i got a d7-3t dozer, has the hydrolic blade, my issue is that the poney motor is missing parts, and shot, so im trying to go to direct start, only problem im having is this d7 has a 7m motor, so the clutch housing is not drilled for the 3 bolt hols for the adapter, iv seen some people do some odd stuf like hydrolic motor for sarting there big motor,exc... what im thainking of doing is using the pony trans and make a plate with a electric 12v or 24v motor on it and couple it to the shaft, , this way the electric motor is turning the tranny from the pony witch will turn the big motor, does this sound like it could work? my only consern is it wont have enough touque
I think if you could repair your poney motor it will be more heasy and I should have some used parts for it
well, i need the hole end housing were the governor bolts up, i need the governor, then i also need rings, and rod berings, and all the gaskets, the mag cap and wires, prob more, im kinda thainking all these parts are gonna run more then converting to electric start. one its home i can do more to it, being i just bought it and its 4 hours away
so any one got any thought on this, iv see a few different ways with hydrolic motors and what not
The conversion has been discussed before here on HEF. Here is a link to one of the threads. HeavyEquipmentForums A Google search for Caterpillar electric start conversion will come up with quite of few results for what you need. Here is another link you can check out. At the bottom of the D7 section of photos is a YouTube video of a D7 3t that has been converted to 24 volt direct electric start. http://www.tractorparts.com/cat.htm
Having worked with hydro start system on US Navy combat landing craft. They are JUNK the parts to support them are a pain you need a accumulator, a hand pump, engine driven pump, the accumulator has a pre charge nitrogen normally 3 t0 5000 psi it will loose its charge when you really need it and the hand pump will take about a thousand strokes and if it does not start the first time then you will spend a long time pumping up the accumulator. Not worth the trouble.
Are you the same "troy 21" that started the post on "Yesterdays Tractors"? Are you doing a survey?? The original pony is 24hp....the largest starter (50MT) is 12 hp....might get a run at it by spinning with compression released then load....might not. Plenty of 3T's have been converted with conventional installation. Other info is posted at that site.
The one hydraulic starter I had the unfortunate job of using,was on a GM diesel. I don't remember the size of the engine, but it was an inline configuration. The engine was mounted to a six inch water pump. I had to pump that stupid hand pump for what seemed like forever before it accumulated enough power to crank the engine. It was a nightmare gone bad because that GM never started on the first try.
i would just fix the pup engine.
Your easiest way out is to fix the pony motor.
well thanks guys for the info, i dont see the poney worth the time fixing right now, see ths is a machine i bought and its four hours away so i just need to start it to load onto a low boy so i can get it home
If all you need right now is to get it started either pull it or push it. If the blade is on the ground push or pull it backwards. I ran a D7 3t many years ago and the pony motor would not start. We push started it every morning. I parked it at night with the dozer blade on a railroad tie. Even though it didn't start on the length of the tie the blade would stay up long enough to get it started.
We put a 24v direct starter on our d7 about 5 years ago. Small shot of either in the air cleaner while it's turning over it fire's right up even when below freezing. The whole kit cost somewhere around 700 dollars at the time minus batteries. Been working great ever since. Kit came with starter and mounting plate. I think we had to modify the monting plate can't remember what we did without looking at it but I think we tapped some threads in it. Deffenitly recomend going with electric starter.
I converted a D8 a few years ago and It will start with a shot of either but its been a constent pain because the soilanid cant handle the load and it burns up the contacts and about every three years new batt just this fall I spendt 750 dollars on two batterys and a new soilnad Wish i would have fixed the pony motor. Razz.
if a pony motor runs properly i would rather have it than electric start on these older machines. i start my old girls alot in cold weather so the pup engine works great.
here is a link to an old thread about the conversion. Also here is a pony motor for sale on ebay http://www.ebay.com/itm/Caterpillar...661?pt=LH_DefaultDomain_0&hash=item20c072ecc5