Audi CVT replaced by VW Tiptronic? Will it work?

[nickthomas17]

I have an 03 A4, 1.8t, CVT with a bad trans, can I replace it with a tiptronic from an 02 Passat, 1.8t.
Im pretty sure it will bolt up, my concern is with the TCM.

Yes I searched and could only find swaps to manual, the tiptronic I already have in a donor car. Didnt want to go through the trouble of bolting it up and couldnt get car to recognize the TCM. Would wiring need to be changed as well? I have a VAG-COM, if this can be used to assist reprograming if needed.
Thanks in advance

[nickthomas17]

Both cars FWD

[redline380]

Seeing as how this is the B5 section, I think you should bring your question elsewhere.

However, I am about 99% sure you can't just "bolt up" a tiptronic tranny in a CVT car. The two transmissions are way different

[TDR]

That's something I wouldn't even attempt on a Japanese car based on my knowledge of their electrical systems. German can only be worse.

[ianwpb]

I would do some research on the TCM from the 03 A4 1.8t Quattro. I believe the CVT was only used in FWD models and the Quattro's had regular auto trannies. It may be possible that the TCM would work with a FWD auto trans from another model.

The easier thing to do would be to swap over a FWD manual trans from the same year.

Or... you could go all out and do a Quattro swap with a regular auto.

[Nebone]

Hmm. Interesting swap.

You would need to change the engine harness and axles and that should be it. The transmission will bolt up no problem.

[nickthomas17]

Sorry if im in the wrong place, if an admin need to move me, then please do.

Engine harness move also, great idea. Engine would be exactly the same, this would take care of any trans sensor adaption issues.
I have measured the axles on each car, not the same. axles will need to come with the tip.
I would do the quattro swap if I had the donor parts, not too many Audi wreckers around here.

Thanks for the replies, any other thoughts?

[Scotty@Advanced]

It may be possible but likely not probable. Lots of differences exist.

[walky_talky20]

Everything will bolt up, but tons of work with wiring. Where does your Tiptronic TCU plug in? Where will your Multifunction Range Switch plug in? You have none of these connectors. All of the harness will need to transfer. (IE: you'll be tearing out the dashboard.) BUT, you don't have a matching-model-year tiptronic B6 to transfer from. It's a Passat. So there are big differences. While "possible", this will be very challenging to do.

Better idea: 5MT FWD swap. Transmissions can be had for $150. Another $75 for some axles. Clutch kit, a couple pedals and you're golden. Well...maybe not quite that easy, but way more doable than a Tip swap.

[nickthomas17]

Yes I see where you are coming from, probably more work then I need at this point. This is why I asked.
Thanks guys

[walky_talky20]

5MT FWD swap is "where it's at" for a car with the CVT blues.

If you had a car with a working CVT trans, you could probably *make* money by doing the swap.

[redline380]

I'd like to know what kind of electronics go into a CVT tranny. They are basically the same principle as a snowmobile "cvt transmission" and those require zero electronics. Its all mechanics. (Walky know anything about sleds?)

If my hunch is correct, since CVT trannies require little, if any, electronics, a FWD manual tranny is indeed "where it's at." I think walky is dead on here

[walky_talky20]

Walky knows fairly little about sleds. But I understand the mechanical CVT bit.

The Audi CVT is highly electronic. It chooses ratio not based on merely centrifugal force, but on engine load, throttle position, and the all-important "sport factor". Of course there is the ability to manually choose ratios as well. And the rate and willingness to snap between the ratios is also fully electronic.

My recommendation is based on the following facts. There are 3 different types of transmissions equipped in B6 A4's:
CVT: electronic contol
Tiptronic: electronic control
Manual: no electronics

So if you want to convert from one type to another you have to consider this. For example, swapping a tiptronic transmission into a car that originally had a manual trans is a big undertaking. You have to add ALL the wiring to support it. And it's not easy, separate wiring. It's integrated into the entire wiring harness. It's almost not do-able unless you pull the interior and dashboard and swap the entire wiring harness. Same thing with swapping CVT to Tiptronic (or the other way). The harness is so different and integrated, you'll have a couple days just getting the harness changed over. Assuming you can even get a full harness to do the job.

But going from either CVT or TIP to a manual trans is easy. This is because you are just *abandoning* some of the existing wiring. You are lowering the complexity, not raising it. You tap 2 wires for Reverse Lights, run 1 wire for the clutch switch and you're done.

So that's reason number 1 that 5MT is "the stuff" for a broken CVT car. The other reason being the 5MT FWD box is CHEAP. Like mega cheap. $100 all day. Compared to $2,000 for a used CVT box, this is a no brainer. Bolt in some "actual gears" and be done with the CVT drama. The TCM's, the transfer clutch, the expensive fluid changes. All of it.