Installation of an automatic _into_ a T3.. factory did it, easy, right?

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Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Piledriver » Wed Jul 05, 2017 12:28 am

There will be pictures. I promise.

Installing a T3 automatic (3.69 R&P) and beefing it a little, $500, rather than spending $5-6K on a fully beefed T1 trans/clutch that probably won't last 5K miles anyway with a blown 2.5L T4 hanging on it.
Got everything from the shifter to the axles for $300, plus master kit w/frictions and custom trans bands, just under $500 once I fill it with Redline D4. Using a handy 86 Vanagon converter with 2750 RPM stall.(simply fits)

It may eventually get an 090 with a taller R&P if I kill the 003 too many times, but I can afford to do that a few times considering how cheap the parts are and how easy they are to work on.

Good news:
The front mount is there and like new.
It bolts right in, and I have the correct automatic axles to match.
The trans looks pristine enough inside that it went right back together and is initially going to be installed and tried after only replacing all the potentially fatal-to-the diff seals (front and rear pinion seal, and governor shaft seal).

I have the whole master kit, lovely carbon metallic bands from Alabama Transmission Bands, and Attomatic (Raybestos) green semi-metallic "High Energy" frictions for when I actually do the full rebuild, came as part of the master kit from Cobra Transmissions, and strongly recommended for use vs.having them relined with carbon metallic by Alabama Bands.

Bad news: Car has early 944T aluminum trailing arms that take Very, Very Long 944T//Vanagon axles.
I am extremely disinclined to revert those mods (custom coil over shocks, modded mounts, huge brakes, 944t wheels)

Sooo.

Just spent the last couple days yanking the perfectly good engine and manual trans out of the sguareback and working on how to install the automatic----while retaining the 944T rear arms etc.

Also hopefully doing something like a frame horns/kafer brace setup so I can ditch the rear crossbar, which interferes with some stuff I want to try, like test out the dry sump setup on a the all-used-parts 1.8L etc. (It may get some handy 96s while its out)
The rear crossbar may just get some rework for clearance if all else fails.

As to the trans itself, It's doable, given some work to the drive stubs, and a custom axle for the drivers side. :twisted:

I was originally going to JUST offset the trans/drive flanges, as the motor doesn't have a seal around the outside, just on the air intake or the fan. BUT---I'd really prefer things on centerline, so I started looking at alternatives.

For the passenger side (long axle) the solution appears relatively easy, esp as this is an early trans with the drive stub retention flanges, and I need to weld on some T4 flanges anyway.
Turns out the thickness of a dead T4 CV joint body is ~perfect, so I will weld a dead CV outer to the flange, grind to perfect thickness on the lathe as needed and install helicoils or timeserts in the existing holes, which oddly happen to be the ~right size and place for inserts...

For the drivers side, there is a larger problem... or simply: It's FAR easier to extend a drive flange than make an axle shorter.

After a bit of Google-ing for axle lengths and raiding of my personal parts cache.... Turns out a 914 axle appears to be ~the perfect length, 20.25", just a 1/4" shorter than a short vanagon automatic axle.(latter might also be right length)

I just have to counterbore the splines of the T4 CVs so they slide on far enough to seat the snaprings, needs about 3mm, maybe a little less., basically open up the factory countersink a bit deeper.

The original trans drive stub will get turned down a bit and mated to a machined German t4 flange then welded, small bit of length adjustment possible at this point if needed.

The retainer flanges were ~20mm deep and the 90mm flanges spun within, but now they are ~5mm thick so the larger t4 flanges have plenty of room. The bolt pattern is ~5x110, so a small axial groove on the OD of the flange will provide sufficient clearance to get the flange bolts in/out, now flathead machine screws countersunk in.

For reference: Some data from blindchickenracing.com, some my tape measure
T1 axle=16 5/16" 28mm splines
944 axle= 16 1/8" (need to verify, may be same as 181)
bay bus manual axle 18 3/4" 34mm splines (some space taken by spring cone washer)
914 axle (manual) 20.25" t1 depth splines but cv joint splines can be relieved inside for std length, or outside as needed to adjust assembled length, can be std, ~+3mm or +6mm. Same trick works on T1 axles.
vanagon manual trans/944T axles 21 1/2" (need to verify)
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Re: Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Jadewombat » Sat Jul 08, 2017 5:41 pm

I had some custom length axles for my T1 SSC into my '66 bus from an offroad place, don't remember which one but both were equal length of course. Aren't the T3 autos axles unequal length IIRC?

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Re: Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Piledriver » Sat Jul 08, 2017 7:53 pm

The T3 and Bus 003 or 090 vanagon autos all have unequal length axles.
The transmission is on center, but the differential is offset to clear the large automatic coaxial input shaft and pump drive etc.

I just basically had to deal with the new custom lengths needed for the 944T rear arms etc, which take a pair of long Vanagon axles from the factory, the stub axles at the outer end are very short compared to a ACVW, it uses the std sealed dual row bearing like most Porsches and a great many FWD cars, later Porsches use the same bearing up front in 2WD or AWD configurations.

I have half corrected the offset with a passenger side drive stub extension, but the drivers axle is still about 30mm too long if the trans is mounted on center as desired.

The shorter drivers side 914 axle (with a little quality time spent grinding on the T4 CVs beveled end) allows the trans to be centered in combination with the passenger side vanagon axle and drive stub extension (basically a welded on t4 CV outer shell, with threaded inserts).

So L axle is 914 with slightly modded T4 CVs, R axle is Vanagon manual trans (R axle same as std 944 Turbo) rear suspension is 944T. Trans/bell housing is on centerline.

Some might be concerned about the slightly smaller T1 CV splines, but I have never even heard of factory axles and Lobro CVs splines stripping in any use. I'm using all factory axles and CVs.(just not for a T3)
No EMPI parts here.
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Re: Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Piledriver » Sun Jul 16, 2017 2:44 am

New extended length drive stubs, about 4MM longer on the short, ~28mm wider on long one.
This centers the trans perfectly with a 914 axle w/modded 944 CVs and the std (for a 944T) Vanagon (manual trans) length axle on the passenger side, with proper offset axle lengths for the 944T arms and automatic..

The long one got a complete T4 CV outer welded on, the CV body got partially turned to the same OD as stub, which had the lip turned off, and both deeply V-cut to match to allow for a good, deep weld. Flowed them together while clamped with TIG, welded nice, 2 more passes with std carbon steel TIG rod, no evidence of cracking etc, then MIG pass on the ID simply to seal the cup, as I left the somewhat overlapping bolt holes open. I installed 8mmx1.25 mm helicoils in the bolt holes, which was interesting due to the hardness of the CV bodies towards the middle. There wasn't quite room for timeserts.

The short ones T4 100mm drive flange was sacrificed from a dead 002, the remainder still keeps things sealed up on the 002. These proved a bit more difficult to weld, as simply TIGing the machined press fit bits together (even with preheat) had a crack follow me around. Ground that out a bit then TIG using 347 SS rod. Ground much of that back out to verify no cracks/voids etc.

Everything got a long bath in phosphoric acid and wire brushed to make pretty, rinsed, dried, then simply hit with Break Free.

These early style stubs are retained with a circlip/thrust washer to the 5 bolt aluminum stub/seal carriers, the outer flange turned down from ~16mm to ~5mm, countersunk, and SS flat head machine screws used for retention to provide clearance for the larger t4 cvs. (the T1 CV drive cups ran inside the and flush to the outer surface of the unmodified seal carriers/retainers.)
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Re: Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Piledriver » Mon Jul 17, 2017 10:57 pm

New motor mount setup on the Bay bus crossbar, much like the old one, but based on 914 mounts for added strength/stiffness and the ability to get the inlet and outlets lines to/from a modified CB drysump pump (not on this motor, the new one will get that)

Inner L mounts are std 914 rubber and metal, R mount has L side wall removed and has an over-the top support added to allow passage of the 3/4" ID pressure stage inlet hose.
The welded on "wings" hold Vanagon outside rear mounts to prevent twisting.
They are largely made of the old, dead mounts.

Those also limit max engine roll/side to side motion with folded over steel tabs, even if the 914 mounts come apart.

They are not as preloaded as the 914 center mounts, which do most of the "holding things up" work. This setup raises the engine about 1/2" (some simply due to new mounts) and moves the motor back a bit relative to the bar to provide room so that the AC pulley doesn't ever kiss the crossbar.

(it really only made contact due to shot motor mounts, they were ~OK used when I built it 90K miles ago, but I wanted provisions for the DS setup. The automatic is also a touch longer with the stock front mount)

The crossbar is hard mounted on shortened Bay bus mounts bolted to the T3 mount consoles via some steel tube 2x4s.

Sorry for the one photos odd angle, the forum software seems to insist on landscape orientation...
Last pic is old setup (when new) kept for later use.
motor-mounts-1.jpg
motor-mounts-2.jpg
Vanagon-busmounts.jpg
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Re: Installation of an automatic _into_ a T3.. factory did it, easy, right?

Post by Piledriver » Sun Jul 23, 2017 3:12 am

How to kill an evening, thanks to a PO or some idiot mechanic... I wanted to stuff the engine and trans tonight to make sure everything worked...
At least the Vanagon converter is now in place...
https://www.thesamba.com/vw/forum/viewt ... 0&start=52
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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