Engine/Transmission (1994 - 1998) 47re-Turn up pressure?

[tgrfan2]

It is nearly time to service my stock 47re with 135K miles. With stock power I had no slip in OD pulling my fiver GCW 19760#. Since adding a #6 plate, I have to back out at beween 22-24# boost to keep it from slipping in OD locked up. transmission still shifts good and runs cool. According to pressures I got here and from DTT, the pressure is about 10# low at speed locked up, but does not indicate any signicant leakage internally. Do you think it wise to turn up the pressure considering the mileage and is it likely to hold the load at that pressure? Or should I just run it as is until time for an overhaul?

 

[SBrandon]

i would turn up the pressure and make it last as long as possible

http://www.dieseltrans.com/phpBB/viewtopic.php?t=68

 

[tgrfan2]

Turn up

Thanks for the link. I guess with 135K I am on borrowed time anyway with the load I pull. I'll post my results in a few weeks unless I have to sell the 'puter to buy a transmission!

 

[stressedout]

i would turn up the pressure and make it last as long as possible

http://www.dieseltrans.com/phpBB/viewtopic.php?t=68

I may be interested in turning the pressure up in mine,what am i looking at in the top picture of the trans?

 

[WaynesWorld]

turn up the pressure?

Hi tgrfan2,

Have you gave any thought to adding a triple disc converter ?

I replaced mine at goerend brothers where it locks up with less pressure thereby saving the added stress on the trans. That insures longevity of the trans. The truck also runs better. My 2 cents.

WAYNES WORLD

 

[tgrfan2]

Yes I have been checking on upgrades for that day when the transmission goes out. I hope I can do a complete rebuild with everything I need for heavy towing then.

 

[fox]

Goerends makes some good products, but don't EVER believe the pressure doesn't need to be raised!!!

quite a few dodge auto's slip the front clutch BEFORE the converter slips.

When mine was new and I added power, it started to slip. Pulled it apart and there was no/none indications of the converter clutch slipping. This usually shown with blueing around the converter bolts area.

Mine had real heavy blueing to the front and rear clutches/steels.

Good luck with what you choose.

 

[Rattlin_Ram]

If you want to increase the pressure on the stock 47re, I've read on here that there is a safe amount... I'd have to look that up... But anyway, how do you know where you are??? How do you know if say someone else turned it up or not???

 

[1dslram]

If you can feel your lockup slipping it is about to be toast anyway. Turn up the pressure drive like you have an egg on the loud pedal, and pray. Give all the trans guys a call and pick the one you like as it won't be long. From one that has been there.

Bruce

 

[tgrfan2]

As I said I did not have any problem with the transmission slipping stock pulling the same load on the same route. The #6 plate will make it slip on hills especially if using the cruise as the power comes on quickly. The truck was strong stock and is way stronger than my 95 with the same plate. I know I can burn it up quickly slipping so I limit boost to 22-24# towing and it does fine.

According to DTT's website I am about 10# under recommended pressure. I just was not sure given the mileage if the old seals will stand max pressure. I know max pressure is best for the clutches.

 

[Lsfarm]

Not just pressure

Just turning up the line pressure may help a little for a little while. But as mentioned above if any clutch is slipping now, it already has an engraved headstone waiting for that final day when it is slipped one last time and can no longer hold any power. Then you are on the end of a tow truck, and the headstone is planted.



Think about the stock transmission as a garden hose that is used to provide pressure to some device at it's end. This hose came from the factory with a few leaks, these leaks were the result of poor manufacturing, some design oversights, some price reduction efforts, and sometimes poor assembly.



Lets say that device at the end of the hose needs 60 psi to operate, and the hose needs 70 psi supplied to deliver 60 psi to the device because of the leaks. This hose gets old, gets stepped on a few times, gets baked in the sun, gets frozen in the winter, so the rubber shrinks or developes more cracks and leaks, and soon there is less pressure to the end device. So the device starts to not work. If you open up the spigot to increase the pressure in the hose and thereby to the device, the device will start working again, for awhile, but the added pressure through the hose only opens up the leaks and holes more, untill the leaks are worse and the device again fails to get enough pressure to operate.



The 'device' in the above analogy is the combination of any or all the clutches inside the trans including the TC's lockup clutch. The spigot is the VB. The hose is the transmission with all the seals, servos, accumulators, lip seals, gaskets etc.



Now lets say that someone comes up with a new style 'device', one that only needs say 50 psi to opperate, and this is attached to the end of the leaky old hose. It will work for awhile, but soon the leaks will get worse, and soon not even 50 PSI is available to the device and it will fail too.



The new 'device' in the above analogy is a tripple lock style clutch, which in general need less pressure to lock and hold. [not a bad idea right?] But all the other devices in the trans are standard, and still need the required pressure to work. So if we add a VB with higher pressure [open the spigot] then we just make the leaks worse and soon the trans fails.



This is why just adding a TC and VB [from any provider] to a trans is not a good idea. Some transmissions [hoses] came from the factory with few leaks, and can support more pressure. But the designed in flaws and leaks are still there, and the devices still cannot work up to their potential. Even a brand new 'hose' can be a pretty bad one and have lots of leaks right from the beginning.





I hope the above helps explain what is going on in a trans. I also hope that I didn't insult anyone's intellegence. There are some assumptions and flaws in the analogy, so please don't pick it and me to pieces, I'm just trying to help explain why some things work and some don't.



Greg L. The Noise Nazi

 

[PullinRam]

I understand what your saying Greg. But, iv'e talked to many guys who have had the trans slightly upgraded (internals) and added an aftermarket TC/VB, and have had no problems for many many miles.



The internals of my trans have been upgraded to the max w/o going full aftermarket. I just didn't have the $$ at the time to go full. I had a new "towing" converter put in and it's held fine for over 2 yrs now. Until I put the #5 plate in a few months ago, i had no problems. Now i can slip the TC at high boost levels (25-30psi) with OD on. All gears shift firm still and I really give my truck a beating on the weekends. Just read my sig. I didn't build it like that to drive on the street all week long. I actually just got back from a 4hr trip to state college pa 2 weeks ago and all went well the entire ride. Even got to smoke out some punks in an explorer on the turnpike.



Once $$$ permits i plan on buying a DTT TC and VB to give the trans some much needed help. I just can't afford to take out a darn loan just for a new trans ya know.



On a side note, Can i turn up the line pressure, as shown in the photos in the link above, w/o removing the VB? Sorry for the long post.

 

[tgrfan2]

I know you can do those adjustments just dropping the pan. I diid that months ago. It helped the shift points considerably. My truck would shift into drive at 10+ mph before adjusting it. I turned up the pressure at the same time according to what Bill K recommended on his site as "safe" without gauges. I wasn't having trouble with slippage stock, but apparently my transmission was lower on pressure than I thought. I guess a transmission is like a chain, only as strong as the weakest link. I hope the seals aren't the weakest link because unless I chicken out I am going to turn it up some more. I used to have a John Deere with a powershift transmission. It had an adjusting screw under a cap that you could adjust the shifts depending on the load you were pulling. After softening the shift to bale hay a few times, I decided that it just did not feel right. Since then I have always been leary of soft shifting transmissions. I back off a little on shifts under load, but I like fior the transmission to shift quick like the old torqueflite.