my tranny went out and i dont know whether to go with a built 4l60e or a built th400. if i went with a th400, how would highway driving be like with my gears since it will be a daily driver? what about the costs? which would be less? what parts would i need for the th400 swap? who makes the best th400 or 4l60e? any info would be appreciated.

 

Lots of questions!

How would it be on the highway? It's kind of subjective, what's ok for one person is intolerable for another. A lot depends on your exhaust system. If it's quiet, the highway rpm's will seem a lot more tolerable with a TH400 than if it's a noisy system. Fuel mileage will suffer (a lot) if that matters to you. FWIW, when I was young (sixties) very few cars had OD. I drove a Dodge Charger R/T with a 440 wedge and 3.73 gears all around the Eastern US for years.

Cost? Depends on what you get. No matter how much you spend on a 4L60 there is no way to make it as strong as a good TH400. IOW, you can't get a "bullet proof" 4L60 at any price.

You don't say much about your setup. The real question is: do you need a TH400 to handle the power you are making? Just to pick a number, if you are in the ~450rwhp range I'd call that a practical limit for a 4L60. You car will be slower with a TH400.

The swap from a A4 to a TH400 is pretty simple.

Carl Rossler builds excellent auto trannies.

Rich Krause

 

I would never bother with a TH350. You lose the OD and it's not as strong as a TH400. Only advantage: about 15-20# lighter and a little less parasitic loss (couple of hp) than a 400.

Just IMHO.

Rch

 

look at my sig for setup. i raced my buddy with almost the same setup as mine and i beat him. he dynoes at 435rwhp and 476 ft lbs torque. he's doing 11.8@11X. that might give you an idea.

 

if i go with the th400, how much slower would it be? what parts are associated with the swap? i might be spraying a 150 shot at most but i dont know yet.