Question : Transmission Woes

[Jaxom]

I have an '88 s-10 p/u 4x4 that has a 2.8L engine/700R4 combo. I had hoped to wait until I bought another daily driver before I did any major work on this truck, but my trans is on it's last legs now. It stalls out if I drive it more then a mile or more, and a few times after putting it in park and shutting the engine off, it'd start to roll on me!

Definetely time to have the trans rebuilt or replaced. The thing is, I really wanted to swap the engine out and install a hybred 3.4L, as discussed here and other s-10 boards. This will require an upgrade from the 700r4/4L60 to a 4L60E. I just can't see spending money on a rebuilt 700R4/4L60, only to have to buy a 4L60E down the road. Even if I don't put much milage on it, I won't get what I paid for it.

So....Looking at my copy of the Haynes repair manual as well as doing some heavy googling..I know that there were some s-10's that had both the 2.8L engine combined with the 4L60E transmission installed at the factory.

I know in order to get a 4L60E trans to work in my truck I'll need to find a ecm for it. What I don't know how to deal with is, do I need to replace the entire engine wiring harness, or is there a way to adapt in the proper 12 wire harness that'll fit the 4L60E trans? Also, my truck came with a mechanical speed cable. From what I've read, I need to convert this some how so I can send a VSS signal back to the ecm in order for it to know when to send the signal to the trans to shift gears.

Beyond all this is there anything else I would need to do to convert over to a 4L60E?

I know this seems like a big head ache to do this type of swap. Esepcially since I'll need to swap ecm's once again when I install the 3.4L engine. But that sure beats he heck out of loosing $100's buying two transmissions!

And while I have asked at local bone yard, I can get a trans from them for $140, but they won't cut it out for me. And that's a ton of work not knowing if the "new" trans isn't as bad or worse then the one I have now.

Comments? Suggestions?

thanks

Jax

[robertisaar]

i don't think it would be necessary to use a 4l60e.... i don't see why you couldn't use the tranny you have now, or just a regular 4l60/700r4(assuming it has a 60*v6 bellhousing pattern)

[bszopi]

Agreed. No reason at all that you need a 4L60E tranny for your future swap.

[Jaxom]

Isn't the HT 3.4L MPI? How would that work with a 700r4? Where would I attach the TV cable to?

[robertisaar]

Isn't the HT 3.4L MPI? How would that work with a 700r4? Where would I attach the TV cable to?

HT3.4?

http://www.crateenginedepot.com/store/HT-34-V6-Crate-Engine-S10-Truck-Repower-12363230-P25C56.aspx

this?

"Technical Notes:
This is for engines with carburetors only, not released for TBI usage."

[Jaxom]

And there's dozens of threads on converting this to a hybred version using late model grand am head, plentium...ect converting it to MPI. Not tbi.

[robertisaar]

And there's dozens of threads on converting this to a hybred version using late model grand am head, plentium...ect converting it to MPI. Not tbi.

i believe my wife's GP uses a TV cable for determining the shift points(and the vacuum modulator for line pressure), and thats a stock 1990 3.1MPFI setup

[Jaxom]

The 3.4L has the throttle body, center front of the engine. I can't see how a TV cable can be ran there or how it would be attached.

But that's all for later... For now I need to concentrate on wheither I can swap the 700R4 for the 4L60 E by just switching the ecm out?

[robertisaar]

i would think they would have the same bolt pattern, so i'll sugges this: get a TB from a 3.1MPFI 4speed auto car(as long as its not hooked up to a 4t60e, which would be 93-94). that would have the provisions necessary for a TV cable.

[candychevy87]

get the trans out of an 80's 6 cylinder camaro they work great for the swap you plan on you might have to change out the tail shaft to get the transfer case back on but

[Jaxom]

Update: Some lucas transmission additive sealed the front end leak and smoothed out the slipping issues. This will give me enough time to save for a 3.4L and a 4L60E and all the assosicated parts for the swap.