doorgunner

I checked into the "hunting condition" which mine has sometimes.....GM installed a vacuum restrictor in-line before the vacuum switch....it looks like a one-way check valve but it has a tiny hole in the center of the diaphragm to buffer the "oscilating" vacuum. The one I found at a salvage yard was damaged/broken open---the hole was about .010" in diameter---about the size of a single strand in a dash wire.

I think I'll get a common "straight pin".......heat the end of it....insert it into the port....and make a small hole in the one-way check valve that I bought a while back.....and install it "backwards" so it works like a vacuum restrictor.

riverracer au

i'm happy with my mish mash controller, and it mounted of the brake booster stud, up alongside the fuse panel and steering column.
out of the way, but still easy enough to get to to adjust the speed setting, if i crawl on the floor..

doorgunner

Your setup looks good.....just wanted to let you know about the GM primitive way of solving the "Hunt" condition.

How are things working out/did the trans-guy check things out?

riverracer au

see my setup is not complicated at all...
and i'm no electrical engineer, just a fitter n turner/toolmaker
but i know enough not to get myself electrocuted or let the smoke out

doorgunner

Got it........turn right at the (LED) light.......go one block.........

Good to hear it's behaving now!

speedreed8

nice setup, and schematic. my setup is almost like yours also used a relay to turn on a led dash light to let me know when its locked.

doorgunner

Update: I finally got around to installing the new cable and drive gear.......I will test drive the car tomorrow.

aussiejohn

'75,

I was under the impression that the TH200.4R and the TH400 were dimensionally interchangeable and that the original TH400 tailshaft, er "driveshaft" could be re-used when changing to a TH200.4R, but your drawing implies that a longer driveshaft would be needed, even though the transmission mount is in the same position. Can anyone shed some light on this please?

Regards from Down Under.

aussiejohn

Haggisbash

200-4R fitted in my 70 without modifying the drive shaft or tail shaft.

'75

My 75 had a TH400 that I removed for the 2004R, the original drive shaft worked just right. I had to use a slip yoke from a vette with a TH350 or Powerglide. By the chart, the 2004R would be 3/4" shorter than the TH400, no mod is required.

Cool bean

I know this is an old thread, but I'm posting to say thank you! I just put my new motor and 700r4 trans in the car today and the mod you described for the crossmember (74 stock th400) worked perfectly! I only had to extend the slots by 5/8 inch.


The dremmel and grinder worked perfectly. The tailshaft housing came from the local pick 'n pull yard for $25 bucks. I can't wait to drive this puppy!

doorgunner

I found this 6 y.o. thread again.....

it's worth reading for new members doing a 700R4/4L60(non-PWM) transmission swap/Torque Converter Lockup/ETC.!