I have been rebuilding automatic transmissions for more than 40 years. Here is my advice:

Let it sit overnight. Pull the pan and clean the pan and filter thoroughly. Reinstall the filter and pan. Replace the fluid that you drained out and then follow Mark's fluid flush procedure. https://www.ford-trucks.com/articles...-transmission/. If after a few thousand miles, the fluid does not look really clean and fresh, repeat the flush procedure. Drive it and repeat flush procedure every 30,000 miles. RTF.

 

I'm sorry, I thought you meant the yellow plastic plug that you find in the pan when you open a 4R70W for the first time. I wasn't thinking drain plug. Some 4R100s had them, some didn't. I do not know which ones did and which didnt.

 

Well, after another 200 miles, i'm noticing that my 1-2 and 2-3 shifts are very soft, like almost can't feel it shift at 1/4 to 1/3 pedal. rpms stay around 2100 at 1/3 pedal, can see small decrements in rpm as it shifts, but not firm at all. 3-4 shift seems pretty normal, and seems to coincide with TC lockup, can feel that one, but is not harsh. Large rpm drop going to 4th. No lights, no indications.... yet...


I'm afraid that it is not long for this world..

 

I thought that was normal they make modern trannys shift softly for the yuppies. It isn't good but normal, thats what shift kits are for. I think your just paying too close attention now. Let it ride.

 

So, 1 week after my last post, driving home from my dads, (7 miles), the trans started slipping BAD, lots of slipping in any gear except 1 and reverse.

It was Doomed.

So last weekend, My son and i took the tranny out!. Rusted bolts were the order of the day. BUT, I think that this trans has NEVER been out. I think it is the original trans! Even the driveshaft yoke bolt still has the factory Loctite on them (that we had to heat up to break loose). The (pretty sure) original TC was also there. Gold in color, (probably got hot at one point) with no paint. I'm pretty sure this TC is toast, and was probably was slipping as well. I'll cut it open later. I don't have to send the core in for the new one.

Through the week, I tore it down, Found the expected burnt clutches in OD and coast (toasted), Direct(black rings on frictions) and Forward (rings, but not too bad) Intermediate and L/R were fine, in fact, could still see the writing on the frictions.

I got all my new parts now, Alto Red Eagle super master rebuild. (best one, with all the bushing, seals, gaskets, transgo accumulator, and steel shift valves, new steels, including the pressure plates.

Had to get 3 more parts not included. One Thrust bearing, (forward planetary to Hub) and the two steel backed copper 3 tab thrust washers for the Rear planetary. They were completely worn out, no copper left.

Cleaned all the parts, All hard parts were good. no damage to anything.

I took them to the trans shop to have all the bushings pressed out/in. So next week, after the last bearing comes in at the dealer (they were cheapest), I'll be starting re-assembly!

New Triple-disc Low stall converter from Torco. (not billet, not making that much power, just extra cost), New Pump gears from Sonnax, and a Sonnax accumulator valve for the VB too. (.472 orfice), and installing the FULL transgo HD2 tugger.. Did the VB mods last night.. Ready to install on the trans.

I have a new Hayden 30,000# GVW trans cooler ready to go in also.

 

So it is done, rebuilt, air tested, all together, waiting for a nicer day to get it up and in.


Wish me luck! I will post back with results when i get it installed and road tested.

 

Great news that the trans rebuild is finished. Did you do this on the ground or have the truck on a lift?

 

In my driveway, truck up on 6 ton jackstands, as high as my 3 ton floor jack would lift it. ( about 8 inches off the ground ). This seems to be the perfect height, as the trans, once lowered (on a 2 ton, low profile trans jack) just fit under the rockers.

Trans was rebuilt in my garage (can't fit truck in it) on my workbench. I used an old F250 rim to stand it up vertically to load all the internals. The only thing I had to load horizontally was the coast clutch, as it has the PTO gear on it, which makes loading it into the case hard without the overdrive planetary and sun shell/ring gear falling out as you place it in the case. Loading it horizontally lets you use the input shaft to guide it in easier.

With the PTO model 4R100, you can't load the OD clutches after loading the coast clutch housing. you have to line up the clutches before putting the coast housing in. Just one of those nuances that you find with different models of 4R100.

 

Congratulations on the rebuild! Waiting to hear about the install and test drive!

 

Thanks,

I couldn't have done it without the ATSG rebuild manual. That thing is a lifesaver.

 

New trans cooler is in. Old one had to be broken out... the aluminum fittings on the old cooler would not budge. the aluminum gave way. ripped the whole fitting off the cooler.

so plumbed in the new one with 3/8 rubber trans line, and hose clamps.. Ready to go..

 

ok, so got the trans hung, but I ran into a stumbling block, a couple rather..

so as i'm bolting up the converter, I get 4 out of the 6 converter nuts on. swing the crank around for the last 2 and when i get there, the studs are barely thru the flexplate.. I thought, no big deal, it'll pop in as i tighten it up, Well, it did, but as I'm tightening the 5 nut, i hear a 'TING " This scared the crap out of me.. (not because it was loud, actually it was pretty soft.. but a distinct sound..) The flex plate was deffinitely tweeked, (four tightened, 2 not and not seated was flexing the flexplate. (1/4 - 3/8 of an inch and the widest one).

Was the ping due to cracking my flexplate?

I continued to tighten the converter nuts, and then it did 'POP" into place...

I had only torqued the nuts to 15ft-lbs, so i gotta go back and tighten to 26ft-lbs, I couldn't remember the spec when i was under there.


the second problem... I need a gasket for the extentsion housing to the transfer case. NO ONE HAS ONE! Not a parts store, or the dealer..

Can i RTV the extension housing? if so, Blue, or Black RTV?

 

Can't answer your flex plate question but I have used RTV numerous times instead of a gasket and always had good luck. When I installed intakes on many of my older motors, they tell you to throw away the rubber end gaskets and use RTV instead.

 

Well, it got in, but it's coming back out......


No 2nd gear . From looking at the apply chart in the ATSG manual, and multiple internet posts, seems like i installed the intermediate sprag upside down.


So, getting it back up in the air to take it all apart again..


Good news is that all other gears worked good and shifted nicely, just no 2nd....

 

Oh MAN....that's awful. I bet it will go faster the second time around.