meyestone

Hey, so a few weeks back I got my automatic transmission rebuilt at a local shop and when I got it back, it always shifted from 2nd to 3rd at 45 when I'm accelerating, or driving up a hill.
The next day I took it back to them and they said that its normal for that to happen when I have a tow package, for extra power or something. I'm just wondering if what they're saying is true because I don't really wanna get ripped off if it isn't.

Radi

Shift points are controlled by the TCU, rebuilding the transmission shouldn't change them.
Might be a difference in firmness, shift quality, etc...but not timing.
Are they different than from before the trans was rebuilt?
Have you checked the TPS? It has quite a bit of input related to shift points.

IIRC, the "towing package" contained a hitch, wiring plug and trans cooler. No changes to the TCU or the transmission itself.

salad

Yar, if they be rebuildin' tha tranny ye might want to peek at the TV cable... Arrr... Can change the shift points like you suggest

A couple years also had 3.73 gearing instead of 3.55, but again same transmission and TCU. RENIX XJs had a power/comfort switch but the TCU is permanently in Power mode later on.

Zack92MJ

I'm confused on what your problem really is. You seem to have forgotten that part. Is it not doing that? Is it doing it later or earlier?

meyestone

It sounds like the RPMs are getting too high and it's not shifting into 3rd early enough. Like if I was driving a manual, I would shift around 30 or so, not 45.

Also, is it okay to change the shift points? Because I'm not doing any towing with it anyway. And I would do that through the TPS?

Elexwiz

Do the automatics with tow packages have "Tow/Haul" settings or similar options?. If I select Tow/Haul in my truck it will change the shift points. You will still go through all the gears but the shift points are all increased to higher rpms.

djb383

Negative on tow/haul settings, the XJ has very light duty towing capacity. It's the TV cable adjustment, not the TPS. The factory max tow capacity requires the XJ to have a auto tranny, with an auxiliary cooler, heavy duty engine cooling and the 4.0L motor. Take any of those 4 items away and towing capacity is reduced.

jakbob

if it is a 92, your TCU is preset in power mode. from what you suggest, when you accelerate, and going up hill, its normal for the transmission to stay in the lower gears. maybe you arent used to a rebuilt transmission?

jakbob

x2

meyestone

Okay, so I'll adjust the TV cable, thanks guys.

And I don't think that it's me not used to a rebuilt tranny, because I drove somebody else's cherokee and it shifted just fine. (no tow package)

jakbob

when was the last time their transmission was rebuilt? a rebuilt tranny is just about as good as a new one. just saying its a possibility.

Zack92MJ

X2

meyestone

So there's no way to change the tcu from power mode to comfort in my '92?

And I adjusted my TV cable and all it made it do is shift harder.

meyestone

I got it shifting smooth now, but is there any way I could change the tcu from power mode to comfort?

jakbob

No. You do not have a power/comfort switch. Besides, all comfort does is wear your clutches out faster.