T-56 AWD (not the usual questions)

[AKToast]

I've been collecting parts for a V8/T-56/AWD project for a couple years and am trying to resolve a few loose ends.

I'd like opinions on the best way to create an input yoke for a remote mounted BW4472 (a 1350 u-joint connected to a 27 spline shaft). And who is the most likely to be able and willing to build such a thing?

How important is having a CV joint in the propshaft? I'm starting from a 4x4 so I don't have one and I'd rather not add one unless it prevents handling issues or significant vibrations.

Is anyone running belltech leafs w/o the overload springs? Any adverse effect?

Thanks for any input,
Ralph

 

[myclone]

Re: T-56 AWD (not the usual questions)

I'd like opinions on the best way to create an input yoke for a remote mounted BW4472 (a 1350 u-joint connected to a 27 spline shaft). And who is the most likely to be able and willing to build such a thing?

A divorced xfer case seems like a huge PIA to me (not that mating a t56 and an xfer case is any less of a PIA) as well as one more U joint to explode under abuse. Theres already a guy on here who had the tail section of a t56 modded to allow the xfer case to be bolted on the back of it. Might do some searching since he posted a ton of info a while back.

How important is having a CV joint in the propshaft? I'm starting from a 4x4 so I don't have one and I'd rather not add one unless it prevents handling issues or significant vibrations.

Its not important but the balance job on the drive shaft must be right on the money...no "close-nuff" balance jobs. Anyone who runs an upgraded gilbert front drive shaft uses all U joints including myself. No vibrations so far up to ~120-ish mph.

Is anyone running belltech leafs w/o the overload springs? Any adverse effect?

I run bell techs and dont recall them having over loads. Are you talking about removing the stock over loads from the stock springs and installing them on the bell techs? IMO its added dead weight since I didnt run the over loads when I had the stock springs nor when I installed the bell techs. No probs running like that so far.

 

['JustDreamin']

Re: T-56 AWD (not the usual questions)

Hey Boss....

I'd expect that somebody out there (like 4x4 shops) would already have a 27 spline setup for divorced cases. I'd check with those kind of guys.

I think a divorced case is probably the easier solution technically, but neither divorced case nor a custom tailshaft housing are particularly easy. It was just one of the reasons that I elected to stay away from the T56.


A CV joint is only necessary if the angles in the shafts require it. So, if you can match the transfer case angle and front diff angle (so they both sit the same) you don't need a CV joint (assuming that you keep the u-joints within their working range). If you can't match the angles, then you're going to need a CV joint.

'JustDreamin'

 

[AKToast]

Re: T-56 AWD (not the usual questions)

The reason I'm trying the divorced setup is somewhat less involved fabrication, better weight distribution, it allows for the tranny to be replaced, and it could be used with the viper output shaft.

I'll surf some 4x4 sites for divorced tcase parts, is 27 spline the typical gm output arrangement?

Good to know the CV joint isn't mandatory.

The belltechs I have are 3-leaf. The bottom one doesn't look like it does anything until the others are compressed at least several inches.

-Ralph

 

[Philntex]

Re: T-56 AWD (not the usual questions)

Here's a couple of pictures of a project that Barry Grant is working on using a transfer case mounted near the rear differential:

 

[maty111]

Re: T-56 AWD (not the usual questions)

man that looks sweeeeet. i wish i had that much time and money. mine looks like a hill billy ride compared to that. i like the irs too. but with the notches in the crossmember it looks like their going to put torsion bars on it.

matt

 

[midnightbluS10]

Re: T-56 AWD (not the usual questions)

I'd bet on exhaust.

 

[HectorM52]

Re: T-56 AWD (not the usual questions)

I thought about the same thing a couple years ago. I also believe that the divorced t-case is the way to go.

That pic above looks like a great idea - it would be nice to have a custom "driveshaft" made up so the slip-yoke went into the tranny, then immdeiately had the u-bolt, then immediately turned to an output shaft that slipped into the t-case.

From there, you've got your typical setup going back to the rear end.

I'm sure that part described above would be nearly as expensive as the "custom" output housing on a t-56 case.

PLUS, it would take care of any driveline angle issues, as you are ALWAYS going to have account for a little "flex" and "shift" since your motor & tranny sits on a rubber/poly mount.

Great pics!!!

 

['JustDreamin']

Re: T-56 AWD (not the usual questions)

I'll surf some 4x4 sites for divorced tcase parts, is 27 spline the typical gm output arrangement?

Standard output shafts are:

27 Spline (used on PowerGlides, TH350's, 700R4's, probably some others)

32 Spline (used on TH400 & 4L80E. maybe some others).


'JustDreamin'

 

[AKToast]

Re: T-56 AWD (not the usual questions)

Thanks for the input guys.
I can't find any off-the-shelf parts. I think I'm going to cut the splined section off a 2wd output shaft, combine that with a shortened slip yoke and see if it holds up.

-Ralph

 

[BofoMills]

Re: T-56 AWD (not the usual questions)

Alright whats the difference between a Divorced T-case and a normal T-case.. Sorry im still learning AWD stuff, im still stuck in the 2WD world.

 

[#2875]

Re: T-56 AWD (not the usual questions)

Alright whats the difference between a Divorced T-case and a normal T-case.. Sorry im still learning AWD stuff, im still stuck in the 2WD world.

look a the pics. notice how the t-case isn't bolted right to the trans? it is divorced.

 

[#2875]

Re: T-56 AWD (not the usual questions)

I think a divorced case is probably the easier solution technically, but neither divorced case nor a custom tailshaft housing are particularly easy. It was just one of the reasons that I elected to stay away from the T56.

'JustDreamin'

if it was easy everyone would do it.

hey Philntex do you have any more pics? i am working on a similar project and hungry for more info...

 

[HighPerformanceTrucks]

Re: T-56 AWD (not the usual questions)

Directly linking the t case to the rear housing would only work if the housing was fixed as in the corvette irs setup in the photos.

 

[Philntex]

Re: T-56 AWD (not the usual questions)

Here's one more from the front, but it doesn't show much of the drive train.
He went coilovers, so the notches in the crossmembers are for the exhaust.

It does have a massive blower attached to the "Front" of the engine, 40's style!

You might drop a note to Barry to see if he can put you in touch with his driveline guy.

 

[AKToast]

Re: T-56 AWD (not the usual questions)

Directly linking the t case to the rear housing would only work if the housing was fixed as in the corvette irs setup in the photos.

I was thinking that with a double-cardan joint and firmly mounted engine/tranny there would be minimal potential for binding... maybe... hopefully...

 

['JustDreamin']

Re: T-56 AWD (not the usual questions)

Directly linking the t case to the rear housing would only work if the housing was fixed as in the corvette irs setup in the photos.

I was thinking that with a double-cardan joint and firmly mounted engine/tranny there would be minimal potential for binding... maybe... hopefully...

I think Ivanko's comment was focused on the drive between the tcase and the rear axle, not the tcase & engine / trans.

In the case of the pictures, the tcase can drive the rear axle directly because of them both being rigidly mounted. But if you're running a normal rear axle, you'd have to have a conventional driveshaft between the tcase and rear axle to allow for axle travel.

The shaft between the engine / tranny and the tcase should be ok with minimal flexibility (ie 1 u-joint) if everything is fairly rigidly mounted and aligned properly (shafts need to be parallel and on the same centerline). The more the individual components can move around, the more you will need some form of CV joint.

'JustDreamin'

 

[HighPerformanceTrucks]

Re: T-56 AWD (not the usual questions)

Pushrod suspension! Bad to the bone engineering!

Here's one more from the front, but it doesn't show much of the drive train.
He went coilovers, so the notches in the crossmembers are for the exhaust.

It does have a massive blower attached to the "Front" of the engine, 40's style!

You might drop a note to Barry to see if he can put you in touch with his driveline guy.

 

[Fast Eddie]

Re: T-56 AWD (not the usual questions)

Here's a couple of pictures of a project that Barry Grant is working on using a transfer case mounted near the rear differential:

You've GOT to tell us more on this build! I Googled both Barry Grant (Demon carb) and Barry Grant (Bracket racer) and found nothing on this car. I have always thought a divorced setup would be too bulky or clumsy, but hard-mounted to an IRS makes complete sense. What a great idea. Holy $$ though.

The fab quality leads me to believe this is a show car, but a front-mounted blower? Is this a salt 'liner?

 

[SIMPLE]

Re: T-56 AWD (not the usual questions)

Any news on this build?