doing a rebuild on a 504 gas engine

jehepe · Jan 17, 2015

hello I am a first time poster here I,m looking for a little info on a 504 gas engine rebuild that the owner of the farm that I work at asked me to do. I have no info on this engine at all, and anything will help me get it done.
I just found out that the motor is not wet sleeved like I thought it was.that means that I'm going to hone out the cylinders. and In have a question about doing the rear main seal do I have to split this apartto do it.
thank you in advance
pete

Janicholson · Jan 17, 2015

I believe the split is needed. The cylinders should not have more than .005 taper (wear) measured at the top of the top ring travel. If you can feel a ridge there with your fingernail it should be measured. If OK the ridge must be reamed/or machined out to assure that the top ring will have a place to break in. Check piston ring grooves for wear and clean them to metal (depth). There may be a source for oversized pistons, but they would be pricy. Best of luck. Jim

Cory Schmidt · Jan 17, 2015

Like any other tractor for rear seal replace splitting is needed to remove clutch/flywheel... to get at the seal. If you have a lot of blocking and a pallet jack( or some type of hoist), the whole front and engine can be removed as a unit. Just block up from pallet jack to frame rails/engine and under rear end, remove bolts and anything else in the way, and slide apart. If you have a hanging hoist or loader chain assembly tight, near back of engine/frame rails and remove carefully. Block securely when off and working on it. Did this method to split on Farmall706, Cub, A and JD2440 (maybe others, just don't recall). Didn't have any problems yet.

jehepe · Jan 18, 2015

(quoted from post at 18:56:47 01/17/15) I believe the split is needed. The cylinders should not have more than .005 taper (wear) measured at the top of the top ring travel. If you can feel a ridge there with your fingernail it should be measured. If OK the ridge must be reamed/or machined out to assure that the top ring will have a place to break in. Check piston ring grooves for wear and clean them to metal (depth). There may be a source for oversized pistons, but they would be pricy. Best of luck. Jim

thank you for the info

El Toro · Jan 19, 2015

Measure those cylinders for wear, it may need to be bored oversize. They used those tractors where I worked for mowing off the artillery ranges
and had a heavy shelter made from armor plate to protect the drivers. They were pulling wide rotary mowers and when they started to use a lot of oil they had the engines torn down and it cost too much money to rebuild them so the US government decided to send them to property disposal to be sold. Hal

Duner Wi · Jan 19, 2015

Pistons if you happen to need them pistons seem to cost about twice what a piston/sleeve assembly would cost for engine with sleeves.
C113 ,C123,C135,C146, and C153 seem to share some parts. I found kits starting at over $1,000.00.
Pistons each up towards $200.00 and more each.

jehepe · Mar 29, 2015

Well thanks again to all. I'm writing in to up date on the rebuild. I did split the tractor, took the engine out and had it over sized at a locale machine shop. They put it all together for me and even though it cost a bit but time wise, it was worth it. I'm putting the thing back together and I noticed that the cam and governor gears were pretty chewed up from old age. My question now is can the cam gear be removed and installed without removing the cam?I found new parts to replace them with at a good price and I talked to the sales men about it. He told me that it can be done by removing the gear with a gear puller and heating up the new gear to 300F. I'm looking at the gear and there seems that there is no room to get the puller in there. Any thoughts on this..I am open to all ideas and any experiences you might have to share..thanks again.

Owen Aaland · Mar 29, 2015

When I overhauled my C-153 35 years ago .010" pistons were still available. I had one cylinder bore that didn't quite clean up 100% at .010" over but I went with it like that figuring that I could get at least one more overhaul out of the block without resleeving it.

doing a rebuild on a 504 gas engine

jehepe

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Janicholson

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Cory Schmidt

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jehepe

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El Toro

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Duner Wi

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jehepe

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Owen Aaland

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