4th 700r4, going sm465

[6.2Blazer]

Let me just clarify that I'm not saying the 700r4 is the be-all, end-all transmission.......but I still stand by my point that it has an undeserved bad rep. I also think it's quite ironic that bad reputations are being discussed on the 6.2 diesel engine board, which is probably the king of all undeserved bad reputations. I have a lot more people try to bad mouth the 6.2 in my truck than the 700r4. I also still hear the term "Quadra-junk" referencing the quadra-jet carb on a regular basis and you will be hard pressed to find somebody stating how crappy the 6.2 or quadra-jet on this board is nowadays.

Design flaw? Maybe in the first couple years of production but so does just about any other brand new major component on a car. 250k miles on a TH350 or TH400.....come on now, don't try to pull that crap. Sure, there are some that can make it that long but I also know of 700r4's that can make it that long also. Growing up every farmer and construction company seemed to have a Chevy/GM truck with a TH350 or TH400 and almost every one of them needed rebuilt somewhere in the 100k-150k range. Sorry, but I also didn't any SM465's go 250k untouched (I consider the clutch part of the transmission)...granted it's not a full rebuild but still rather pricey to have a shop do it.

There are a ton of trucks on the road today well into the 100k range on the original 700r4's.

The comment about "a factory crate replacement only lasted 20k so that means 700r4's are junk" is just as bad as any other comment about rebuilts or replacements not lasting. How long did the original last? So what is the supposed exact same component failed in 20k when the original lasted 100k, 120k??? Just says the same thing.....bad installation. Finicky? There's really only one adjustment and that's the TV cable........and making sure you flushed out the cooler and other items that are just as important as any other transmission replacement.

Again, not saying the 700r4 is the all time best, or cheapest, or easiest to work on...just that it is a decent trans with a undeserved bad rap.

 

[kennyw]

I didn't say the 700R4 is junk, it's a great transmission for use in light duty cars and S10's... I don't think it belongs in a 6500# 3/4 ton truck, or even a 1/2 ton used often for towing. But I look at the best value for the dollar spent and the 700R4 can't compare to a TH400 or SM465 in that department.

My 1990 K20 Suburban has 275,000 original miles on it. The motor was rebuilt at 175K but the TH400 is still original and shifts perfectly. The original owner just simply changed the fluid/filter every 50K or so.

Yet, every truck I have looked at with a 700R4 has burnt transmission fluid, including my '83 K20 that recieved meticulous maintenence by the original owner up to 230K when I bought it. The tranny was replaced multiple times while he owned it however and the last replacement he went to a crate tranny from GM expecting it to end his tranny issues. It didn't so he finally put it up for sale when he was retiring.

Again, its not that the 700R4 is a junk tranny, its just undersized in many area's for use in a 3/4 ton truck and your better off spending your money elsewhere if you don't want to spend a fortune or deal with a hassle.

 

[6.2Blazer]

Again, its not that the 700R4 is a junk tranny, its just undersized in many area's for use in a 3/4 ton truck and your better off spending your money elsewhere if you don't want to spend a fortune or deal with a hassle.

I agree, and exactly why there were very few 3/4 ton or larger trucks ever roll out of the factory with a 700r4.

 

[kennyw]

Actually the 700R4's were very common in the 83-9x's 3/4 tons. I've got two 83's now that were originally 700's, my '91 K2500 was a 700... about 50/50 700R4 to TH400 is what I have personally seen. They were standard in the lighter 7200 GVW 3/4 ton where the TH400 (replaced by the 4L80E in '91) was the 8600 GVW standard.

 

[6.2Blazer]

Actually the 700R4's were very common in the 83-9x's 3/4 tons. I've got two 83's now that were originally 700's, my '91 K2500 was a 700... about 50/50 700R4 to TH400 is what I have personally seen. They were standard in the lighter 7200 GVW 3/4 ton where the TH400 (replaced by the 4L80E in '91) was the 8600 GVW standard.

Okay, so maybe 50/50 but only in the lightest duty 3/4 tons which don't seem as common as the heavier GVW models. The only post '88 3/4 ton I've ever seen with the 700r4 were the 6-lug models, and they seem few and far between.

 

[kennyw]

That probably depends on where you live more than anything. Out here the 6 lug 3/4 ton's are found about as often as the 8 lug in the '88 up body.

In the '80's body about 9 out of 10 of the 3/4 ton parts trucks I have picked up have been 700R4's. Usually it's a failed tranny that made them cheap enough to be a parts truck too so that's skewing the #'s greatly. The TH400 trucks are still out there working and not being sold for parts.