hi
transgo tfod-diesel kit works for me!
also added a drain plug to pan .
stock convertor with lock up switch .

 

what exactly does a TC lock-up switch do? my impression is that it prevents TC clutch slippage and thus extends clutch life, which i believe is one of the more common causes of tranny failure in these trucks. i intend to put this truck to work and don't want to be constantly burning things up.

 

A lock-up switch DOES NOT prevent slippage.
The original intent of a mystery switch was to work around the pathetic fluid coupling of a stock converter and lock the clutch when you needed power to the wheels. It did prevent the clutch unlocking when you used full throttle which in those days was usually stock.
It also holds the clutch locked if you are on and off the throttle. This does give a little clutch saver.

The 47RH & RE transmissions are actually pretty stout unless they have internal problems. The stock converter was poorly matched to a relatively low & slow rpm and high torque diesel engine.
Increase the hp & torque from stock and you can overpower the converter at around 220 hp.

Rebuilding a VB with a Transgo kit is not difficult, but requires meticulous detail to assemble as gmctd pointed out in previous post.

 

okay, i understand that the TC clutch is manually locked on demand w/ the switch; isn't this done to prevent the clutch from slipping, under load, during partial engagement(slippage), to prevent premature burnout/failure due to inadequate fluid delivery(coupling)? why not just keep it locked on (to prevent burnout while stopped/in park ?) from what i understand the inherent problem w/ the dodge diesel transmissions(47rh & re) is that the diesel eng. operates @ too low an rpm to deliver adequate fluid for efficient coupling and overheats the fluid. so a lock-up switch will resolve this issue, at least partially ? won't overpowering the TC w/ more torque as you mentioned in line 7 of your post, just fry the clutch/s ? please bear w/ me i'm kinda inexperienced w/ transmission theory and practice.

 

He meant the TCC lockup switch doesn't prevent slippage if the TCC is bad or over powered - it does provide 100% lockup on demand, good for moving in DRIVE, not good for standing still in DRIVE - that would be like trying to idle a manual transmission in 1st gear - works only when the clutch pedal is on the floor, held there by the driver's left foot - thus, the switch is ON when driving (clutch pedal up), OFF when coming to a stop(clutch pedal down), actuated by the driver's brain thru his\her finger - or thumb

As mentioned the 47\48 slush-boxes are stout, but are engineered for slush-shifting to survive thru the warranty period - a shift kit will vastly improve a good 47\48 box, won't even help a bad one - the oem torque convertor was engineered with much slippage, again for the warranty consideration - an aftermarket tc is much more aggressive, much less slippage, and the clutch is improved to handle lower-rpm lockup and greater power input - install both upgrades together, and the most likely damage to the 47\48 will come from improper useage of that computer between the driver's ears - the TCC switch can be a good thing - remember, switch'em if ya got'em..................

 

alright, i'm starting to comprehend a little, (i think), maybe i can get some clarification please. if the OEM TC was deliberately engineered w/ much slippage, wouldn't that cause it to fail more prematurely than it would w/less slippage? also which combination of upgrades would benefit the most, budget being a major consideration (my primary desire is durability);aftermarket TC w/TCC switch, TCC switch w/shift kit, new TC w/shift kit etc. etc. i'm pretty sure the previous owner installed a new TC, but i doubt it's an aftermarket version. fom what you guys have told me it seems like the OEM TC itself is the weakest link in the whole drivetrain. would a shift-kit combined w/ a TCC switch make up for the deficiencies in the stock TC ? how would a new aftermarket VB effect things? as i said in a previous post once i get this thing on the road i want to invest in some bolt-on insurance to strengthen my weakest link. i intend to put this thing through its paces hauling stone, firewood, const. materials, etc well off the beaten path and can see myself in the middle of nowhere, w/ a load of something, brokedown because of a weak trans/TC.

 

Sorry, missed the "rebuilt trans part.

 

just thinking, is it possible that the stator sprag clutch could have been damaged or misconnected or something during installation of new TC. i don't think i revved it much while going through the gears

 

A broken stator sprag would prolly not prevent the vehicle from moving in any gear range - it just would be very, very sluggish from a dead stop, requiring increased engine rpm to get the job done

But, don't let all this pre-thought confuse the issue - start with the easy checks first, getting deeper into the trans as the easier stuff is eliminated as being good, not causative - right now you're blindfolded with a bat in your hands, swinging at a pinata (which is in another town), hoping to hit something -anything - that will open and dump the goodies

Troubleshooting is doing individual checks, easiest to more difficult, that eliminates the good stuff - each thing that you eliminate as being good means that the bad stuff must be amongst what's left - continue checking till the bad thing falls apart in your greasy hands.............

 

anyone wanna kick this one around ? you sound well informed, JD from texas

 

I can say this, do NOT go cheap on the TC if you have to go in there.

My stock rebuild TC took a dump after 30K, trans is still perfect, but I still had to drop it to put an upgraded TC in after I lost TC lockup.

Personally, I would switch her over to a NV4500 rather than mess with it too much unless you put in a good full built trans.

 

i didn't get a response the first two times i posted this question;maybe it's a dumb one, but here it is again. (might be fun to just ponder the possibilities)

 

What you need to do is put a gauge on the tranny. A 100 PSI gauge should do. The threads in the tranny are 1/8" pipe thread. Connect to the port in the middle on the right side. That should be the accumulator port. You should get at least 50PSI in drive. No pressure in P or N. This will tell you if the pump is pumping and if the PR valve is working. From there you can test other pressures but this test must be done first. Rule out the pump and valve body first.

It is best to get some 1/8" plastic air line tubing and some brass compression fittings that adapt to 1/8" pipe. That way you can run the tube into the cab where you can see the gauge as these test need to be done in gear and sometimes moving.

 

I had a similar thing happen to my 96, start truck and shift into drive and nothing happened. Trans was showing full of fluid and all else seemed as it should be. It ended up being the two lines that run to and from the trans oil cooler. They were leaking just enough to not maintain pressure and were causing the trans not to engage. Replaced both lines and it fixed the problem.

Hope this helps.

 

check out www.goerend.com web site. even call dave he can get you pointed in the right direction. http://www.goerend.com/intermediateshaft.php This technical instruction document will guide you through the disassembly, inspection and assembly of the intermediate shaft.