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'96 12V build about to begin

4K views 35 replies 9 participants last post by  Frostbit 
#1 ·
Hi Guys,

Thanks for the information on the exhaust brake question earlier. He's a list of mods about to happen on my truck with 140,000 miles on it.

KDP fix.
Gauges
60 # valve springs
4" turbo back exhaust Flo Pro Stainless with muffler
S&B Cold Air Intake with filter wrap
BD #8 plate
3k BD GSK
Exhaust Brake with Auto Loc.
Replace non-functioning fuel sending unit

I'm retired at 62 on a fixed income but plan on keeping this truck forever. We haul a very heavy Alpenlite cabover truck camper and after a 16,000 mile trip last winter we realized the stock 5.9 was too anemic especially on long grades and nasty headwinds.

Also didn't like trying to keep the speed controlled on descents with the service brakes.

We've had suspension beef up work dome already.

Trans is stock and regularly serviced and I realize we will likely need a rebuild in the next 40,000 miles sometime and have money assigned for that.

The work is being done by a well regarded diesel mechanic with 12V experience so the pump will be "properly" tuned with the plate and governor spring change.

Anything I may not be thinking of? I'm not looking to turn the truck into a beast. Simply would like more power for hauling up the longer grades and maybe some better MPG.



 
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#2 ·
seems like you pretty much got it all covered. The truck will seem a million times faster!
 
#3 ·
Who wants to guess what kind of HP and Torque will result from this?
 
#4 ·
Good start! If you are mechanical or have the ability to eventually go to a little bigger turbo it makes all the difference. With my setup I can pull 11k pounds up almost any hill at 60+. The he351 turbo made all the difference . your tranny won't last long. That should be high priority.
 
#5 ·
#8 ·
Thanks, but I read the beginners thread start to finish. One of the reasons the KDP and Gauges were mentioned in my original post.

The trans will certainly get attention but not immediately. I've talked with three shops up here and a rebuild with upgrades is in the $6,000 neighborhood. All three shops also stated that it didn't matter if the rebuild occurred before or after failure.

It seems you are certain the trans will be toast with the upgrades I listed. Does this include driving sanely? It's a serious question. I have no plans to treat the truck as a drag beast.
 
#6 ·
He's got gauges listed but without a good convertor and shift kit the trans will be toast in short order with the 8 plate and that camper.
 
#9 · (Edited)
Stock auto trans barely handle a stock 5.9's torque let alone the extra 200 plus lbs an 8 plate can give it. You wont have to hot rod it, the extra torque the engine will have hauling the camper up hills will be enough to cause a stock trans to start slipping along with convertor slippage causing the trans to over heat. With only 140k miles on the trans there's no need to rebuild it, all you need is a good billet convertor and a shift kit or upgraded valve body to get it to live with the engine upgrades you've listed.
Why burn your trans out and have to pay big bucks to rebuild when for a third or less money on convertor and valve body upgrades before adding power to the engine could get you many more thousands of miles of service from trans before it will need rebuilt.
 
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#10 ·
Stock auto trans barely handle a stock 5.9's torque let alone the extra 200 plug lbs an 8 plate can give it. You wont have to hot rod it, the extra torque the engine will have hauling the camper up hills will be enough to cause a stock trans to start slipping along with convertor slippage causing the trans to over heat. With only 140k miles on the trans there's no need to rebuild it, all you need is a good billet convertor and a shift kit or upgraded valve body to get it to live with the engine upgrades you've listed.
Why burn your trans out and have to pay big bucks to rebuild when for a third or less money on convertor and valve body upgrades before adding power to the engine could get you many more thousands of miles of service from trans before it will need rebuilt.
Thanks! Appreciate any and all suggestions.
 
#11 ·
How's that thing handle with the camper on it? How long is the camper, looks like 11.5ft? You running air bags in the rear? What kind of suspension works been done to accommodate it?
 
#12 ·
The rear suspension has a "double beef" done with two extra leaves added and rearched so truck sits level with camper on board. Sits about like a '69 Roadrunner with airshocks unloaded. Also extra heavy duty shocks and front and rear antisway bars added.

She rides very nicely with the camper in and shakes your eyeteeth out unloaded.

The camper is a 1994 Alpenlite I snatched off Craigslist about four years ago. I do believe it is 11.6
 
#13 ·
 
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#14 ·
OK, ya'll talked me into it. Here's the planned build for the transmission. Should stand up to the engine mods.

Overhaul Master Kit w/Performance Clutches & Steels
Borgwarner Band
New Internal Electronics
New Thrust Washers
New Overdrive Piston Retainer
Billet Servo Cover
Billet Band Strut
Billet Accumulator
Billet Input Shaft
Billet Direct Apply Piston
Modified Valve Body
DPC Triple Disc Converter
SFI Flexplate
Steel Rear 6 Pinion Planet & 48RE Sunshell Upgrade
 
#15 ·
Transmission upgrades are necessary to handle power upgrades but that's throwing some serious cash at it.
With only 140,000 on the trans if it hasn't given any problems, I'd just stick a billet single disc convertor and Trans Go shift kit in it and drive on.
Stock convertors are very inefficient and make a lot of heat, installing a good billet convertor will help reduce stall speed and lower trans temps.
A shift kit will increase line pressure giving the clutch packs more holding power and improving overall shift performance.
These two improvements alone have helped keep transmissions alive in truck's making over 300hp.

I wouldn't tear in to a perfectly good 140,000 mile trans when a convertor and valve body upgrade should keep it going for another 100,000 miles or more.
 
#16 ·
I appreciate you trying to save me money. The thing is, if the build I listed gets me a completely bullet proof automatic, regardless of the final HP & Torque of the engine build I noted, than I would rather have this transmission built once and spend the extra.

Maybe it's overkill, I don't know, but I suspect it's all we will ever have to do to that trans. Agreed?
 
#17 ·
My transmission is built the way Destroked suggests. After I bought the truck, I found the bill (excellent records with the truck) and talked to the transmission shop. The transmission guy told me to change the fluid and adjust the bands every 25k and the transmission would stand up to 750 lb-ft of torque very well. He said if I did not service the transmission, and pulled heavy, then it might only last 50 k...so at least in his opinion, that would not be all you would have to do to it; they need routine servicing.

I am just getting to 25k on the converter and valve body, and 250k on the transmission and truck. I bought the truck at 225k, and have not been pulling heavy. Still running stock engine, more or less, though I plan to take it up to about 300 hp - just changing fuel control, no injector changes.

As my own knowledge of auto transmissions is low (just what I have read on this site), the plan was to follow the transmission tech's suggestions. Any and all input welcome.
 
#18 ·
I can't blame you for wanting the best trans you can have in the truck, just showing you options.
Had a couple of trans failures in my old truck so we built one using the best of everything but stayed with a HD billet single disc convertor. It did a good job but due to electronic issues later on causing the convertor to lock mid shift it split the case so now I have a manual trans truck.

I did a lot of research on convertors and decided against a triple disc after talking to some of the convertor mfg's. A couple of them finally admitted that there's only so much room inside of a convertor to add clutches, in order to add more disc they have to be made thinner with less material and for my heavy towing (24-32,000 gcvw) a HD single disc or double in a billet case would give me a longer service life. The HD single I installed was strong enough to split the trans case and was reused in another trans that's still going today.
I'm not going to bash any ones triple convertor but IMO they are more for racing than daily usage or heavy towing.
 
#19 ·
Here's another build option offered for my transmission that is much less than the build I listed above. It would seem to match your criteria am I correct? And in your opinion this build would handle the power upgrades I listed in the original post.

Overhaul Master Kit w/OE Clutches & Steels
Borgwarner Band
New Internal Electronics
New Thrust Washers
Sonnax Servo Cover
Sonnax Piston Retainer
Billet Band Strut
Billet Accumulator
Modified Valve Body
DPC Single Disc Converter
 
#20 ·
Looks like a good list without all the extra parts you really don't need for the engine upgrades you plan on doing, if the overhaul kit with the performance clutches isn't much higher I'd go ahead and get them.
 
#21 ·
Thanks! Appreciate the advice.
 
#22 ·
Ended up having the heftier transmission build done including the billet input shaft. Now presently under the knife getting the engine mods. Looking forward to seeing what this truck is like after the tweaks.

If the #8 plate delivers 230/605 in the stock position how much more of an increase in HP & Torque might one expect with the plate moved forward with other proper adjustments?
 
#23 ·
Sometimes you get lucky. Truck's with my chosen diesel tech for mods and the KDP tab was part of it. Turns out the KDP was loose and about halfway out. :thanks2:
 
#24 · (Edited)
#25 ·
Thank you Sir. I had already read that a bit ago.

Cheers
Jim
 
#26 ·
Mods are done. It's a completely different truck. Well worth the investment. Will put the "white whale" camper back in the bed this week and see how she does under load. So far it feels like the truck Dodge should have built in '96.
 
#27 ·
Spent the last two days making her look as good as she runs.

 
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#28 ·
Good looking truck. Hope it's with you for many miles to come.
 
#29 ·
Wow!! Put the camper back in and took it for a ride. The truck pulled a hill that before the mods normally required coming out of OD. It cruised right up the hill in OD with about 1/3 pedal and EGT's never went over 1050.
 
#31 ·
Back from first long trip with the big camper loaded up. The trip included a couple mountain passes. The power increase was amazing. Seemed to barely need to depress the pedal. Exhaust brake worked great on the descents.

Along with the increased power we got about 2 more MPG over the pre-mod mileage. Doesn't sound like much but if you do the math that is a 16% increase in mileage.

Very happy with results!!

Thanks for all the advice.

Cheers
Jim
 
#32 · (Edited)
Good deal, another happy Cummins owner with power the truck should have had when it was new.
An extra 2 mpg is big for me getting 14 empty, 10-12 loaded local driving, would love to see 4 mpg increase empty.
My trucks presently in the shop getting the new engine I built last year installed along with some suspension upgrades.
 
#33 ·
I haven't had the truck empty for a full tank yet so I don't know what it will get. If I remember I was getting 17 or 18 empty before and got a steady 12 with the heavy camper. Maybe I'll top 20 empty if I'm lucky.

Either way the increased power was worth the work alone.

Cheers
Jim
 
#35 ·
I believe it's a 3.54. I have after market anti sway bars front and rear and they eliminated almost all of the body sway with the camper. The way it's set up now it's great with the camper but jars out your eyeteeth and is raked high in the rear without the camper load on board.
 
#36 ·
Update -

The '96 12v is still running great. It's retired from camper hauling duty as we now have an '06 DRW Cummins with an even heavier Bigfoot camper. The 12V is our backup daily driver as I will still keep "Big Red" forever.

Love our every other year Mega-Roadtrips and are now planning on a new Ram 5500 Chasis Cab with a custom Sherptek flatbed to haul the Bigfoot. I don't like riding right at GVW and the Sherptek will give us an extra 100 cubic feet of storage.




Sherptek Video
 
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