42RLE Transmission : Engine rev / delay going into high gear

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
03 Liberty with just under 55K miles ... yep, 55K
Bought new in 03 and had fluid changed in transmission once, several years ago.

In the last year or so, the transmission had gotten pretty bad about engine rev before going into high gear. I overfilled the transmission by a few ounces of fluid and that seemed to improve shifting but the rev/shift delay into high gear was still there and it has annoyed me.

Don't know what I'm doing, but thought I'd give something a try. I got to thinking, well, wonder if the Transmission Throttle Valve Cable had become stretched or something?

So I checked the cable behind the throttle body and sure enough, there was a BUNCH of slack in the Transmission Throttle Valve Cable.

I don't know how to adjust the cable. So I thought I'd try putting a small zip-tie on the end of the cable to take up some slack.

Lo and behold, shifts improved !!! But still not "perfect". And there was still a good bit of slack in the cable. SOooo I put a second zip-tie on the end of the cable. And hot dang, not only did it correct the engine rev/shift delay into high gear, but shifts are better all the way up and down.

Wouldn't advise this as a fix, but the hack is working on my Jeep. Maybe there's a way to adjust the cable and proper procedures, or maybe the cable should just be replaced if possibly stretched ... dunno. In the meantime, I'll just enjoy a transmission that shifts better than it has in years and years.

You must be registered for see images attach
 

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
... and maybe that's a Speed Control Cable and not a Transmission Throttle Valve Cable ?!?!?! ... and if it is, how come that hack improved shifting, dare I say dramatically ?!?!?!
Maybe I better check if cruise control still works D'OH !!!

EDIT: Yep, cruise still works great. Wonder what this hack tells me I need to fix? Haven't yet found a way to adjust that cable to take up some slack but taking up slack dang sure helps shifting. Two little zip-ties improve shifting more than they should LOL
 
Last edited:

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
8,314
Reaction score
978
Location
B.C. Canada
I'm not that familiar with the throttle body cables, never had to deal with them. Possibly someone knows more about this cable slack.
The 42RLE is electronically controlled, so I'm not sure how this effect things if at all.
From the FSM, the slack part is called a "throttle body bell crank" & seems to be related to speed sensor.
Ran down to the Jeep, mine has a lot of slack, yet mine shifts fine.
You must be registered for see images attach

Still you might be onto something here IDK..
 

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
Thanks !!! ... makes not sense really just by nomenclature and assumed functionality. But it sure did corrected a shift problem I've had for a while. It WAS engine revving and there was a shift delay going into high gear (or overdrive). Shifts smoothly now (taken it out 4 times, put 36miles on it just to make sure) and I won't mess with it anymore unless something else comes up, I get a code or something. Don't know why but the zip-ties made a huge shift difference ... for me.

I also noticed not only did this cable have a BUNCH of slack in it, which is apparently normal I guess, but I noticed too that the accelerator cable has a BUNCH of slack. Acceleration is fine. Didn't mess with it ... just this cable. And I only messed with it because I thought it controlled a valve in the transmission for fluid flow, like a lot of dual throttle body and carburetors with a cable that incorporate a Transmission Throttle Valve Cable control.

Maybe I messed with it for the wrong reason ... but (somehow) got the right result LOL.
 
Last edited:

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
When I read "Speed Control" ... I think cruise control. Those two zip-ties have no affect whatsoever that I can tell on the cruise control. CC works fine.

Maybe I'll get around to tracing that cable out. Dark outside ... and cold ... right now.
 
Last edited:

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
Section 8P of the 2003 KJ Service Manual describes "Speed Control" in detail but no way ties it or that cable to the Transmission. I.just.don't.know. but glad shifting has improved for me.
 

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
Remove the zip ties and see if it goes back.
There was a day when I would have pulled the trigger on that idea right away, and it had crossed my mind, but my thinking goes like this and I quote ...

"You know you've had this problem for a quite a while with engine revving and shift delay going into top gear. It was a consistent problem. Happened each time the Jeep was driven. You know when you put on one zip-tie, the condition improved. You know when you put on the second zip-tie, the condition was corrected. Why not leave the zip-ties on and see if the condition returns?"

Think I'll just enjoy the better/correct shifts if and until I find the zip-ties causing any problems. So far so good.
 
Last edited:

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
HA !!! :D

Went for another drive this morning, from a cold start of course. Definitely MUCH smoother shift and better shift points. Won't be shocked to find better gas mileage too. After topping the tank back off, preliminary indications are at least a 2mi per gallon increase in city driving. Those two little zip-ties fight WELL above their weight LOL.

The Speed Control Cable isn't directly tied to the transmission that I can see. Speed Control encompasses among other things, a servo and the vacuum loop which I MIGHT find works somehow in conjunction with the transmission ... dunno. But everything is tied to the PCM.

Right now I'm just calling it pure D luck I stumble bumbled onto trying the zip-ties on a cable I thought was something else entirely. But for right now, I'm not changing nothing.

No idea how the zip-tie hack might affect a system working properly, but for my condition with the proper transmission fluid level and transmission otherwise working properly except experiencing a consistent engine rev and shift delay going into high gear ... this hack fixed it for sure. Smoother shifting across all gears and proper shift points now.
 

03GoingStrong

Full Access Member
Joined
Jun 26, 2020
Messages
117
Reaction score
52
While I can't explain how this hack changed the shift point and while no codes were being thrown before or now ... I've got to believe there is a failed component somewhere or another or something is somehow compromised. I just don't know what it might be.

The slack I found in my Speed Control Cable is no greater than the slack LibertyTC posted in his picture, so the slack in my cable is apparently normal ... and he says this transmission is working properly. So I dunno, something may be failed somewhere in my Jeep and this hack just compensates for it somehow. I just don't know. It's a riddle, but the hack just flat out works for me and I sure am enjoying the improved drive.
 
Top