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TH400 vs. 700R4. Which is better?

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Gyoas759

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Just wondering what the advantages and disadvantages are to each tranny and if one has shown itself any better than the other. I originally thought I had a 700R4 trans in my 89 3/4 ton burb, but yesterday when I was looking for a replacement pan gasket for the trans I discovered that it's a TH400. Which is better?
 
This could be argued for days, but it depends on what you are doing. For a daily driver on the highway a 700R4, for a mudder truck definitely the TH400. For any rig it's going to depend on the purpose.

The TH400 is much stronger, but it doesn't have overdrive and the first gear is only 2.48:1.

The 700R4 has an overdrive gear (0.7:1), and a 3.06:1 first gear, but it's not as strong.

So it depends on what your using it for and how much power you have. If you need an overdrive with the strength of the TH400 you want a 4L80E.
 
My #1 priority is durability. I want this truck to last and last. It will be used as a secondary vehicle for when is uses are asked for - towing, some light to moderate off roading and trips when the 9 seater capacity will be called upon. Not looking much for speed or performance. (though I wouldn't mind it.) Just looking for rugged durability. The truck has only 48k on it. I'd like it to see 250k on this same set up.
 
Stick with the TH400 - they were standard in the 3/4 ton Subs until 1991 model year when the 4L80e was introduced. The 700r4 only came in the 1/2 tons.
 
Keitha said:
Stick with the TH400 - they were standard in the 3/4 ton Subs until 1991 model year when the 4L80e was introduced. The 700r4 only came in the 1/2 tons.
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AFAIC....the only adavantage to the 700R4 is lower first gear, and overdrive. Other than that a POS....

And they put them in at least some 7200GVW 3/4 ton also.
 
76zimmer said:
AFAIC....the only adavantage to the 700R4 is lower first gear, and overdrive. Other than that a POS.....
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How so? That is a broad statement. It's pretty simple, the TH400 is stronger, the TH700R4 has overdrive. If you are planning on using the Suburban for long distance trips, the overdrive would be nice. There is absolutely nothing wrong with a nicely built TH700R4. Calling it a POS is very ignorant.Martin
 
The 700r is a great trans. It is basically a TH350 with overdrive.

I have 2 Blazers, one has a TH350 the other a 700r. Needless to say, but the 3 speed one stays parked and is only used off-road. I can't afford the gas to drive it on the highway. Have you ever heard the expression, "I can pass anything but a Gas Station." With the 4 speed I can do 70mph and still get about 15mpg.

Now having said that, If I were you I wouldn't bother swapping a transmission. Why? Well, the hassle and cost involved is NOT worth the results. You have to have the right T-case adapter, front and rear driveshafts, kickdown setup, and on and on.

It's not worth the swap unless you tranny is blown and you have a donor vehicle with everything you need.
 
READ: AFAIC.....(meaning my opinion from someone who has owned one)
Well for one thing you have to have enough engine to pull a 700R4 at highway speeds. A 305 don't do that very well unless empty. My truck wasn't an everyday commuter, so when I did drive it at highway speeds it wasn't empty, so that meant it was hunting for a gear appropriate to the speed I was trying to maintain. Pulling a 7000lb. trailer meant pulling in Drive anyways, yielding 7-8 mpg while doing 70 mph (with 3.73 gears). In 85 you could only get a 350 if you ordered a HD 3/4 ton (C6P option). That meant 8600 gvw. Then you couldn't get an overdrive trans. to go with the 350 engine. So basically the 700R4 option was worthless to me....read again AFAIC!!! I'm not saying it doesn't have its place, but for a towing truck I do believe its worthless as a stock 4L60E, which it basically is without all the electronic functions. The GVW of that trans was rated at 11,400lbs. and that was only if you didn't use the OD capability.
Practically any trans could be made into a decent, or desirable trans. given enough money, but a 400 would win hands down, overall, in a stock (as produced) environment.
 
Jees :rolleyes::rolleyes:!! The 700r4 was never designed to be a HD towing trans. That is why it was put in 1/2 ton trucks/ cars and some light duty 3/4 tons DuuuuH!:D
It was a light duty trans that did what it was designed for very well.(well.. errrr...... after it was modified in 88)
Later model post 88 700s are just as strong or better as a TH350.
I dont understand why you are slamming them. They are a good trans.
yeah they are not a TH 400 or 4l80E
But i have blown more Th350s and TH400s than 700r4s in my trucks.
Course i have been around a lot longer than the 700s and have had more oppurtinuitys and engines built to blow 400s.
 
The 700r4 is no POS. I have an 84 700r4 and it has been reliable to say the least. I have abused it through the years behind three different engines, currently a 454. The trans. is stock with the exception of a shift kit. It has been run low and overfiiled,yet still bumps out like a champ.:wink1:
 
If you already have the 400 I say keep it

The 700 is just fine, IF its built by someone who knows what they are doing. It also has to be installed by someone who knows what they are doing. A misadjusted TV cable can and will damage a 700

If you are wanting to go to an overdrive than it is probably cheaper to bulletproof a 700 than to get everything that a 4l80 will need
 
OK, guess I'm getting beat up over my comments.....but those were said on my experience, and the voice of a local trans shop. I've had 2 700's and 84, and an 85 model, both were only rated for 11,400 GCWR, which leaves about 5-6K for trailer etc. Not much comfort room there....Although the 85 did perform well, IN MY OPINION it is no 400. A Trans-go shift kit didn't help the shifting firmness much, it always felt soft, almost slipping. Yes I adjusted the TV cable by the GM manual procedure, to no avail. I just never got a confident feel about those trans. And the 4l60E, I don't even want to go down that trail......The 400 on the other hand was a hard piece to kill, Overloaded, overheated, coolant in the oil, no cooler other than radiator.....it just never let me down.
That was kinda the point of this thread wasn't it, 700 vs 400? I guess if towing isn't a concern, the 700 would be fine if prepped well. In stock condition "I" feel the 400 wins hands down. I guess the majority feel otherwise, but I'm sold on the 400.
 
76zimmer said:
AFAIC....the only advantage to the 700R4 is lower first gear, and overdrive. Other than that a POS.....
Click to expand...


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
 
Well, my 92, and 95 4L60e's are junk....again AFAIC....both have broken parts right at or before 100K, and the 92 I had rebuilt twice in 3 years.....now that one was a plow truck too, but I never had that unreliability with the 400's.

So enough of that you can have your OD trans, I'll take my 400.

Its ok to disagree ya know.
 
i've had/got both, the 700r4 in the '89 Burb, and the 4L60e in the '94 Silverado P/U, both have had to be rebuilt now, but then again, BOTH lasted over 200k, actually the Burb lasted till 215K and the Silverado lasted till about 210k, both have been used for towing, previous owners of the Silverado (retired folks) used it to tow a travel trailer, guess the 4.3 wasn't enough for them, although they drove it till 150k, when we bought it...

the 400 i had was in my dually, i understand they are strong transmissions, which is probably why it was stock in a 1-ton truck, but with only 3 speeds, and the lower tires i installed on it, it really hated the freeway pushin like 3500 rpms at 70mph with 29.5" tall tires.

both the 700 and the 4L60 have been rebuilt with better quality parts for long lasting performance, and both were reworked for firm, but not harsh shifting.

i am just partial to the 700 now because of the overdrive i guess, as i kinda do alot more highway driving, not alot of towing, but some sometimes...
 
I agree with Zimmer on this one. Ive killed more 700R4's than I can remember(Ill admit most were my fault). And while Ive yet to have a 400, Ive beaten all my TH350's like it was my job and they have only asked for more. If you drive nicley, rarely pulling a trailer, a 700 will probably be ok. Comparing stock to stock, I dont think the 700 can really compare to a TH350, let alone a TH400.
 
I have a 82 k5 383 th400 on dana 60's w/38's and they say the 700r4 can take 1000hp, but I have broke 3, and switched to the th400 and havnt broken yet..So i would say the th400 is the way to go. with the np205
 
this is almost like comparing apples and oranges.
700r4 good low 1st gear and overdrive making it a good dd transmission and light towing.
th400 3spd great for hd use in stock form atleast the one i had was built more stout. but as stated but have there differences and they are good trans depending on application. if you have the 400 keep it if not find one that will suit your needs.
 
Comparing a 400 and 700 is like comparing a 10 bolt and D60.

Sure the 10 bolt can be built stronger but its always gonna have the weak link with the axle shafts.

The weak link in the 700 will be the 27 spline shaft where the 400 has 32 splines and a larger diameter material.

I don't think its fair or comparable to judge the 700 and 400 together. If someone wants the durability and strength of the 400 but also wants/needs the overdrive, then stick with the 4L80E.

Otherwise just go with the 400 and be done with it.
 
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