Stock 48RE HP Limit

[AWeaver]

Hey guys... just wondering how much hp you could reliably run through a bone stock 48re. Seems to me that they are quite a bit stronger than the previous 47re. Just looking for some advice/experience you have had. I know I will have to have it rebuilt sooner or later, but I figured I might as well have fun trashing the stocker before I have it rebuilt. Gonna get a smarty eventually. Thanks in advance.

 

[JMarketos]

I'm not a trans expert, so please do take input from other gurus over my own. Everything I have read on here and elsewhere consistently indicates that the stock 48RE isn't reliable to handle anything much above stock HP. Weak spots appear to include the stock torque converter and flex plate. There seems to be a fair amount of debate about how much increased HP can be handled by "minor" upgrades (such as TC, flex plate, valve body) vs. needing a complete upgraded trans with clutches, hardened shafts etc.

 

[Wertles]

It will reliably hold about a hundred hp less than stock. Driving like a grandma with cataracts on a bone stock truck, I blew out 2nd gear at 50,000 miles. Just did a complete rebuild at 75,000 and the parts didn't look like they were going to last more than another 10,000. I did fluid changes every 15,000 and towed lightly (4-6k) 30% of the time and heavier (10k) 5% of the time. Most have had much better luck with their 48re's so maybe I got one put together on Seis de Mayo.

 

[AWeaver]

LOL... damn that sucks. I think your right... must have been seis de mayo. Did you beef it up any on the rebuild. Just wondering what parts you might have used and if you were happy with them. Also, did they inspect the torque converter? How did it fair?

 

[BIGNASTY]

It will reliably hold about a hundred hp less than stock. Driving like a grandma with cataracts on a bone stock truck, I blew out 2nd gear at 50,000 miles. Just did a complete rebuild at 75,000 and the parts didn't look like they were going to last more than another 10,000. I did fluid changes every 15,000 and towed lightly (4-6k) 30% of the time and heavier (10k) 5% of the time. Most have had much better luck with their 48re's so maybe I got one put together on Seis de Mayo.

WOW I must be doing something wrong I have stock HP and stock trans and have 92K on my trans. Pull 10K TT and at times have pulled (Im almost ashamed to admit Ive abused my Trans)23K on a 30 Big Tex gooseneck. Trailer weight 8850 14K of roofing. The only thing I dont like is it will not push a load up hill in reverse. But other than Maint. and not gouging the HELL out of the long peddle I have no problem with the Trans.

 

[cerberusiam]

It will reliably hold about a hundred hp less than stock.

Thats probaby true at times. :-laf A lot depends on how its driven of course, but his experience is not the normal one.



The front band and direct clutches are the weak point enhanced by the low line pressures. Fix those issues with a shift and a few other parts and it significantly enhances the life of the trans. A couple servos and band hardware and its good for quite a bit.



The gov presure solenoid is not up to the task and when it misfires it stresses the clutches and front band. The OE pieces are good for about 40k then replace the solenoid and transducer for best results.



If you want to remove a lot of the TQ management and daily drive it, even with minimal power upgrades, replace the front band with a rigid type or you will just have to do it later.



I got about 55k out of a stocker running a Smarty on 40-100 HP tune, driving sanely but not easy, and towing 6-10k frequently. Smoked the fornt clutches from lack of line pressure. I have about 75k on the rebuild running 100 HP constantly with most of the TQ management removed and it ate the front band up with too much slower speed driving.



The upgraded flex plate, billet shafts, etc, are really for specific applications and hard use. If you run a triple disk TC then a billet input is almost an absolute need due the shift\lock strategies in the later trucks, also needed if you run any type of lockup controller.



Lots of little things you can do to help the trans handle power upgrades before you have to layout big bucks for the better pieces.

 

[BGlidewell]

55k on a stock 48re running #9 on tm#4 speed limiter set at 250mph.

 

[Wertles]

LOL... damn that sucks. I think your right... must have been seis de mayo. Did you beef it up any on the rebuild. Just wondering what parts you might have used and if you were happy with them. Also, did they inspect the torque converter? How did it fair?

I upgraded the entire transmission. Triple disk converter, upgraded flex plate, billet input, upgraded valvebody, Kevlar clutches, GM solenoid, band and some other random parts. I only have a thousand miles on it so far but I am for the most part very happy. I only added the Smarty Jr after I had the upgrades done. When I am on the petal, it will go like a bat out of hell but that is not my driving style (in my truck at least). For daily driving and towing, I don't believe my TC is as efficient as I would like it to be. It is tighter than stock but from reports of people with Georend torque converters, it sounds as though they slip less. I have never driven one of those transmissions so I cannot compare. DISCLAIMER: I also paid less than half of what a Goerend transmission would cost so I don't expect the same performance. I am only looking to make a reliable transmission for the next 50,000 miles. The salt here will have killed the rest of the truck by then. If I had planned on keeping the truck longer than 3 years, planned on more power or depended on this truck for work, I definitely would have invested in a name brand transmission.

 

[BIGNASTY]

Dont know if I could handle the 250mph but there was a time that I would have tried it I think age makes some smarter but not always maybe its because I dont bounce as well as I use to

 

[sag2]

All 48's are torque managed in stock form to handle the STOCK power levels. Driven with common sense and maintained properly most will easily last 100,000 miles on a stock truck. Adding ANY power will cause it to fail earlier than it was designed for.

 

[AWeaver]

cerberusiam, i dont want to get you in trouble in this thread so answer if you feel like you can. Im like wertles in this situation. I upgraded my 47re in my 01 and was satisfied by the performance that I got from my investment in my transmission, which was less than half of that of a namebrand full replecement. I was wondering what parts and brands you used to replace them. Only reply if you think you can without creating a war. You know how this kind of thread can spread like wildfire. Dont want to cause a ****storm. TIA, Aaron.

 

[AWeaver]

cerberusiam, are you running a smartyCR not the JR? That is what im planning on for electronics. Did you do any billet shafts as well? The shop that rebuilt my 47 said the stock shafts would hold till around 500hp as long as I didnt do any towing. It hasnt failed yet and I drive my 01 pretty hard but sainely. Sorry for all the questions and TIA. Aaron.

 

[cerberusiam]

Aweaver, when it smoked the direct clutches it ruined the imput shaft and I got a good deal on an Opie standard input. I was already running a lockup switch so the billet input was just safety. The way I drive most of the time a stock input would have been sufficient.



I used the Opie input, a TransGo shift kit, a Sonnax front servo cover and billet band strut, a standard rebuild kit with better seals, and single disk lower stall TC from Idaho Transmission Warehouse. I have since added billet front servo and accumulator and a GM gov solenoid.



I purposely used the front flex band because the original at 105k was just fine. Thought maybe they weren't as bad as advertised, wrong!! They are wimp and don't like reduced TQ managemennt and lots of shifting. I went from the west where the truck was at road speed 80% of the time to the SE where road speed is almost unheard of and there is a lot of stop and go. Use the rigid band if rebuilding.



I am running a Smart Sr on 90-120 HP tunes all the time with TM 3. That is hard on the front band when shifting all the time and the OE gov solenoid did not help I am thinking. The GM upgrade firmed things a lot and is highly recommended.



I used the Borg High Energy clutches to see how they stand up to power with extra pressure. When I replace the front band I will see how they worked and rebuild the clutch packs probably with the Raybestos Stage 1 reds for better holding power.



I purposely did not set the trans up for harder shifts because of towing trailer and horses a lot. The shifts are positive and firm but I am betting there is wear on the Borgs and stock steels.



I am lso going to go with a higher efficiency TC. The one I have works fine but under WOT throttle can still drive thru it and bang off the rev limiter. I want a TC that will hold at 2800 rpm's or so with 900-1000 ft\lbs input TQ and about 200 rpm lower flash stall to really solidify the trans and how it works.



I could have all this with $5k from any of the good builders but its more fun to me to try different things to see where the limits are. I have half of the cost of really good trans in it and will still be less when I finish tweaking. It works for me as I do all my own heavy lifiting and service while just hiring the in-depth knowledge. I learn more this way and it still has cost me less.

 

[FFL8N]

Still running the stock trans. I have stacked Smarty and Edge Juice with attitude (although I just use the juice for the gauges now). I usually run the Smarty on level 3, but have made several high speed runs on level 9. I am guessing I have done some damage, but not sure. I do know that my Edge will tell my my trans will slip from 2 to 4% just driving around. Not sure if that is normal. I also know that my Edge will say it has defueled 100% because of trans slip when I have hit the go pedal hard. I have 70,000 miles on it now and bought it with 30,000. I have had most of the power since I bought it.

 

[BIGNASTY]

All 48's are torque managed in stock form to handle the STOCK power levels. Driven with common sense and maintained properly most will easily last 100,000 miles on a stock truck. Adding ANY power will cause it to fail earlier than it was designed for.

well said Really I have no idea about such things. But I do agree with the common sense comment. Just because they have the power doesnt mean you have to play hard ALL the time. The reasonable use of the foot will make things last longer than most think, ask my son he's learning the hard way if you want to PLAY your GOING to pay. But what does DAD know.

 

[pwerwagn]

My 48RE has over 130K miles on it now, totally stock. When I bought the truck (~60K I think), the owner said it was due for its first fluid change... which I have never done. I have ran a smarty/edge stack before, but now I just run smarty TNT. The truck is my daily driver, and I also tow ~12-16Klbs behind it regularly (about 10-12K of the miles I have put on it have been with the 5th wheel and jeep, or 5th wheel and boat, in tow... ). Also been to the dragstrip a few times, and I have chased/pre ran a few desert races in the truck.

I have had the trans hot enough to force lockup at low speeds numerous times, and all that junk. I also run 37" tires, and 3. 73 gears... so the trans does not have an easy life at all.

When I bought the truck, I figured the trans would last 5K miles, and I would have to rebuild. With that in mind, I didnt take it easy on the transmission. ~70+K miles later, its still chugging along. I developed the 1-2 shift problem about 6 months ago, readjusted the band, and its been good ever since. I am knocking on wood, however... but I have been VERY pleased with my stock 48RE.

 

[AWeaver]

WOW... that is crazy. I guess you would have to be pleased if it is still chugging after all that abuse. That makes me feel a little better now. I might just have to go ahead and get my smarty asap. Thanks for the report. Cerberusiam, thanks for the info. Im going to do a little research on transmission parts and you have given me a place to start... preciate it!

 

[cerberusiam]

The problem is stories like that are the exception not the norm. For every one that reports good luck with programmersm big tires, etc, there are 10 more with solid proof its not common.



Law of averages says it will bite, but, I would get the Smarty anyway and just NOT reduce the TM while using the lower power settings for extended use. You can use the Smarty while driving wisely with good luck. Just don't expect to do 15 psi boosted launches very long before something gives up. :-laf

 

[NavyDood]

My 04 has 160,000 miles on it. I have never flushed the transmission and I have never adjusted the bands. I just do the regular fluid and filter changes. I run the Smarty Jr. on 70hp unless I tow and then i go back to the 40HP tune. I don't race stop light to stop light and don't mash the go pedal from a dead stop. I always roll into it.

This past weekend I changed the fluid, filter, gov pressure solenoid with the new style borg warner and pressure transducer. There was nothing in the pan and the magnets had minimal fuzz. I change my fluid every 30-40K. I have zero issues going to 40K since I added the MagHytec DD. It holds four more quarts. It took me 10 quarts to top back off.
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[BIGNASTY]

My 04 has 160,000 miles on it. I have never flushed the transmission and I have never adjusted the bands. I just do the regular fluid and filter changes. I run the Smarty Jr. on 70hp unless I tow and then i go back to the 40HP tune. I don't race stop light to stop light and don't mash the go pedal from a dead stop. I always roll into it.



This past weekend I changed the fluid, filter, gov pressure solenoid with the new style borg warner and pressure transducer. There was nothing in the pan and the magnets had minimal fuzz. I change my fluid every 30-40K. I have zero issues going to 40K since I added the MagHytec DD. It holds four more quarts. It took me 10 quarts to top back off.

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There you have it NavyDood's right foot has an IQ