Porsche Automatic Gearbox Conversion into my Caravelle

[Dueller]

Hi again everyone

My last project of fitting the Ford Mondeo st220 into my Caravelle thread was a real good story board so thought id start another re the autobox failure and what ive decided to do about it

Here's the engine fitment thread...
viewtopic.php?t=178862&sid=52f549f91b75 ... 374a2c4b82

So anyways, after i fitted the engine it was incredible to drive and the box didnt like it, it would shift up then get to third and drop back again to second. Lots of adjustments followed but i came to accept the box was faulty and would need replacing or repairing.

The history goes like this:

1. Bought the van, been stood 2 years with a starting problem
   
2. Sorted the engine out, Steve at Flat4Mania got it going, even passed the MOT emissions test! My tester was well impressed with it
   
3. 2 days later it sounded tappety (90k VEGE engine and autobox - have receipt) and out came the engine to rebuild, no main bearings available so after a 5 month search gave in and reused what i had, luckily it came with a spare short motor so had a choice.
   
4. Sorted and driving again, big whine from the autobox while driving, pulled it out and took it my gearbox guy that stripped it and identified a very worn ring gear, unobtainable at reasonable money, USA has some but payment method made me nervy
   
5. Sourced a good used box from Nick Tune, top bloke, proper saved me as nearly scrapped the van, took 6 months to find one
   
6. Box always had a jerky reverse but for 2k miles a year i wasnt bothered and drove around a good bit until i decided i wanted more power
   
7. See my other thread for what happened next in the link above
   

So anyways as it now wont do third or Reverse gears i believe the forward drive to be broken, cant get parts here in the UKso considered buying in from the states, good threads on The Samba for rebuilding these plus ive bought a VW manual but no one will sell me parts to repair, so back to the drawing board. Could always order a box i suppose...

Then i saw a 924 autobox and its the same as the vw one, as fitted to all sorts of vehicles from that time, audi 100/200 Turbo being the most relevant to myself, even Fiat used it.

But its not a straight swap as the internals differ, where the autobox input driveshaft fits to the differential output shaft, typical vw. So bought one as decided to do a flip box conversion on it ala Tim at Ultimate Engineering does for other vw/Audi stuff.

Only real problem i have to figure is the oil breathers on top, one for each section, will need closing and/or rerouting. The rest is pretty normal as per this conversion, drive shaft angle may be an issue though.

Essentially im rotating the differential section and putting the autobox back onto it

anyone else looked at or done this before??

[Dueller]

Started on the adapter template today, a lot larger than the vw box and will also need a starter motor position

Fitted my engine adapter to see how they'd mate and its looking good

Last time I used the plasma cutter but on this one I'm going to get the price for laser cutting the flywheel hole

[Dueller]

Last week I measured up and sent my steel for the adapter plates to a laser cutter, used a plasma last time and didn't like it so a better effort this time

Also dropped the Ford autobox flywheel and Porsche torque converter off at my other guy as need some drilling and spacers to make it work

Should see them all back in a week or two

Thought I'd flip the diff box and position it on the autobox to make sure this part of my plan would work, needs some holes drilling as expected, unsure whether I will do this or get them done professionally as a cutter would be better but how the hell do you hold the box while you do it? Maybe a vertical mill but it's a tall item

Also found the Holy Grail, a 4 gear set up, vw used the 3 gear so I've a stronger set up. It's on the box I wanted to use too, the other is a 3 gear set up but still stronger than the vw offering. I just wanted the 4 gear as I knew it existed so bonus

[puddlefluff]

Good to see this, interesting write up and looking forward to seeing how this goes. Mine is audi 200 box, porsche starter motor run with 1.9tdi. I literally have no idea about the finer details but it works really well (3 speed). Conversation was done in Germany by the previous owner. You are welcome to have a look if that helps you out!! Keep up the good work steve

[Dueller]

Cheers Steve, good to hear it can be done

Should be getting it drilled this week so will update over the weekend

[Dueller]

Had an issue with laser cutting, took from the incorrect x or y or whatever so they're redoing the adapter plates for me

Drawing it up in CAD then cutting it out

Also have the gearbox flip mod in progress, nothing lines up so welding tabs to the outside of the diff and autobox to hold both pieces together.

It's incredible that they are joined by only 4x m8 studs and nuts so should take this ok

The drilling option didn't work out as the pattern isn't equally matching from hole to hole

Hopefully start to see some parts back next week

[Dueller]

Finally getting on with this after a few setbacks

Here's some comparison pics of a standard box and the modified one. The studs have been relocated for attaching to the differential once flipped and its good, can see where extra metal has been added on



The torque converter to flywheel is 3 spacers that I will triangulate and weld together, then colour code so they will line up every time. Should help with strengthening them too.



I came across a post where a guy modifies his autobox to shift faster by blocking a port that allows pressure to build then shift. Modified, its blocked so harder, faster and quicker shifts, that's the theory anyways!



Also have my oil cooler and hydraulic oil filter system that feeds off the inlets from the back of the case. Will drill and tap the filter housing for a temp or pressure gauge or maybe both. Similar system as GoWesty sell with the Derale thermostat.

[Dueller]

Some pics of it mocked up together with the differential flipped

[Dueller]

Well, it came out



My son and I started the van Saturday morning just for a motivation engine run, and then started to pull the engine and box out

Separated the engine and box today, then took the auto box off the differential section

Will start the adapter plate Tuesday

[Dueller]

Been busy setting up and welding the adapter templates onto the steel plate

Drilled a few holes but ran out of time tonight, more tomorrow

[Dueller]

Made the engine plate for the adapter today, went very well compared to last time round

Easy to shape and drill out as already had the tooling

Decided to cut the extra steel off where the starter will go as need to sort fitment out for height, depth etc so will drill a plate up and weld it on once assured it turns the motor over

Using a Focus ST170 starter as this is what Wozza used in his adapter for the Mazda gearbox, see my engine conversion thread for the video

[Dueller]

More progress today

Tomorrow I will join the engine and gearbox to confirm the measurement needed for the sandwich steel, lots of welding to do then

Still haven't built the autobox back up but will do that by Saturday

Then I can hopefully get it all back in the van over the weekend and figure out the driveshafts for next week

[Dueller]

This was harder to complete than the vw conversion

Finally gave up trying to get the bolts in and studded the torque converter instead and then joined both plates together and welded into alignment

Had some spacers made to allow for everything and all is fine, just the right depth. Need to triangulate the bushes for strength so more welding to do

Spent today fitting the starter to the adapter plate as no factory fit here like the vw autobox. When i got the motor, Wozza had it set up ok a Mazda rx8 adapter plate, see the video on my build thread, the starter now lies alongside the engine block.

Close fit to the block and my exhaust manifold is in the way so took some working, had to make more of an ugly mess of an already ugly adapter plate

Will finish up tomorrow and take some more pics

[Dueller]

Pics and progress from the weekend and today

Had to clearance the gearbox for the starter, pretty neat I think, still got a bit more to remove to clear the starter top bolt otherwise it's an engine out job



Starter clearance on the 8mm +ve stud is tight, will find a thinner nut, maybe use an 11mm too for ease of access



Couple of other pics

[Aidan]

are you going to make a heat shield for the starter ?