700R4 question

[71chevylowrider]

Hey guys, what are the "good" years of 700R4's wasn't there something about the earlier ones had weak parts in them or somehting? I found a deal on an 88 700R4 out a cop car & I'm wondering if that is worth messing with. it's for my 71 C-10 with a 350

[Pyrotechnic]

Not sure exactly on the years but I believe it's 1987 and up that had better parts in them. With a 700R4 though, I would definetly go for a rebuilt one either way. Anything used and still on the factory build will probably not last long.

[nvrforgotten52]

87 and up i believe was the 30 spline. i believe they also had the better lockup... not totally positive though..i would go with something above 87

[brak]

I also believe that the truck tranny's were beefier than the car tranny's.
I see it alot in the 3rd gen Fbody crowd, people ditching their 84-87 700's in favor of the early 90's Truck 700's.

I will be running a 700r4 from a 92 camaro, primarily because i have one sitting in my garage. I recently sold my 84 camaro, and it was one of my unused parts, so i may as well put it to use.

[71chevylowrider]

cool, thanks you guys, I'm gonna pass on this one cause they say the mileage is unknown, my search continues.

[cooters]

87 and up are good trannys because they use an auxilary valve body and most updates are done. Stay away from 83 and 84 which had 27 spline input. V6 trannys have less clutches and are less desirable.

[MrOverkill]

did they make manual (not computer operated) 700r4s past 1987?

[67ChevyRedneck]

All 700R4's had computer assisted operation.

[Pyrotechnic]

All factory transmissions have the electronic lockup clutch, but I've seen some that have been modified to engage the lockup hydraulically. Thats strictly an aftermarket thing though.

[cooters]

the 700 is not computer controled, the lockup is elecricaly controled but has no computer to run it. All 4l60 trannys are a computer controled version of the 700 which is why they dont have a tv cable. The diesel trucks were hydraulically locking tcs from the factory, which is what i do to my 700s instead of running wires.

[LockDoc]

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Here's the skinny. The most desireable ones for our trucks with the stock type engines are the 1985-88 passenger car & trucks. The pre 85 units are not as strong and the later ones use electronic sensors to operate properly. The rear tranny mount will have to be moved also. I had to drill new holes in the frame for mine...

If it's a decent looking one & cheap enough I'd probably buy it and have it checked out and rebuilt if it needs it.

LockDoc

[71chevylowrider]

Hey thanks LocDoc, I do want a good one, & the only reason i was considering one from a car is they said it was from a cop car, & I'm sure those would have some beefier components in them, it was only $225 but there was no pic & the Mileage was unknown.

[cooters]

the only difference to the fuel injected 700s is the electronic speedo gear which can be changed easily. The fuel injected 700s use 10 or 13 vein pump instead of 7 vein, and the drum and planetary are updated also

[jlaird]

don't mean to hijack, but what is the more desirable tranny for a street truck, a thm350 or the later 700r4? just starting to learn about trannies...

[snj8198]

strength wise they are similar. The 700r4 has a steeper 1st gear at 3.06 versus the the TH350's 2.52. The 700 will launch you out of the hole faster and has a .73 overdrive.

[cooters]

everyone loves the 700 but they are more likely to fail compared to the 350. For strength the 400 or 4L80 are king.

[snj8198]

stock units tend to fail however any local reputable tranny shop can build a unit that can stand a lot of torque and won't cost too much over a standard rebuild. I'ver ran a 700R4 in 4x4 applications behind a supercharged small block, stroker, and a big block. I liked it for towing but admittingly it will last longer with a steeper rear gear.