Hey fellas,
So I decided to upgrade to a 350 from a 305 on my 91 z28.
Along with that, I decided to upgrade to a 350 turbo trans rebuilt 30k miles ago from my 700r4 with over 200k on it.
A couple little problems present themselves, like the support beam bracket not being there on my newer trans, and the cross-member needs to move up an inch. No biggy.
The question I have is, the speedometer cable on my old one was electric, and had a little plug. The turbo trans has what looks like a mechanical port. How will I be able to hook this up to my instrument cluster?
I hope Im clear enough about this, and I hope you guys know what I mean.
Any ideas would be great.
Thanks in advance!

 

Take the speedo parts and tailhousing from the old trans and put them on the "new" trans.

 

Welcome to TGO. Many after market companies, associated with TGO, sell cross members for the TH350.

JamesC

 

Sounds simple enough, although I only have just the trans. I guess Ill try a junk yard and see if I can find it.

 

Sorry to use a different person's thread but I have a similar issue with my trans. I am take everything out of my 88 and putting it into my 91 but I already have the 91 trans in that came with the car, how do I swap from electrical speedo to mechanical speedo? Do I have to take the whole tail end of the tranny off and swap them or can I just get that little piece out of it and swap that?

Please help, it is urgent and I need to get it done asap.

 

... if the the drive gear inside the tailhousing on the output shaft is identical to the other one, they don't need swapped.

 

If I understand correctly, you're swapping an 88 mechanical into a 91 electric. If so, simply remove the mechanical speedo gear and housing from the 88 and plug in the VSS from the 91. As JMD mentions, if the 88's drive gear is the same as the 91, all's good. If not you'll need to replace it with the proper gear or the speedo won't read correctly.

JamesC

 

How do I remove the housing though (the piece that goes into the tailhousing)? I took the single bolt out that holds a flap looking piece and tried to pull the electric one out but it wouldnt budge. It slightly moves on the bottom but I can't get it out.


I am also wondering if I pull that out will I have tranny fluid pouring out all over my face? haha.

Figured I should double check before I get it out xD

 

The fit is snug. You may have to gently pry. A bit of fluid may dribble out.

JamesC

 

Thanks a lot for the help!

So if I pull both out and the colors on the gears are the same, I can just pop my mechanical cable hook up right in there and I am good to go?

 

Both the drive and driven gears must be the same.

JamesC

 

Sorry I don't really know anything about these.

So I will have to pull them both out, check what color the gears are on the piece and then look inside the tailhousing on the 91 to see if the drive (?) gear is the same color (?) as the driven gear (which is the piece the speedo cable connects to, correct?)

Sorry for all the questions, newbie at this and I don't want to keep running into problems so I like to cover all the issues and make sure I know exactly what I am doing first.

 

Both drive gears (on the input shaft) should be the same color and have the same tooth count. Both driven gears (speedo connection) should be the same color and have the same tooth count. For example, with 3.23's, I have a
blue 7-tooth drive gear and an 18-tooth driven gear.

JamesC

 

So how can I see if the drive gear is the same? Do I just try to look through the hole? (both trans are in cars while I work on them)

Also, my 91 had a magnetic connection (I dont know if that is normal) but my 88 had a red gear on the piece that I pulled out.

Here is a picture of both of them side by side:
https://www.thirdgen.org/forums/tran...ical-help.html