It's fun to point out that the smaller transmission has a 23% lower first gear, so it's "designed" to put 1% more torque to the wheels
Hahahaha!
CK5
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TH400 vs. 700R4. Which is better?
- Thread starter Gyoas759
- Start date
Hahahaha!
Not experimental, they made millions of them. They have progressively strengthened various components. Some upgrades are backwards-compatible. My built 1983 700R4 is likely to last longer than the tranny it replaced, assuming the rebuild shop did a good job. Because they put in better parts than they took out. But it's still a marginally-better 700R4, no matter what parts you throw at it.
blackandgold51
1/2 ton status
I just don't get why GM didn't make the 700r4 better out the gate . While Ford done note bad on their transmission.
I mean was it that difficult to make a strong 4 speed transmission, compared to the turbo 400, to help with fuel savings if not by a lot?
Say what?
The 700R-4 was designed to make good fuel economy behind wimpy smog engines. I wouldn't say they tried to make it weak, but there were some areas where they didn't maintain the strength of it's predecessor, the TH-350 (like smaller input shaft). The TH-400 is a lot heavier and has a lot more drag, so the "1-ton" 3-speed wouldn't have been a good starting point to make their first 4-speed. For the 80's GM still used the 400 for heavier duty applications and created the 4L80-E as a direct replacement later.
If you're saying Ford didn't have any reliability issues with the AOD, I don't think that's fair. The AOD was like an earlier FMX with an overdrive tacked on and the overdrive did fail, similar to the 700. They used a triple input shaft with different inputs for "main" and "OD" that dictated special torque converters and other issues. Ford kept changing things (swappers beware!) all through the '80s and into the '90s.
As said above, the TH700R4 was designed to be a light-weight light-duty transmission. It did a fine job at that (look at how many are still running around the roads even 35 years later). Did they try to make it weak? Yes! That's the tradeoff if you want a light & efficient unit. It's strong enough for its target market (i.e., not dump trucks), and that's all that anyone cares about. It may get a bad rap from people with oversized tires or improperly geared trucks, but GM doesn't care about guys who mod vehicles. They care about people who buy vehicles.
And for Ford? Like any company, they've won some battles and lost others. I'd take the worst configuration of 700R4 over an AXOD. Any day of the week. But I'd take an M5OD (which Ford borrowed from Mazda) over any flavor of 700R4.
No, it wasn't hard. And when GM felt the need, they did so, with the 1991 introduction of the 4L80. That's exactly what you mentioned, a 4 speed comparable to the TH400, with some fuel savings.
blackandgold51
1/2 ton status
Ive been thinking of today of putting a 480Le transmission with the carburated 454 my Suburban has, that is c20. Along with other light modifications to help with a little mpg.
There's times that I want to go over 55 in a 70mph speed limit
