Modify the right side case to fit the flipped crown wheel. Clearance for the differential carrier, crown wheel and crown wheel bolts should be checked by progressively fitting each part to the right side case. It's finished appearance should be similar to the left side case when complete.
Subarugears machined case ..........................................Customer hand ground and finished case
If you are using the transmission in it's 4WD state then that is the extent of your case modifications. Move on to fitting the Subarugears ring and pinion and differential set up.
Check out the video of how to clearance the case :
Shortening theAWD case to a 2WD case for Beetles, Kombis, Vanagons.
As we are only using the 2WD part of the transmission, the casing can be shortened to 565mm length (plus 80mm length of shifter support tube that is placed over the top of the torsion bar).
This should be performed on the later style center differential housings from 1999 onwards ( 8 bolt or TY754/755/758)
Earlier style center housings (4 bolt TY752) are difficult to shorten effectively. These are identified by their square panel on top of the center differential case. Newer center differential casings are interchangeable with older style casings.
Alternatively, you can now purchase our Subanose - one piece cast nosecone compatible with all 5 speed Subaru transmissions. No need to use a grinder or TIG weld, simply transfer the parts from your donor center differential housing and bolt it all on. The shape has been optimised to give the shortest possible shifter support length and maximum clearances.
Mark out the cut line.
9cm (3 1/2 inches) from the end with the cast bosses for the mounts. Do not mark all the way around - leave the base of the shift rod support tube unmarked and uncut.
Carefully mark above and below the shift rod support tube. The castings are left thin there so are easy to cut through.
Be very careful - there is a bolt just to the right of this round plate (gearshift interlock) that holds a ball and spring in place. Do not grind off the bolt. Do not grind down the flat mounting surface for this bolt or the tension that the ball and spring places on the interlock will be incorrect.
Rough cut complete....Back................................Right hand side.............................................Left Hand Side
Note there are three holes to fill :
1) Large hole with Subaplug
2) Hole on inside of shifter support shaft, filled with TIG weld, threaded plug, Devcon or Silicon
3)Weird shaped hole on right hand side, filled with TIG weld, Devcon or Silicon
After some finish grinding and flap disc work plus holes filled with Subaplug, threaded plug, TIG weld.
Complete shortened Subaru transmission casing
The casing needs to be welded in 3 areas : (1) On the shift rod support (2) On the outside of the threaded hole that holds the oil splash catcher on the inside (3) In the area where the steel welch plug from casting has been removed :
Check out the video of how to shorten the casing :
The Subaru transmission has a small case breather built into the dipstick. Since the dipstick is no longer able to be used and the dipstick tube is sealed, a case breather should be built into the transmission in order to relieve pressure build up.
TY754 and later transmissions can often use the Subarugesars supplied dipstick cover/breather. This is a hi-temp silicon cover that incorporates an oil block-off/breather device and external breather/filter. However, in some circumstances oil flow has been too great even in TY754 and later trnamsissions to use the supplied dipstick cover/breather and a hole in the casing is required.
TY752 transmissions cannot use this breather device as their internal design means they pump a much higher volume of oil up the dipstick tube. The dipstick tube must be entirely covered with a silicon plug and a secondary breather location made.
The ideal location for the case breather is in the rear of the transmission case, as far out of the way from flinging oil as possible. The suggested case breather consists of one hole that passes form the outside of the non-starter motor case into the hollow cast section in the rear.
As you can see on the inside shot, this are of the transmission is casting hollow only and is not part of bearing or gear lubrication areas. It is a void in the casting and even has some webs that operate as 'oil barriers' for our purpose..
In addition, once the "horseshoe" that holds the input shaft in place is fitted, there is additional protection against oil slinging.