Currently I have a stock 47re trans as far as my knowledge ( Previous owner had it rebuild but no records of the work done). End goal is to take the truck to 300 - 350hp and cap it. I want to build a reliable towing trans out of what I have and eventually look at a GearVendor gear splitter if I ever get around to it. As it stands now though, its a completely stock motor and trans combo that all works like it should but I want to try to get ahead of the ball on doing the preventative maintenance on it. I'd like to know what I will have to get swapped out and recommendations on what to get. I'd rather overkill the trans than it give out on my 1000+ mile road trips with the Deckover trailer behind it. Any opinions are appreciated. 

How much does trailer/payload weigh?

Trailer weights empty about 3700lbs but its a 14000lb trailer. Understand that is putting the truck over the manufacturer's rating but that's my problem to deal with. 14000lbs is the max combined weight of trailer and cargo I want to put behind my 20 year old truck for sanity sake

I’d talk to @Dynamic a lot of guys on here including myself are running his transmissions or at least his valve body’s. 

Are you equipped with 4.10's or 3.55's?. For that weight, 4.10's would be best. The factory rating is up to 12,000lbs with the 4.10 gears. 4.10 gears with a matched  converter/valve body/line pressure would be needed for sure. 2nd gear lockup with the knowledge to use it wisely would be helpful. Lockup will help keep the heat down when in 2nd for prolonged periods,. But most of all, I agree with Threadzy, Dynamic is who you need to talk to. 

ATM I have a 3.55, curious to know if the gear splitter would help the offset with the absence of 4.10's. Id like to keep the 3.55's for the daily driving fuel economy but I think the double OD of the gear splitter will make up for it. Either way the potential regearing and splitter will be a little ways out on this project (Just had my carrier and pinion bearings replaced). Does Dynamic build your core or can you swap for a built one? Understand there will be downtime in between but want to try to keep it minimal.

I've personally never used a GV, but I saw where a guy performed an Allison conversion specifically because the GV he was running failed multiple times. It would take a lot of positive information from proven sources to change my opinion about GV's not being a good solution for a diesel powered pickup. I don't mean to be a burst a bubble, but I hate to see someone lay down hard earned cash for something that doesn't work for their intended use. Is your truck a 4x4? 

Edited August 18, 20204 yr by jltait

Ive heard few things about them tbh and im glad im hearing a different opinion on them too. I pesonally only hear good things out of them but only by a handful of people who have them. Yes I use 4wd but ive heard some have gotten it to work. Weather they used a divorce transfer case or not they dont make it clear. Thata why im looking for options and suggestions 

Btw appreciate everyones input. This helps a lot

I think since you have 4x4, for hauling the type of trailer you are referring too, you'd be fine with a properly set up 47re. Get a 2wd low kit that allows 2wd low operation. Use that for maneuvering low speed, soft ground, hilly terrain. Get it setup to allow 2nd gear converter lockup, learn how and when to use it properly. A place called froehlichsuspension sells a separator plate that allows this, but I know there are other methods too. The two most irritating things I find about towing with the 47re(and 3.55 gears), trying to get my 5th wheel up on leveling ramps(which I now use low range for) and when it has to stay in 2nd gear for extended periods without the converter locked. The coolant temperature will quickly rise as the transmission sheds heat into the cooling system when running w/o the converter locked.

One of the first thinga I did to the truck was install the posi lock cable kit for that. If excessive heat is gonna be an issue should I add another rad/fan combo to the current system? It has the factory HD tow package but better safe than sorry. Ive heard the 2nd gear lockup is worth it and I do plan on getting that

the Derale 15960 paired with the ATS 4+ deep pan, or another equivalent is an excellent set up to control the trans temps. I’m grossing 21.5k  pulling  the passes in Colorado and keeping the tranny temps right along with the engine temps,  It drops to 160 on the flat roads, that’s also running the factory heat exchanger and factory cooler up front , and measuring the temps on the trans out put line.

 

I like the idea of the GV gear splitter but really don’t know about the reliability of them either, and while quite pricey too, Im not even sure if there is room with a shortbed and 4x4 either, although it would be nice to split the OD down a half a gear, It seems that the factory OD is a bit to long legged with the 3.54 gearing even running empty,  but when towing I  pretty much just keep it locked out, 

@Blueox01 transmission setup may be the best for this heavy towing, but IIRC would fall in the "very custom" category.

However, I may very well not recall correctly!

 

When I was looking GV units, I determined it might be a good solution for a guy with 4:10 gears who didn't tow a often, or not very heavy. They need fluid changed like every 5k miles, and that may be for light duty daily driver service. They don't like heavy loads in reverse, per their own website.

 

I have 3.55 gears and would love a gear between 3rd and 4th, but double over would be for downhill only!

So it seems that building the current trans, adding additional cooling, and a combo of going to 4:10s and maybe running a 33-35" tire will be the most "reliable" solution? 

I'd shoot for 400ish horse.

 

I run 3.55gears 47re I feel the 4.10 trucks are wrapping higher rpms than I like.

Im getting great mpg and run 80mph with 18k in tow

 

Maybe its cause I've been doing it with the same truck for 15 years. When in others trucks I'm always looking for another gear as 4.10s have em spinning 2500rpm 

 

My trucks spent  a fair amount of time running 7k heavier though latly a 10-12k machine is the heaviest I tow.

 

I lock over drive out if driving in town or speed limit is 65 or lower.

 

If I didn't run the freeway alot and lived in a mtn town where speed limits are 40-65 then maybe id lie 4.10s

Only thing that scares be about creeping the HP numbers above 350hp is how much I have to beef up the current setup as far as the trans. Currently the truck is Stock at stock power and is quite "Interesting" pulling hills in Dahlonega ( Steep grades) and in the mountains. Not going for the boil tires going hwy speed with 10k behind it, Just looking for a safe way to give it more *** without costing too much in the future. I've read probably hundreds of posts about the stock 47re being barely strong enough for stock power levels (wished I have a stick). Eventually I want to get a Quadzilla on the truck but i'd like to have a little more confidence on the trans not wanting to go if I try to squeeze a little more power out of the current stock setup. Again do appreciate all the feedback guys

I just got done with installing my new rebuilt 47re in my 2002 2500 4x4 long bed I’m running 35s not sure of the gear ratio haven’t looked much into it but best investment I made 3,800$ But that was (billet tc, sovo kit, deep pan, Hd Kevlar clutches & bands,overhaul kit, HD OD support, valve body and shift kit super hold servo higher trans fluid flow new sensors and trans pump and new hd bushing and springs and Lucas atf 4 fluid) but it can handle everything I through at it so far 165gph fass phatshaft turbo 125hp injectors comp box and a VP44 pump that I believe is trying to go out on me ??? but if your going to put the money towards it look into spending the extra little bit to where you won’t have to worry about it again for awhile 

Edited September 7, 20204 yr by Duncan32367

Id hope with all of that it would settle with your setup. Debating on either getting the tuner now and watch what I do or sink the money into the trans wait out a bit longer before getting a tuner. I do plan on getting injectors at some point (rv275 or similar) but I have that at the bottom of the list, current ones are doing just fine (stock)