Hey folks I have watched several videos on repairing the pony engine but I have never come across one on taking the little fellers off. I’m working on a d2 4 U machine. My concern is the pony exhaust runs thru the diesel engines intake thru a tube. So would I take the pony exhaust off at the pony manifolds. I’m simply trying to get a plan before I start. As always I thank you in advance and I wish all a good day.  Mike Hudson 

Hi, Mike Hudson.
If my (limited) memory serves me rightly, the pony exhaust should unbolt from the Diesel air intake as well as at the pony motor so that you can get it right out of the way.

Just my 0.02.

the main air cleaner, air pipe, bonnet and dash, pilot fuel tank and controls have to be removed first. then you unbolt the pilot exhaust from the intake manifold and the upper coolant pipe before you can then unbolt the pilot engine itself. you should drain the coolant before starting the removal so you don't get coolant where it shouldn't be.

there is 4 nuts under the cylinders 2 each side that are 'fun' to get to, you need a open ender or ratchet wrench(have a spare spanner trust me. crack em with a ring spanner first).
then you can evenly pry it up free of the dowel pins.

these are heavy little bastards so have suitable lifting gear ready.
the output gear protrudes below the block so you need suitable timbers to sit it on. 3x2 is suitable.

a diagram of the bolt placement is in the parts book and service reference book.

From memory TK 88 there is 1 or 2 bolts around the front side between the pony and the main engine (yes in that tiny gap) blow the junk away with compressed air to find them, make sure these are out or you are in for a fight until the casting lets go, I used a few long socket extension bars to reach down from the top.

Thank you Mann I can imagine how difficult it will go back. But I’ve got quite a bit to do before I put it back. But it ain’t nothing but time

yes there is 2 bolts inbetween the main and the pilot engine need long 3/8 or 1/4 drive sockets and extensions to get to them. also need to hold you mouth the right way to get the tool onto them. installation would be a real pain in the arse.

Hi all, new member here working on the same Pony...only this 7U has a (front) cover casting that impinges on that center bolt....so much so that the last mechanic didn't or couldn't tighten it all the way...can't figure out why Cat would allow an employee to spend an hour on placing ONE bolt !!

I have used 1/4" drive ratchets with lengthy extensions to get at the bolts, not too difficult. Just a few curse words about engineers. If you don't have a hoist to lift out, a 2x10 board is handy to lay it and slide off to the side without breaking your back. Best of luck. JM

I have found a true universal joint socket, NOT the extension universal joint, work a much better. Have not attempted that bolt on a D4, but very similar on a D6 .Another trick is a heavy grease in the socket to hold bolt in as you reach in to start it.