1Z-AHU trans into A4?

[dieselherb1]

Gear ratios are better with the 96-98 TDI trans(3.15 r&p,.75 5th) than the A4(3.38 r&p,.75 fifth) I'm thinking better fuel mileage? Holes in case are smaller(bolting to engine) but can be drilled out. Any other problems? Or is the reason they run 15" tires? Would change the ratios that much?

[Powered by Spearco]

The shift tower is different. Unless you swap them. The trans mount bracket is different. One less bolt hole.
The holes in the bellhousing side should not need boaring out. If they are smaller, then boar them out.

[8v-of-fury]

Less than a 200 rpm drop whilst cruising. Completely not worth it.

You could achieve the same rpm drop by driving four (4) miles per hour slower

For the amount you'd save with the lower gear, it would take years and years to make back what you spent lol

[dieselherb1]

I have 2 ALH, 1 1Z trans now. Only 200 rpm diff. between 3.38 and 3.15 R&P? Plan was to put into Caddy with hydraulic-cable shift.

[8v-of-fury]

Yep. About 152rpm drop if you want an exact answer lol.

I think the ALH trans is an 02J isn't it? That will be a bit harder to get sitting in the caddy bay. the 1Z trannies will be a lot easier to get mounted.