BritishV8 Forum

General Category => Engine, Transmission, & Rear Axle assy. => Topic started by: Anarchy99 on February 05, 2016, 02:37:26 PM

Title: Transmission direct to rear end questions...
Post by: Anarchy99 on February 05, 2016, 02:37:26 PM
So I'm trying to measure for an engine trans swap and cutting, welding, etc isn't the issue, it's, well... The tail shaft of the trans I was thinking of using basically would be real real close to the rear end. No room for a drive shaft. I think the cheetah car was directly bolted to the rear from the trans, so I'm pretty sure it's been done before, and if this isn't the right forum, please move me around... But what would needed to be done, solid motor mounts and an independent rear setup? Should that make it all work and allow room for flex under acceleration, etc? A single joint linking both yokes? Thanks in advance.
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Title: Re: Transmission direct to rear end questions...
Post by: DiDueColpi on February 05, 2016, 05:17:23 PM
What you need Jim is a transaxle from a C5 or newer Corvette.
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They normally are connected by a torque tube to the engine. These can be shortened or lengthened as needed.
I've lengthened mine to use in my 62 Impala.
If it needs to be really short you can bolt on the bellhousing from a later 4L60E and bolt the engine directly to the transaxle.
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You will need some form of independent suspension and the Corvette is a good donor for that as well.
Like we are doing to a little Suzuki Carry with a 6-71 blown 377 SBC.
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I've bought two of these setups now. One is standard and one is the auto.
They have been relatively easy to find and prices aren't that bad at all.

Live like you mean it.
Fred
Title: Re: Transmission direct to rear end questions...
Post by: Anarchy99 on February 05, 2016, 05:27:03 PM
Yeah... I just sold the supercharged c5 I built up... I'm familiar with the torque tube, etc... It will not work in this application. I don't really want to toss my cards on the table just yet for the exact car, etc... but I'm thinking I have to mate a tail shaft to a c4 independent suspension with no driveshaft.

This is going in a small British car,etc... Trust me... Running the tape measure, it's too close from trans to rear I'll be scratching my head to fit joints in between. Please keep the inputs coming.
Title: Re: Transmission direct to rear end questions...
Post by: DiDueColpi on February 05, 2016, 05:55:40 PM
What dimensions are you needing?
From axle C/L to block face.
You could use a single Ujoint and a slipyoke. Or better a double cardan joint. But your alignment between the trans and carrier would need to be spot on and rock solid.
A 4X4 trans and a transfer case coupling with a little fabrication might work out as well.
Title: Re: Transmission direct to rear end questions...
Post by: Anarchy99 on February 05, 2016, 06:13:24 PM
More to follow tomorrow... You guys will figure it out when I post the details, but long story short, what do you need to do to mate a trans to a rear diff, without using a driveshaft
Title: Re: Transmission direct to rear end questions...
Post by: Orange Alpine on February 06, 2016, 06:49:22 AM
A coupler that will allow misalignment.  Something like the industrial setup that uses a sprocket on each shaft, joined by a double width chain.  Not pretty, but effective and strong.

http://www.mcmaster.com/#standard-shaft-couplings/=1107cb3

Even if you luck out and get them perfectly aligned, flex will be an issue.

Bill
Title: Re: Transmission direct to rear end questions...
Post by: Anarchy99 on February 06, 2016, 11:03:01 AM
Would 6 inches of driveshaft length be long enough to run a live axle rear end without issues?
Title: Re: Transmission direct to rear end questions...
Post by: joe_padavano on February 06, 2016, 04:48:59 PM
"Would 6 inches of driveshaft length be long enough to run a live axle rear end without issues?"

Sure.  So long as the rear axle was welded to the frame and unable to move...

You need to lay out the suspension motion (up and down as well as side to side and rotationally while cornering) and then figure out what the driveshaft and u-joints need to do.  The answer will show that a live axle will need a LOT more driveshaft for reasonable amounts of suspension travel to avoid binding the U-joints.

Your only other option is an independent suspension so the diff can be hard mounted and the half shafts provide the suspension travel.  That's why the Corvette transaxle was suggested.
Title: Re: Transmission direct to rear end questions...
Post by: Anarchy99 on February 06, 2016, 05:04:03 PM
I haven't ruled out a c4 suspension... Going to a manual will be tight in the footbox but will be a lot shorter than the auto I was looking at... It would give enough length, i think(without having it all sitting in front of me), to have a short driveshaft, but I think long enough to keep from binding
Title: Re: Transmission direct to rear end questions...
Post by: DiDueColpi on February 24, 2016, 11:52:35 AM
So what's happening Jim?
You're keeping an idiot in suspense.
Title: Re: Transmission direct to rear end questions...
Post by: roverman on February 24, 2016, 06:06:17 PM
Jim and clan, Transaxles vary a lot, from mounting face to CV centerlines. As example , Corvette C5, mounting face to CV centerline is 24". On Porsche Boxster "S", it's only 8". I needed the 8" CL for cabin room.  Food for Thought.  roverman.