95' Junker Drag Truck

[Big Blue24]

I'm almost done rebuilding the transmission. I ended up adding one extra clutch in the direct/OD pack so now 10 clutches by purchasing thinner steels 0.054" thick for $1.39 each and one extra friction for $2.95. No other modification is necessary for this upgrade.

My rebuild kit came with new bushings so I have added pictures of how a "poor man" installs a bushing without a shop press. It involved using my wife's old hair dryer, my freezer, a round piece of plywood, and small sledge hammer. Obviously you freeze the bushing and heat the aluminum case with the hair dryer.

I also bought a new pump with the correct number of lobes, I have no idea why my old pump had 11 lobes on the outer ring, the new one has 12.

 

[Big Blue24]

My overdrive "brake" clutch came stock with 5 clutches. I upgraded this clutch pack using a used stepped pressure plate from a 48re transmission that cost $10.58 one more 0.087" clutch at $2.81, and one more 0.068" steel at $1.58. To gain proper clearance for the clutch pack, you also remove the "extra" waved snap ring below the pressure plate #280 in the attached picture. There is a standard snap ring #862 still there to make sure everything works properly.

 

[Big Blue24]

I also got a new billet 3 friction lockup converter from a no-name supplier. We'll see how well it holds. The manufacturer rates the converter for 1200-1400 ft lbs so hopefully it will perform ok.


I also got a new rubber transmission mount and a Transgo TFOD HD-2 shift kit. I got the shift kit installed, I can't give any feedback till I get this tranny put back together 100%.

 

[Big Blue24]

I also upgraded the lockup cover plate assembly. The transgo shift kit came with an updated metal holder and instructs you to drill the hole larger. I purchased and installed this nice one piece unit that incorporates cover plate and spring holder into one piece. The one-piece coverplate also came pre-drilled with a 0.092" hole which is on the small end of Transgo's instructions for firm lockup. I left the hole 0.092" since I have a triple disk converter and stock input. No sense in banging lockup harder till I get a billet input and slicks to help maintain traction during lockup.

 

[CumminsCowboy97]

Big blue where are you getting your trans parts from?

 

[Big Blue24]

Wittrans, PATC, Ebay, and Rock Auto.

Brett at TNT performance offered the best pricing on Billet lever, anchor, and strut.

 

[CumminsCowboy97]

I'm curious to see how the billet converter from wittrans will hold up behind a 12 valve

 

[CSM diesel]

Did you consider upgrading the clutch count in the direct drum? WITtrans has 0.061" frictions at $7.64ea, and 0.070" Kolene steels for $3.76. This would give room for 5 frictions in the direct drum. 5 each (frictions/steels) is $57. I used PO #'s: A22108HD and 22126K respectively.

 

[Big Blue24]

I actually got 6 friction in the direct drum and had little extra room with the 0.065" clutches so I ended up using (3) 0.065" and (3) 0.096". There was almost enough room to get (7) frictions in this pack, just needed 0.061" frictions. I'm not a tranny guru so I don't know where you can/can't get tighter than spec clearance and not burn up the pack.

I figured out a cheap way to get (6) frictions in the forward drum as well.


So I planned to stay with stock clutch count but ended up with (1) extra OD/Direct Friction, (1) extra OD friction, (2) extra forward frictions, and (2) extra direct frictions. After checking the overall play in the OD section, I'm pretty sure I could have went to (11) frictions in the OD/Direct drum but for now (1) extra gives me a little more surface area/holding capacity and the overrunning clutch can probably soak up a little bit of the slip that happens in this pack anyway.

 

[Big Blue24]

I'm curious to see how the billet converter from wittrans will hold up behind a 12 valve

I didn't know Wittrans sold billet converters when I bought mine so I purchased it elsewhere. Also, I bought a triple friction converter and the Wittrans billet is a single friction lockup unit. But for a mild rebuild, I'll bet that sub $400 dollar converter is a good option.

 

[mondtster]

I actually got 6 friction in the direct drum and had little extra room with the 0.065" clutches so I ended up using (3) 0.065" and (3) 0.096". There was almost enough room to get (7) frictions in this pack, just needed 0.061" frictions. I'm not a tranny guru so I don't know where you can/can't get tighter than spec clearance and not burn up the pack.

I've gotten 7 in them using the thin frictions and an alternate pressure plate.

The big thing to remember is that the direct clutch is a shifting clutch so it will need greater clearance than the forward clutch does.

I'm pretty sure I could have went to (11) frictions in the OD/Direct drum but for now (1) extra gives me a little more surface area/holding capacity and the overrunning clutch can probably soak up a little bit of the slip that happens in this pack anyway.

I think I mentioned it before, but there are guys who have had the OD direct snap ring break and all they lost was reverse. It makes me think that little sprag in there is pretty rugged and will hold quite a bit of torque without a problem. The OD direct would be the least of my worries. Just my opinion though.

 

[CSM diesel]

I figured out a cheap way to get (6) frictions in the forward drum as well.

Care to elaborate?

 

[CumminsCowboy97]

I didn't know Wittrans sold billet converters when I bought mine so I purchased it elsewhere. Also, I bought a triple friction converter and the Wittrans billet is a single friction lockup unit. But for a mild rebuild, I'll bet that sub $400 dollar converter is a good option.

I was on their site one night just lookin around and happened to come across it, before I order it I'm going to call them and get some more information on it. There's also a guy out in cali that builds converters for $500 I'm also curious t see what he brings to the table.

 

[Big Blue24]

Care to elaborate?

The stock apply plate in the forward drum is tapered .122" to 0.280" thick. The stock reaction plate is flat and about 0.280" thick. I replaced the stock flat plate with a used stock apply plate and gained enough space to add another friction. If you use the super thin 0.061" frictions, you can get 6 into this pack. A stock 48re forward drum only holds 4 frictions and with a simple shift kit, the 48re is good for 500 hp. I really think you only need 1 extra clutch in all but the most extreme transmissions.

 

[Kronic_187]

are you in the tranny business blue ? do you have any recomended reading material if you arn't ?? just an adventures backyard mechanic like the rest of us or ?

 

[cumminsturbo94]

do you have any recomended reading material ??

i was looking for some as well

 

[Big Blue24]

are you in the tranny business blue ? do you have any recomended reading material if you arn't ?? just an adventures backyard mechanic like the rest of us or ?

I'm not in the tranny business. Just asked a few questions here and there, read on the internet here and there, spent a lot of hours measuring parts and figuring out what will and wont fit inside this 47rh that's torn apart on my work bench.

Honestly, this is first time I've seen the inside of a transmission on anything larger than a dirt bike. My lack of funds for a professionally built tranny combined with the relative low value of this truck has given me courage to experiment.

 

[cumminsturbo94]

i gotcha. does any one know of any other good threads on here or other sites bout a rebuild? iv already come across the manual from this website Dodge Trucks TechTran A500 42RH A518 46RH A618 47RH Service Manual altho i havent had a chance to reead it all. any 1 got any more???

 

[npe3484]

Big_Blue and mondster have contributed some really good info to my 47RH Budget Rebuild thread. It's 2 or 3 pages back in the 94-98 tech section.

 

[Big Blue24]

I got my tranny back together and installed. Went for a test drive and it was shifting funny, hunting up and down, and binding up. Checked my fluid and I was 1.5 qts low.

Lost reverse, burned up the fluid, and filled the pan with clutch/friction debris.

Thanks to Bponci for helping me figure out I had cross leaks in the valvebody and Mondtster for helping me trouble shoot some other issues.

I ended up dropping the pan only to discover two valvebody hex bolts laying in the pan. Long story short, many of the bolts and screws I torqued to "spec" backed out in my short 5-10 miles of test driving.

I tightened up all the hex bolts and torq screws, just used my hand as a gauge for good n tight. Readjusted the rear band, installed new filter and reinstalled the pan. I then added 9 qts of Type F.

Tranny shifts beautifully! It will lay rubber in 1,2, and 3rd although it is a 1 wheel peel so not very hard to do. I also installed my Pac Brake 4k GSK today. I left the idle shims under the largest spring and installed all of the supplied springs and spring seat. Set up at initial plus 4 hard clicks. Idle in N sits at about 900 rpm, idle in gear sits around 750 to 800. It's about 50-75 rpm higher than pre-GSK just like Pac Brake claimed it would. Truck will free rev over 3800, that's all the higher i've revved it since it gets a little raspy and choppy above 3600 rpm. Could be GSK, could be lift pump, could be timing. With my current setup, I'm happy with the GSK tuning.... got lucky on my first try!


I made it to the Las Vegas Motor Speedway track tonight.

My best pass was 15.575 @ 86.16 MPH.

2.275 - 60'
6.402 - 330'
9.902 - 1/8 mile @ 69.61 mph
12.964 - 1000'

Power wise I have added GSK, Modified AFC, Removed Fuel Plate, and Disabled the stock wastegate. Turbo hit around 32psi boost in OD.

I still need to verify lift pump pressure and possibly stretch the overflow spring. Traction off the line was an issue and using the lockup switch didn't help times because it bogged the motor. I guess you've got to make more than 240 HP to benefit from the use of a lock up switch in 2nd gear.

According to the Comp D HP calculator, nearly free mods raised this truck from stock 160 at the crank to nearly 240 at the rear wheels. I plan to bump up the timing and manually shift the transmission next time out to try to see what 20-24* will net over stock timing of approximately 13.5*.