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TH400 vs. 700R4. Which is better?

Or build a 700r4 to be stronger. I took the specs from Bowtie Overdrive and had my local shop build me a very beefy 700r4 and it has been flawless. I can now cruise easily on the freeway out to my wheeling spots in overdrive and then enjoy crawling around the desert with a low first gear and coupled with my triple stick doubler, it is heaven for wheeling.
 
if i had to chose id take the 400... bullet proof and much better for me.(towing)...
 
The 3-4 gears tend to fail in the 700r4 even in regular daily driving. TH400 is a brute.
 
Another :zombie18: thread from the dead brought back to life!..

My vote is for the TH400....never liked any overdrive automatics,not even the coveted 4L80E they say is so great...all the computer controlled automatics with solenoids seem to fail a lot..
That said ,I'm not really fond of any of Gm's manual transmissions either,though I have never owned or driven any with the newer 5 speeds..the gear spacings are just too wide in most of them..
 
Easy....

TH700 - 1/2 ton, Stock, DD, Light towing, Hwy driving, Light off road
TH400 - 3/4 - 1 ton, Stock - heavy modified truck, Med - heavy towing, Med - heavy off road.
 
1-ton said:
My question is...how could this person have driven this truck, and not know they did not have a transmission with overdrive?
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Probably bought it not running...
 
rayfin said:
The 3-4 gears tend to fail in the 700r4 even in regular daily driving. TH400 is a brute.
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My experience is that the tv cable needs proper adjustment. Quite a handy skill.

Also be certain to flush the radiator of clutch debris after 3/4 clutch replacement or you will be back underneath again in 3 months.
 
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IMO the biggest killer of a 700R4 is to lift the vehicle 4 - 6 " off the ground. Put 35 and larger tires on it and leave the stock 3.08 gears in it. I pull my 3000 pound boat 150 mile round trips to the lake in overdrive. except on long uphill grades. This 700 R4 is locally rebuilt with all the good upgrades and a very large cooler. It has no shift kit. i have abused it for 15 years and it still chips the 35 going into second. I have 4.56 gears. Most all 700R4 failed due to user abuse. My 2 cents worth.
 
If you are chirping your tires on the 1-2 shift you definitely have a shift kit and probably a billet servo. No stock 700 is going to shift hard enough to chirp tires!
 
Not to argue,but I've seen many 700R4's that were "babied" and never used to tow or plow,and they failed with under 70,000 miles,usually from a broken sun shell ,they lose overdrive at first,then 3rd,and though most still would propel the vehicle in some forward ranges enough to limp to a shop or home,reverse usually failed too...

I think the 700R4 could have been a very good transmission if GM had done more "torture testing" and not skimped on the quality of the hard parts inside them...the TV cable is another weak point that was responsible for frying a good many of them as well..
The main advantage to the 700R4 is the lower first gear ratio,that and the overdrive,especially if you have low gearing in the diffs and stock tires...heavy duty they were not though,in stock form..
 
MAXMAN said:
If you are chirping your tires on the 1-2 shift you definitely have a shift kit and probably a billet servo. No stock 700 is going to shift hard enough to chirp tires!
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No shift kit or billit servo was added to the rebuild.
 
Thats not chirp thats clutches slipping.
 
82355 said:
No one said the TH400 was better, equal to, or worse than a TH700R4. Everyone pretty well agreed that the TH400 was stronger (it also has a heavy parasitic power loss, I don't care for them, I'd rather have a TH350 if I was stuck with an auto, but that is a different point all together), and that the TH700R4, while weaker, did have the advantage of a lower first gear and overdrive. You said they were junk. You do realize that the 2 that you have experience with were both pre-87 which means they didn't have the upgrades from GM, right? A 1987+ TH700R4/4L60 is a superior transmission to the pre-87 TH700R4's. It was a pretty broad, and unsupported statement.

Martin
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Basically the 700r4 before 1987 were like experiment transmissions until everything got right after 1987.

Today , a 700r4 with today's technology can be built to withstand 500 to 600 horspower from a 454. Just not way above that if you want to do drag racing
 
I have a built 700R4 in my K5 with a strong 350 and 40's. This is the 5th year this truck has been running this trans, and I absolutely beat the snot out of this truck. I am a firm believer that a built 700 can do what you need it to do. That being said, I have a TH400 sitting waiting for the day the 700R4 finally lets go. Why? Because I want the brute strength associated with the TH400 and plans to combine a doubler behind it. My 700R4 has gone above and beyond what everyone has told me it was capable of.
 
The number assigned to a trans tells you the application. For example, 4L80-E has 4 speeds, is longitudinally mounted, with a relative torque rating of "80". Those with a "T" in them are transverse mount (i.e. front-wheel drive). E means shifted by electrical solenoids. In this nomenclature, 700R-4 is 4L60 and TH-400 is 3L80 (TH-350 would be 3L60, but that designation is not official).

Apparently "80" = 440 lb-ft and "60" = 360 lb-ft, so the bigger transmission is "rated" as 22% stronger. (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 :pimp:). However, it seems like in practice the '00s 4L60s improved in strength from the early 700R-4 even more than the 4L80 improved from the 400 (3L80). The disparity is therefore more than 22%, but a later model 4L60 does seem to have the strength of a TH350.

As an aside, be wary of the ratings from aftermarket transmission builders, as they seem to be focusing more on breaking strength, where the GM factory ratings are accounting for 150,000+ miles at those loads.
 
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