AWD trans

[snj8198]

Did GM or BOP ever provide a production all wheel drive trans with the standard 90 degree bell housing?

[DieselSJ]

Transmission would not be the "AWD" component. You want to look for an "AWD" transfer case.

[snj8198]

ok then i'd still be stuck with a two component set up and even if the t-case was a 1 speed all wheel drive unit im still stuck with t-case of typical physical size?

[DieselSJ]

Yep. Look for a Syclone...that was a factory hot-rodded S-10 sized truck that was AWD.

https://en.wikipedia.org/wiki/GMC_Syclone

Something like a BW 4473 would bolt to the back of a GM 4x4 transmission.

[snj8198]

interesting. thanks for your insight.

I have an option to build either a mid 80's Caprice Classic or a Town & Country station wagon where im looking to convert one of them into an all wheel drive ifs/irs with a little more clearance over stock and run a modest LS but i dont want to do a typical body onto 4x4 chassis swap. Just doing some homework for now.

[clinebarger]

The 1 speed full time AWD Borg Warner 4481 from GMT-800 Cadillac Ecalades can easily take 500 ft lbs, No electronics & light weight., Splits the torque 40% front, 60% rear at all times.

The 1 speed full time AWD New Process 149 from a GMT-800 Silverado SS can handle 400-450 ft lbs, No electronic, Little heavier than the BW4481, "Normally" Splits the torque 38% front, 62% rear, But can apply 100% torque to the front or rear wheels via a "Viscous Coupler"

The BW4481 works better with "stability control", Lets say the right front wheel losses traction, The stability control will apply the right front brake & applies engine torque to the left front wheel. Without stability control the front diff will act just like a open diff.....All 40% of torque will be applied to the spinning front wheel.

The NP149 doesn't rely on stability control, The viscous coupler handles all the Torque Biasing, The more slip one axle has.....The more torque that is redirected to the other axle.

[snj8198]

Thanks clinebarger, I appreciate the push in the right direction from both of you.

[Captainfab]

I don't know what transfer case they use but the Express/Safari vans were available in AWD.

[95 S_Trucker]

Originally Posted by Captainfab

I don't know what transfer case they use but the Express/Safari vans were available in AWD.

Borg Warner 4473. It's torque is distributed 35 front/65 rear. It can increase/reduce torque when slippage is detected by using a viscous coupler.

[James the III]

What was used in the AWD astro's.. and how much power can you throw at one..

[Bigdav160]

There's also the BW 4476 used in the Cadillac SRX wagons. No viscous clutch to burn out.

[snj8198]

Thanks guys, ya i was doing a little reading last night and it looks like since the late 80's there is a couple of NVG and Borg Warner model single speed t-cases that offer awd in roughly that 65r/35f bias configuration. I was hoping to eliminate the need for the tcase since im looking to build a car which is not going to have the tunnel molding area for a t-case. Again, i dont want to turn this into a car body on 4x4 chassis but merely an awd car with front and rear independent suspension using an LS motor. I found some all wheel drive trannys but they are side ways mounted motors and nothing with the 90 degree bolt pattern.

I havent looked into the Caddy BW unit yet Bigdav, I'll check that out and find some pics of the underbody. Thanks.

[95 S_Trucker]

I don't know how you would get awd without a transfer case on a longitude mounted engine. Even high end Mercedes and bmw sport sedans use a transfer case.

The only car I can think of that has a longitude mounted engine and awd without a separate transfer case is the Subaru. But the engine is mounted in front of the front axle centerline, and it obviously wont bolt to a gm engine.

[snj8198]

I see. Welp maybe it's not ment to be.

[Bigdav160]

There are also New Venture Gear transfer cases in Trailblazer/Envoys.

[snj8198]

I will have to do some measuring to see, but if the t-case landed roughly under the front seat that would allow for some floor contouring to keep it up tight with the body. I can make a clocking ring to rotate it flat but then I need to think about the front drive line. This is all why i was hoping there was such a thing as an all wheel drive trans for a longitude motor rather than going the tcase route.

[Bigdav160]

The engine oil pans on Envoy/Trailblazer/SSR have accommodation for the front axle passing through. I'm not sure the transfer case is much of issue.

I worked on an AWD G35 the other day. It uses a transfer case behind the transmission.

[snj8198]

i've seen some of those oil pans in certain apps. Pretty neat. How flat was the AWD G35? Did the body on this vehicle sit high off the frame to accommodate the drive train or was the the tunnel wide enough for the front driveshaft?

[88Ironduke]

I have an Envoy Denali with the 5.3 but they are 4wd and not AWD. I'm pretty certain that only the trailblazer SS with the 6.0 came in AWD.

[mongocanfly]

Im sure It was built with a unlimited budget but ken blocks mustang was 4wd....https://m.youtube.com/watch?v=RGvKjk_VrHE

[Captainfab]

I don't remember what TC this guy used but there are a couple links in the comments to follow.

https://www.youtube.com/watch?v=Wtnvpgdfq9c

[D13]

Olds Bravada used the viscous coupling also. But yes, if you are using a GM drivetrain they are all trans + transfer case.

Suggestion - take one of the above units, make a block off plate and stub shaft set up for the front, and use it divorced. Allows you to place it where you want (within driveshaft limitations of course). Similar to a standard divorced transfer case.

[snj8198]

Im sure It was built with a unlimited budget but ken blocks mustang was 4wd....https://m.youtube.com/watch?v=RGvKjk_VrHE

Yep, just what I need to go to work, haha!

Neat stuff guys! I'll find the full build sheet on that Cutlass. I see he used a 4l80 trans but doesnt mention what t-case. Regardless, he must have clearanced the floor a lot. Not a big deal as long as that case lands under the seat where the custom floor pan can be raised without affecting foot wells for the case and front drive line. Regardless, I would run few inches taller than the Cutlass's stance which should help for drive train clearance.

Read that he used the front and rear diffs out of a ZR2 S-10 truck and aftermarket shafts. So like some of you said, this is Typhoon and Cyclone drivetrain thus im betting the t-case too. Good call!

[Overdriven]

There are other vids of that cutlass where he goes into a little more detail about the drivetrain so search YouTube for "AWD Cutlass". I don't remember all of it but I believe the Bravada/S10 parts were the steering knuckles. Front diff may have been also but it could've been Trailblazer, pretty sure trailblazer was mentioned just forget what part it was.

[snj8198]

Thanks, will do!