So the rear is very limited in terms of how it is mounted(there is adjustment but ill get to that after)
the with torque tube installed and properly engaged in the transmission it leaves "X" amount of space to fit the bellhousing and engine and clear the firewall.
After having calculated "X" ( i use x because i have notes somewhere but they arent very detailed since i did a lot of this on the spot and worked it out vs documented) i now knew the space i had between the flange on the TT(where it bolts to the 944 bellhousing) and the tip of the driveshaft(for pilot bearing engagement).
Lets just say its about 5.5"
This means i had to calculate and make it so the engine block could fit a bellhousing all of the needed clutch components and than be able to mate it to the TT.
This is where i chose to use a Longitudinal DVZ 2.8L gearbox.
well by use i mean i had it, i cut it up and well turned it into a bellhousing.
I dismantled most of it, and than got creative with a sawzall/ angle grinder, die grinder hacksew and all kinds!
there wasnt much play room once calculated but it was going to work,
i believe the pilot bearing i fit into the crank was the stock EURO BGW(manual bhw equivalent- or 1.8) needle bearing style pilot. Which if not mistaken was probably like 11-13mm deep. so i installed it with full depth(flush with end of crank)
Test fitted this multiple times once the basic bellhousing was made. i was able to get full depth.
that meant just to make sure i could use my slave/starter etc afterwards
The base of the bellhousing was the remnants of the DVZ case, this meant i could use the stock bhw starter which is a beefier version of the 1.8 i believe, which mounts along the engine nut bellhousing. This is a much easier way to do this, all the guys running the 02J modded bellhousings man... why would you want to cut up or bang up your tunnel/fireall... sad sad day...
I than after measurements welded on a 1/4" 6036t6 or equivalent sheet of aluminum. with sides to box it in and the whole 9 yards.
The biggest plus to using a Longitudinal bellhousing as base! the (oem) input bearing. well this big ass bearing unfortunately is an open bearing so its semi useless but.. the principle is good, a lot of people have an issue with allignment or such to properly allign clutch pilot bearing etc, since the 944 TT is just basically a long input shaft and the size is 99.99% exact match to the input shaft of the dvz, it slides right into that hole, making calculations and mounting a easier base.
Another worry of mine was the TT.. will it have a lot of vibrations and such because the TDI 's nature. well on the stock TT the closest bearing to the clutch is say 12"(from memory) which (for later 944s actually created an issue, but thats another day) so i thought wouldnt it be great to utilize this well placed bearing(spot) and help reinforce the driveshaft. of course the stock input bearing is something like 58mmx30mm or something. which is after research a 1 off bearing apart from a 100$ chinese (sealed version)bearing..
Lucky for me, my neighbor and friend who runs a machine shop and has made me numerous parts in the past was more than willing to now make me a modified version of a delrin part id already had made.
so instead i used a 58x35? bearing and used a delrin insert(same design for the rebuilt torque tubes i offer) to snuggly fit to the driveshaft!
and tada a nice solid addition to the system was added and it helps keep properly allignemnt. This i do not have pictures of currently as i actually only now have the proper parts and for testing and fitment(was and currently have the original Input bearing installed)
Than it was a simple matter of calculating the proper depth and position for the Stock 944(yup you read that right-oem off the shelf parts
Slave cylinder mounting. and to drill./ Time-Sert the proper and needed holes.
The only other calculation which after measuring and such i realized was in order to actually use the stock slave and with minimal mods was that i needed to clock the TT flange so that it could fit and the slave bolt up without needing to modify those, and since when done properly cutting and rewelding it would cause no damage to the casing or issue with future rebuilding it was the smartest way.
so i now know i can mate the 3 together Engine ->TT<-Transaxle
But how will this look and or fit in the engine bay. will it hit will it rub..
So once i managed to have the bellhousing completed enough to bolt the 3 together i got to work
i very soon found out, unless i want the fuel pump eating away at the AC Lines( i hope to one day use) i need to push the whole assembly forward...
Well this can be done but there is only so much room at the back.
Now..
During all these tests the stock 944 gearbox was used as no need to make a lot of complications trying to allign 3 or 4 new things vs having a base to work off of.
when installed stock the 944 transmission has a upper crossmember that it hangs off of.
this does give it a bit of swing left to run but next to none front to back. and for good reason as the spare tire hole is about 1-2" behind it and well the TT would need to move the entire engine to go forward... mind you also back.
So i got a little creative and started with simply cutting 2 1/8" steel plates which i installed between the gearbox mount bracket and the mount itself in turn just pushing the gearbox forward about 1/4" and the mount not moving
Bam it actually worked pretty well !
Now the only issue with this was the 944 TT im working with has a stock design of sort of dog ears. which in the instance of an accident are there to prevent the system from sliding too far forward or too far backwards. Well these needed to be trimmed as the freeplay window i needed wasnt within there limits, so i trimmed off a section of the points so i could slide it where i needed. No worries there.
so now that the transmission was at or close to its limit for forward movement i needed to compare and see how the engine adjusted.
Well i now have some clearance, maybe not quite as much as i wanted but itll have to do. I also realized the clearance on the firewall really depends on the height the engine is resting at.(later noticing i had it quite high. so once lowered ended up with closer to 7/16-9/16" of space much better !
