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Auto to Manual conversion notes

Written by My Friend Chris Foogle

Okay so I finished the conversion about 4 months ago, so I figured give anyone looking to do this swap a little info on everything I encountered and what i did along the way. These notes should pretty well cover everything from 94-97, beyond that there may be subtle differences I do not know about. So here goes...

1. you DO NOT need a different flywheel housing, the auto and manual housings are the same.

2. you DO NOT need to change the entire brake pedal assembly out. The auto and manuals share the same support bracket, just get the pedal set and hang it in....shouldn't take more than 5 minutes to convert it.

3. you DO NOT need to retain the main and auxilary trans coolers (I know...duh). Take them out now to make room for some compound turbos!!

4. I ordered my trans as a 98+ with a '95 extension housing. Why?
A. Because I wanted the transfer case shifter mounting bosses on the housing like my auto was. Somewhere after 98, the bracketry changed and was not secured to the extension housing. In retrospect, I found the mounting bosses to be 1" narrower anyway on the manual, as well as the shifter being closer to the tcase, requiring a removal of about 3" of shift rod, and opening up of the holes in the bracket to accomodate the narrower pattern on the if I had it to do over again, I would probably update the entire Tcase shifter and rod assembly to the 98+ style. Compounded with that, I opted for the 98+ center floor console instead of the bare boot that was offered in '94-'97. While the early shifter worked okay in the later console, a little bending was necessary to make it look and function within the boots.
B. I wanted to install the BD short shift kit, and it is only offered for the late style 98+ shift tower. Now that I have it, I love it. The gates are super narrow and the throw is less than 6". It really makes rowing the 5sp fun and crisp. I highly recommend making sure you get a trans with the 98+ top cover, or swap it on, in order tho utilize this neat little gadget. The kit installs in less than 10 least for me, as I had the trans on the bench.

5. The manual output shaft is a larger 29 spline, and your auto uses a smaller 23 spline. You'll have to order a new input gear for the Tcase. Again, this is not a hard install, but the Tcase must be mostly disassembled to get access. There is no rocket science inside, I did the conversion in about an hour. Note that there are two different input gear bearings out there on the 241HD's. A narrow and a wide. They will interchange fine in the case, but the one you need is dictated by what you already have versus what the new gear needs, the only way you're gonna know is to run the numbers and ask. Or wait till yours is apart and take it in stride. it will be obvious, as the snap ring groove will either be close to the gear teeth, or farther up the gear snout. Either way, a new bearing is about $ big deal.

6. Trans crossmember is fine, as is the auto soft mount. The manual needs about an inch more height over the soft mount, so a simple hoop type bracket can be made or bought from an adapter oulet, to bolt on to the soft mount, then to the bottom of the trans, raising it about an inch. The front to back alignment is right on, so no need to compensate for length.

7. driveshafts will have to be made over. The rear is 6" too short, and the front is 6" too long. I share a building with a machinist, so we just made a new rear, and shortened the front. I will say, at 6" shorter, the angle is pretty steep on the front shaft. I have 2" levelers on the front, and while in the air, the cardon joints rubbed on their yokes. Once on the ground, it was just fine, but keep it in mind if you're lifted very high. A custom high angle shaft will be needed if so. Being a standard cab, I also don't have a rear carrier bearing BTW.

8. Clutch master/slave. Buy the MOPAR kit. It comes complete with the resevoir, master, slave, rods and hydraulic lines, and is prefilled and bled. But beware, SOMEWHERE along the way the mounting style was changed. Being that I ordered my trans as a 98+, the master i received had an extra 2" of rod, which flat didn't work. I ended up shortening it. Normally early 2nd gens masters merely snapped into place via a bayonet twist mount in the brake pedal support bracket throught the firewall. My master came with an extra cup with studs on it for I guess a later style of mounting. I removed it and mounted the master up using the bayonet base, which left the piston rod too long. Moral of the story, order your hydraulics per year of your truck and you'll be fine.

9. The flywheel uses longer bolts than the auto flexplate, so be sure and get the right bolts.

10. Your starter will work fine, the autos and manuals use the same one.

11. Clutches....hmm, well there's plenty to choose from. I went with the SBC ConFE 13" conversion. While the clutch can be chattery when starting in second, I found a few more RPM while slipping the clutch out, smooths it right out. In reverse and first, no chatter....and that's with 35's and 3.54's. Don't be afraid of this clutch, it is not as finicky as some report. If you have the power, don't short change yourself with the OFE just for a smooth engagement. The FE is not bad at all, but it's all relative to the driver, so my experience and expectations may be different than yours. Just suffice it to say, I am VERY pleased with the FE, and especially the size of the hub and springs from the ETH style disk as well as the extra diameter.

12. okay...electrical. I had and RH, so PCM mods were slight and simple. If you have an RE, I'm afraid I don't know what needs to be done in order to maintain cruise control. The nuetral and back-ups should be the same though and the mods for both of those are easy.....
A. Nuetral safety sw - your new clutch master has the switch built onto it, and the truck, even though an auto, also has a provision for it. There is a 2 pin plug mounted to the right side of the fuse block under the dash. It is green in color and the auto trucks simply have a jumper placed in them. Remove the jumper and plug in the master's nuetral harness and your done. Down below, you will have to wire a relay into the existing auto wires that simulate the auto's nuetral sw. I won't go into detail now, as I have already posted a diagram here... ...that shows how to wire it in. In short, the function of the wires must change to both get the truck to crank, but then allow the cruise to work, as a full time nuetral signal will inhibit the cruise control. If there are any questions on this subject, I will answer email, but post here instead so others can see, and I will answer in like.
B. Back-up - the new trans will (or should) have the back-up switch already installed on the top cover. It is a simple open/close two pole switch. Just hook the positive center wire from your auto sw harness to one terminal, and the back-ups to the other and you're done. If you can scrounge up a plug from a manual truck, it's even easier, otherwise you have to deal with a molded weatherpack type plug with small terminals.

Okay I know I haven't mentioned everything, and I'm sure there are many more questions, so fire away and I'll do my best within the knowledge I gained on my '95 conversion.

Good luck and thanks for the look.

28 Posts
I just did this swap and everything is in and working accept the speedometer and odometer. Neither registers at all right now. Both were working before I did the swap. I can't figure how the different trannys would have made any difference because the speed sensor plugs into the transfer case. Another funny thing is that most of the time I have to turn the key on and off a bunch of times before it will turn over. The warning lights and everything come on and off like they're supposed to but it dosn't always turn over. There dosn't seem to be any ryme or reason to it. Sometimes it starts the first turn and then the next time I have to turn the key on and off 6 times before it starts. Any ideas?
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