1959 cat d4 7u questions

Better get yourself signed up on the ACMOC site. (Antique Caterpillar Machinery Owners Club). They love to go on and on about pony motors.

Old Magnet, I have ordered a book from ebay. Hopefully it will show all fill plugs and drain plugs. In the photo, is the drain plug directly below the larger fill plug? Or is it underneath? I have removed about a ton of dirt looking for plugs. lol At least it is getting a good cleaning. I am amazed at how well the engine starts and runs. It is almost like this D-4 had a complete overhaul shortly before it was left sitting in a field. Previous owner died suddenly and it was just left sitting there. Has sat there for 10 years. Thanks for your help. OT

This weekend I will try to remove the pony motor flywheel to get at the seal. 1 1/4" nut holds it on. I have a puller and hopefully it comes off easily. And hopefully, the book will shed some light on it as well. Will try to post more photos as I go along.

Look under the tractor. The FD plugs (same type as the rest of the drain plugs) are vertical on the back side of the FD case facing inward. Look for the bolted on semi circle shaped cover plate, that's where you will find them.

Ok so I have a family friend who wants me to do some grading with the dozer for him and the deal is he pays for fuel and will get me the oil to change the trans clutch and finals but I need to know what kinds and how much. I know 90wt for the trans and finals but not how much I also need to know both what kind and how much for the clutch.

Fill to?

Old Magnet said:

Yes, those are the fill plugs. If there is any water in there they would be overfull but you'd need to crack the drain plugs to check.

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Old Magnet, Service manual arrived. Unfortunately there are no fluid level specs. Can I assume that the fill plug on the FD is fill to top of fill plug as I can't find any overflow plug on the vertical FD plate. Thanks, OT

You are correct on the fill level for the finals. Lube info is to found in the "Operation and Maintenance Instructions" for the Caterpillar D4 s/n 6U1-up and 7U1-up. Form #12244-5 edition or higher. They usually show up on ebay.

Ive got a 49 & 7U serial 5382. I don't think the pony engine has a rear seal. I put rings in my pony engine 30+ years ago and I remember it didn't have cam bearings or a oil pump. I run the pony engine on a mixture of 50-50 lucas and 30 weight engine oil. There is a pinion gear and a latch that holds the pinion in contact with the ring gear when starting. you shouldn't have to hold the handle. Before starting the pony engage the starter pinion first. That keeps from grinding the pinion trying to engage it. You can unbolt the whole starter pinion & starting clutch assembly and remove it as a unit. If your finals are leaking In hot weather use as heavy of grease as you can find.

I remember back in the day my dad had a couple D4-7U's through the years. He or some one before would remove and replace the old button head fittings on the rollers and idlers with regular grease zerts, and just use modern grease, but only 1 or 2 pumps per day. The old button head always seamed to not connect right and leak while lubing.

how can I check the final drive oil if I have a hyster d4d winch on my machine I just bougth it year 1959 d47u thanks for any info mr septic

The two 1-1/4" plugs sticking out the back of the winch are now your new final drive fill plugs.