Re: Torqueflite 727 conversion

Posted by Predictor On 2009/9/6 14:34:32

Hi all, new guy here. Thirty years of turning both stomachs and wrenches here so please allow me a few observations between the alternate transmixers:

727 Throttle Valve pressure controlled by pressure linkage, neutral/reverse light switch on case
400 Throttle Valve pressure controlled by vacuum modulator (electric kickdown)
2004R Throttle Valve pressure controlled by cable, simple electric circuit for lock up NO COMPUTER NEEDED
700R4 Same as above, larger case, longer tail and ratios not as good

{the model numbers above are NOT typos, the correct model numbers are indeed 2004R and 700R4, seems far too common to mistakenly refer to them both as 200R and 700R though!)

While I haven't done a Packyderm conversion, I have done so with other cars including Steadybreakers and am here to tell you that unless you're going drag racing or towing a 5th wheel trailer loaded with scrap iron up mountains at 90mph then the 200R is probably the best choice overall. Small and efficient and can be rebuilt to be quite strong.

Some other things to ponder:
Best to not use a unit older than 1987, the newer the better...lots of running changes.

Lockup converter circuits are a simple deal, the internet is filled with diagrams. You do NOT need to buy the expense version that has a vacuum switch.

Neither the 200 nor 700 require a computer! Only the later versions which were renamed 4L60E (E = electronic control), and even those can be adapted to work with a stand alone brain box of sorts. Too much for this old dog...keep it simple and stick with a 200 or 700

Have had some bad experiences with adapter plates that weren't centered on the engine's crank which WILL lead to vibration and converter or even pump failure. The Studebaker shop manual goes into detail on how to dial indicate bellhousings, they were originally select fit mated to the engine at the factory (although they and the dealers used a locating tool to do this...the manual shows how to accomplish this without this tool)

Is anyone CURRENTLY offering transmission cases with a modified bell? For the record, GM offered several bolt patterns, Chevy being one and Buick/Olds/Pontiac/Cadillac being the other (I'm not going to get into the oddball AMC Postal Jeep etc variants!). There were some cases that are known as multi-case which combine both bolt patterns...anyway, what I'm getting at is that if someone can convert a TH 400 then he should be able to convert any of the other Turbo Hydramtics (assuming his tooling fixtures don't have an issue with locating on the innards of the different cases).

Well that's probably enough drivel to clog your brains for now.