Is it safe to manually shift 545rfe?

Drunken Hamster · Jan 19, 2018

Is it safe to manually shift 1-2, 2-1, D-2-1, 1-2-D, etc on my 545rfe equipped hemi ram? I've been doing it occasionally, but never REALLY thought to ask if it was 100% okay or not.

If I AM doing it {especially the manual downshifting} would it be safer to try to 'rev match' it, especially if I want to maintain rolling speed before acceleration, or should I just let off the gas, let it shift, and then proceed from there? Is it safe to do under braking? I've felt a clunk a couple of times I've done it, but it's even rarer than how often I actually do it. Perhaps 1 clunk every 20-30 manual downshifts, which I only do on a few times on a single drive cycle on a single day once ever few weeks to couple months at most.

Just really wondering if I'll kill it early with this despite the infrequency, and what steps I may take to lengthen the lifespan of the tranny in the even that I 'have to' downshift it manually.

Also, can I like leave it in 1 to zip through the back parking lot of home depot at speed to get to something like the post office before it closes and such?

chrisp2493 · Jan 19, 2018

Yeah it’s perfectly fine to manually shift, I do it all the time. It’s most fun to drop it to 2nd on a 40 mph roll and stomp it haha

Drunken Hamster · Jan 19, 2018

chrisp2493 said:
Yeah it’s perfectly fine to manually shift, I do it all the time. It’s most fun to drop it to 2nd on a 40 mph roll and stomp it haha

Nah dude. A 20 roll from first. Straight NASTY, and my ***** is STOCK!

Side note: I've spun 45 in the wet before. On the aging Firestone Destination 275/60's I have on it now.

Thanks, though. Still wanna confirm with others that this it okay, as my godmother -and boss, who owns other trucks and didn't like me manually shifting them- have expressed that it'll grenade my trans one day.

chrisp2493 · Jan 20, 2018

It’s seriously no different then the computer shifting it. That’s why it’s there. Unless you drive around at redline in 1st gear for an hour, it’s not going to hurt. My new transmission is going to be setup to be manually shifted every time since I’m losing the computer control. I think you are over thinking this

Drunken Hamster · Jan 20, 2018

chrisp2493 said:
It’s seriously no different then the computer shifting it. That’s why it’s there. Unless you drive around at redline in 1st gear for an hour, it’s not going to hurt. My new transmission is going to be setup to be manually shifted every time since I’m losing the computer control. I think you are over thinking this

Okay.

Sent from my magic 5-inch

chrisp2493 · Jan 20, 2018

It’s actually better in some ways. You don’t want to go wide open throttle out of overdrive to pass because it stresses the trans too much. That’s why it’s better to let off, manually shift to 2nd, let it pass through the 2nd prime step down gear, and actually take off in 2nd gear. I downshift going down steep grades instead of braking, I manually shift up at the drag strip going full blast.

One more little 545 tip. If you are going full blast wot pull, you don’t want to let it slip into 4th, which is an overdrive gear. So by manually shifting 1-2, 2-D (for 3rd gear). When you get to ~4000 rpms in 3rd, you can actually shift back down into manual 2nd. This will HOLD 3rd gear all the way to redline (as long as you are keeping the pedal to the floor) so you don’t actually slip into 4th and blow out the overdrive. As soon as you let off, shift into D and you’ll be all good. This is how to do a dyno pull in the 1:1 ratio 3rd gear.

Drunken Hamster · Jan 20, 2018

chrisp2493 said:
It’s actually better in some ways. You don’t want to go wide open throttle out of overdrive to pass because it stresses the trans too much. That’s why it’s better to let off, manually shift to 2nd, let it pass through the 2nd prime step down gear, and actually take off in 2nd gear. I downshift going down steep grades instead of braking, I manually shift up at the drag strip going full blast.

One more little 545 tip. If you are going full blast wot pull, you don’t want to let it slip into 4th, which is an overdrive gear. So by manually shifting 1-2, 2-D (for 3rd gear). When you get to ~4000 rpms in 3rd, you can actually shift back down into manual 2nd. This will HOLD 3rd gear all the way to redline (as long as you are keeping the pedal to the floor) so you don’t actually slip into 4th and blow out the overdrive. As soon as you let off, shift into D and you’ll be all good. This is how to do a dyno pull in the 1:1 ratio 3rd gear.

But if you do that on the dyno, wouldn't that mean you could only do the pull from ~4000 to redline? Doesn't sound like that'd be a fully accurate dyno pull since you're missing more than half of the powerband...

Also, I'm about to purchase a deezee tailgate assist. Do I need the 43300 or 43301? The 01 says it's for the 09+ rams, and the 00 says it's for the 02-08 trucks, but I read a while ago that the 01 was just an impoved version of the 00 that wouldn't have the binding issue the 00 had. In any case, I don't wanna get the wrong part and have to send it back and wait for the right one, you know?

chrisp2493 · Jan 20, 2018

No when you are in D, accelerating through the power band, when you get to 4000 you shift down to 2nd. You are still going through 3rd gear all the way to redline. The computer won’t actually let it downshift or upshift when you do that.

I’m not sure on part numbers. Just order the 02-08 like you have. It probably was binding on the 4th gen trucks so they probably improved it

xtremewlr · Jan 20, 2018

When you are doing all this shifting, are you using tow/haul mode or standard? Doesn't tow/haul disable the lock up of the converter or something and change the shift pattern some? I know that when I use tow/haul, the trans will hold a gear much longer and never goes into lock up mode in top gear, great for climbing grades or going down grades, loaded or unloaded.

ST-8 · Jan 20, 2018

xtremewlr said:
When you are doing all this shifting, are you using tow/haul mode or standard? Doesn't tow/haul disable the lock up of the converter or something and change the shift pattern some? I know that when I use tow/haul, the trans will hold a gear much longer and never goes into lock up mode in top gear, great for climbing grades or going down grades, loaded or unloaded.

I believe our year is the odd ball with the tow haul mode. I’m pretty sure all other years other than 04s when you hit the button twice it will lock out overdrive all together. Of corse we hit it twice it just shuts tow haul off. It will deff hold the gear longer when engaged

Drunken Hamster · Jan 20, 2018

xtremewlr said:
When you are doing all this shifting, are you using tow/haul mode or standard? Doesn't tow/haul disable the lock up of the converter or something and change the shift pattern some? I know that when I use tow/haul, the trans will hold a gear much longer and never goes into lock up mode in top gear, great for climbing grades or going down grades, loaded or unloaded.

I've done it both ways before. In tow/haul mode, I've noticed it likes to stay closer to 2-2.5k rpm than 1250-1750. It also locks out 5th from what I can discern.

The button only has 2 functions in my truck as far as I know. On or off.

Sent from my magic 5-inch

chrisp2493 · Jan 20, 2018

I think mine is just overdrive on/off. And since I have an 05 computer, I think it only locks out 5th. Pretty much pointless for me

ST-8 · Jan 20, 2018

Hmm I know 03 an 06 an 07s did it. Figured it had something to do with 04 being the first yr going to a integrated pcm.

Fishstickz · Jan 21, 2018

I gotta 06 3.7 with the 42RLE 4-spd, kinda wondering if dropping into second gear for passing around 60ish mph or below would destroy the tranny or not, or if it would perform any better than just pushing the gas and letting it downshift on its own

Drunken Hamster · Jan 21, 2018

Fishstickz said:
I gotta 06 3.7 with the 42RLE 4-spd, kinda wondering if dropping into second gear for passing around 60ish mph or below would destroy the tranny or not, or if it would perform any better than just pushing the gas and letting it downshift on its own

The 545rfe on my Hemi takes 2nd all the way to 85mph on 3.92 gears and a 275/60r20 tire.

Sent from my magic 5-inch

Fishstickz · Jan 21, 2018

Drunken Hamster said:
The 545rfe on my Hemi takes 2nd all the way to 85mph on 3.92 gears and a 275/60r20 tire.

Sent from my magic 5-inch

My v6 struggles to get up to that speed :Big Laugh:

One day out on the back roads I might put it in second, floor it and see how fast it'll run, probably better to test it that way than to risk my tranny becoming 1000 pieces scattered all over the road

Drunken Hamster · Jan 21, 2018

Fishstickz said:
My v6 struggles to get up to that speed

One day out on the back roads I might put it in second, floor it and see how fast it'll run, probably better to test it that way than to risk my tranny becoming 1000 pieces scattered all over the road

True. Or you can just leave it in 2nd during your next interstate merge and floor it then, see how high the revs take you.

Sent from my magic 5-inch

Fishstickz · Jan 21, 2018

Drunken Hamster said:
True. Or you can just leave it in 2nd during your next interstate merge and floor it then, see how high the revs take you.

Sent from my magic 5-inch

Not a half bad idea, wouldn't have to worry bout the cops up there, I swear they drive the county road in front of my house more than I see them on the interstate

nascar72 · Apr 6, 2024

chrisp2493 said:
I think mine is just overdrive on/off. And since I have an 05 computer, I think it only locks out 5th. Pretty much pointless for me

I had an '03 1500 and without the tow/Haul feature and when I hit the button it would cancel both 4th and 5ft gear with no difference whatsoever in shift pattern or holding 2nd gear longer than usual. Now with my '08 2500, I now have the tow/haul mode and what it does, is cancel 5ft gear so it will go: 1-2, holding 2nd longer than normal then 3rd, then torque converter lockup holding 3rd until the vehicle speed stabilizes then it will go into 4th dissengaging converter lockup while shifting from 3rd to OD4th. When I use OD/OFF wich I end up using anyways when towing my 8k lbs 5ft wheel camper, the shift patter is exactly the same as when in TOW/HAUL except it will cancel 4th gear and keep it in 3rd and converter will lock up at around min 30 mph same as when in TOW/HAUL.

nascar72 · Apr 6, 2024

chrisp2493 said:
I think mine is just overdrive on/off. And since I have an 05 computer, I think it only locks out 5th. Pretty much pointless for me

I had an '03 1500 and only had OD/OFF on the button and shift pattern was the same but it locked out both OD 4th and 5ft gears.

Is it safe to manually shift 545rfe?

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