Is there a possibility of excavator junkyard anywhere, mine is a 15 bolt pattern and the newer ones are 14 I learned this the hard way of course
Are you referring to the number of final drive mounting bolts to the track frame ? You have a machine serial # ?
12h-24560
I see no serial # breaks at all for the track frame or the final drive for a sn # prefix 12H EX120. Are there any casting #’s on the flange / housing that bolts to the track frame ?
I've got the model n serial off the final
Is that info from the model / serial tag on the propel motor ?
What was the part # that was ordered / supplied ?
Yes
hey, I plugged the information into an AI (Claude and Grok) and hoped for a miracle. Claude fell flat, Grok provided a bit of information -but it ended with 'try a salvage yard', lol. Thank you for providing that specific information. The part number HMGC16CA and serial # 089-12254 for your 1990 Hitachi EX120 excavator's propel motor gives us a much better starting point. Based on my knowledge of hydraulic components from this era: The HMGC16CA appears to be a Hitachi travel motor from their HMG series. This specific designation indicates: HMG: Hitachi Motor Gearbox series C: Likely indicates the generation/series 16: Displacement size class (likely in cc/rev) CA: Variant specification (could indicate mounting style, port configuration, etc.) For cross-compatibility, here are some potential matches worth investigating: John Deere equivalents: AT190058 or AT215962 (used in Deere 120/490D models) The Deere 120 and 490D would be the most direct equivalents to your EX120 Aftermarket options that may be compatible: Nabtesco GM18VL or GM21VA series (many aftermarket suppliers carry these) KYB MAG-33VP (commonly used as replacements for Hitachi motors of this era) Other possible OEM cross-references: HMGF15/16 series (later Hitachi versions that might be adaptable) Isuzu-manufactured hydraulic motors with similar specifications When searching for these alternatives, verify: The 14-bolt mounting pattern Hydraulic port locations and sizes Input/output shaft specifications Brake system compatibility (if applicable) Have you contacted any heavy equipment salvage yards? They often have these older components or might know of compatible substitutions across brands. Additionally, hydraulic repair shops that specialize in excavator components might be able to rebuild your existing unit or suggest adaptations to make a more readily available 15-bolt variant work with your machine. Anyway, thought I'd paste the whole response since it did get some other numbers... impossible for me to say if they are useful or not.
The info on the propel motor tag only pertains to the propel motor not the complete final drive. The EX100, EX120 and Deere 490D final drives all use a 15 bolt mounting pattern to the track frame. I did find there is a serial break on EX120 final drive which pertains to the gear reduction ratio only. The final drive reduction ratio was lowered at EX120 machine ser # 18867 and higher. The complete final drive you need is used on EX120 machine serial # 18867 and higher and Deere 490D machine serial # 014961 and higher. The same final drive components (except the motor) are used on EX100 machine serIal # 21752 and lower. Should help with your search of the scrapyards.
Contact Head Equipment in Moss Tennessee if anyone has parts for those older Deere/ Hitachi excavators they most likely will. 931-258-3653.
Thanks for the info, I'll call them
I'm exploring options if I can't find a 15 bolt pattern drive, I hate to go thru all the trouble of welding another plate and switching it over to a 14 bolt pattern, I bought a burnt machine at scrap price and already got a ex-2 drive, the third hose is supposedly high and low speed I hope I can cap off
I really appreciate all yalls help, I made some mistakes but we do that in life trying get out cheaper, mine was buying a old machine but I'll get thru it because I'm too hard headed to give up
What’s actually wrong with the original EX120 final drive ? What model -2 is the burnt machine ?
That was dead end he didn't have anything The drive on the 120 had been taken apart and was in a bucket, everything on the sprocket side anyway, the burnt machine was a ex100-2
Is there any gear oil in the 100-2 final drives ?, maybe drain the oil and check for sparklies. I agree , installing an EX100-2 final drive would be a huge amount of work with unknown results. If you haven’t already done so, I would try and determine what all is required to get the original final drive operational. Are any major final drive parts missing or obviously damaged ? Does the hydraulic motor on the side without the sprocket etc. turn in both directions ?
Far as I could tell the travel motor is fine, looks like gears broke on the drive itself, only way I could rebuild it is to find out what's missing by looking at other side with cap off, I'm pretty sure it's missing a center shaft
See screenshot below of final drive breakdown.
I did a search for pinion shaft number 37. T2300648, jdgfarmworks.com shows to have three in stock. they are out of Brentwood New York.
OP’s EX120 sn # is 24560 . Final drive serial break is at EX120 machine serial # 18867 and higher or Deere 490D machine serial # 014961 and higher. Proper part number for item 37 is # 2022128 .
Far as I could tell the travel motor is fine, looks like gears broke on the drive itself, only way I could rebuild it is to find out what's missing by looking at other side with cap off, I'm pretty sure it's missing a center shaggy Thanks this helps allot, unfortunately it looks like half these internal parts are missing, ones that ain't have broke teeth
Fridayparts shows that part number to be in stock.
Thanks I'll look at it
Hey Samsstuff I know this is an older thread, but did you end up finding a gearbox for your machine?