Speedo / Tach / Gauges: 200 4R Hook-Up

[345 DeSoto]

What do I need to adapt my Sky Hawk speedometer cable to my GM 200 4R automatic transmission?

[sweetolbob]

Depending on what you currently have on the transmission speedo drive wise, it should be pretty straight forward if you Google 2004R speedometer adapter. Google will tie you into folks like Monster, Bowtie and most of the usual suspects that handle what you need. It could be a simple gear or a different drive/adapter gears set that needs to be adapted to the tailshaft.

They should also be able to supply the drive cable you need if you already have the mechanical drive on the trans. Usually the GM cable from the 60's and 70's will fit.

Bob

[Mike Van Veghten]

That's what I thought the internet was for...things like answering the above questions..!

Mike

[345 DeSoto]

Is the cable end which goes onto my speedometer, pretty much universal? If that's the case, I can pretty much do what SWEETOLBOB suggested...just buy the appropriate length cable for a Chev w/200 4R transmission...

[wittsend]

I've done it with a 700R4 in a '64 Daytona. Here are some things to know:

1. Some of the GM transmissions have an elecronic speedometer drive. If yours does it will need to be replaced. On the 700R4 (and I assume the 200R4 being similar) there are gear to cable drive housings. You need the right gears based on your rear ratio, tire size and the gear on the main shaft.

2. Of these gear drives they range if I recall correctly from the low 30 to the mid 40 in teeth count. About teeth count 39 the housing needs to be changed to the "larger" housing. This can add up with the housing and the gear pushing $80-$100. Or, CASO (like the life I lead) and I got both for $5 at Pick Your Part.

3. I took the speedometer "nut" to Pick Your Part and found that many cables fit the Studebaker configuration. However, with the 700R4 I found I needed a rather long cable. I found one from a late 70's/early 80's Dodge Pick up that fit the speedometer, the GM trans AND had sufficient length.


Hope that helps.

[bensherb]

What do I need to adapt my Sky Hawk speedometer cable to my GM 200 4R automatic transmission?

How long is your drive shaft, or do you have a two piece? The 200R is 3" shorter than the 700r4 /4L60, and with the 4L60 I had to legnthen my drive shaft almost 4" to over 55".

Or, CASO (like the life I lead) and I got both for $5 at Pick Your Part.

I'm not sure where you are "north of the equator", but you'll never find that speedo drive in a wrecker here, or the trans it fits.

Both the drive and driven gears can be found on ebay for $10-$15 each and the late style plastic housing with the seals for $10-$15 too. The low gear set is 34 to 39 tooth, and the high set is 40 to 45 teeth, each uses a different housing due to their diameters. A six driven gear, 4 drive gear set with the complete metal housing and hold down sell around $90. A GPS speedo that needs no cable or gears sells around $65.

[Treblig]

I installed a GM overdrive (2004R non computer) in my '59 Silver Hawk and as it turns out I was able to use a standard Gm speedo cable off a 70/80 GM car. You can check the lengths on ebay.

treblig

[wittsend]

I'm not sure where you are "north of the equator", but you'll never find that speedo drive in a wrecker here, or the trans it fits.

"North of the Equator" is 63 miles south of Goleta in a city known for a significant number of trees. The yards were in Sun Valley roughly an additional 45 miles way. I was relating the 700R4 (and its speedometer gear drive) with the stated "assumption" that the 200R4 and the 700R4 used the same drive. The internet has a LOT of confusing information some even implying the 350, 200R4, 700R4 all use the same speedometer drive. I did an additional search this morning and am now inclined to say they are different. But in my defense I did say it was an "assumption" and my application was a 700R4. I apologize if that caused any confusion.

That said, when I got my 700R4 there were about a hundred of those and about 20 or so 200R4's in the two self serve yards I frequented at the time (2012). I'd think a few could still be found today. Some people prefer to shop from a chair and pay the going rate. Like the person who enjoys a long walk in the woods I enjoy spending a full day in a wrecking yard and saving significantly. I simply mentioned it as an additional source. The original poster is listed as "New York / Florida" and their options may be different than Goleta / Tracy, CA.

[bensherb]

Now that you mention it, I believe you are correct. The 2004R does use different speedo gears than the 700R4/4L60. The info I posted was also for the 700R4/4L60 trans, The 2004R gears are about 30% more expensive.

Ok, years ago you might have found the GM AOD transmissions in wreckers here too, but in the last 5 or so years they've all dried up and have become quite difficult to get even from rebuilders around here.

Some of the very early 700R4's did use the same small speedo drive as the TH350. You rarely see them but occaisonally come across an extension housing for it, at quite a premium price.

[Mike Sal]

There are no 200 4R tranny's in the wrecking yards around my neck of the woods anymore. They all got scooped up or crushed. Last summer I finally found a core at a local mechanic's shop that they had laying around. I plan to either have it rebuilt or exchange it for a rebuilt so I can put it into my Avanti II.