Engine/Transmission (1994 - 1998) Transmission building

[Pardy]

Just bought a 94 12 valve completely stock and want to amp up the HP however I need to build up my transmission before I even think about hp. Any ideas on what I should do first?
I have been reading up on it and i think i will be putting in a new tc and vb, shift kit, and maybe an input shaft. any suggestions on makes our models? Not looking to throw to much hp into it so I don't want to completely build the trans as the truck runs great as it is.

 

[BigPapa]

Sounds like you want to do what I did, stock rebuild, Goerend constant pressure VB, TC, billet input and band anchor. Worked great for me.

 

[Pardy]

How much did that put you out?

 

[BigPapa]

Right around $3300. It was 6 years ago. I paid someone to do the rebuild.

 

[CharlieFoxtrot]

I've read that the billet input isn't needed unless you're doing 4wd drag-race launches on boost, or pulling competitions, and/or setting up your converter to not unlock for shifts.

I've had no problems with a stock input over many years of reasonable towing and 2wd hooliganism. My truck is probably close to 350HP and 800ft/lb.

 

[BigPapa]

You're probably correct. The shafts are $750 now. Seems like mine was $400 or $450. I went with the billet input for insurance. You have to pull the transmission to replace it. Easily the cost of the shaft. Plus, I hope to do a little drag racing some day.

 

[fest3er]

I've read that the billet input isn't needed unless you're doing 4wd drag-race launches on boost, or pulling competitions, and/or setting up your converter to not unlock for shifts.

I've had no problems with a stock input over many years of reasonable towing and 2wd hooliganism. My truck is probably close to 350HP and 800ft/lb.

'98 12V, stock plate slid mostly forward, 215 injectors. ATS TripleLoc TC and VB installed around '05. Except for the extra power, it works and shifts like it did when stock. Input shaft stripped late Oct. '12.

So, given enough time, very moderate power/torque can strip the input shaft.

 

[SSage]

Goerend for parts if you have a builder or want to do it yourself. They have all the preferred parts for a rebuild in kit form, I think the basic rebuild kit is $750.00, master kit is $925.00 or so. Add a valve body shift kit or a custom built VB and a good torque converter with fresh flex plate at a minimum.

Here is the custom hard parts they offer: http://goerend.com/index.cfm?Page_name=dodge%20diesel%20parts

I put in the premium master kit stuff in my 47RH and I don't regret it, its held up great over the years even though I tow heavy and have major torque. Mine is a custom mix of parts built by DTT, one step below their racing version. Its been a tough trans built for towing, it shifts smooth under load and shifts hard under light load, so its best to get on the throttle when running light. I used all new Mopar cooler lines also. Its been years now of towing my trailers from 10,000 to 18,000 pounds, still shifts solid and has no slip. Best mod I ever did.

I would put a master rebuild kit in, a custom VB, a billet flex plate and the best TC for your application. You can then decide if billet shafts are worth it. I would want fresh shafts in a transmission if I was running power, or if its stock power, then I would just do the input. TC is $800 for a single disc billet, rebuild kit is $975, shafts are $750 each. Valve Body price can vary, I have a DTT VB and DTT/Goerends single disc TC myself. I think I paid $450 for the VB, buts thats with a core and its been years.

I just followed the direction of my DTT builder, the guy chose the best group of parts for me. I've been running a heavily fueled truck for the last 40,000 miles and its still shifts like new.

 

[SSage]

double post

 

[cerberusiam]

Not looking to throw to much hp into it so I don't want to completely build the trans as the truck runs great as it is.

HP won't be the problem, the TQ will on a stock transmission. A good shift kit, Superior or Fairbanks will solve a lot of the problems and create some more. Adding a front servo cover or even a super servo, billet band strut and anchor for the front band is advised. You might need a new band if the old one is stretched and worn. A slip in is available or you can do it when the TC is added.

A lot will depend on miles on how if feels now. The 47RH's had all aluminum planetary cases so after enough miles they started howling. The Added TQ will not do worn parts much good on the front and OD planetary. Just keep in mind those are the weak spots.

TC will make the most difference in drivability you can feel, stocker is pretty sloppy. Unfortunately that and the added TQ will immediately start to hammer the direct clutch pack. When you do the TC plan on rebuilding the forward and direct clutch packs and add a clutch to each.

The 47 input is weak, much added TQ, a lockup controller, or a triple disk TC and it is probably not going to last.

No constant pressure VB needed, not applicable. A good shift kit is all the is needed. You can do that yourself as those VB's are pretty simple or buy one but the cost difference is huge for what you get.