage floor. Another part of the reason fkr fiting an SF box was to convert to a hydraulic clutch so i get some more clamping pressure with a stock clutch kit. Plus the clutch cable was too short with a body lift Sounds like a bit of a bearing noise from the rear.

DCCD will go onto stock Foz box when the KAAZ is at home in a healthy diff and it can all go in together.

taza · Post by **taza** » Tue Apr 28, 2015 4:32 pm

Great to see we are in the same boat with this jerky-ness..
My SF has a very similar issue which makes the car unbearable to drive in traffic. I do not remember it always being there and have changed pretty much everything under the body. I'm now at the point of giving up and flogging the car off.

AndrewT · Post by **AndrewT** » Tue Apr 28, 2015 6:02 pm

May as well throw in my experience along the same lines. I've had this issue plaguing me in my L series for so many years and maybe it too is related to rear diff. Trouble is, it's followed me despite replacing all related parts, including the entire car!

Not too much bunny-hopping, but perhaps I am sub consciously driving around it. More what I have is a growling/grinding noise, accompanied by a bit of vibrating "in tune" with the noise when coasting along with minimal load. Ie, just cruising. It sounds like it's coming from around the rear of the gearbox, or the tailshaft at that end.
Nothing on decelleration, and nothing on hard accelleration, but just cruising or very lightly accellerating, it's there. It's worse the higher the gear - not really there in 1st, but quite noticable in 4th / 5th.
There is also a noticeable *ping* noise when I take up slack in the driveline - like put my foot down a bit in 3rd or 4th.

Used to do it in Monsterwagon (when it was AWD and also when it was RWD - tried two different rear diffs with no difference).
It also used to do it in my RX turbo (which was AWD) and actually did it at the same time as running Monsterwagon too.

Now I've built an entirely different L series wagon, with completely different gearbox, different tailshaft (brand spanking new one), but used the rear diff I used to run in old Monsterwagon - noise is still there! Follows me around like a bad smell.

Reading this thread makes me think perhaps it's excessive backlash in the rear diff, combined with crappy old driveshafts. The driveshafts don't click but do seem to have slack in them.

NachaLuva · Post by **NachaLuva** » Tue Apr 28, 2015 6:36 pm

AndrewT, yours could be the tailshaft centre bearing. Mine had that at certain speeds, esp around 80-100kmh. It got worse when I put my first lift kit in. I noticed the tailshaft wasn't straight at the bearing so I shortened the blocks by 10mm. Still there but better.

Mine also has that "ping" as the driveline takes up the slack.

Back to the jerkiness on take off. After my poor little Foz sat idling in water (gearbox fully immersed) I noticed it had gone. It's come back now, which makes me think it's a buildup of friction plate material. This is also one of the common theories that gets thrown around Subaru forums.

At the time I joked I should stick a hose in to wash it out but now I might try it! In the meantime, I drive around it by using more reviews as I release the clutch, above 2000rpm

vincentvega · Post by **vincentvega** » Wed Apr 29, 2015 9:08 pm

we all drive old cars with lots of kms that have had a reasonably hard life.

the subaru drivetrain is complicated. when you think about the number of components / joints from the motor to the wheel, its not surprising that we all notice some slop.

a little bit of wear in each joint adds up to a lot when you put all the parts together.

vincentvega · Post by **vincentvega** » Wed Apr 29, 2015 9:09 pm

There is one solution I know of. a torque converter!

I never noticed all the slop until i fitted the manual box. Its handy having a shock absorber in your drivetrain.

Venom · Post by **Venom** » Sat May 02, 2015 9:37 pm

So we had the car running on the hoist before swapping out for a stock rear diff. Guess what? Left rear driveshaft was bent like a fking banana. Backlash on rear diff was spot on, still going to pull it apart for inspection.

Car is now driving like a dream. Front right shaft is also a little bent. So, now i know what the problem is i can keep an eye out for it. And look for an alternative if it is reoccurring.

pezimm · Post by **pezimm** » Sat May 02, 2015 9:52 pm

Yay! This is great news!!!!

I'm glad the saga is over and the H6 beast can once again put a smile on your face!

Pedro.

YouTube · Post by **El_Freddo** » Sat May 02, 2015 10:06 pm

bent drive shafts? Interesting but I don't understand how these could possibly create the shuddering issues you've been experiencing.

I can understand at speed with an oscillating vibration as the shafts change speeds around corners and line up in harmony or out of sync. I've had this on Ruby Scoo, VERY annoying!!

Cheers

Bennie

NachaLuva · Post by **NachaLuva** » Sat May 02, 2015 11:33 pm

Damn! Wonder how you bent the driveshafts...too much H6 torque perhaps

:p

Very glad you got it sorted & wasnt that lovely KAAZ diff!

AndrewT · Post by **AndrewT** » Sun May 03, 2015 10:30 pm

wow that is absolutely awesome news! I think I'll get my car up on jack stands, running in gear and have a really close look at my shafts!

vincentvega · Post by **vincentvega** » Mon May 04, 2015 10:15 am

I don't understand how that could be the problem either.

everything you have described has sounded like driveline slop. Bent shafts will give a vibration regardless of throttle.

Did you put a straight edge on them? you have seriously bent a solid steel ~20mm shaft? Never heard of that before - but that doesn't mean it is not possible!

Could be that your joints are stuffed, making the shaft appear bent when on the hoist?