TD 18 IH Crawler

Alternator Conversion


TD-18 Generator to Alternator conversion to the TD-18 known as Blaine and the TD-18 known as Dually which will give you enough info to get start. zoom in on the pictures to see more details because every generator and TD-18 are different from the ones i used. thansk

September 2019

I have had TD-18 cats in my collection since 2003 and the biggest problem is figuring out how to get a cheap 12 volt charging system. Plus be able to tighten the fan belts because the factory generator had big and small bolts for mounting. Also when putting a new style alternator with internal regulator the hardest part is finding a double pulley for the 7/8” fan belts. The pulleys are out there but are expensive when you live at the end of the world in northern Canada. Plus the alternators used on most equipment at about $600.00 new with the core charge because this is a new install and no core to hand in for the refund on core charge. I decided to copy a few ideas I have seen on the internet over the years because I have had 15 years to think about this because it is now 2019. It was easier to leave the factory generator in place because it has worked for 70 years tightening the fan belts but not very good at charging the batteries.

just a quick picture of the alternator and generator on the shop bench to give an idea of what took place.


First remove all the copper wires inside the generator which can be cashed in to buy the beer required for this project. With all the copper gone off the armature, you have a shaft that a 3” pulley will fit where the brushes used to run. I chose a big belt pulley so the 4L260 belt sits low in the pulley for more clearance when inside the generator housing. the pictures i took of the armature with the pulley by its self did not turn out so this picture will have to do.

pulley close

Now take the generator housing and figure where to cut it so the belt can come out to drive the GM 1 wire alternator. The generators I used had the opening for the brushes which was covered with a tin band. I just torched the one opening a little longer for belt clearance. I also used a heavy wall 2.5” square tubing as the alternator support. I built this system based on the belt I use on my other cats that drive the alternators that way only 1 belt size in stock for 16 machines.


the generator is bolted to the pulley drive by 4 bolts in a square pattern. The generator housing has to be turn ¼ of a turn for the alternator belt to be pointing in the right direction to clear the intake manifold on the TD-18 motor. This clearance is needed because I used these long 4L260 belts. Each set up will be different depending on the generator and belts used. With the generator housing turn ¼ of a turn that mean new holes have to be drilled at the back of the generator end plate because there is only 2 bolts not 4 holding it on.


the generator itself is lubed by 2 oil cups that had oil dripped in them to soak the felt that lubed the shaft of the generator. I tossed the oil cups and felts away and tapped in grease nipples. Sealed up all the holes with gasket goo and called it good. The drive pulley end has the factory grease nipple already.


also I have found over the years IH used the same part number for different length fan belts. The alternator system I whipped is based on the 7/8” x 65.77” outside circumference belt by Gates TR30652. This gives the alternator enough room by the intake manifold.


since I’m colour blind I use only black wire because why should I buy colour for others to enjoy which also goes for my computer printer too. I used a 10 gauge wire from the GM 1 wire alternator back to charge the batteries. Every TD-18 is different so pick a good place to send the power to charge the batteries. I used 12 gauge wire to jump the power from the power terminal to the 2 small terminal on the side to excite the alternator to charge. All my equipment has master switches so this keeps the batteries from being drained when I remember to turn the switch off.


the volt meters shows a good charge when the lights are on when the engine is idling. (volt)