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4r100 TC seating help

4K views 25 replies 3 participants last post by  cesspool 
#1 ·
im replacing the TC in my excursion, 4r100 with 126k. I bought one form Racer X, the eagle 6 stud. i am trying to seat it, its dropped down but the hub is sticking out about a 16th past the transmission bell housing. Ive been pushing and turning on this for an hr and it wont go anymore or am I doing something wrong? i bolted it up once thinking that was just it, but it touches the flex plate as soon as the bell housing is drawn to the block.... I was told the hib should be about 1/4" below the edge of the bell housing and it shouldn't touch the flex plate
 
#2 ·
Did you put a straight edge across the bellhousing with the old TC in to compare to?

What's important is, once the engine & trans are mated, is that you can turn the TC free of the flexplate. If you can do that, then the TC is fully engaged into the pump. If not then you're not fully "in".

Do you have the old TC still? Can you compare the size of those engagement notches and length of the hub? (lay them both on their faces and measure the overall hight)
 
#3 ·
i could not turn it freely.
I have it, but its boxed up and the trans isnt dropped all the way, I just backed it up a bit to try and turn and push some more.

and yes, with a straight edge,
just barely not flush
 
#4 ·
i also changed the input shaft, but he said it will only fir one way and it fit right inside the trans
 
#5 ·
i pulled the trans again, I can get the old TC to seat, but the new one sits up just a bit more. they look the same size....
 
#6 ·
and I cant get the new input shaft out. it just slid in and out before i put the new TC on
 
#7 ·
I wouldn't worry about the input shaft. You're only 3/8ths of an inch or less out from seating as you describe. If this were the wrong spline on the input it would be out much farther I'd think (plus, the old TC would have a problem with it). This sounds like a problem with the new TC.

Look very carefully at the new ones Hub and compare it to the old one. I can't think it could be anything else...
 
#8 ·
i tried to measure the tolerances etc. it actually seems the old one in a hair taller, tho I dont know on what side it is. the only difference i see is on the old there is a shoulder at the bottom of the hub and then the weld, the new one looks liek the weld is right at the shoulder. The hub on the old one also has a beveled edge both inside and out and the new one just the outside... Ill try to take some pictures and post, but Im at my wits end..
 
#9 ·
the blue one is the new one
 

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#10 ·
that shoulder at the bottom of the hub has really got my eye now i dont know what else it could be
 
#11 ·
either that or maybe a pump issue idk....
 
#12 ·
or there is a pump issue, idk....
 
#13 ·
so i measured the inside and the new one isnt as deep I put a screw driver in the old one and grabbed it with a pair of pliers level with the hub and then put in the new one and I can see there is ~.5" difference
 

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#14 ·
Got a Micrometer? I would measure the flats, it is those that engage the pump and are what you're aligning as you spin it. Are they the same distance apart? Is there a "taper" on the new one that gets wider as you go down maybe?

That 1/2" is interesting, did you ever compare the overall length of the old & new input shafts?

You might have to wait until Monday to call Racer X... :(
 
#15 ·
Lay both TC's with the snout facing up and resting on the mounting pads(use blocks of some sort) -- make a U shaped bridge that fits over the TC, so you can take measurements from the bridge down to the TC

Measure the distance to each snout, the internal large spline and the internal small spline -- measure also the distance from the bottom of the TC pilot guide to the bench -- next measure the diameter of the pilot guide

All the dimensions near the same?

As @NoRalPh mentioned a trial fit and straight edge across the transmission before you try to install

Try the old input shaft into both TC's, make a mark on the shaft to compare depth
 
#16 ·
ill take some tomorrow, im done for the night. thx for the help guys
 
#17 ·
RacerX did email back and say the distance isnt the issue but it looks liek my old hub is gouged where I thought it was a shoulder, Ill see what he says next
 
#18 ·
I see what they're talking about, that there is some galling there and maybe the ft bushing might be keeping the new hub from passing that spot.

I'd think you could pull the ft pump and replace the bushing (you should be replacing the ft seal now anyway). Might not be a big deal...
 
#19 ·
this is my 1st foray into a TC swap. I believed that was just a machined shoulder. it looks very uniform around the hub. I also never saw any metal, but I have an external canister filter. Ill see what he says. maybe my bushing is bad
 
#20 ·
below is my reply from racer X. Ill talk to him tomorrow. is the pump a simple swap part?


Based on the photos, it looks like the old converter had excessive wear and end play, possibly it’s come apart inside. That would wear the pump and hammer it, possibly explaining the ding in the front of the pump shaft. It that’s a gouge in the hub, it’s been hammering against the pump inside, the photos look like it’s been hammering on the hub end too, the score marks are probably from excess end play or pump wear. If the converter is completely drained and doesn’t have enough ATF residue left inside that would provide a cushion, try shaking it and see if it rattles or you feel the internals move back and forth while shaking it. Has the transmission pan been removed and checked for metal particles?

We’ve covered as much as possible here, you’ll have to talk to the tech dept on Monday if possible, or have a tranny shop inspect it if possible.
 
#21 ·
so I removed the input shaft and the new TC seated right. I measured and the new and old shaft are the same length. but i put them in the new TC and the old one sticks n the TC an 1/8" more and then I did the same in the Trans and the new one sticks out 1/16" more. so thats 3/16" of an inch which is exactly how much I'm off. so I put the old shaft in the trans and worked it and I got the new TC to seat 1/8" below a straight edge across the face of the bell housing. so maybe the whole issue all along was the input shaft. Ill wait to talk to racer X, but I think Ill just go back with my old input shaft
 
#23 ·
hell if I know lol the beveled edge on the new shaft isnt quite as steep as the old one thats the only real diff I can visually see

thanks for the help, as soon as I talk to him, ill be bolting it back up.
 
#24 ·
well its back and running. old shaft new TC. no vibrations. just kind of worried about leaving monday for a 1600 frip into Canada. Ill drive it the next few days and see if any thing comes up. I imagine of there was an internal issue with my install I might no relatively fast.

thanks for the help, hopefully no Canadian emergencies lol
 
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#25 ·
Would suspect that at some time the TC bolts were loose or the flexplate was cracked -- the wear is from the tranny front bushing -- did you check to see if the TC wobbled in the bushing when you fit it in the case?
 
#26 · (Edited)
sorry for the delay... Just got back from the trip!

wobbled, like when the TC was seated all the way in the Trans? there is a bit of wobble there...

So my trip was 2934 miles. I did notice some things that had me worried quit a bit while I was 18 hrs form home in french speaking part of Canada where the high ways end and ferrys begin :grin:

I have a new distinct vibration at 20 to 25 mph
I also have a rumble at 55. Not like before though.
and also while sitting at idle I have an intermittent pulsing vibration

when the trans was out I also;
replaced rear drive shaft U-joints (spicer 5-1410X)
diff fluid front and back (amsoil synthetic and friction modifier)
Transfer case fluid (Schaeffers all trans supreme)
Installed Diesel site cooler line bypass kit
New internal filter
new external filter (for dieselsite external filter)
new fluid (schaeffers all trans supreme)
grease both slip yokes

I also tried to replace the the front shaft u joints, but i couldn't get the strap bolts off so I didnt get them quite yet, I just bolted it back up after greasing the slip yoke. I do know that it isn't in the same location on the flange though. I've read it doesn't matter, i've read it does. I don't know. I'll prob put it back. I would have anyway just to be sure but I accidentally rotated it and said screw it I was in a pinch for time and i was on the 4th bolt before I realized it.

I've read the tensioner and the fan clutch can cause some vibrations at idle, so I may just swap both. Also My tires being balanced kinda concerns me too, that will cause def vibrations at certain speeds as we all know. But all the driveline vibrations are driving me insane especially when It could be trans related...

My trans has a Factory tech valve body since 56 k and the external filter since 61 miles. I also wired up a TC lock up switch per Guzzles 7.3 write up.

The pump concerns me tbh. I may pull it again in the spring and do a pump from racer X also, and get the billet input shaft to fit when I have more time. I just know the pump requires some special alignment or something. Possibly also a billet flexplate.
 
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