73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: 87Deluxe on October 28, 2014, 12:50:36 pm
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Hello All,
I've purchased an 87 Custom Deluxe 4x4 which has the 4-Speed Manual tranny. I'm going to swap out to 700-R4 as I believe it'll make it more road worthy and a daily driver. I plan on purchasing mostly brand new or reman parts needed for the swap.. one thing I need to know is can I just change out the input gear on the NP208 transfer case from the 32 spline to a 27 spline one for the 700-R4? I'm hoping I can, and not have to purchase a whole new transfer case. Also here is a list I came up with for the swap.... am I missing anything?
700-R4 4x4 Automatic Transmission
NP208 Transfer Case (27-spline for 700-R4) or 27 Spline Input gear for NP208
700-R4 to NP208 Adaptor
1987 Chevy Automatic Brake Pedal Assembly
1987 Chevy Automatic Steering Column
Automatic Steering Column linkage to 700-R4
Driveshaft Modification
Flywheel/Flexplate (Part No. Z-166)
TV Cable (Part No. Y-752)
TV Cable Bracket (Engine Bay, Throttle body)
ATF Fluid - Trans Fluid
ATF Fluid - Transfer Case Fluid
New Radiator with Trans cooler
Trans cooler lines
Thank you in advance for any info.
Ted
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The 700r4 uses an electronic Lock-Up Torque Converter. This is controlled by the PCM/ECM. Your TBI setup should have all the sensors needed, but you will probably need a PCM/ECM from an 87 w/ a 700r4 to control the converter properly. Hopefully someone with a little better knowledge on this will chime in.
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timthescarrd, thanks for the quick reply.
Yeah, I was thinking of that too, but then again I could use a stand alone kit so that the OD kicks in only in 4th. On my 65 Chevelle I have a 200-4R which operates the same as a 700-R4 and I just put in a toggle switch and only use when highway driving. No computer involved. I'll get a better kit from Bowtie Overdrives or similar... I'm also wondering if I would have to change out the cross-member at all. So far the only thing I see to do is possibly have my rear (or front) driveshaft resized.. not sure. I need to research of the dimensions and placement of the 4-speed vs. the 700-R4. I'm doing the shopping now online cause I'm in Afghanistan and when I get home I'll have everything needed to do the swap in one long weekend.. just want to make sure I don't miss any details.
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imo you will be paying dollars to save pennys in mpgs. i know it would be easier for you to drive but it would be harder for someone to steal since most criminals arnt smart enough to drive a stick lol. but i would get a truck the same as yours (ie LWB or SWB) as a donor and just take what you need it will be cheaper if you find one.
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We're almost done gathering all the parts to replace our 4 speed with a 5 speed from a '06 silverrado
Supposed to be a mostly bolt in deal with the right T-case
For yours it IS a bolt in swap
You already have the hydraulic clutch and the 5 speed will bolt up to your T-case
Use you same clutch plate even
Finding the 5 speed is the hard part
The best ones are from 98-07
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Thanks folks! Okay, so far I pretty much have everything needed to do the swap and have a new Monster transmission being built as we speak. Here's the list so far:
700-R4 4x4 Automatic Transmission (being built now)
27 Spline Input gear for NP208 (I will "rebuild" the NP208)
700-R4 to NP208 Adaptor
1987 Chevy Automatic Brake Pedal Assembly
1987 Chevy Automatic Steering Column w/OD gear indicator to go in dash P-R-(D)-D-2-1
Automatic Steering Column linkage to 700-R4 (don't have yet, wondering if Lokar type rod will work)
Driveshaft Modification (will get it done when everything else is done)
Flywheel/Flexplate (Part No. Z-166)
TV Cable (Part No. Y-752)
TV Cable Bracket (Engine Bay, Throttle body) (still researching this, may have to fab a bracket or look at boneyard)
Any thoughts on missing items?
Okay, here's my dilemma..... LOCK-UP!!! I know there's a million and one kits out there but I have yet seen one offered WITHOUT some kind of MANUAL switch. I want the truck to act as if it was a "Factory Automatic" and I know Factory Autos didn't have a "toggle switch" or separate "adjustable box".
So here's my idea: The ECM is the same for manual trannys as automatic equipped trucks. I'm pondering the idea of looking at the pinout diagram of the ECM and switching or adding or rerouting the proper wiring to transmission. Thus having the ECM control the Lockup as designed by GM.
HAS ANYONE DONE THIS? HAS ANYONE GONE THE EXTRA MILE IT TOOK TO HAVE A "FACTORY" LOCK-UP AND NOT JUST GO THE EASY ROUTE WITH A "BOLT-ON" KIT?
If anyone has, please share your experience. Also, if I'm forced to use an "add-on" lock-up kit, which is recommended for our trucks? Vacuum switch, brake light switch, or a combo of all? Basically, I just want to be able to get in the truck and go and only have to worry about the lock-up (turning it off) when towing.
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I haven't done it, in fact I've been running mine without the lockup for several years, but there are two options I know of that bypass the ECM and still act fully automatically. The first is TCI kit 376600, here's the manual:
http://static.summitracing.com/global/images/instructions/tci-376600.pdf
the other option uses a th400 kick-down connector switch, here's instruuctions for that:
http://www.73-87.com/7387garage/drivetrain/lockup.htm
Best of luck!
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Not sure if the ecm would lock up the convertor using the manual ecm.They may be the same but the difference would be in the prom.Another option is to use the vacumn switch setup off like an 82 to 86 suburban,just make sure you get the vacumn delay valve with it so the convertor doesn't act busy in and out
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Thanks timthescarrd and 78BIG-TEN!! Definitely good options... I think I'm getting closer to my conclusion. I appreciate your help.