Dandy Dave

GM- 700R4 trans upgrades for towing???

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My old Suburban lost 3rd and 4th. Not an uncommon problem... Now for the fix. Just wondering if any of you who use your GM trucks/ Suburbans for towing have had a 700R4 trans rebuilt. And if so which upgrades for towability, from who, and has it been reliable? Trying to sort thought the tons of stuff I have read. Some good. Some Evil. Thanks, Dandy Dave!

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Dave, I don't know your engine size or year so this is just a stab in the dark. Rather than rebuilding your old, tired unit, I would go with one of these. Developed and built for extreme towing. Hopefully, it will be the last tranny you will have to buy. I would also get a new, heavy duty converter, and a big trans oil cooler with a gauge. I know it will be expensive, but it will be done. I would expect that you will have to shell out about $5K, which would include the removal and replacement of the tranny. Sorry for your loss, and good luck. Let us know what you decide to do. Good seeing you in South Bend.

http://www.summitracing.com/search/part-type/automatic-transmission-packages?keyword=towing%20transmission

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I've had several rebuilt for my 1/2 ton Suburban. We used it to tow a 16 ft enclosed trailer.

Watch out for those who try to sell you a heavy duty racing transmission. Sure, it's beefy, but not what you want.

First upgrade is a shift kit. It holds you in the lower gear a little longer and then shifts harder. You want that for towing. Next, upgrade your parts. We upgraded to Corvette parts because the mechanic said they were more heavy duty than a std Chevy.

That's where we stopped. Added less than $500 to the rebuild cost. The tranny served us well.

You can spend gobs more $$$ in upgrades. I stayed away from Summit because they are drag racing oriented.

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Yeah. Thats what I have been reading. The great and powerful tranny monster wanted me to go with their SS version and the salesmen did not give me correct info. Since when does an automatic trans bind up? From my experiance just the opposite happens, they need replacing because they slip. Some other companys have never returned my inquiry. Sounds like it is all about numbers and volume with them. Sell the most expensive even if it is not right for the app.

With all that said, I slipped in it once again and found a GM Good Wrench 700R4 rebuild a local fellow had here. He had it in a vehicle for a month a number of years ago and the motor swallowed a valve. He pulled the trans and scrapped the rest of the vehicle. Only wanted $100 bucks for it. Said it was $1,200 when he purchased it. I had to get a new converter as the one that was with it filled with water and trash as there was a leak in the roof above it. The rest of the trans looks fine. Worked on getting the old one out yesterday. I have one stuborn bolt that is giving me a hard time. Time to get the fire wrench out when I get up a little ambition. Dandy Dave!

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Be sure that when you put in the new transmission (and any automatic transmission replacement) be sure to flush the transmission cooler in the radiator BOTH ways with cleaner to be sure there is no trash in the cooler. Can not tell you how many vehicles have had repeat failures because of clogged coolers.

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All ready done Larry. The trans has worked out well. I pulled the pan and cleaned everything out. There was little water and crap in the bottom from sitting for so many years. Even though the trans sat for a bunch of years, when I pulled the filter and replaced it, clean red oil was still up in the lines.... That reminds me, I need to get a Priority Mail envelope and send you something.... Dandy Dave!

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In testing an axle lubricant in the desert, at maximum towing capability of a 1/2 ton pickup, I destroyed three transmissions. The only way we kept the test vehicle together was to add (1)a massive fan-cooled auxiliary radiator and (2)a canister type fluid filter. We ultimately succeeded in keeping the transmission functional, after wiping out three.

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