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New Cat owner. What year is my D7?

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2 months 5 days ago #230705 by kracked1
My guess is the clutch disks in the pony clutch are stuck together. You can run ATF in that compartment. It helps to keep the clutch disks from sticking due to the heavy oil originally put in there.

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2 months 5 days ago #230722 by edb
Hi,
these tutorials from Toby on the RD6 pony clutch repair should help--the D7 is essentially the same except the D7 had the 2 speed transmission--no room on the Rd6 for the Trans.






Hope these help.
Cheers,
Eddie B.

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2 months 4 days ago #230731 by trainzkid88
seal the welsh plugs with "stag" joint paste it cleans up with methylated spirits. or use hard setting form a gasket. the old method was to make a paste of litharge (yellow oxide powder) and glycerine. stag is easier to obtain any good industrial supply should have it.

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2 months 3 days ago #230763 by Larry B
I bet your right about the clutch discs being stuck together. I'm hoping some lubrication and slight persuasion will get it to free up. The videos of the disassembly and assembly help to understand what's going on in there. Had no idea those were called Welch plugs. Have to find the right size and some of the stag to get them put in. Gonna be a few weeks before I can get back at the dozer but hopeful to get the main motor turned over when I do.

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2 months 3 days ago #230768 by PhilC
Welch plugs are also known as freeze plugs and core plugs among other names. They were named after the inventor the Welch Motor Car Company not after the Welsh people. If the bore is in good condition and a new plug is tapped in correctly then they shouldn't need sealant but it is best to use some type of sealant just in case.

944A - Machine SN 43A2589 Engine SN 90A284
955K- Machine SN 71J3772 Engine SN 83Z0704
D6 SN's 4R732sp, 5R2724, 5R4832
D8 SN's 15A1254, 15A2287, 15A2723
The following user(s) said Thank You: trainzkid88

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2 months 3 days ago #230769 by trainzkid88
welch i think is the correct spelling not sure on that but yes they are also called freeze plugs here too. many things in engineering have different names depending on what part of the world your in and especially were said item was made.

plug and bottoming taps for instance what is often called a plug tap here is a bottoming tap in the US the difference a plug tap has a 1 thread taper a bottoming tap does not.
stag is available through j. blackwood & sons industrial suppliers

note: stag wont seal alcohol as that is the solvent it contains or Nitric acid, citric acid or ammonia and not suitable for oxygen as it is a oil product.

clean surfaces with solvent based cleaners if needed before application.

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