1994 4x4 5speed TDI swap

[chickenman]

This will be my documentation of how I TDI swap my ranger. Stay tuned.

I will be posting most updates on my new member page, and saving this one to big updates.

 

[chickenman]

Update!

Clutch replacement, drive train inspection, power steering box replacement

I got all my parts in last week, that I think i will need to fix my clutch problems, and the huge play in the steering. Not to mention a couple specialized tools.

I was able to get everything off reletively simply with the transmisssion removal, until the manual said remove the exhaust, since the v6 pipe crosses under the transmission. Unfortunately all the bolts were ver seized after almost 30 years. A reciprocating saw works really well.

More is to come soon!

 

[chickenman]

Turns out what i thought was a bad slave was actually the clutch wheel its self, as you can see. The kit off ebad I bought also had the needle bearing which was easy to remove and replace with a slide hammer.

 

[chickenman]

As the day approaches that the body of the truck is ready for the engine, I have been thinking about how the new engine will perform compared to the 4.0 l in the truck. There are so many factors that play into fuel economy, acceleration, and cruising rpm. Im building this truck for fuel economy, but off road and power are still in my mind. I found a calculator online to compare the original jetta trans/ diff ratio/ tire size to that of the ranger. I have attached the pdf of the graphs below.

The ranger has the 3.75 diff ratio, and my hope was to put a 32 in tire on it. However as you can see things are a lot different for the engine.. I will say i need to fact check the rangers diagram because i remember pretty high rpm on the interstate for cruising, but I could be wrong.

 

[chickenman]

Upon further thought, I graphed the shift points with the sought after axels with 4.10 diff ratio.. the plot looks a lot better.

Needless to say, I see a new axel in my future.

 

[RonD]

What the torque curve on the TDI?

4.0l OHV makes best torque at 2,400rpm

 

[chickenman]

From what i see, some where around 177 lb- ft @ 1,800 rpm. other sources, 177lb- ft @ 1,800-2,400 rpm. Completly stock.

Upgraded, 300 ish Nm @ 2,400 rpm.

Hp 99 hp@ 4000 rpm stock

 

[chickenman]

What the torque curve on the TDI?

4.0l OHV makes best torque at 2,400rpm

 

[chickenman]

300 Nm = 221 ft-lb

 

[chickenman]

The truck currently has the dana 35 with the 3.73 gear ratio, obviously if i switched axles id have to go to the dana 28 with the 4.10 gear ratio.

 

[RonD]

There is about a 400rpm difference between gear ratios, 2nd and up

Which if stock TDI would be the difference in peak torque, 1 gear ratio

If you calculate same peak torque RPM on new engine as the 4.0lOHV then you can used the 4.0ls calculation for best axle ratios

 

[chickenman]

Using the same calcultor, but with shifting TO the optimal rpm, I think I conclude that if i swap the diff gears for the 4.11 s it will be very close to stock, when running 32 in tires.

 

[RonD]

Yes, if stock tires were 28" with 3.73 and you changed to 32" tires and 4.10 it would "act like" 3.60 ratio, so close to 3.73

 

[chickenman]

Yes, if stock tires were 28" with 3.73 and you changed to 32" tires and 4.10 it would "act like" 3.60 ratio, so close to 3.73

Yeah stock on the truck are 265x75/15 so basically 31s

 

[scotts90ranger]

The truck currently has the dana 35 with the 3.73 gear ratio, obviously if i switched axles id have to go to the dana 28 with the 4.10 gear ratio.

Not necessairly, there were factory D35's with 4.10's although not common, mostly just 4 cylinder 4x4's...