Skydive@AI

So some of you might know that my car is actually a B5 S4 equipped with GT28RS turbos making something over 600 horsepower and 480 pounds of torque. I had a Level10 built 5HP19FLA gearbox in it, which failed dismally the other day. (The transmission won't engage 4th or 5th, and exhibits very stiff engagement from 1st to 2nd.

I have consulted with both IPT and 2Bennett, both of whom have offered to build a better mousetrap using the same 5HP19FLA. However, I have also spoken with a former Level10 employee who has admitted that very little was actually done to my transmission in the first place, using Home Depot parts.

So... on to the next idea. I have acquired a lightly used 5HP24FLA from an RS6 salvage at a good price. The case and bolt mounting physics work, and since I know that Champion ran 6 speed manual gearboxes on the race RS6s, I know that that part of things will likely work also. I may have to work out a custom driveshaft, but that's not difficult. I don't know much about the TCU, but I have been told that it is very similar.

I am concerned about the RS6 transmission failure modes. I know that the same gearbox has been used in some other very powerful cars with success. (See the link below.) So... what makes them fail in the RS6? I am already planning to fit an auxilliary cooler, and I may send the torque converter out for rework. The S4 is significantly lighter, and doesn't have a mammoth 4.2 motor parked in front of the transmission, so conditions will be better in that way too.

Can those of you who are familiar with transmission failures provide me with details? What fails, and why?

I will keep you all posted as I continue to delve into this project. Meanwhile I suggest that you all avoid Level10. If you are looking for alternatives, I can point you in the right direction.

Thank you!
-Michael<ul><li><a href="http://en.wikipedia.org/wiki/ZF_5HP24_transmission">http://en.wikipedia.org/wiki/ZF_5HP24_transmission</a</li></ul>

hahnmgh63

The DRC is a simple fix compared to this with suspension choices from Stasis, Biltstein, and KW. Compared to this, the tranny is an expensive and subjective fix, although it doesn't sound as though it is as common as the suspension. My DRC is working fine at 50K but I'm not too worried about when it goes, the tranny on the other hand, that worries me....

Skydive@AI

Well... as a B5 S4 owner, that's not a problem I face.

Radiation Joe

... Driving downhill on an onramp at about 45 mph steady speed looking for a point to merge in. The car was holding a gear, sort of like it was waiting for me to make up my mind. So far, so good. When I hit the throttle, CLUNK! then the car accelerated normally (quickly). It's never done this before.
Anyone else had a similar occurrence?
TIA

maxcpa

Felt like the bottom was falling out. I've discussed with mechanic and he is coming by the house to check into it.

The clunk is an eye opener.

rs6mad

any issues, that means keep it in tip for hard driving.

Ive given mine a hard time and running quite a bit of torque and havent had any issues but I have also upgraded the cooling system and fluid

Skydive@AI

Thank you.

maxcpa

The mechanic came by yesterday and confirms an unusual sound. Further, he did a scan of error codes and test drove. He stated there was one event that was an "incorrect gear ratio" error code. He reset and drove it around and did not receive any further error codes.

The mechanic wants to try a "tranny fluid and filter change". No "warm fuzzy feeling" that this is going to correct the issue.

This means another trip to the dealer so they can "trial and error" the issue.

To add insult, I just had the entire suspension rebuilt (shocks, valves, sway bar, control arms, etc..). Yet the car also was returned to me above with a new "clunking" on left rear tire. The mechanic confirmed while he was here and suspects it is "something" with the suspension. They are to look at this issue as well during this continued repair epic that started in Nov/07 when the service dept. performed the 75K service.

AoA does not seem to give a rip. However; I am going to bend their ear once again to see if they can do something to get my car back on the road.

I feel that I have been overly patient. The car is great when operational- but has been a nightmare since Nov/07.

rs6mad

No problems

rs6mad

Sorry to say but that error means there is a total failure on its way