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Discussion Starter #1
Hey y`all

I am planning to do a swap in my 98 Explorer. I will of course be putting in a 4BT and I have a 47RH to go in behind it. Will I need to find a computer from a donor to operate this transmission or will it work without one? Are the shift valves operated by pressure only or are they sensor and PCM controlled ? Any informational help or direction for transmission swap references I can I can find from the memebers here will be greatly appreciated.

Thanks to you all.
 

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The overdrive and lockup are controlled through a vacuum switch. Just curious how you are going to make it work with no vacuum on the diesel engine.
If I'm missing something please let me know.
 

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The overdrive and lockup are controlled through a vacuum switch. Just curious how you are going to make it work with no vacuum on the diesel engine.
If I'm missing something please let me know.
Probably the usual confusion between the gasser and diesel versions of the Chrysler automatic transmissions. See: http://4btswaps.com/forum/showthread.php?t=1281 and the other links in the "Topics Index" under automatic transmissions - Chrysler.
 

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I didn't know the 4bt doesn't have vacuum pump. I guess I still have a lot to learn. Then you gonna have to add a pump.

Eugene
 

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You don't need a vacuum pump if there is never any change in vacuum!

That is only for gas engines when vacuum actually CHANGES
 

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Discussion Starter #9 (Edited)
The overdrive and lockup are controlled through a vacuum switch. Just curious how you are going to make it work with no vacuum on the diesel engine.
If I'm missing something please let me know.
I will be adding a vacuum pump to operate the brake booster. But after checking out the link provided in one of the posts by Febrocks, I have determined I only need the correct pressure switches and some simple wiring to get this thing streetable.

I really appreciate the input from all of you. The ideas put forth on these pages are very important to rank amatuers such as myself. They say knowledge is power, but I believe that if you don`t share the knowledge, your just another seeker like myself.
 

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I'm a little slow so please bare with me. Is the reason you don't need vacuum because the 47rh in gas engine is different from diesel engine?

Eugene
 

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I'm a little slow so please bare with me. Is the reason you don't need vacuum because the 47rh in gas engine is different from diesel engine?
Sort of.
Using a vacuum switch to control a transmission function would imply that different things in the trans happen at different vacuum levels, EXACTLY like what happens to the vacuum in the intake of a gas engine.

A diesel engine with a vacuum pump will pull the SAME amount of vacuum at all times, regardless of load or RPM. A vacuum switch that reads from a source that NEVER changes is useless to control transmission functions.
 

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Thanks LincTex.

I didn't know vacuum pump only pull constant vacuum. The light bulb finally came on and I understand how it works. I think I got confused by the physical connection part.

Eugene
 
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