MACH-E55

So im going to be getting ecu+tcu flash with pulley. Ive noticed that there is a decent amount trans failures recently. Ive also noticed that a few guys with the failure have tcu tunes. I was just wondering if the tunes have a negative effect? Does anyone know or have exp with this? Or are these failures just bound to happen due to the nature of mileage on the vechicles and the power they put down(aggressive driving)?
Thx guys or any input!

GregMB

You could argue that one from either side.....

Faster shifts with a TCU tune should result in less slippage, and therefore less transmission heat and wear

(or)

The removal of torque management limits will increase the power going to the rear wheels..... with street tires, this is probably more of a tire wear issue than a transmission wear issue. With drag slicks, it's a whole different story. Plenty of traction = plenty of stress on everything.

I'd say it's hard to point the blame at the TCU exclusively for ANY transmission failure. It's not like the guys losing transmissions are 100% stock otherwise.... these guys have tons of other mods and are pushing a couple hundred extra HP too.... oh, and the a lot of these cars are now at 100,000+ miles....




-G

kompressede

First I would recommend a tranny service (flush). Then I would really weigh out doing a TCU flash.
You'll find people that do a TCU flash highly recommend it, AND you'll also find people doing some very good 1/4 mile times on a stock TCU flash?

berti_00

+111111111111111 on the trany flush... when we say flush it meas just drop the pan drain the oil swap whatever filter necessary stuff need and refill it back up. and as far as TCU goes, i did the TCU after my flush along with ECU car shifts like butter its quick and its awesome...

AKnight55

I can think of a few members whos tranny failed after a flush..

Toadster

I'm curious as to how many transmission failures occur from:

1. 1/4 mile junkies
2. daily drivers
3. occasional drivers

I don't believe it's all #1...

SilverStrk

I'm doing both as we speak, tranny flush and TCU tune from EC... Hope all goes well...

jcjmw

I believe you are correct.

A trans flush is when there is that machine that is actually connected to the lines and it actually flushes the trans of all the old/original fluid and whatever containments therein. The only reason why I know about this is b/c when I was at the dealer for a trans service years ago, they told me about the trans flush and pointed to some machine used to do it at an extra charge. I told them I just wanted a trans service.

A trans service is just dropping the trans pan, replacing the filter and gasket, then refill with trans fluid. No flush.

Of the threads about trans failure, I believe they were after a trans flush on higher milegae trans with no prior trans service or trans flush.

GregMB

My impression is that a lot of it is related to deferred maintenance or poor maintenance.

Automatic transmission service gets ignored almost as much as the brake system on most cars (not just Mercedes, but ALL cars).... most people ignore their brakes until the pads are shrieking or the fluid is so contaminated that it eats the system from the inside-out.....


-G

e55amgrocket

I've never been a fan of a trans flush. It breaks anything that's stuck on various places free and usually gets stuck somewhere else that it shouldn't be and causes problems. If anything just drain the fluid and refill. I loved the TCU upgrade from Eurocharged.

jcjmw

You got a point there. Thanks for reminding me about the brake fluid. I will take care of that this weekend.

MACH-E55

Alot of good info, def will go do a trans job regardless if I do a tcu flash. I was just curious if it was a patern like first came a tune then 2 months later a tranny blows, but from what you guys are saying its more from neglect thn the tune itself