Builds Another Prado in Montana (4 Viewers)

[Nas90tdi]

Way easier than when it's in a VW, I can promise you that. I have changed 2 of those timing belts. Getting to them is the problem.
I can't wait to see how this performs in the Prado. Makes me wish I had a manual trans in mine. Those engines get crazy fuel mileage in the VW's.

 

[AirheadNut]

Yeah, I’m really looking forward to the mileage and low end torque. My current daily is a ‘97 Jetta TDI, and I get about 50mpg out of it. The way it pulls from idle, even in third, is really nice.

 

[AirheadNut]

A couple of days ago I got the old engine mounts cut off, and was able to finally get the engine dropped down far enough to line up with the bell housing.

At this point I realized that the TDI vacuum pump mounted on the rear of the cylinder head posed a major clearance problem. With the engine still nearly 3 inches away from the bell housing there was little space left against the firewall. Luckily the vacuum pump comes off easily; and only needs a block off plate.

 

[AirheadNut]

So I picked up a little chunk of 1/4" aluminum plate, traced the outline, and cut out a blanking plate. I still need to get some correct length bolts and seal it up with gasket maker, but it serves to keep the dust out until then.

 

[AirheadNut]

Back in with the engine! I spent several hours wrestling with it trying to get the input shaft to line up and go into the clutch spline and pilot bearing.

Now I discover that there are more clearance issues! The oil feed line for the turbo hits the fuel lines, and the manifold comes really close to contact with the insulation. For being such a tiny engine it sure fits tight against the firewall.

At least my oil pan has plenty of space, and I will be able to run the stock AC compressor on the RH side under the turbo, with the VW compressor on the LH side converted to an air compressor.

At this point I see two options:
1. Slide trans/t-case forward 1+ inches to help the engine clear the firewall. This may involve shortening the front driveshaft.
2. Source a 3.4 (5VZ-FE) bell housing and input shaft (the 3.4 input shaft and bell housing were about 1" longer than the 3.0)

Any thoughts? Leaning toward option 2, it will probably cost less and be easier to accomplish.

 

[JimmyPrado]

I'd vote for Number two, easier and quicker with less potential for But, I'm not the one to ask.

 

[AirheadNut]

I have potentially sourced another complete R150f from a late '90's 4Runner, which should provide the bell housing and input shaft. Now I just need to figure out if the additional length gained will be enough.

 

[AirheadNut]

A week or so ago I picked up an R150f from a '98 4Runner. It came with the bell housing and transfer adapter. The plan is to swap input shafts and bell housings to gain an extra inch of clearance from the firewall.
Here it is after a bit of disassembly:

I also got the transmission and transfer pulled out of the Prado:

I tried to unbolt the intermediate plate and transmission case from the transfer adapter, but the two bottom bolts are on the inside of the transfer adapter. Next I tried to remove the transfer case from the transfer adapter, but there were several bolts inside there too. SO...the whole thing has to be taken apart, just to get to the input shaft! It's like having to start at the clutch to replace the front crank pulley!
Here is the staked nut on the rear output flange:

Output flange and bearing retainer off:

Next up: get a 36mm socket to remove the staked nut on the transmission output shaft.

 

[JimmyPrado]

This went from “interesting swap” to “way beyond anything I want to do”. Good on you and maybe the best part....doing it on gravel and plywood! You’re a beast with a wrench. Hats off!

 

[AirheadNut]

Thanks for the compliments! Not sure if I can agree about the "best part" though It is definitely beyond what I had intended on doing as well, but I figure it is a learning experience.

Here is the rest of the donor R150f teardown. (I didn't take many photos, it was a really messy job and my phone doesn't appreciate gear oil!)

This part required way more force to pull off than I felt comfortable with. I was convinced that something would go catastrophically wrong, but it finally gave way and slid off.

 

[AirheadNut]

My brother lent a hand and we got the transfer case all torn down.

Also got the transmission separated from the transfer adapter.

The Prado trans is WAY cleaner inside than the donor trans. But then it should be after only 70k miles.

 

[AirheadNut]

It was a lot easier the second time around!

Trying hard to keep all of the little bits and pieces straight.

 

[AirheadNut]

I have decided to replace the four main bearings in the transmission, so this part of the project is held up for a bit while I wait on parts.
Here are the transmissions waiting to be put back together: on the right is the Prado trans with the post-'95 input shaft, on the left the 4Runner trans with the Prado input shaft.

Output shafts look pretty much the same:

 

[AirheadNut]

Progress has been frustratingly slow, but things are getting done. Upon inspection of the transferase bearings I discovered the cause of the grinding noise I thought was coming from the transmission. Both tapered roller bearings on the main output shaft were pitted and rough, so I added new ones to my order. Quick note for those that may need to replace these: on the parts websites there are two options for the bearings, 90366-35011 and 90366-35035. I wasn't sure which I needed, but it turns out that one is the front bearing and one is the rear, so one of each is needed.

A box showed up and I could get back to work:

New bearings pressed on:

The rear output bearing was bad too, so I replaced it as well:

 

[AirheadNut]

New transmission input shaft bearing:

And then all of the transmission internals were given a wash in the solvent tank:

 

[AirheadNut]

I have also spent some time working on routing the new engine wiring. Originally I didn't think that I would be able to fit the VW ECU under the dash in the stock location, so I was planning on making a sealing aluminum box in the engine bay to house the ECU and fuse panels. This was my hi-tech mockup:

There was also the issue of getting the massive ECU plugs through the hole in the firewall and threaded up to the glovebox area:

However, I revisited these problems recently and discovered that the VW ECU does in fact fit under the dash, and it fits so tightly that there is hardly a need for a bracket to hold it in place.

I also found that if I cut off the glow plug harness, I could thread the wiring harness out from inside the dash. This is a win-win situation because the VW glow plug harnesses tend to get brittle and break, and since there isn't a plug where they attach to the main loom, the wires have to be cut and soldered every time it is replaced. Now I will only have to add connectors to the new glow plug harness if I ever have to replace it.

 

[AirheadNut]

The TDI wiring is in!

But it does need some tidying up...

 

[GTSSportCoupe]

Good progress, and thanks for providing us with the updates!

 

[AirheadNut]

Made some more progress during the last couple of days. I started by giving the transfer case parts a wash and then launched in on the transmission. I must have been tired because several times I had to take it back apart to put in a bit I had forgotten.

And the finished unit:

I bolted on the shifter to see if everything felt right, and then waited for the sealant to cure.

 

[AirheadNut]

The next evening when I went out to assemble the transfer case I noticed two little bolts left and immediately knew what they were for. The whole thing had to come apart again!
Take 2:

The missing bolts were for the shift forks; it is a good thing I saw them since only 5th and reverse would engage without them!

I also found that I had not staked the 32mm nut on the end of the counter shaft, it must have been a really bad day!

Getting everything sealed back up again.