Army · Combat service support — maintenance
91B Wheeled Vehicle Mechanic VA Disability Claim Guide
Army 91B Wheeled Vehicle Mechanics work in motor pools performing maintenance and repair on tactical vehicles ranging from HMMWVs to heavy cargo trucks. The job combines chemical exposure — solvents, fuels, degreasers — with awkward-posture work under and around vehicles, impact-tool use, and sustained motor-pool noise. This guide describes what the 91B occupational record typically shows and where these claims tend to run into adjudication problems.
Educational only. A military occupation is not presumptive evidence and does not establish service connection, a diagnosis, or a rating. Last updated 2026-09-06.
What 91B duty actually involved
Mechanic duty is shop- and bay-based: diagnosing and repairing engines, transmissions, brakes, and electrical systems on tactical vehicles, often working from beneath or inside a vehicle in cramped, awkward postures. Cleaning parts with solvents and degreasers, working with petroleum, oils, and lubricants (POL), and running pneumatic and impact tools are daily tasks. Vehicle recovery and field-maintenance operations add outdoor exposure to running engines and, during deployment, austere-environment repair work with less ventilation and fewer controls than a garrison motor pool.
- Diagnosing and repairing engines, transmissions, brakes, and electrical systems on tactical vehicles
- Working in awkward and prone postures under and around vehicles for extended periods
- Cleaning parts and components with solvents, degreasers, and other petroleum-based products
- Operating pneumatic and impact tools, generating hand-arm vibration
- Handling batteries, fuels, and hydraulic fluids during routine maintenance
- Working in motor-pool bays with sustained running-engine and tool noise
- Field and recovery maintenance in less controlled, sometimes outdoor conditions
Also covers: 45B/63B (legacy mechanic designators consolidated over successive reclassifications)
What this occupation may help establish
Each item below supports the in-service event or exposure element only, and only when the veteran's own records back it up.
Solvent and petroleum-product exposure
Daily use of degreasers, cleaning solvents, and petroleum products for parts cleaning and lubrication is a defining feature of motor-pool maintenance work.
Records that corroborate it
- · Motor-pool duty assignment records and shop job descriptions
- · Hazardous-material or hazard-communication training records
- · Material safety data sheets on file for the unit's motor pool, where available
What it does not establish: Working in a motor pool does not by itself establish a specific skin, respiratory, or neurological condition; a current diagnosis and an opinion connecting it to solvent exposure are still needed.
Hand-arm vibration from impact and pneumatic tools
Regular use of impact wrenches and pneumatic tools exposes mechanics to hand-arm vibration, associated in occupational-health literature with peripheral neuropathy and joint symptoms in the hands and wrists.
Records that corroborate it
- · Tool issue and maintenance-bay assignment records
- · Sick-call entries describing hand numbness, tingling, or joint pain
- · Physical profiles (DA Form 3349) if issued for hand or wrist complaints
What it does not establish: Tool use alone does not establish a diagnosis of peripheral neuropathy or carpal tunnel syndrome; current nerve-conduction findings and a nexus opinion are still required.
Awkward-posture and overhead/underbody work
Working under vehicles and in cramped engine compartments requires sustained kneeling, crouching, and overhead reaching, which are recognized mechanical stressors for the back, shoulders, and knees.
Records that corroborate it
- · Job-book or maintenance-task records showing frequency of underbody and overhead work
- · Physical-therapy or orthopedic referrals during service
- · NCOER narrative describing shop duties
What it does not establish: This posture pattern does not by itself establish a joint or spine diagnosis; current examination findings and evidence of onset during service are still required.
Motor-pool and tool noise
Running engines, pneumatic tools, and impact wrenches in an enclosed shop bay produce sustained noise levels that can exceed hearing-hazard thresholds.
Records that corroborate it
- · Hearing-conservation audiograms (DD 2215/2216) if enrolled
- · Shop assignment records
What it does not establish: Shop noise exposure alone does not establish a hearing-loss disability under 38 CFR § 3.385.
Battery, fuel, and hydraulic-fluid handling
Routine battery servicing and fuel or hydraulic-fluid handling exposes mechanics to caustic and petroleum-based substances during normal maintenance tasks.
Records that corroborate it
- · Hazardous-material training and handling records
- · Treatment records describing skin irritation or chemical burns, if any occurred
What it does not establish: Routine handling of these substances does not by itself establish a skin or systemic condition; documented incidents or a supporting medical opinion are still needed.
Conditions that commonly arise from these duties
This is not a list of conditions to claim. It is a record-driven view of why the occupation may be relevant and what evidence VA looks at. Only you and your treating providers can identify what you actually have.
| Body system | Condition | Why the occupation matters | Evidence VA weighs |
|---|---|---|---|
| Skin | Contact dermatitis and other skin conditions | Daily contact with solvents, degreasers, and petroleum products is a recognized cause of occupational skin irritation. | Current dermatological diagnosis, treatment records, and documentation of the specific products handled. |
| Peripheral nerves | Peripheral neuropathy, carpal tunnel syndrome | Sustained hand-arm vibration from pneumatic and impact tools is associated with nerve compression and vibration-related neuropathy. | Current nerve-conduction study findings, tool-use records, and a nexus opinion addressing vibration exposure. |
| Lumbar/cervical spine | Lumbar and cervical strain | Prolonged awkward postures working under vehicles place cumulative strain on the spine. | Current imaging, in-service sick-call records, and documentation of underbody work frequency. |
| Shoulders | Rotator cuff pathology | Repeated overhead reaching into engine compartments is a mechanical stressor for the shoulder. | Current diagnosis with range-of-motion findings and job-book documentation of overhead work. |
| Hearing | Tinnitus and hearing loss | Sustained shop-bay noise from running engines and tools contributes to cumulative noise exposure. | Current tinnitus report or audiometry meeting 38 CFR § 3.385 and shop assignment records. |
| Respiratory | Asthma and chronic bronchitis | Inhalation of solvent vapors and exhaust in an enclosed shop bay is a plausible respiratory stressor, particularly where ventilation was limited. | Current pulmonary testing, documentation of shop ventilation conditions, and a nexus opinion. |
| Knees | Degenerative arthritis | Sustained kneeling and crouching to access vehicle undercarriages is a recognized mechanical stressor for the knees. | Current diagnosis with range-of-motion findings and job-book documentation of kneeling frequency. |
Your occupational claim profile
Tick what actually applied to your service. Nothing is stored or sent — this builds a records list you can copy and take to your provider or representative.
Records that corroborate an occupational history
- DD-214 (Member 4 copy) — Primary specialty, awards, badges, and deployment remarks.
- Complete service treatment records — Sick-call entries, profiles, and separation examination.
- Personnel file (OMPF / enlisted record brief) — Every assignment, duty code, and date you served in it.
- Hearing-conservation audiograms (DD 2215 / DD 2216) — Baseline and periodic tests document noise-hazardous duty and threshold shifts.
- Current medical records with a diagnosis — A current disability is required regardless of what the service record shows.
- A medical opinion connecting the condition to service — Occupational history supports the opinion; it does not replace it.
- Lay and buddy statements — Fill gaps where nothing was written down at the time.
- Shop job books / maintenance task records — Document specific tasks and frequency relevant to posture and chemical claims.
- Hazard-communication training rosters — Support solvent and chemical-exposure claims.
An occupational history supports the in-service event or exposure element of a claim. It is not presumptive evidence, it does not diagnose anything, and it does not establish service connection on its own.
Why these claims get denied
Denial language tells you which element of the claim failed. These are the patterns that recur in decisions on 91B claims.
Skin condition attributed to a non-service cause without addressing solvent exposure
Examiners sometimes attribute dermatitis to a general or unrelated cause without discussing the veteran's documented daily solvent contact, which can make the opinion inadequate.
Peripheral neuropathy claim denied for lack of tool-use documentation
Because vibration exposure from hand tools is rarely logged individually, claims without job-book records or lay statements describing daily tool use are more likely to be found unsupported.
Joint claims discounted for absence of a single injury event
Cumulative-trauma mechanisms from years of kneeling and overhead work are sometimes overlooked when an examiner looks only for a discrete in-service injury.
Respiratory claim denied for insufficient specificity about ventilation and chemical exposure
General motor-pool service without documentation of specific products used and ventilation conditions can be found too vague to support a nexus opinion.
Hearing loss denied despite documented shop-bay assignment
As with other combat-service-support MOSs, VA sometimes finds mechanic noise exposure less probable absent range or hearing-conservation records, even where shop noise was significant.
VA accepted my exposure but still denied me
This is the most common outcome for occupational claims: VA concedes what the job involved, then denies on the medical link, the current-diagnosis element, or the rating criteria. A decision review looks at which element the decision actually turned on and what evidence would address it. Oakridge Claims focuses primarily on post-decision representation — Higher-Level Reviews, Supplemental Claims, and Board appeals — and also accepts initial claims and claims for increase based on case fit and current availability, at no fee for initial-claim representation.*
*No fee is charged for representation before VA issues an initial decision. If representation continues after an initial decision, fees may apply to eligible post-decision representation under a written VA-compliant fee agreement. See Fees for details.
91B claim questions
Does being an 91B automatically qualify me for a skin condition claim?
No. The MOS supports the exposure element — daily solvent and petroleum-product contact — but a current dermatological diagnosis and a nexus opinion are still required.
I have hand numbness from years of using impact wrenches. What should I document?
A nerve-conduction study establishing a current diagnosis, and records or lay statements describing how often and how long you used vibrating tools, are the key pieces of evidence to gather.
Can motor-pool noise support a hearing loss claim even without range records?
It can, but the claim is stronger with documentation — hearing-conservation enrollment, shop assignment records, or lay statements describing daily noise exposure — since mechanics are not automatically presumed to have hazardous noise exposure the way infantry are.
What if I don't remember which specific chemicals I used?
Unit hazard-communication training records and general product lists for that era's tactical-vehicle maintenance can help reconstruct exposure; your own detailed description of tasks is still competent evidence.
Does field or deployed maintenance work differ from garrison motor-pool duty for these claims?
Field and recovery maintenance often involves less ventilation and fewer controls, which can be relevant to a chemical-exposure argument, but the same evidence requirements apply either way.
Is knee pain from kneeling under vehicles worth discussing with a provider?
Sustained kneeling and crouching to access undercarriages is a recognized mechanical stressor in this occupation, so persistent knee symptoms are reasonable to raise and document.
Related occupations
Sources
VA accepted my exposure but still denied me
This is the most common outcome for occupational claims: VA concedes what the job involved, then denies on the medical link, the current-diagnosis element, or the rating criteria. A decision review looks at which element the decision actually turned on and what evidence would address it. Oakridge Claims focuses primarily on post-decision representation — Higher-Level Reviews, Supplemental Claims, and Board appeals — and also accepts initial claims and claims for increase based on case fit and current availability, at no fee for initial-claim representation.*
*No fee is charged for representation before VA issues an initial decision. If representation continues after an initial decision, fees may apply to eligible post-decision representation under a written VA-compliant fee agreement. See Fees for details.