VW TDI auto to manual converted - Fuel Economy, Hypermiling, EcoModding News and Forum

UFO · 09-14-2015, 07:17 PM

Finished up my conversion this past weekend. I removed the 01M 4 speed automatic from my 2001 Beetle and installed a 02J 5 speed (TDI ratios). I'm looking forward to 20% better mileage without coasting, and even better now that I can truly coast (no engine off though, not going to lose vacuum or power steering).

MkVer · 09-15-2015, 08:38 AM

Do you have electric or hydraulic power steering? A lot of newer VWs have electric power assisted steering that gradually turns off as your speeds go up. Efficiency as well as safety, harder to make large abrupt inputs at speed. I know that's the case on my 2005 Jetta. So EOC would just be a Vacuum loss.

UFO · 09-15-2015, 11:38 AM

It's hydraulic. If the engine is off, the steering effort is considerable. Electric assist would be great, but it sounds like an involved conversion even if the parts bolted in.

One thing I now notice with the transmission conversion is how much drag the automatic presented. I did a lot of coasting in N with the automatic, and got used to how the car rolled. With the manual it seems as though the car has been freed, it just rolls and rolls. So coasting in neutral with that automatic did net better mileage, I think it may also contribute wear to an already inefficient and unreliable transmission.

MetroMPG · 09-17-2015, 01:52 PM

How are your numbers looking with the new transmission?

Did you document it anywhere? Can you give us a summary of the job, cost & how difficult?

UFO · 09-17-2015, 02:20 PM

I don't have any mileage numbers yet, my Scangauge calibration is completely off, but now I have at least calibrated the "speed", meaning the miles indicated. I did fill it yesterday and I may fill it again this weekend to get a first look at the new mileage capability.

I started this thread on tdiclub just showing the issues (minor) I had in doing it.

Starting a automatic to manual conversion - TDIClub Forums

Total cost looks to be about $1500. I bought the shifter, clutch pedal, starter and transmission with a lot of other miscellaneous parts from a local person for $900. The rest of the expenses were for fluids, hardware, shift knob, new relay, new flywheel and clutch, and an aftermarket shifter to avoid interference with the power steering hose (manual and automatic are different).

The main difficultly was extracting the old transmission. I supported the engine with a Harbor Freight support bar ($65), and used a transmission jack to get it out the bottom once separated. It's very heavy and needed rotation forward, and of course the axle flanges wedged between the subframe and the engine. Installation of the manual transmission was much easier as I removed the axle flanges, it's almost 100lb lighter and needed no rotation.

The trickiest part was the wiring. The reverse switch was spliced in to one of the old automatic connectors, and there are two switches on the clutch pedal to wire, one to the starter interlock, the other to the cruise control. Unlike the gasoline VWs, the TDIs share an ECM between manual and automatic models, so I just used Vagcom to tell it the good news about the new tranny.

MetroMPG · 09-17-2015, 02:49 PM

Quote:

Originally Posted by UFO

Unlike the gasoline VWs, the TDIs share an ECM between manual and automatic models, so I just used Vagcom to tell it the good news about the new tranny.

That's a nice bonus.

Well keep us posted once you sort out calibration & get some tank numbers.

deejaaa · 09-17-2015, 03:42 PM

there are several autotragics for sale much cheaper than 5 speeds around Houston. would get one of those and perform the swap if my jetta ever gives up.
EOC is not really that hard with the MK4. brakes are good for 3-4 pumps before vacuum is depleted. steering is only harder on slow turns. I have a push/pull kill switch mounted to the shifter. I bump start all the time if the light changes before I have to stop. next is to install a push button wired to the starter next to the kill switch.