We have a powersports dealership and recently got a JD 125…

The oil change itself If done properly with the specified oil covered in your models operation and maintenance manual, should not cause these type of symptoms. However, if there was already an existing problem forming before the service, it is possible that it became more noticeable and prominent immediately after the service.

Sounds good and you're very welcome.

Per website policy, those need to be on a new request. One subject  matter per request or questing thread.

This model machine was in production in 1983 to 1984. It is over 35 years old before the internet ever existed.Most of the manuals were paper copies and parts manuals either paper copies or on microfiche that eventually got transferred over in some cases but some parts may be discontinued or obsolete. This is not your typical common in the industry skid steer that is currently in use by contractors. This is an antique machine. There are likely very few out there that are still in operation. This being said, I would recommend having a copy of the manual on hand for this machine that you own before they are no longer are available.

Great news. I found you a PDF version manual for download for $60.00.

https://www.epcatalogs.com/john-deere-125-skid-steer-loader-tm-1167-technical-manual-pdf/

Click this link for the parts manual to reference for component locations. This should bring you right to the page showing the auxiliary hydraulic control foot control. There was also a hand lever option shown in the parts manual.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/79900/referrer/navigation/pgId/286984

Thank you for the updated information. Unfortunately, If one or the other is the failing component, the secondary component usually suffers damage and contamination from the initial. Anytime you have a failure within a hydrostatic drive system, all components should be sent out for bench service and at the very least re-bearing and reseal after inspection. If there is no metal contamination that looks like fine glitter in the oil and filter, you may be able to have a technician do a flow test for both pumps with a flow meter and have your pressures check confirm whether or not they are within factory specifications covered in this machine model and serial number service book. You can check for a faulty drive motor by checking for excessive case drain pressure. Push up against a loading dock or equivalent prevent travel and then had that drive motor with a hose running from the case drain port of the drive motor into an empty 5 gallon bucket. You should expect to see a very low volume of oil from the case drain when engaging travel with the drive motor deadheaded. It comes out under high pressure or volume, that drive motor is faulty and in need of rebuild or replacement.

That is great news and thank you for the follow-up and updated information.

You're very welcome and it was a pleasure working with you.