How well is the 48re holding up to some power behind the 5.9? I had heard some guy was pushing some good numbers with a stock tranny and it was holding up just fine. If I got the 5.9 with this tranny, I would just plan on a small box, 35's and an exhaust power as far as things that could make the tranny slip. How well do you think that the 48re could hold up to this? Also, if I tow anything, its nothing extremely heavy, heaviest thing would be a 21 ft. boat.

The reason I ask is that I found an 07 for 32,000K after the 10,000 rebate with alot of good options, etc.

 

I personal think the 48re is the weakest part of the truck; I’m not impressed with it at all. I have 52,000 miles on mine and it shifts really weird sometimes, sometimes when I nail the pedal at 25-30mph it down shifts to 1st gear and just seems to sit there and slip and the RPM’s are 2800 or higher I have to let off the throttle before seems to engage, I don’t know what’s going on with it but it does concern me, but it also has not let me down yet.

 

Mossy,

My trans is still stock and has been holding my power so far. Smarty on level 9 and recently added MP-8. I recently dyno'd over 506hp a dynocom dyno (believed to be true) and 478hp on a stingy dynojet.

Luvnacumins made 570 with his stocker trans.

Some guys are lucky and haven't had many problems with them even in stock form. Some will break even on stock power. So it really just depends on the truck. Regardless, I would recommend having some money set aside for upgrades. And even if the trans will "hold" the power, it still won't "perform" well without upgrading it. My stock torque converter sux. IF you don't plan on big power, just add a good aftermarket torque converter and Valve body and call it good. IF you want more.....be prepared to spend some bigger bucks and get a fully built tranny with billet shafts. HTH.


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what rear gear is in it, 3:73/4:10? does'nt really matter w/what you plan to do.
I'm stock in an 07, 5.9, auto, 4:10 pulling 12-16K on a pintle and have had no issues as of yet. we use the gear selector as well as the tow/haul and the OD on/off modes as needed.
think of it this way your most likely saving 4-6K off from what the majority of us paid months ago if your really that concerned about the strength/durability of the stock unit with your savings you could get at the least as previously mentioned a tourqe converter and valve body and still be ahead of the game with peace of mind.
After reading some of your other questions I would definitely do a build up on the tranny to meet your needs/power.
I say go for it!