Vert tranny into s4 coupe, now speedo off!!!!
 

I searched for the last hour and a half and have come up empty handed. I put a S4 vert tranny in my s4 sport, now my speedo is off. It reads quite a bit faster than it should. I still have my old tranny, can I swap the speedo gears to correct the problem? If not, what do I need to do? :dunno: Thanks for the help! :bigok:

If it reads faster than you have too low ratio of a speedo gear than the dif.

If I'm not mistaken, the dif on the vert is 410 or 430.

You probably have a 390 (or 410) speedo. 390s came from automatics.

Anyhow, you need a new speedo gear. I've got a spare 410 if it turns out you need it.

Isn't this in the faq?

Edit: unless you changed wheel sizes. Then who knows what you need.

Well.....I got a s4 sport, it ONLY came with a stick, so I KNOW I have 4.10. 4.30 came on GTUs models, and a 3.90 came on a auto....... My tires didnt change, ONLY the tranny,and there was a VERY noticable change from the last s4 tranny I had in it.

BTW this isnt in the FAQ.......hence the pharase SEARCHED...............

Nevermind I found it. Verts came with a 3.91 rear gear EXCEPT 1990. Great, anyone know how I can correct this besides swaping in a vert rear gear?

i need my 390 speedo gear. Get one off an auto-tranny from salvage. All autos to my knowledge had a 390 rear dif to go with them

10-4, so all I need is an auto tranny speedo drive gear. Thanks for the help.

just swap your old speedo gears.

Pull the 4.1 (20 tooth) from the old M85 tranny (S4 non turbo tranny) and put it in the M50 (vert tranny)(19 tooth- speedo gear).

and only the 88 vert had the 3.9 rear end. all other verts came with the 4.1 rear end (even the auto tranny versions).

Didn't S4 automatics also have the 3.9 rear end?

Yes, but there were no US spec verts except the the 88 that had the 3.9 rear end.

So if his speedo is off, then he has a M50 tranny from a 88 vert and needs to use the M85 speedo gear from the old tranny to fix the speedo being off.

*NO* you need a 5-speed coupe speedo gear, the 3.90 speedo gear is whats causing your problems.