'91 7.3L IDI Tranny Rebuild - Stuck in 1st Gear

[BossHog]

New to the Forum. Just bought a '91 with the E4OD and it wouldn't come out of 1st when I picked it up. I was hoping it was just a bad sensor but I replaced the speed sensor on the rear diff and no change. Dropped the pan and found that the previous owner had put some additives or something in with the transmission fluid. Also found excessive amount of shavings on the magnet. Tore the tranny down and found a cheap aftermarket torque convertor had been installed. The OD sprag was trashed with the plastic spring chewed up pretty bad. Other than that just minor wear on some factory aluminum components. The planets look good and clutches all in good shape. I think after replacing these worn transmission components I want to make sure I address the root cause. I plan on replacing the tach sensor in case that created problems with the torque converter.

Any ideas as to what may have caused this issue initially and where I should start looking to replace parts?

 

[NeverHave-I-Ether]

You sure the clutch packs were good? Usually when they go out or fluid is replaced it's time for them to go.

Never-Have-I-Ether

 

[Jesus Freak]

I'm with @NeverHave-I-Ether on that. Sometimes (and someone will throw sticks at me for this) when the transmission fluid is changed it breaks up stuff in the torque converter and it can stop valves from moving in the valve body. All the shifts are electronic on those I believe. Make sure all the valves move in the valve body, possibly a bad shift servo? Or the transmission controller or PCM is bad?

 

[BossHog]

@NeverHave-I-Ether The clutch packs looked good to me. I had the tear down done at a shop. But I looked at the components after they were all out. The builder there said they were good.

@Jesus Freak I am getting the truck back tomorrow. The whole tranny was torn down so anything blocking those valves will have been cleaned out. Also got a new torque converter put in so that hopefully takes care of that. We will see what it looks like after they put it back and flush it. I’m hoping to identify what caused the problem in the first place. Maybe it was just loose junk from the torque converter after an additive was used…

 

[BossHog]

Here is a picture of the torque converter that was taken out, and the sprag that was shot. Both have been replaced now.

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I’m not all that familiar with the E4OD components so I’m approaching this as a newbie. I appreciate all feedback!

 

[Jesus Freak]

I'm not super familiar with them, but it looks like you're on the right track.

 

[typ4]

I'm with @NeverHave-I-Ether on that. Sometimes (and someone will throw sticks at me for this) when the transmission fluid is changed it breaks up stuff in the torque converter and it can stop valves from moving in the valve body. All the shifts are electronic on those I believe. Make sure all the valves move in the valve body, possibly a bad shift servo? Or the transmission controller or PCM is bad?

That is when it gets a flush that all hell breaks loose. If the trans, no matter what kind of vehicle, has been flushed regularly in its life its no issue.
When someone buys a used car , takes it to the shop for service , the shop sells them a trans flush. Within a week the trans ***** the bed. I am up to 23 and 0 of this happening on friends trans.
Just a drain and refill usually does not do this.
To the OP , if you arent paying 800-1k for a convertor , or buying one with a known rep, its not going to last.

 

[typ4]

Make sure the cooler is not plugged, Its very hard to get debris out of the rad cooler.

 

[BossHog]

@typ4 Thanks for all that. That’s helpful. The torque converter along with the rest of the rebuild was not cheap… I’ll post parts here after I get the invoice.
Truck has a new radiator. Not sure why but it shouldn’t be plugged or anything. Im gonna go through the whole truck and clean everything up. It’s not a daily driver but I want it to run like it’s supposed to.

 

[BossHog]

Update: The shop put the transmission back in and wouldn’t you know it, still won’t shift. They went to the FIPL to check for adjustments to the sensor. NO FIPL! How did I miss that? That’s what I get for cheap as a first time diesel buyer…
So anyway, the shop I went to is super cool and is swapping the part off of a 1990 e350 for free. When I get the truck home I’ll install a brand new one.
To add to my frustration the radiator isn’t bolted in at all. After further inspection the radiator is clearly not designed for this vehicle as none of the mounting bracket line up. So there’s probably a new radiator in my future too…
I bought this truck to learn about diesels and to challenge my mechanical skills. I guess I got what I wanted.

 

[quickster]

Was the fipl bad, or it physically wasn't there? I just replaced thr rad on my 91 with a Champion. It isn't leaking so I guess thats a good thing. I'd spend a day going over the whole truck to make sure everything is good. Wheel cylinders, brake lines, axle seals, everything.

 

[IDIBRONCO]

Was the fipl bad, or it physically wasn't there?

I read it as the FIPL wasn't there. That would certainly make the transmission not shift.

 

[BossHog]

Yes the FIPL was missing entirely. So waiting on that part then hopefully she shifts! @quickster I was looking at putting in a new champion cooling system. When I get the truck home I am going through the whole thing. I’m starting with radiator, exhaust pipe needs new brackets, new glow plugs and harness, air intake upgrade etc.

 

[Big Bart]

That is when it gets a flush that all hell breaks loose. If the trans, no matter what kind of vehicle, has been flushed regularly in its life its no issue.
When someone buys a used car , takes it to the shop for service , the shop sells them a trans flush. Within a week the trans ***** the bed. I am up to 23 and 0 of this happening on friends trans.
Just a drain and refill usually does not do this.
To the OP , if you arent paying 800-1k for a convertor , or buying one with a known rep, its not going to last.

Ditto too many horror stories. Just drop the atf pan, drain converter (If possible), change filter, and refill.

Try to keep the same brand and types (Synthetic vs non-sythetic) of ATF In your tranny. Mixing brands and types can cause long term issues.

Flushing causes debris to loosen, go into your system, and do bad things.

 

[BossHog]

So the transmission shop gave the truck back and still wasn’t shifting… I was able to track down the FIPL bracket and got that installed, hooked up the new FIPL and sure enough she shifts! I drove my truck home for the first time. However, i lose my lower gears after it shifts. If I put it in park it starts back at 1 but then after shifting up it won’t go back automatically. To pull hills I had to put the shifter in 1 to get up. Would FIPL adjustment help with the transmission downshifting? If not I need help diagnosing this issue.