Installation of an automatic _into_ a T3.. factory did it, easy, right?
Posted: Tue Jul 04, 2017 10:28 pm
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.
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)
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.
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)