Has anyone tried to upgrade the 2001 automatic to the newer six speed automatic, or is this even possible?
Ive often wondered if a 48re could be put in a 99?
The problem is the transmission control is integrated into the ECM. You'd need an aftermarket transmission controller if they exist. Another thing is there's a lot of torque management happening and I suspect the transmission isn't as strong as people think. For example, full engine power isn't available in lower gears.
The 68rfe has a stand alone TCM.
Everyone The 68rfe is plenty strong - ~500hp/1100lb-ft and plenty of abuse didn't take mine out, it was all that power AND 4wd power-braking to build boost for a green light launch that left me needing a flatbed.
I've been wondering about the gearing in the 47/48RE -- since it's a three speed with an overdrive on the end, can it be run as a six speed with the right control? Basically you're engaging the overdrive in first and second to get more gears.
Its not stand alone, its integrated with the ECU. Thats the big problem of getting a system that will allow installation in other vehicles. The PCM controls the trans but relies on lots of other inputs to do its job. All those have to be yanked out and a program designed to make the trans shift and react in a predictable way. Its not a simple task by any means.
Its not just the clutch counts that make a 48RE. The inut shaft is larger and stronger. The TC is beefier. The last of the aluminum planetaries has been removed. The fluid flow from the pump is higher and the lubing better, plus, the case has been strengthened in places.
All the except the case strength can and has been done for years on a premium 47RE build but thats a $5-6k option. The 48RE as is needs fewer upgrades and tweaks to perform well with moderate power increases.
On the other hand, the 48RE is out of production so its not as easy and cheap as it used to be to swap.
Without major upgrades it was on borrowed time even without the brake stand. You just found the first glaring shortcoming of the 68RFE with power upgrades.
Its the same as the competitors, over managed and under clutched. Once you turn the wick up and remove the TQ management the trans is looking for an excuse to break. The TC is crap and won't take the abuse. The clutch count is too low to hold the TQ and the stock algorithms that control line pressure are not up to the task of handling the power. Once you fix one weak area the problems just move to another. The fix is still under design. As sson as one area is addressed the next just shows up. Some of the needed parts are just no available to address the problems.
At stock power and stock TQ management it is adequate and that is all. Abuse it and it will break easily.
The ECM and TCM are not integrated into one unit as was previously stated, they're separate devices bolted to different locations.
Your statement that the trans is adequate only for stock power levels with stock torque management is a bit incorrect.
I did not say it was integrated INTO, I said it was integrated WITH the ECU. Vast difference in the concept. The statement it is stand alone is incorrect. If it looses communication with the ECU it goes into fail mode and you are stuck with limited operation. It is wholly a subsidiary component that relies on external inputs for correct operation which I very clearly pointed out. That is not the definition of stand alone.
On the other hand you have the units that have issues at stock power and with moderate upgrades. Remove the TQ management AND drive to maximize the TQ its a different story. Some have good luck, and it really seems to be operator specific, but for the most part if you try to run it stock and bag on it, be prepared to fix it.
The algorithms have gotten better every year but it is still border line at even stock power. Too many builders are telling me this to ignore it.
It was previously stated that the TCM was integrated INTO the ECM, which is what I was correcting.
This may seem contradictory, first saying it's fine and then suggesting that it's not, but what I'm getting at is the factory program is the weakest link. Running the H&S Overdrive software made driving around town a lot more bearable and it was easier on the transmission.
however the transmission is still bone stock with aftermarket software.
Increasing shift points doesn't put added stress on the hardware, it actually relieves stress.
there are built 48's that will handle the power just as well and for less money when factoring in the cost of purchase plus transmission management.
As far as the supposed mistake with the quote, it was no mistake. I quoted your post on purpose, and clearly stated that it was previously stated that the TCM was integrated into the ECM. I didn't attribute that quote to you. .
Your signature shows you have an 05 and a 92, neither of which have the transmission in question here. Do you have any experience with it, or are you just armchair quarterbacking with no real knowledge of the product?
Thanks for the info. It was just a thought.The ratios are not useful and there is no way to effective mesh the hydraulic shifting and the electronic OD.
The 68RFE is a 3 pinion transmission where the 47\48 is only a 2 pinion, you need 3 pinions and full electronic control to make a 5 or 6 speed.
Seriously? Since the 68RFE is full electronic control, adding software still makes it stock?![]()
Oh sure, moving the shift points to a higher point on the TQ curve does NOT add any stress to the hard parts.![]()
Six speeds as opposed to 4, deeper 1st gear to get loads rolling, better splits on all the gears, a double OD with decent splits as opposed to a single OD with a huge jump. Nah, there is NO reason to even want such a transmission.![]()
Ummm, when you quote somebody's post you ARE attributing the quote to them.
And last but not least, when sounding like a donkey start with the personal attacks.
I didn't realize you were one of THEM. My bad.![]()
Yes, you're not touching the transmission.