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Newly-Rebuilt 700R4 Blew After a Month

I just had the 700r4 rebuilt in my '90 last fall. The shop is a little hole in the wall place that has been in business for a long time and came highly recommended by everybody I talked to including the hot rod, truck pull, and even pulling tractor crowd. The guy said that the '87 and newer versions were much better and didn't need a lot of upgrades. This is also consistent with all of the internet research I have ever seen. The above post is the first time I have ever heard anybody say the older versions were better.

The guy I used also said they always replace the sun shell with a HD version. He recommend a mild shift kit but not the typical Vette servo also as he said it makes a neck-snapping 1-2 shift in low range.
 
My 700r is starting to slip in 3-4 which tells me the 3-4 clutch pack is on it's way out. It was a working trans and I didn't rebuild it before I restored my truck taking my chances. Well, it sat for 8+ years and then I went back to running it. I've put 3k on it since the restoration and now it's slipping. Oh well! Anyway, it's my understanding that the 87' up trans have more vanes in the pumps and that is what makes them much better. There are other improvements but the pump is the major one. I am looking at Monster Transmission and Performance HD units with the diesel TC. Looks like about $1,500 but it will still be cheaper than having this one rebuilt I bet. I am going to ask our local shop who's been doing these old 700's for years what the cost would be. A local warranty is good but I'm only using this truck for a summer rig and probably won't have an issue until the warranty is long gone. Here is the link on the MT&P trans: http://www.monstertransmission.com/700R4-Transmission-Heavy-Duty-4x4-4WD_p_5078.html#.U-gil2NJSM8
 
Did you drive the truck in and have this guy crumpy pull and rebuild then reinstall the trans or did you do a "carry in" meaning you brough him your trans to rebuild and you installed it yourself? The reason I ask is because you can burn up a 700R4 VERY QUICKLY if the TV cable isn't SET correctly (there is no adjustment, you SET the TV cable). If you drove/towed the truck in then picked it up all done i'd be asking him for a tow truck to get your truck back to him.
 
I took the truck in. Dropped, rebuilt, and installed at his place. As far as towing, no one is going to include that in a warranty. Especially not 300+ miles of towing.
 
I agree with those who tell you the 87 up trans is far superior to the older models in many different ways, durability being chief among these. If the builder knew your truck was rocking 35's I would think he would install upgrades to the trans to compensate for the additional stress of the tires, that may mean different types of frictions or increased capacity clutches/band, better servoes, increased pump output, lube mods, valve body upgrades to improve shift quality etc. all in the interest of having the trans last as long as possible. He may have built a real nice trans for you only to have a part unexpectedly fail, this happens too. Hopefully he will repair and upgrade your trans for you and get you back in service soon.:woot:
 
'87+
TV cable has to be set correctly
Upgrades are good
Clean out or replace cooler, maybe even TC
BIG coolers for 700r trans
If not using quadrajet style carb, most other carbs do not have correct geometry for the TV cable, even if you're using a Holley adapter. Look into the BowTie Overdrives TV adjustable cam style linkage. Not the "TV Made EZ" thing, just the linkage.
 
airemdwn said:
Maybe i missed it but what "blew" in the trans? What is it not doing?
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Clutches are shot. At this point, it won't go into reverse at all. Right after starting the truck, it has no problem going 1-2, but has a hard time going 2-3. As it warms up, it has trouble going 1-2.
 
The guy who told you the early models are better is crazy.

As far as "shift kits" They are usually just instructions. Most good transmission guys do a lot of little upgrades, and don't bother buying a shift kit.

Martin
 
Keep us updated on what they find out. If all of the clutches are toast I would think it got really hot or was run low on fluid.

The 700r4 in my '90 lasted about 115,000 HARD miles with the main cause of death being it was ran low on fluid because of a leak. I've owned the truck since 49k Long story short it was stored at my parent's place out in the country for about a year while in the process of moving. My dad took a cruise through the fields after a big snow storm and got it stuck in a ditch in 2wd, then tried to get out in 4 high (40" tires and 4.10 gears). The low fluid and strain/slip from using 4 high was the final straw.
 
The fluid is full. I was checking it daily. And, I had just checked it about 30 minutes before it started having problems. I was in stop-and-go traffic for about 20 minutes, which did cause the temp to creep up. But, I pulled over once it hit 210. But, maybe it did get too hot. I'll let you guys know what Crump finds out.
 
1902808_10202714325964921_7755129133038955806_n.jpg


wasn't able to add a pic earlier
 
4X4HIGH said:
My suspicion is an incorrectly set TV cable did you in.
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I would also check to see if the lock-up in the torque converter was working also. If it's not locking up it will cause excessive heat and failure.
 
The torque converter was new with the rebuild. He'll get the rig tomorrow morning. I'll let you guys know what he says after he's torn it apart.

A far as gears, I have no clue. I haven't changed anything, and have no idea what the PO did.
 
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