Liquid trans rebuild?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Dec. 22, 2011 6:29 a.m. ultraclyde HalfDork

Yeah, I know I can't really rebuild a trans by pouring something in, but I'd like to find an additive to keep it alive a while longer.

Here's the long version: 1997 Explorer V8 with the 4r70w auto trans, towing package w/external trans cooler. this has been our tow vehicle and vacation excusion ride for several years after being retired from being DD by my wife. It has about 200k on the clock and about 5 years ago the trans started acting up - mainly a viscious stutter as it dropped into OD about 45mph. After consulting with a well recpected local trans shop, I took their advice and changed the trans filter twice, filling with full synthetic Mercon. Suddenly the trans was fine. Cool!

NOw, several years of not much mileage later, it's starting to have issues. the 1-2 shift is pretty hard - enogh to kick you in the rear but not chirp the tires, and the OD stutter has returned intermittently. I've swapped the filter and refreshed the fluid, but no change.

So, any recommendations on a trans additive that will tighten it up and may poistpone a rebuild for another year or so? I used one called TransX in a Toyota many years ago, but I haven't seen it lately.
Dec. 22, 2011 6:49 a.m. 44Dwarf Dork

Look up the J-mod. Stands for Jerry's modification. Jerry was on the design team for the trans when he worked at ford. It helps fix all the problems as yours is 97 it has the all Alum accumulators my 98 f150 did too, get the rubber coated units this will fix the slam shifts I put a temp sensor in the oil pan and even hauling my 20 box truck trailer with 4 tons of wood pellets trans temp only got to 190 I'd recommend Max ATF by Royal purple. it really worked well. I got it in a 5 gallon pail. You should have a converter drain plug too to get it all out.

http://www.tccoa.com/articles/tranny/transmission/index.shtml

Heres a repair kit for 1-2 accumulator http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=2&Pr...

There was another Sonax part i used but mind is going blank My trans was fine when i did all this work but i was new i was going to abuse the hell out of the truck and could not afford to tow it or replace it so i upgraded what i could. I beat it for 3 years and sold it to a friend who used it 1 year and sold it, i still see it around town. :)
Dec. 22, 2011 5:27 p.m. iceracer SuperDork

Do a fluid and filter change. I have "rebuilt" several with good results. These were all GM transmissions if it matters.
Dec. 22, 2011 7:57 p.m. Trans_Maro Dork

A small can of brake fluid added to the ATF will make a slipping auto shift nice for long enough to get it sold.

I don't know any tricks to make it shift more smoothly though.

Shawn