Hi forum. I am currently purchasing a Cat 17a dozer which runs the pony engine for starting. The previous owners have had a lot of trouble with starting the pony engine and I wish to change it out for the starter motor conversion. I run a Cat D7 3T dozer which has the 24 volt starter motor conversion running a Delco Remy 40MT starter motor with the 11 tooth helix gear. Is the conversion plate and the flywheel ring gear the same for the 17a ? I understand it is a different engine with higher horsepower for the ripper attachment.
Starter conversion for the 3T is different than the 17A. You can buy a ready to go conversion off ebay, just be sure to request the RH helical pinion. It is a direct bolt up to the outer diameter bolt circle.....or you can convert a 50MT starter yourself if you get the pinion and drive end conversion housing. https://www.ebay.com/itm/NEW-50MT-P...ash=item19d37f3f6e:g:TGUAAOSwSrNaDHVA&vxp=mtr
How will you use the dozer? Are you sure you don't want to stick with a pony motor, either fix what's wrong with the one on there, or convert it to a Honda? The Amish around here will use a honda instead of batteries to start their big diesels, even if the batteries and electric starter are not "verboten". Typically it's a belt drive to the armature of a starter. Just throwing the idea out there if that's something that would fit with the way you want to use the dozer, that is, more hassle to start up if you use it often, but cheaper and easier than changing batteries if you let it sit too long etc. or only start it occasionally.
Thanks Delmer for your input. My D7 3T has no charging circuit for the batteries. The pair of 12 volt 150 batteries start it several times a day with no problems. This is used on a prospecting lease. I have rigged up a solar charging station when I am not here and remove the batteries from the dozer and place them on charge. The ground here is quiet hard and the 3T blade skims over the ground in places. This is why I am purchasing the 17a with the ripper. Sounds like a lot of effort for the Honda fitment.
Thanks Old Magnet, the conversion on the 3T is a bolt on adaptor plate which has a profile on the back which fits into the main hole and the front of the plate is bigger and fits over the 3 bolt holes and is bolted in place. It has then been machined to take the starter motor. Are the hole centres and hole in the bell housing different.?
Yes, I am aware of the 3T bolt pattern and adapter. The 17A bolt pattern is symmetrical and does not require an adapter plate like the 3T. Just makes use of the larger diameter bolt circle which is accommodated by the conversion drive end housing. You can see the outer bolt ring in the picture here that still has the pony in place
Here is what you are looking at for starter mounting. The 17A (same as 14A D8) is pictured here. Completely different hole patter and flywheel housing hole size than the 3T.
swear at my old 17a every year at the first start up post winter . What are you going to use for heat ? fella told me there is a conversion for the heads to take glow plugs . I gave up on the idea and go through a number of steps starting with renewing the insulation tape on the end of the magneto spindle under the rotor cap , point clean etc etc . Its often lunch time before its going just in time to shut the beast down . From then on its a short two minute job to start till heavy rain wets the mag , repeat post winter tricks . Pony motors are a kind way to start a diesel motor , I'm sure it must help old Caterpillars live longer than instant key starting machines .
Cheers for that. It is a lot more clear now with the photos. I have to get the old Cat going and drive it about a mile out of the bush to the main road and be able to load and unload on the low loader. I will have a go trying to start the pony engine. The spare engine I purchased for the 3T had the pony engine still attached which I have removed for the rebuild. It seems the carby is very worn from vibration from the dozer operating. I think this is the issue with the 17a. I will look further into it.