Starting a 4.0L SOHC without Transmission.

[cjmedina]

I,m almost finished with my 4.0 SOHC rebuild. The transmission was taken out to be installed in my son's 99 Explorer because his reverse band broke.

I need to test my engine rebuild before I put any more money in to this project.

My question now is can I remove the bell housing from the broken trans to install to my engine so that I can mount the starter to start the new engine. I assume the neutral start switch will be one issue. how about the other trans wiring?

Also the engine now will only be secured by the engine mounts.


Your Thoughts?

Thanks,

Cliff

 

[cjmedina]

I'm surprised nobody can answer the question.

 

[jevchance]

Not the kind of situation people ru in to often.

I can't imagine it will start without the wiring hooked up to a transmission.

 

[2000StreetRod]

O2 sensors

Your idea seems rather risky to me. The front mounts will not prevent the rear of the engine from moving vertically and to a lesser extent laterally. I assume that you're thinking of resting the removed bellhousing on something to support the weight. You can probably insert some jumpers into the transmission connector to make the PCM think the transmission is in Park. I'd have to check my wiring diagrams to see which ones. As I recall the O2 sensors use the transmission wiring harness. Without O2 sensors the PCM will stay in open loop.

I can understand your desire to see if the engine runs. However, if it does or doesn't without the transmission what would you do different than with the transmission? If it doesn't run when installed without the transmission would you part out the vehicle instead of fixing the engine? It just seems like extra work and additional variables to contend with.

 

[SlammedExploder]

it will be fine if you run a support on the bellhousing... as far a wiring goes aslong as it gets a signal from the crank sensor, and cam sensor it should run (to run well you need the MAF sensor and IAC) personally i would just do a compression (dry and wet) and a cylinder leakdown test, if it passes it will run... also the neautral safety switch can be bypassed by running a jumper with a constant 12v to the terminal on the starter cylinoid (i cant spell LOL sorry)...

 

[2000StreetRod]

C113 Jumper

If you insert a jumper between connector C113 pin 11 (pink wire) and C113 pin 6 (tan/red wire) the starter motor relay will be energized in Start. However, the digital transmission range (DTR) sensor also reports the shifter selection to the PCM. It looks like the default is the Drive position without the DTR sensor connected. In Drive (and any other gear) the PCM should enable the fuel injectors and the ignition. The commanded idle speed may be different in Drive than in Park or Neutral.

 

[Blueraven]

I agree with StreetRod, what's the point of running the engine? If it starts you still won't know how it will perform under a load. If it doesn't start then what? What makes you think there may be an engine problem? If it ran the last time you started it, it should run now. Of course if it's been sitting a while there may be some seals leaking but it will still run. If it ran before, go out and get a "good" used transmission and put it in. If the engine turns out to be dead, then you can always sell the transmission and then all you've really lost is your time.

 

[Stevenmccall417]

They keep

I,m almost finished with my 4.0 SOHC rebuild. The transmission was taken out to be installed in my son's 99 Explorer because his reverse band broke.

I need to test my engine rebuild before I put any more money in to this project.

My question now is can I remove the bell housing from the broken trans to install to my engine so that I can mount the starter to start the new engine. I assume the neutral start switch will be one issue. how about the other trans wiring?

Also the engine now will only be secured by the engine mounts.


Your Thoughts?

Thanks,

Cliff

 

[Stevenmccall417]

They keep asking why u would want to start it without a transmission! And my guess is to know it’s running decent enough before u spend all the time of putting it back in. I’m getting ready to try it too after a head gasket timing chain replacement. Bolting the bell housing/starter on. Then possibly putting the trans shift indicator du dad back on. Screw the o2 sensors…I’m just checking to see if it sucks up water…blows white smoke…overheats…or makes any timing chain noises. If it passes…..then I will replace the 80lb trans and 100lb torque converter.

 

[Stevenmccall417]

Reverse bands kinda suck. I’ve noticed people hate all these Ford servo,band trannys. But I find them quite heavy duty. They definitely hate old burnt or dirty fluid. Ruby red fluid is always king. But if you have disassembled as many of these a4ld or 5r55 trans as I have..u begin to understand them. The main issue I’ve noticed with reverse is they lose fluid pressure to the reverse servo. Sometimes they take a few secs to engage..they slip…or they won’t engage without higher rpms if at all. If u want to fix it at home I suggest finding a way to stand it straight up from the output shaft. Then pull it apart drum by drum placing them in order of removal. Keep attention on plastic spacers and bearings locations. Remove servos/springs/band adjustment struts/pins keeping them marked for original locations. Cleanliness is godliness with trans parts. I suggest cleaning as u replace. Most those trans have no reverse band adjustment. So make sure the servo isn’t just binding or sticking in its bore. It should fall right out and in if it’s good. If those trans have been sitting a while..there could be failure of almost every rubber ring or bushing in them. I’ve even seen bands break causing a servo to snap off usually associated with a flashing O/D light and/or a flare of gears.
Clean everything while it’s off the vehicle.
Inspect bands,orings,servos,clutch plates
New filter and fluid
And for gods sake make sure to do a good job with band adjustment. And u should get it shifting and driving solid.