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Discussion Starter #1
I have been thinking about going to a 700R4 in place of my NV4500, but the heat generated from slow crawling seems undesirable. I prefer technical slow speed crawling rather then point and shoot wheeling, but why not have both!

Why couldn't you use the lockup circuit to lock up on demand with a steering wheel mounted switch and then allow the normal servo's or ECM lock up for high speed driving?

My thinking is to use a 5.0+ t-case with 4.88 gears, probably the Stak Box, combinded with the 3.06 low of the 700R4 that would give me a final ratio of 81:1 with the converter locked. That way I would have the control of a granny gear without the excess heat generated from converter slippage, if I needed to bump up something I could release the converter and hammer down.

Anybody see any problems with this?

Oh, am running a 454 small block chebby with 511hp and 571 ft/lbs....
 

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that tranny won't like you much...the lockout is the weak point of the 700 otherwise it's a turbo 350...good luck with the project but
 

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mudtruck44 said:
81 to 1 isn't going to feel very low when its locked up.
I do most of my crawling in 2nd gear now and thats a 56:1 reduction, I am just wondering if it will hold up.... My tranny guy assures me it will be fine I am just looking for real world experience..
 

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As far as I can tell.. when you're poking around where the engine speed nearly matches the input shaft speed, there is very little heat generated from TC slipping. Having a deep geared t-case will help with that..

The guys running a TH350 with a NP205 and 4.10's are the ones building all the heat. :D

You better build that 700 well for the power you're making though.
 

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With that kind of crawl ratio in an automatic you may not be able to stop it with the brakes. The torque convertor multiplies the torque of the engine when under its stall speed(so make sure you get the right stall speed for your application) and you may need to pop it into Nuetral to stop.
Not quite sure how locking the converter will effect this. infrom me if you know because I am running a 700r4 as well in a 86 k5 blzr.
To keep it cool install a guage at least one cooler, the biggest you can find, and add a filter or two. Keeping these trannys cool and clean lets them live a long life. I have 2 coolers 2 filters and the temp never gets over 170*, usually runs 150-160*. I have 75,000+ miles on the tranny no issues yet.
 

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MrWillys said:
Contact TCI, I talked too them last year and they had almost perfected this.
Stock 700r4 won't lock up in 1st gear. Did TCI change the hydraulic routing to fix this?
 
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