01 / Occupational profile
Your 91H occupational profile
Motor pool and engine test noise
Common occupational factor
Running engines for diagnosis, impact wrenches, pneumatic tools, and overhead crane operations create sustained high noise levels in enclosed bays, and vehicle runs for testing add engine and track noise outdoors.
Heavy lifting and awkward-posture strain
Common occupational factor
Track sections, road wheels, and powerpack components are heavy and are often handled with hand tools, pry bars, and sledgehammers in cramped engine compartments.
Fuel, hydraulic fluid, and solvent contact
Common occupational factor
Repairing fuel and hydraulic systems and degreasing parts puts repairers in repeated skin and inhalation contact with diesel, hydraulic fluid, and shop solvents.
Outdoor and field recovery work
Common occupational factor
Recovery missions and field maintenance happen outdoors in all weather, sometimes in deployed desert or cold-weather environments.
02 / Your service
What did you actually do?
Your MOS is the starting point. Your actual assignment, era, equipment, location, and duties determine which parts of the occupational history are relevant. Use the Evidence Builder below to select your actual duties and see records that may corroborate them.
91Hs troubleshoot and repair tracked vehicle systems: diesel power plants and powerpacks, fuel and electrical systems, suspension and track components, steering and braking systems, and hydraulics. Track and suspension work means breaking and re-laying track, hauling road wheels, pressing bushings, and swapping torsion bars and sprockets by hand with pry bars and sledges. Powerpack jobs involve disconnecting linkages, lines, and harnesses, then lifting the engine and transmission out as a unit with a hoist. Recovery missions put repairers in the field dragging disabled vehicles back to the motor pool, often under time pressure and in poor weather. Garrison bay work and field or deployed recovery operations carry different noise, chemical, and physical-strain profiles.
63H was the designator before the mid-2000s CMF 91 consolidation folded track-vehicle maintenance into the 91-series codes as 91H. Duties, fleets, and the shop environment are continuous across the rename; the vehicle family and era served matter more than which code appears on the DD-214.
Duties that may vary by assignment
- Diagnosing and repairing diesel power plants, fuel, and electrical systems on tracked vehicles
- Removing, lifting, and reinstalling engine/transmission powerpacks
- Breaking, repairing, and re-laying track; replacing road wheels, sprockets, and torsion bars
- Servicing hydraulic, steering, and braking systems
- Vehicle recovery operations with winches and tow equipment
- Operating overhead hoists and heavy shop equipment in motor pools
- Field maintenance in mud, dust, and extreme temperatures
- Hydraulic fluid, solvent, and fuel contact during repairs
Related historical codes: Legacy 63H Track Vehicle Repairer (pre-consolidation designator)
Private, on this page only
Military Occupational Evidence Builder
Based on what you actually did in the military, what records might document it? Select only what applied to you. No name, file number, contact details, free text, or upload. Nothing is saved or sent.
Military service
Army · 91H Track Vehicle Repairer
For another specialty, open its guide from the MOS library. A job code alone does not establish individual duties or exposure.
Era(s) of service
Deployments
Already have a VA decision?
Your Evidence Builder identifies records that may document your service history. If VA has already decided your claim, the next question is different: what did VA accept, what did VA reject, and why?
Request a free decision review03 / Corroboration
Building your occupational history
Records matter because they can connect a job title to an individual's actual work and circumstances.
Motor pool and engine test noise
Records that may corroborate it
- · Hearing-conservation audiograms (DD 2215/2216) and DOEHRS-HC records
- · Assignment records placing you in a maintenance platoon or motor pool
- · Evaluations describing shop or field maintenance duties
Limit: Documented noise supports the in-service event only. A current hearing disability under 38 CFR § 3.385 or a tinnitus complaint, and a medical link, are still required.
Heavy lifting and awkward-posture strain
Records that may corroborate it
- · Sick call and physical therapy entries during the assignment
- · Line-of-duty or incident reports for a documented injury
- · Evaluations describing powerpack or track-maintenance duties
Limit: Typical track-maintenance demands do not by themselves establish that a specific joint was injured in service; a current diagnosis and medical opinion are required.
Fuel, hydraulic fluid, and solvent contact
Records that may corroborate it
- · Occupational health or hazmat-program records, if enrolled
- · Evaluations describing maintenance-bay duties
- · Unit safety or environmental records for the motor pool
Limit: The MOS does not establish contact with any specific chemical or the level of exposure. Facility, era, tasks, a current diagnosis, and a medical opinion all still matter.
Outdoor and field recovery work
Records that may corroborate it
- · Deployment orders and unit location records
- · Sick call entries for heat or cold injury
- · Evaluations describing field or recovery operations
Limit: Outdoor work alone does not establish a specific heat, cold, or skin-injury diagnosis; clinical findings and a medical link are required.
04 / Evidence standard
What your MOS can — and cannot — establish
May help document
Work performed, circumstances of service, consistency of an alleged exposure, and the nature or duration of duties where supported by individual records.
Does not automatically establish
A diagnosis, medical causation, severity, percentage, presumption, or entitlement to service connection.
05 / Medical evidence
Conditions that may be relevant to the occupational history
This is not a list of conditions to claim. A veteran's actual diagnosis and individual service record determine relevance; occupational evidence is not medical causation.
Hearing +
Tinnitus and hearing loss
Why the occupation may matter: Engine testing and shop tool noise are sustained features of track-vehicle maintenance.
Records and clinical evidence: Audiometry meeting 38 CFR § 3.385, service audiograms, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
Spine / joints +
Back, shoulder, and knee conditions
Why the occupation may matter: Lifting track sections and powerpack components in cramped compartments loads the back and joints repeatedly.
Records and clinical evidence: Current diagnosis, in-service treatment or duty records, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
Skin +
Skin conditions from fuel and solvent contact
Why the occupation may matter: Repeated hand and forearm contact with fuel, hydraulic fluid, and degreasers is part of routine repair work.
Records and clinical evidence: Current dermatology diagnosis, duty records, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
Hands / wrists +
Carpal tunnel and hand conditions
Why the occupation may matter: Repetitive use of impact tools and hand tools under load is a recognized mechanical demand.
Records and clinical evidence: Current diagnosis, nerve-conduction findings where applicable, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
06 / Exposure record
ILER and toxic exposure
For applicable exposure-related claims, VA may review the Individual Longitudinal Exposure Record (ILER) and a toxic exposure risk activity (TERA) memorandum along with deployment and occupational records. An ILER entry does not automatically establish exposure or service connection.
07 / After a decision
Why a 91H claim may still be denied
An exposure finding is not the same as a grant. These are examples from the researched guide, not predictions about a particular case.
VA may accept
A duty or event consistent with the service record
But may deny
A diagnosis, medical relationship, or rating element
Record to examine
Decision findings, service and private treatment records, examination rationale, and medical opinions.
Exposure described too generally
Statements like "I worked in the motor pool" without the vehicle family, bay type, and tasks are hard for VA to evaluate; MOS school records and evaluations may add the specifics.
No in-service complaint for joint pain
Mechanics often worked through strains without a sick-call visit; buddy statements and duty records may help fill that gap.
Hearing claim rejected on a normal separation audiogram
A normal exit audiogram alone does not decide a hearing claim, but examiners sometimes rely on it without addressing the full in-service noise history.
Oakridge Claims / Appeals Focused
Already have a VA decision?
The important question is what VA accepted, what it rejected, and why. A decision review considers the decision, examinations, and the complete record — including private and VA records that may need development. Oakridge is appeals-focused — core work is post-decision, but initial and new claims are accepted on a case-by-case basis (no fee for pre-decision work).
Fees for eligible post-decision representation are governed by a written agreement. See fee details. No outcome is guaranteed.
91H questions
Does my 91H or 63H MOS prove I was exposed to a specific chemical or noise level?
No. It documents the occupational field; the facility, fleet, and era you served in shaped the actual exposures. Assignment and training records may help document the specifics.
I have a 63H designator on my DD-214. Is that the same job as 91H?
Generally yes — 63H was the pre-consolidation designator for track-vehicle maintenance. The duties described here are the same occupational family; note both codes when compiling your records.
What records show which vehicles I actually worked on?
MOS school and OJT certification records, unit assignment orders, and evaluations describing your duties are the usual starting points.
Sources and legal references
General education only; not legal or medical advice. Oakridge Claims is a private business, not affiliated with or endorsed by VA. Nothing here establishes a representative-client relationship or guarantees a result. Free accredited VSO help is available.