And it begins...TDI Passat 5 speed

[QuickTD]

I believe I have found my project. Yesterday I dragged home a 2002 passat 1.8T manual with sludged/blown engine and an exceptional body. I wasn't entirely sure what I was going to do with it but...

 Serendipity.

 My freind who was also my truck driver for the recovery, who also messes with vw's, mentioned that he had most of a 2005 passat TDI with severe damage to the right side. He had bought it to repair front end damage on another passat. I had no idea he had this kind of "inventory". Anyway, I now own it as well.

 The plan is to meld these 2 into something drivable. The TDI swap appears mechanically straightforward. Engine fuel tank and lines, Intercooler, exhaust, ecm, accessory drive brackets and instrument cluster will be transferred from the TDI to the 1.8t. I will use the 1.8T transaxle for now though the ratios are not ideal. I may seek out a V6 5th gear or whole trans once I'm up and running. Clutch will be a single mass valeo 1.8T unit and I will be deleting the balance shaft module and installing an ALH oil pump in its place. This is machinery, it vibrates.

 I have the complete wiring harness and electronics are my specialty so alterations will be made as required.

 Only thing needed at this point is someone to recode the ecm for the manual trans as I'm sure the absence of the trans controller will light the MIL. Redrotors, malone, TDtuning you out there?

Pics and story to follow.
   

[JFettig]

Should be a great project but grab that V6 transmission, you can probably get one pretty cheap.

Upgrade the clutch and pressure plate on the Valeo SMF conversion, I am told that VR6 clutch and pressure plates fit but you might want to verify. The stock torque limit on the valeo clutch is pretty low.

Jon

[QuickTD]

The reality is the V6 trans isn't much better. Same final drive ratio, 3.7:1. Fifth gear is .837 for 1.8 and .78 for the six. Thats about a 7% improvement. If one turns up during the build, I'll use it. Otherwise it will happen later. I don't do much freeway around here and 2400rpm @100km/k is fine with me for now.

[QuickTD]

Dragged home another piece of the puzzle today, a V6 012 transaxle. It will be sacrificing its 4th and 5th gears for the greater good. Naturally, I dismantled it as soon as I got home. With the case opened, the wheels began to turn... 3rd gear looks remarkably similar to 5th, only inverted. The 3rd gearset in a 1.8t box is 28:40. or inverted it would be 40:28, a 0.7 overdrive. This would be ideal for TDI use. All these people importing transmissions could use something like this.

 I hit the books (etka) and it turns out the 3rd gear (shifting) uses the same OD bearing and the same synchronizer ring. It is a bit wider but that would be little trouble. Cermet insert and 10 minutes in the lathe = solved.

This is too easy...

The fixed gear is a bit more problematic. The splined inner diameter is considerably larger than that of the fixed 5th gear. I don't do internal splines, but..

5th gears are not really in short supply I'm pretty sure with one more trip to the boneyard I could produce enough parts to accomplish my goal. I would first cut the teeth from a 5th gear until its OD is slightly larger than the ID of the 3rd gear, then bore the 3rd gear hub until the remains of the 5th gear could be pressed nicely inside. A quick bead around it with the TIG and voila, 0.7 5th gear for the 012 transmission.

Might not happen right away but definately food for thought.  

[Syncroincity]

[QuickTD]

Some pics to maintain interest,

The donor,



The recipient,



The donor engine, fuel tank, exhaust, wiring and cluster are out, canadian thanksgiving (time taker... ) tomorrow so no progress until Monday. Should be able to get balance shaft delete done and clutch installed at that time.   

[JFettig]

Here,this might help http://www.v12diablo.co.uk/resources/gearbox/type012/

[QuickTD]

Thanks, thats good stuff right there!

[QuickTD]

I had a chance to finish dismantling the V6 trans tonight and I have some interesting observations. The fixed 5th gear is retained only by a heavy press fit on the mainshaft, no splines, no keys. This is good news beacause it simplifies the fitting of third gear in its place. All I have to do is bore the spline out of the 3rd gear and press in a bushing sized for a tight fit on the mainshaft.

 The shifting 3rd is even better, it is a direct fit in the 5th gear location. I originally thought it was wider but it is only the gear face that is wider, the overall width is identical. They use a slightly narrower single row bearing in the 5th gearset for snap ring clearance, hence the different wear pattern on the bores.

 Due to the helical gears, when flipped the thrust directions will be opposite, no problem on the fixed gear, it is locked to the shaft and the input shaft can accept thrust in either direction. The shifting gear is locked to the shaft between the syncro hub and the fixed 4th gear when under power, therefore no motion relative to the shaft when loaded. The output/pinion shaft can take tremendous thrust in any direction as it is suspended on back to back tapered roller bearings. I see no problems arising from thrust. 

I just have to pull the 1.8t trans, it has the "good" final drive and the 3rd gearset I want and it will be the case I use. Bush the 3rd gear. Then reassemble the 1.8t box using 3rd and 4th gearsets from the V6 to fill in the gaps and top it off with the new inverted third as 5th. The ultimate wide ratio TDI gearbox. Well not quite, a six speed would be better but...

Here is a pic of the V6 3rd and 5th gearsets side by side. 3rd on the left 5th on the right.

[JFettig]

Very interesting, would you mind taking a few pics along the way? I have a spare trans here and I'd love to get it all set up to drop in if I ever wreck the one in my Passat.

[QuickTD]

I will document ther process completely.

What trans are you running in your B5? What are the ratios and how do you like it?

[JFettig]

Mine is the stock 012 trans that came with my passat - DHL is the trans code, its a real TDI trans.

I wouldn't mind having a spare with the torque levels I'm running.

[R.O.R-2.0]

Mine is the stock 012 trans that came with my passat - DHL is the trans code, its a real TDI trans.

I wouldn't mind having a spare with the torque levels I'm running.

those trannies are fairly tough tho..

or do you have ASTRONOMICAL amounts of tq?

[JFettig]

I'm running probably just over 300ft-lbs of torque. A transmission builder(Scott Dewitt of Advanced Automotion) says I'm pushing my luck.

[QuickTD]

JFettig, I looked up your trans code and it does indeed have a very tall 5th (0.68) but a lower final drive (3.889) than the newer 1.8t and V6 transaxles. An overall 2.645:1. My intended build will end up 0.70:1 with a 3.7 final for an overall of 2.59. Having driven a B5 passat TDI, do you find your gearing tall or short? If you could change it which way would you go?