42RLE transmission reprogram/shift kit??

[osufans]

Hey...after a few months of owning my Liberty, there is really only 1 major bone to pick with it....the darn transmission wants to shift into O/D WAY too soon!

I realize this is only a 4-spd, but the doggone thing shifts into O/D so soon, the Jeep struggles to get up to speed unless I give it some pedal and force it to downshift (or tap the O/D button) until I get up to about 50 MPH.

So first off - how quickly does everyone's 42RLE shift into O/D? Mine will kick in about 40-45 MPH.

Secondly - is there a reprogrammer that will change the shift points on this?

Also, I see that TransGo makes a shift kit for this transmission. I have used their kits in other vehicles, some with noticeable improvement, others with so-so improvement.

Does anyone have any recommendations for my dilemma?

Thanks!

 

[belvedere]

I drive w/ O/D off around town, and turn it back on when I go on the highway.

 

[osufans]

I drive w/ O/D off around town, and turn it back on when I go on the highway.

Sorry, not trying to be a jerk, but.....thanks, but no thanks. yupnope.gif

lol

Anyone have any suggestions on how to "fix" this issue, without doing a workaround?

 

[belvedere]

Does anyone have any recommendations for my dilemma?

I guess I was supposed to just "know" which recommendations are acceptable and which aren't. My bad.

 

[osufans]

I guess I was supposed to just "know" which recommendations are acceptable and which aren't. My bad.

Sorry...wasn't trying to be disrespectful. Thanks for the suggestion, but I'm looking for more of a "fix" than a "workaround."

 

[JeepJeepster]

I drive w/ O/D off around town, and turn it back on when I go on the highway.

Ive been doing the same thing for many years. Not really a fix besides giving it more gas to prevent it from locking up early. Or getting the programming changed. A shift kit will only make it shift firmer, not at different times. And in all reality its the torque locking up too soon, not the ****** up shifting too soon.

 

[J-Thompson]

drive the Jeep
I mean dont drive it like you have Mrs. Daisy in the back
push the gas if you want it to work different

 

[KYLiberty]

Just get a torque converter and shift kit from APS Precision, and a flash from B&G, and you're good to go.

 

[tommudd]

Sorry, not trying to be a jerk, but.....thanks, but no thanks. yupnope.gif

lol

Anyone have any suggestions on how to "fix" this issue, without doing a workaround?

Thats what i have been doing for 5 years, its not really a work around, it works, I run mine till I hit 87 then kick it in to OD!

 

[tjkj2002]

The 42RLE has crap gear ratios,add a lack luster torque curve of the 3.7 = piss poor driveability and prone to overheating.

There is no fix,the "shift kit" for the 42RLE is useless and does not do much,changing the shift points will not help either since you still have crap ratio's.


Long live the '02 KJ's with the 45RFE(woot)

 

[autoboy454]

The 42RLE has crap gear ratios,add a lack luster torque curve of the 3.7 = piss poor driveability and prone to overheating.

There is no fix,the "shift kit" for the 42RLE is useless and does not do much,changing the shift points will not help either since you still have crap ratio's.


Long live the '02 KJ's with the 45RFE(woot)

Would it be a direct bolt-in swap to revert to a 45rfe?

 

[tjkj2002]

Would it be a direct bolt-in swap to revert to a 45rfe?

No,it can be done but it is not a direct bolt in per say.

 

[osufans]

The 42RLE has crap gear ratios,add a lack luster torque curve of the 3.7 = piss poor driveability and prone to overheating.

There is no fix,the "shift kit" for the 42RLE is useless and does not do much,changing the shift points will not help either since you still have crap ratio's.


Long live the '02 KJ's with the 45RFE(woot)

So comparing my Liberty to my '05 Chrysler Town & Country, why does the T&C drive so much better? It has the same ratio's in the transmission for each gear, the engines create similar HP and TQ (with similar curves), however the final drive ratio is a bit taller in the Jeep (2.57, compared to 2.70 in the T&C.)

Plus, the T&C has an extra hundred pounds on the Liberty!

 

[tjkj2002]

So comparing my Liberty to my '05 Chrysler Town & Country, why does the T&C drive so much better? It has the same ratio's in the transmission for each gear, the engines create similar HP and TQ (with similar curves), however the final drive ratio is a bit taller in the Jeep (2.57, compared to 2.70 in the T&C.)

Plus, the T&C has an extra hundred pounds on the Liberty!

Different engine with a different torque curve(a OHV engine will be drastically different feel then a SOHC engine) and does not have a 42RLE and also has a different gear ratio in the diff.And not to mention the difference between FWD and RWD/4wd when comparing parasitic drain in the different drivetrains.

 

[osufans]

Different engine with a different torque curve(a OHV engine will be drastically different feel then a SOHC engine) and does not have a 42RLE and also has a different gear ratio in the diff.And not to mention the difference between FWD and RWD/4wd when comparing parasitic drain in the different drivetrains.

Yeah, but it has the 41TE, which is what the 42RLE is based off of. Each gear drive ratio is EXACTLY the same, only the final drive ratio is different (albeit slightly.)

And while a SOHC doesn't employ lifters and pushrods, it is still considered an OHV valvetrain.

I can't find the HP/Torque curves, but if you look, both peak out in TQ at 4000 RPMS, and HP at 5000 and 5200 (Chrysler/Jeep respectively). They are VERY similar.

 

[osufans]

Although, now that I am comparing them more closely...the T&C uses a variable intake manifold design, which undoubtedly improves low-end TQ over the fixed intake of the Jeep.

I guess to go back to the transmission though...is B&G the only company that makes a PCM update for this Jeep, or are there other aftermarket "chips" or flashers that work?

 

[LibertyTC]

The 42RLE has crap gear ratios,add a lack luster torque curve of the 3.7 = piss poor driveability and prone to overheating.

There is no fix,the "shift kit" for the 42RLE is useless and does not do much,changing the shift points will not help either since you still have crap ratio's.
Long live the '02 KJ's with the 45RFE(woot)

I always wondered why the kJ needed a tailwind to get up a hill with overdrive off.
Would changing the rear axle ratio make it any better? The rpm is still low even at 60mph OD on or off, just lacks torque.
I guess a larger ****** cooler would help it out too.

 

[tjkj2002]

And while a SOHC doesn't employ lifters and pushrods, it is still considered an OHV valvetrain.

I can't find the HP/Torque curves, but if you look, both peak out in TQ at 4000 RPMS, and HP at 5000 and 5200 (Chrysler/Jeep respectively). They are VERY similar.

SOHC engine is in no way considered "just still a OHV engine".peak HP/TQ #'s do not mean alot,it's there curve that counts and a OHV valve engines tend to have flatter/earlier torque curve then a SOHC engine.The 3.7 peaks at 210hp at 5000rpms and 235lbs-ft of torque at 4000rpms,if the 3.3/3.8 OHV makes the same(or very close) at about the same rpm the big difference is the OHV engine will make(all made up #'s,have to have the actual specs) let's say 200lbs-ft+ of torque from 2000rpm through 5500rpm.The SOHC engine let's say makes 200lbs-ft+ torque from 3500rpm's through 6000rpms,the SOHC engine needs more rpm to make the same power the OHV engine which makes the same power but at lower rpm's.

There is also more at play then just being a SOHC or OHV,or even a intake design.Another big factor is if the engine "over-square" or "under-square",those 2 drastically effect torque and where it comes into play.Cam design is another big factor.

 

[osufans]

SOHC engine is in no way considered "just still a OHV engine".peak HP/TQ #'s do not mean alot,it's there curve that counts and a OHV valve engines tend to have flatter/earlier torque curve then a SOHC engine.The 3.7 peaks at 210hp at 5000rpms and 235lbs-ft of torque at 4000rpms,if the 3.3/3.8 OHV makes the same(or very close) at about the same rpm the big difference is the OHV engine will make(all made up #'s,have to have the actual specs) let's say 200lbs-ft+ of torque from 2000rpm through 5500rpm.The SOHC engine let's say makes 200lbs-ft+ torque from 3500rpm's through 6000rpms,the SOHC engine needs more rpm to make the same power the OHV engine which makes the same power but at lower rpm's.

There is also more at play then just being a SOHC or OHV,or even a intake design.Another big factor is if the engine "over-square" or "under-square",those 2 drastically effect torque and where it comes into play.Cam design is another big factor.

Thanks...but my whole point in the first place was that they have nearly identical transmissions.

And you've lost me on why an "OHV" engine cannot have the same lift, duration, etc as a SOHC.

If you want to start talking DOHC, then I can agree with you...but that's not what we're talking about here.

 

[tommudd]

maybe same trannys but you're comparing apples and oranges when you mix in the motors