518 output shaft concerns

[cummins12club]

I do lots of 4wd launching and I know that a 47re have a bad reputation for breaking the output shafts under this kind of abuse just curious if the 518s have the same issue I'd hate to find out the hard way

[BC847]

It's been my experience that launching in 4wd at or above 20ish psig boost will in short order bust the chit out of the output shaft. And that's without shuddering the tires.

If you're running and plan on keeping the A518, all three shafts can be had billet/alloy. Most of the rotating assembly can be replaced with 48RE components. I run what amounts to an all billet/alloy non lock-up 48RH in a 46RH case. It does all right I guess.

Just add money and stir.

[cummins12club]

I do believe I will bud a built 47re when this 518 is toast i feel like if u ran a lock up converter David u could see low 12s

[directinjktn1stgen]

where on earth do you find the intermediate billet shaft ? All i can seem to find is billet input and output , also how strong is the intermediate shaft ? Would it be worth just doing a TC and valve body for now and billet shafts in the next trans since i have two ? What parts are you replacing with 48re or should i say what parts should i look at replacing first that are weak oe ?

[BC847]

where on earth do you find the intermediate billet shaft ? All i can seem to find is billet input and output , also how strong is the intermediate shaft ? Would it be worth just doing a TC and valve body for now and billet shafts in the next trans since i have two ? What parts are you replacing with 48re or should i say what parts should i look at replacing first that are weak oe ?

Intermediate shaft (for example): http://www.suncoastconverters.com/shop/ ... ct-details

You'll need to upgrade that front planetary gear-set to a 47Rx as the splines between it and the intermediate shaft are different. Five and six spider-gear planets are available (our stock/OEM is four IIRC). The carriers can be had in steel for additional strength (our stock/OEM is aluminum).

Be sure that input shaft you're looking at is for a NON lock-up converter. For example: http://www.suncoastconverters.com/shop/ ... 1989-1993/


In my case, building to 25psig boost while the lights come down and then launching, has been the troublemaker. I've busted all three of the stock/OEM shafts within 60' of the tree. If you can limit yourself to perhaps 10psig at the line, your stock/OEM shafts may hold up . . . . . . . . till they scatter.

Pending what you're doing with the truck, the stupid trans cost can quickly rival, if not eclipse the cost of the engine.