to much horsepower for auto trans

[flyer1]

I have a 06 Rubicon i6 auto. I have stroked and supercharged it to 265rwhp. My problem is that now my stock 42rle auto trans wont hold (mainly overdrive) I have tried everything in the book and have spent 6k plus over the past 2 years on the trans rebuilding it 6 times. I even sent it to levelten for their (bullet proof )build and still not able to keep it together. There must be someone out there that has been able to adapt another stronger trans to the i6. I have looked into sever different suggestions like Advanced adaptors and novac etc. The big problem is even if I can adapt another trans how will I control it. The ecu and the tcm are one unit on this year jeep. I am running a Diablo Sport programmer and it won`t allow any control of the tcm even though they clam it will. There must be someone out there that knows a way. Now I know some of you will come back and say why didn`t u just put in a v8 or some other engine trans but that would take all the fun out of it. I like showing off my monster (stock) i6. This is why we build strokers.. Please help

[I6FAN]

What size tires and axle gears are you running? If they are big tires with high gears [numerically low] that puts added strain on the tranny especially the OD where there is significantly less mechanical advantage to deal with the higher loads. Re-gearing to something lower [numerically higher] will lessen the strain on that part of the drivetrain. Again, not sure what your comb is, but that's something to consider.

[flyer1]

I am running 488`s and 35 tires.

[I6FAN]

Your gearing/tire choices replicate stock conditions pretty well. With all your research, you probably have seen this already, but pretty pricey: http://www.offroadpowerproducts.com/p-8 ... ep-jk.aspx

[beiwulf]

I apologize for high jacking / throwing a bump in on subject.

I recently had my transmission rebuild on my 1995 GC Laredo. I had this done prior to joining this and several other Jeep'ing groups. I know Child9 prior to becoming a Vendor placed some post on NAXJA regarding extensive posting on transmission rebuild kit. I was hoping to get a second set of eyes (or more) regarding what I had done. This is a primary user site I use regarding my jeep and where I put my eggs so to speak.

http://www.naxja.net/forum/showthread.php?t=1059682

I believe 42RE w/ np249/nv249 95 1

replacement parts used from transmission shop:
Transmission Rebuilding Kit - 12006B
Solenoid Block - 12415B
Input Speed Sensor - 12432A
Front Planetary Assembly - 12582B
Rear Planetary Assembly - 12584B
Complete Geartrain - 12580AB
Transgo Shift Kit - 512174
Steel Plate Set - 12139E

This is what was provided from the shop that did the install/work. (but outsourced the rebuild)

And the NP249 TC - should handle the increase hp/trq.
However curious about upgrading to avoid some of the possible issues Tequila Mike is dealing with.

if it aint broke…. but why not plan for the worst and hope for the best.

bargain shopping prior to the incident or upgrading the weak links prior to.

Thank you for the in-sight and sorry for the highjack.

[SilverXJ]

Child9 is more geared toward the AW4 transmission, not the 42RE. You swapped in a 249 tranfercase?

[beiwulf]

I have my original equipment still - came with np249 considering np242 but not sure that is an upgrade.

NP242 http://ventura.craigslist.org/pts/4133369655.html

I had my all wheel full time 4WD trans rebuild this last year. So… still trying to grasp some of this.

I thought the TC will decide all wheel drive (AWD) and the transmission is another component.

seems going back I see on this page
http://www.naxja.org/forum/showthread.php?t=23644

quote from link:
'The only exception was the 1994-98 Grand
Cherokee, which used the A500.
Chrysler took a different approach
to their four-wheel drives. They went
with a mechanical transfer case instead
of a hydraulic unit like the 1985-94
Toyota four-wheel drives."

I'm still trying to figure out which one they used on my year.
search on quadratec show's 42RE

http://www.quadratec.com/jeep_knowledge ... cle-94.htm

[wjtom]

If you look at the shape of the transmission pan you should be able to match it up on any of the parts stores websites just look up a filter kit. Other way is to get the vin and call the dealer they will be able to tell you for sure as long as it hasnt been swapped to something else previously.

[SilverXJ]

You have the 42RE (newer name for the A500, basically) unless it has been swapped at some point.

I had my all wheel full time 4WD trans rebuild this last year. So… still trying to grasp some of this.

I thought the TC will decide all wheel drive (AWD) and the transmission is another component.

Not sure what you are trying to say/ ask there.

[beiwulf]

transmission is one unit in most cases separate from the transfer case.

on some older models sometimes being physical integrated for rebuild purposes (can't touch one without the other deal).

What determines an all wheel drive for the vehicle? the Transmission and the Transfer Case or just the Transfer Case.

My understanding and looking to be set in a clearer place here… IS my unit fall under AWD because of the fact it's 4H , N, and 4L (because of the TC)?

or is it a 42RE with a NP249 is there a difference when referencing?

[SilverXJ]

The transfer case is bolted to the back of the transmission. They are not one unit.

The transmission determines what 4x4 mode you are in.

42RE is the transmission
NP 249 is your transfer case.

[beiwulf]

ok got it, so from what i recall Child9 on NAXJA boards now in vendor status under another name ( fringe? ) not sure on that.

talks about about the AWD and the similarities between 42RE and the AWD unit. I will spend sometime later looking for that posting again. I believe I was looking for the corrilation betwen 42RE, AWD and there handling capabilities. I think child9 posted about 450 hp on the modifications he was making to help increase the internal pressure to handle the load capacity. Giving reference also to the fact that toyota was using the same housing for the supra's and other vehicle pushing more power.

I was hoping to find anyone else that can provide more insight for upgrades.

Looking for transfer case upgrades came across the Atlast II as an option. Not sure It is needed just yet. I was hearing some squeeling on turns from front tires and checked my pressure to make sure that wasn't the only issue. Just keeping an eye out from signs of what I read being the VC (vicious coupler) possibly going.

appologize for any confusion that it might of caused this is a learning board and resource after all.

thanks

[SilverXJ]

The work the Child9/FringeXVO is doing is for the AW4 transmission used in the 93 ZJ and XJs. Not the 42RE. That thread you linked on NAXJA is about the AW4 and only mentions the 42RE.

[beiwulf]

one can choose to focus on the solution or the problem. Which bears the better fruit?

Confucius once said a picture is worth a thousand words... What did he look like again?


My post earlier was looking for insight into project improvement utilizing a post that is already existing to help to gain more insight. I'm looking for assistance and direction and seems like you have some of that Silver XJ/ Chris and anyone else in the know. I am not an experienced wrench, I do read and not opposed getting dirty. I do not have the garage space to have a block pulled/ car immobile for a period of time geater than a day. I do appreciate the service and knowledge using the boards offer and the people giving of there time to it.

my ego is checked at the door...

and thank you for the insights shared.

Very Respectfully,
Brian

[SilverXJ]

I tried to google your parts to see what kind of rebuild you had, whether it was performance or not. Not much was found going off the part numbers. The Transgo part number doesn't match anything Transgo offers even in the syntax of the part numbers. The only thing I was able to find was the steels kit, which appears to just be a regular steels kit.

As far as upgrades IPT does offer parts and transmissions that are upgraded. http://www.importperformancetrans.com/c ... orwd.shtml As well as Level Ten. I can't say if a stock 42RE would hold up to much of a power upgrade, but they don't have that great of a track record behind the 4.0L. Also, consider flyer1 is not only stroked but supercharged as well so, he is putting out quite a bit more power than a standard stroker. He states 265 hp to the wheels, which is around what most strokers put out at the crankshaft. Being that you are planing only a stroker you may have better luck than he is having. Also, he has a 42RLE, which is again different from the 42RE. How much different, I do not know. From brief research it is a front wheel drive transmission modified for a rear wheel drive layout.

The AW4 is nothing like any Chrysler transmission, be the 42RE, 46RE, or 48RE. It is made by Aisin Warner and no parts will cross over between the two. It would be one thing if the thread on NAXJA was talking about upgrading the 46RE, which is similar to the 42RE, but its not.

Now, your transfer case. Being it is a NP249 it has the viscous coupling. While it is strong enough to hold the power of a stroker the problem lies in the viscous coupling. Its not a question if it will wear out but when. You mention tires squeal while turning. That maybe a normal occurrence and have nothing to do with the VC failing. However, if you do several figure 8s in a parking lot and feel like its binding, clunking, or just like its going then stopping and being jerky that is a good sign that the VC is on its way out. While you can replace the VC with a new one I feel its not worth it. 1) I've heard of problems right off the bat with a new VC installed. 2) Its going to run you $400 just for the VC part itself, not to mention the installation as well as installing it and replacing any other worn out parts. The other option is replacing the transfer case with a NP231 or NP242. The 242 offers a full time option that can be drive on any surface. It does this with out a VC and uses a differential style setup. The 231 does not offer that operation. Its a point of preference which one would be better suited for you. Do you really like being able to have 4x4 on dry/ wet roads? Personally I like the 242 just because I can use it in light snow and on rainy roads. It definitely helps not slipping during acceleration in the wet when you have a stroker, a truetrac in the rear and tires that should have been replaced a while ago due to age, not wear. As far as the swap you need to find teh right year transfer case with the right sized input shaft to mate to the transmission. Then the rear drive shaft may need to modified.. or not. I have heard of people swapping in a 242 for the 249 and using the stock shaft, but I also heard they needed to have the sfat modified, and I also heard that the output shaft on the transfer case was cut about 1" to allow the use of the stock shaft.

You mentioned the Atlas transfer case. Its a very strong transfer case and will hold up to a lot of abuse, much more than a stroker. However it doesn't have a full time position if that matters to you.

PS, for some reason it is a bit hard to understand what you are asking or trying to get across at several points.