I have a few questions about the "switch pitch" as I have one in my daily driver. Is it hard to find a good rebuilder of these vs the more common TH-350/200r4 models? How long do these usually last before they start slipping? What's a common weak spot with them? My trans has 115k on it and other than needing a tailshaft bushing and various external seals, works fine (which amazes me for it's age)but would like to see what everyone has to say.

 

Mine started to slip badly around 65k. It's the only one I've had experience with so can't comment more than that, sorry

 

Easier, actually. It has fewer parts.

I do prefer more speeds with a steeper first gear, however. The 200-4R is a nice replacement for the Junkaway, and the 2.74:1 first is a big improvement over the 1.7:1 first (even with the switch pitch engaged).

 

I can tell you a few guys run these on the local dirt tracks behind big block Buicks and they have better durability than a TH-350.... and they are lighter than a TH-400.

 

X2 Joe on the Junkaway. I never liked them in my 66's due to the horrible first gear even with the switch pitch working, so I either converted my cars over to 4 speed or TH 350.

 

For what you are using it for, your trans will most likely last another 40 years. I'd reseal and service it.

 

i never had a problem with mine, other than seals being old and hard. pulled it from my '69 with 171k on the clock, tranny worked fine(for what it was). the one from the '67 was working fine too, when it was pulled at 64k. the advantage of a real first gear is why i changed to a thm400, and the 425 helped that decision come about.


bill

 

Funny how most guys with street driven cars want 3 or 4 speeds for performance and the drag racers opt for a two speed Powerglide...

 

Not funny at all if you understand physics. A two speed would also be preferred on the street if your street driving was restricted to only a quarter mile at a time at max acceleration in a straight line.

On the drag strip, every upshift represents a fraction of a second when the car is not accelerating. IF the engine's powerband, vehicle weight, tire size, and axle ratio are properly matched, a two-speed car will be marginally quicker than one that requires more shifts over the same quarter mile. That DOESN'T mean that the same car is preferred on the street, however. For street driving you need to maximize vehicle flexibility. More gears give you that flexibility.

 

I guess I should have found a "tongue in cheek" smiley...

 

Yeah, OK, fair enough. It's like the guys who think they need a 5000 RPM stall converter for the street because that's what works at the track...