MDS question

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OCDTech

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I figured the 8 would be better, more ratios to choose from below 1:1
The gap between 2nd and 4th (6 speed doesn't use 3rd for upshifting) is pretty large, and then 4th to 5th is pretty big. 5th to 6th is almost unnoticeable they're so close together, almost pointless.


I glanced at the ratios of the 8 and they are fairly evenly spaced it seems as to be expected with a ton of speeds. 1st is pretty low 4.7 to 1. The thing i do find a little un nerving is when i m doing speed limit or so and gas on it a little too much the rpm go into orbit, seems to be little restraint on its part. So i just have to keep that in mind when i need to go fast. I don't like over revving either.
 

Brandon-w

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More good to know information. Nice to know you can take that new stuff out and retro the 134.
You use the high pressure line still. You will Need to file the ac pump outlet line about 2mm and then file the o ring land as well. Then trim the back plate on the ac end that goes into the firewall enough to get the new bigger line in and bolt it on. Cost me like 100$ for the mod the refill tool and a box of 12 r l134a cans.
The oil has one more atom of carbon vs the 134 oil so its compatable. [emoji106] Better than $1000 for a recharge...
 

OCDTech

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You use the high pressure line still. You will Need to file the ac pump outlet line about 2mm and then file the o ring land as well. Then trim the back plate on the ac end that goes into the firewall enough to get the new bigger line in and bolt it on. Cost me like 100$ for the mod the refill tool and a box of 12 r l134a cans.
The oil has one more atom of carbon vs the 134 oil so its compatable. [emoji106] Better than $1000 for a recharge...


Need to do a sticky! Course you've already done the job.
 

Brandon-w

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Need to do a sticky! Course you've already done the job.
I thought about it but seeing as it's illegal to backgrade from a new style back to old refrigerantsI figured I better not. Damn Honeywell! The only reason I've heard they went from 134 to xy is because the patent was running out and needed a new refrigerant so they could keep a corner on the market.
 

OCDTech

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Oh you know it has to do with money thats for sure. Stuff is actually a little flammable as well.
 

Brandon-w

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Yeah it is. But it is definately cooler than the new stuff though. And cheap cheap lll.
 

OCDTech

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After you retrofitted the line, all you basically did is and evac and refill with new. No other parts changing?
 

Brandon-w

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It was already evac'd third time it leaked down and refrigerant was backordered decided to bypass the dealer again . I changed the line shot a can of leak stop into it and topped it up. Fixed it better the third time than the dealer ever did. [emoji846]

And nope just the hose. If you have files ur set and a skinny one to do the ring land.
 

scott lass 18

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My mds lifter collapsed and started hammering on my cam lobe. Being a mechanic I caught it quickly and knew what it was. I replaced lifters with non mds and a new lumpy cam. There are a few guys who have had the same issue as me. Id hate to admit it but I think it's more common than you think.
yes mine s been off 10 years now 59,000 on it guess what the code po301 came up replace plugs and today it pop up again so not sue should I buy a coil 60.00 ? I m afraid if lucky a injector but could be a lifter trying to save money I dont have so was this like yours did u end up seeing cover off a bad lifter ! Omg if a lifter and cam don't think dealer well cover this cuz truck 10 years old ! help please thanks scott
 

scott lass 18

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Hey all,

I've had MDS turned off (manually by selecting gears) essentially since I bought my truck with 8 miles on the odometer. I had read somewhere that the MDS could cause damage to the truck, specifically the dreaded lifter failure.
That was almost 5 years ago and I've done quite a bit of reading (and driving, I'm at 158,500 miles now) since then and I'm not sure it's true. Is there any actual evidence that the MDS could be the cause of any long term damage to the engine? I mean the system has been out for, what, 14 years or so now? I'd think if it was some horrible thing there'd be huge uproar and widespread failures but I still see a lot of 3rd gens and pre-2013 1500s with the 5.7 rolling around here. Not to mention all the other vehicles with the MDS in them on the road.
I'm not trying to debate if the MDS really does anything for fuel economy. I've let mine run for a few tanks of gas here and there and for my driving style and commute is does actually make a worthwhile difference when I hand calculate my mileage. I'd like to just let the MDS run but I'm concerned about it doing harm to the truck. I want to milk as many miles out of this thing as possible before I buy another truck so to me longevity trumps fuel economy.

So, what's the verdict? Is MDS actually harmful to the hemi or is that an old wives tale made up because we just love to hear that V8 growl all the time?
well met a guf 115,000 lifter went 5,000 he fix it cam and new lifters about the 6 guy now here this from scary right !
 

Brandon-w

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yes mine s been off 10 years now 59,000 on it guess what the code po301 came up replace plugs and today it pop up again so not sue should I buy a coil 60.00 ? I m afraid if lucky a injector but could be a lifter trying to save money I dont have so was this like yours did u end up seeing cover off a bad lifter ! Omg if a lifter and cam don't think dealer well cover this cuz truck 10 years old ! help please thanks scott
Hey Scott. Is it ticking? Mine would tick slightly at start and then once warm 1/2 hr worth of running you could hear it clacking lightly. Then I got the dreaded misfire code and I knew. I'd start with a compression test. It's cheap and really shows you the condition of your engine determining weather you go foreward looking or just straight up replace/rebuild. Then I'd check plugs and maybe try replacing the coil. Cheapest things first. Replace the two plugs on #1 cylinder where u getting misfire and maybe try swapping coils and see if the misfire moves and go from there.
 

scott lass 18

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Hey Scott. Is it ticking? Mine would tick slightly at start and then once warm 1/2 hr worth of running you could hear it clacking lightly. Then I got the dreaded misfire code and I knew. I'd start with a compression test. It's cheap and really shows you the condition of your engine determining weather you go forward looking or just straight up replace/rebuild. Then I'd check plugs and maybe try replacing the coil. Cheapest things first. Replace the two plugs on #1 cylinder where u getting misfire and maybe try swapping coils and see if the misfire moves and go from there.
ya plugs 59,000 on them replace the two old weren't bad at all .50 gap not .44 but feel a missing on running idle not bad ok ! so no noise as seen on youtube owww crazy right dodge should fix them all free ! still po 301 pops up some time like in a day or two ! maybe do coil see what happens ? ow warning in california ! dealer says they have a update california wants on older dodge truck ya wounder what bs there doing now right ! so don't want to go to dealer cuz u know they well put it on anyways if asked not too they were saying california may make it mandatory hate this state !
 

Brandon-w

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ya plugs 59,000 on them replace the two old weren't bad at all .50 gap not .44 but feel a missing on running idle not bad ok ! so no noise as seen on youtube owww crazy right dodge should fix them all free ! still po 301 pops up some time like in a day or two ! maybe do coil see what happens ? ow warning in california ! dealer says they have a update california wants on older dodge truck ya wounder what bs there doing now right ! so don't want to go to dealer cuz u know they well put it on anyways if asked not too they were saying california may make it mandatory hate this state !
Yeah compression test and try coil then. I'm so happy im in Canada. I deleted my emissions crap on my dodge. And refuse to do any recalls like the shift knob lol
 

MRFREEZE57

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You use the high pressure line still. You will Need to file the ac pump outlet line about 2mm and then file the o ring land as well. Then trim the back plate on the ac end that goes into the firewall enough to get the new bigger line in and bolt it on. Cost me like 100$ for the mod the refill tool and a box of 12 r l134a cans.
The oil has one more atom of carbon vs the 134 oil so its compatable. [emoji106] Better than $1000 for a recharge...

doing a search, a set of adapters are available for a 1234yf system. I am retired after 38 years as a commercial refrigerant tech, have never herd of this flavor of gas until buying the ram. checking a pt chart shows they are close in evaporating temp in the range one would use AC. only problem one may run into is overfeeding or underfeeding the evap. I remember when R12 was going out and replaced with 134A, one would have to adjust the TXV to slow down the feed rate where as most automobile systems use only a fixed metering orifice it would possibly not feed correctly, however I would be more than willing to try 134A versus that liquid gold 1234YF or if nothing else get a restriction device from an older vehicle that uses 134A.
 

Brandon-w

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doing a search, a set of adapters are available for a 1234yf system. I am retired after 38 years as a commercial refrigerant tech, have never herd of this flavor of gas until buying the ram. checking a pt chart shows they are close in evaporating temp in the range one would use AC. only problem one may run into is overfeeding or underfeeding the evap. I remember when R12 was going out and replaced with 134A, one would have to adjust the TXV to slow down the feed rate where as most automobile systems use only a fixed metering orifice it would possibly not feed correctly, however I would be more than willing to try 134A versus that liquid gold 1234YF or if nothing else get a restriction device from an older vehicle that uses 134A.
Yeah I seen a refill kit for the yf here awhyle back but completely forgot about it. Had I known about it before I did the mod I would have probly went that way. Wonder if it's possible to use the spin on 134a cans on the yf refill tube. I don't know a whole Lot about the real technical side of refrigeration like you would. I know it works pretty good with it in the truck for over a year now No issues.

The price for the stuff is astronomical and the amount of ac problems dodge rams have had im suprised they Havnt been dinged with environmental fines for the amount of fixed they've had to do with the yf.
 
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RVGuy

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Yeah I seen a refill kit for the yf here awhyle back but completely forgot about it. Had I known about it before I did the mod I would have probly went that way. Wonder if it's possible to use the spin on 134a cans on the yf refill tube. I don't know a whole Lot about the real technical side of refrigeration like you would. I know it works pretty good with it in the truck for over a year now No issues.

The price for the stuff is astronomical and the amount of ac problems dodge rams have had im suprised they Havnt been dinged with environmental fines for the amount of fixed they've had to do with the yf.

The 134A cans don't fit on the YF fittings but you can buy cans of YF now. I have one in my cart on Amazon I just never get around to ordering it.
 

MRFREEZE57

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I see a set on amazon that have 1/4 female flare adapters, I have a set of automotive gauges picked up at harbor freight for about 35 bucks one could just switch them out.
 

JS4024

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Leave the GD MDS alone. The yahoos on here are NOT ENGINEEERS! It works fine! Lifter failures happen, has nothing to do with MDS. Had one fail on number 1 cylinder, has squat to do with MDS. Leave the engine run like it was designed too. These guys in here are not paying your bills!
 

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