Cascade Crew

blue89 · Posted: Wed Dec 20, 2006 9:03 am Post subject: 4L60E with mechanical tailshaft

I can't seem to find any information on TGO about this. I have a stock 4L60E in my 89RS and I want to hook up a mechanical speedo.

I was thinking that all i had to do was take the tailshaft housing and reluctor wheel off the 4L60E. Then put on a speedo gear on the output shaft and a mechanical speedo tailshaft housing. Will this work? The only thing I see not working is the output shaft may not have the holes to mount the speed gear.

Can anyone help?

chevymad · Posted: Wed Dec 20, 2006 11:44 am Post subject:

Yes it will work. Here's a link to a site with more info..

http://www.geocities.com/crosley_az/700spd.htm

blue89 · Posted: Wed Dec 20, 2006 2:16 pm Post subject:

SWEET!

Does the computer use the vss for shifting gears at all? or does the manual shifter compensate for that loss? Noone seems to be able to answer that question yet.

If you look at the schematics for the 4L60E, it looks like the only thing the PCM controls is the downshifting. Otherwise, the tranny shifter itself wouldn't have a cable to the tranny like a 700r4, it would give an input to the PCM. Am I correct?

Twilightoptics · Posted: Wed Dec 20, 2006 2:44 pm Post subject:

I thought the 4L60E was all electronic control? So that you can program your shifts?

blue89 · Posted: Wed Dec 20, 2006 3:00 pm Post subject:

If it was ALL PCM controlled, then you wouldn't need the old style cable gear selector. I think the gear selector still controls the max top gear you can select. But if you leave it in OD all the time, then the computer will control it. I never leave it in OD.... I am the original Shift-matic!

chevymad · Posted: Wed Dec 20, 2006 4:54 pm Post subject:

It's all electronic control. All shift points in the transmission are selected by the ecm. The shift cable is the manual range selector. If it's a 4l60E it will require a computer in order to shift at all. I think even the pump pressure is set by the ecm.

Is it really a 4l60E or is it just a 4L60? The 4L60 is a non electronic version, basically an upgraded 700r4.

BigDaddyVu · Posted: Wed Dec 20, 2006 8:09 pm Post subject:

i found one off an s-10 and a blazer they bolt up the same (vss and mech) are the same physically for the exception for plug and cable

blue89 · Posted: Thu Dec 21, 2006 9:40 am Post subject:

http://www.thirdgen.org/techboard/ltx-lsx/377188-getting-mechanical-speedo-work.html?highlight=4l60e+mechanical

This is what I've got going on at tgo. I would assume that I have the 4l60e because it has that fancy plug that goes into it. Plus the schematics show a separate gear control servo and a pressure control.

So to avoid getting the expensive duel output tailshaft on jtr.com, I'm going to entertain the idea of an autometer gauge. I wanted to retain as much stock PCM as possible, and a new speedo gauge will allow me to do that. I'll let you know what I decide to do.