Late model 4 speed overdrive unit

[garner7555]

I was looking at the later model 4 speed overdrive unit to stick in my charger for cruising. I have heard they are weaker than my old non overdrive 4 speed. My question is how much weaker?  Both units are 23 spline. My car is a street car that honestly gets driven very hard.  My 440 is pretty mild, maybe 450hp at the crank?  Thanks.

[Cooter]

As with anything, one guy gives real world advice and in comes some yah hoo that claims he had one live behind a 700 C.I. hemi for 20 years.

I've never been a fan of aluminum case trans'. The case flexes and thats the weak link. Countershaft bearings catch hell, as in OD your running third gear.

[Troy]

How much do you plan on driving and how? It's not likely to last behind a big block in a car with slicks at the track. If you just want to cruise it's fine. However... in a non-OD 4-speed transmission 4th gear is "locked" 1:1. Everything else requires some combination of internal gears to be moving. In the OD transmissions the locked gear is 3rd and in OD there's a lot moving around. This, inherently, makes 4th gear weaker and also contributes to extra wear when driving a lot in OD. If you only put 1,000 easy miles per year on your car it will likely last a long time.

Troy

[garner7555]

Thanks for the replies!!  I'm not gonna run slicks, but I do treat it ruff.  Maybe I should just stick with my non-overdrive tranny.      

[A383Wing]

Thanks for the replies!!  I'm not gonna run slicks, but I do treat it ruff.  Maybe I should just stick with my non-overdrive tranny.      

probably a wise decision

[Troy]

Well, there are guys here who do take them to the track - just treat it like a 3-speed. Use 4th for the highway. The worst thing you can do is get it to "hook". On street tires driving on the street it's unlikely that you'll ever get "too much" traction.

Troy