6l80e - drive shaft problems rectified
 

I have just updated my Gallery to indicate where we are with the build. Hopefully, Sideshow will have it running next week then it's off to the paint shop then the trimmers then engineering.

As you are probably aware, I have a brand new 6 speed 6L80E Tiptronic Auto fitted behind a new LS2 crate engine. This combination is entirely unique in a Cobra build and required the expertise of a few brilliant people to make it work. The main problems which we encountered were:-

* Getting the transmission computer to talk to the ECU.
(3 cheers for Jimmy I hope. We'll see next week, fingers crossed).

* Adapting the new drive shaft to fit into the 6L80E transmission.
(Neil Streeting and Metropolitan Drive Shafts in Granville NSW solved this expensive problem).

The main shaft through the transmission required shortening and a special yoke had to be constructed to fit into the housing at the rear of the gearbox. A new drive shaft was then constructed which contains a lubricated sliding flange. I have taken a few photos of this setup. I just hope that it works as good as it looks.


http://www.clubcobra.com/photopost/d...ine_Small_.jpg
About 1" had to be removed from the Gearbox Main Spline.


http://www.clubcobra.com/photopost/d...oke_Small_.jpg
The special Yoke to fit into transmission.


http://www.clubcobra.com/photopost/d...aft_Small_.jpg
The new Drive Shaft.


http://www.clubcobra.com/photopost/d...box_Small_.jpg
The new Yoke fitted to the transmission.


http://www.clubcobra.com/photopost/d...oke_Small_.jpg
The new tailshaft fitted to the modified yoke.


http://www.clubcobra.com/photopost/d...iff_Small_.jpg
The lot bolted up to the diff. Hope it works.

Baz,
It is always a good feeling when the solution for a problem is sorted out and ticked off the to do list. As you said, "expensive problem", why is there never a cheap soulution to a problem.

Good luck with your ECU and gearbox computer next week.

Warren

I have no idea how it works, but it looks good! As Warren said it must be a relief to sort out a big problem that usually stops you dead. Hope it works just the way you expect it to when you get it going.

Regards.

This is how my driveshaft was fabricated, with an adapter yoke each end and standard driveshaft components in between. Worked like a dream. Best of luck

Martin

Nice piece of engineering Baz.

Having no slip joint in the back of the gearbox makes life difficult. This looks like a good solution.

Good to see some nice progress shots. We need more project updates on here. They make for interesting reading.

Cheers

Baz,
I too enjoyed the perils of getting a 4L60E to work in my car.
The drive shaft in mine was not as painful as what your looks to have been though.
I had alot of trouble initially getting my auto to select first and shift properly, there was a couple of wires that where floating around in the loom that had been associated with the body module and not the PCM.
The LS2 may however be different.
If you have any auto related fault codes drop me a line and I can tell you what I did with mine.
Works great now though, you won't be dissapointed!

Baz

Remind us what your issue was. It's a nice piece of engineering but I'm not sure what drove your problem.

Just curious.

I guess I'm also now waiting to see what length difference there is between my new TKO600 and the old T5 box in terms of my driveshaft too!!

Cheers

Steve

Thanks for your interest Steve,

The situation with the 6L80E Tiptronic is that it has a really short yoke. The original yoke has a tapered flange which fits precisely over taper on the main gearbox shaft. I couldn't use the original yoke or flexible rubber coupling because of the difference between the angle which exists between the diff and the rear oif the gearbox. The original yoke could only be used if the angle was 1 degree or less, otherwise the power that will be transmitted through this system in my Cobra would rip the coupling to pieces. The actual angle between the diff and the rear of the transmission on my car is about 15 degrees.

In my other car, which is a current model HSV Grange and it is fitted with the same engine and gearbox as my Cobra:- An LS2 307 kw V8 and 6L80E Tiptronic transmission, the slip yoke slides up and down the shaft as the diff and gearbox are in perfect alignment. Unfortunately, this is not the case with the Cobra. The gearbox and diff aren't in alignment.

To overcome this problem, Metropolitan Drive Shafts constructed the hydraulic ram on the tail shaft to compensate for the required movement under acceleration.

Hope this explains the situation adequately.

Baz.

Thanks Gav,

Hopefully Sideshow has it all worked out. He is quite confident in the final result. Thanks for the offer. I will contact you if I need more help.

Baz

Mike,

I have a full history on my Gallery, from start to current. There should also be an update in Kit Car Magazine in the next issue.

Thanks for your interest.

Baz.

Thanks Baz the explanation hits the spot. Obviously you like the engine transmission in the daily driver to copy it!!

I'm a tad happier now as I dropped more gear off to Marty as part of my rebuild and he has freed the binding TKO.

The gearbox had quite obviously been shunted forward in transit as a neat hole had been punched through the front of the heavy cardboard box it was in. The residual cardboard was stuck inside the hole in the front of the input shaft.

Anyway it turns now in all gears and I'll hope it was just a minor bind. Next step to fit box to engine.

Keep at it Baz.

Cheers

Just like the RMC there's a few close tolerances there around the tunnel frame. I fixed this by removing the original and fitting a round frame to clear all the bits. I tried to insert a pic but failed...I will try again