Hello,
I am about to get a 1989 Cherokee with 1996 Grand Cherokee Motor, the swap was completed by someone else before I got it...

Here is what I am wondering, the trans is not shifting by itself, you have to manually shift it...

Here are my questions...

1) Should that swap be possible with out swapping the trans too?

2) If I continue to drive it like it is, shifting it manually, am I damaging it?

3) Is there the possibility of just installing a manual valve body and just shift manually all the time? Will I get all the gears including OD?

4) What are some possible reasons this could be happening, Assuming two possibilities, 1) the trans was swapped 2) the trans was not swapped.

5) Un-related to the trans, what is the difference between the 89 and 96 motors?

Thank you for your prompt response.

Kevin  

Sounds like the Transmission Control Unit (TCU) was not installed/hooked up.

I'd probably stay away from buying somebody's problems.

The Cherokee, if it had an auto original, had a separate TCU. It uses input from the computer to determine transmission operation. The Cherokee also had a Renix injection system and PCM. Very different from the Chrylser PCM used in the Grand.

There might be some compatibilty issues between the tranny electronics, the TCU and the engine PCM.

Check the tailshaft housing and see if the speedo drive is a cable driven or electronic version. If it's cable, I would wonder how the new PCM is getting a Vehicle speed signal. Scary.  

I value your comment about not buying someones problems, but I wonder if I would not be able to figure it out... I would likely do something similar myself (the swap).

Hmmm, dunno  

Swaps that work correctly use complete engine, trans, wiring harness and computer. The ones that run, but don't work correctly, mix and match pieces and parts.

Trust me, you don't want a mixed bag. The time and expense will defeat you.

The knowledge required to mix and match is far greater than most people can tollerate. It actually requires much less knowledge and expense to do "complete" swaps. You'll always know the "Failures" when the discussion starts out as "Free something, what else do I need?"

Sounds like your specimen might provide proof for this advice.  

Well I talked to him again... His wife said it was swapped and thought it was a complete swap, well husband says with a chuckle no, and that it was a long block from the 96, basically stripped down and all the 89 stuff put on the 96.

This does sound better no?

Also it sounds like it is the original trans.

So if this is what was done, what are some possibilities of failure. Also I found out the speedo is non op, would the 89 use a cable, and if so and it is broke would that effect the trans?  

Yes, the '89 would use a cable driven speedo. If this is not working, it definetly would affect the trans shifting. Why is it not working?? That sounds too easy.

Is the Renix system still installed?

I think your dealing with tops, a $2000 vehicle. And that's everything working correctly. The Renix system is not desirable. You could easly pick up a newer Cherokee ('91-'01) without Renix for probably the same money. Cherokees all the way up to '01 go for between $2000 and $4000. I'd hold out for a newer Cherokee.  

I just went out to my local Phoenix CraigsList and I'm lowering my value estimate. Tops $1500 for an '89.

There are some really nice ones available for less than $3000. A '94 & '95. And too many to count for less than $4000.  

OK I did it, I got the Jeep...

Actually with meeting the husband and discussing the swap all was not as bad as it seemed.

Here is the deal, the Renix system was kept, only the long block was swapped. The 89 trans was kept, the speedo cable is connected to the trans, but the speedo is not working. I will look into the trans shifting issue later...

But I just wanted to say I got it, and thanks for the comments.

btw: It has a 3" Rancho lift on it too.