Transmission Repair
Manual and automatic transmission diagnostics, rebuild, and replacement for Class 6–8 trucks and heavy equipment.
Overview
What We Do
Transmission problems don't fix themselves — and a slipping, grinding, or non-shifting transmission will sideline your truck fast. H&H technicians are experienced with the full range of heavy-duty transmissions found in commercial trucks and equipment. From fluid and filter service to complete rebuilds, we diagnose the root cause and fix it right.
Why It Matters
A failing transmission doesn't just sideline one truck — it disrupts your entire operation. Slipping gears, delayed engagement, and hard shifts are early warning signs that, left unaddressed, lead to complete transmission failure and costly tow bills. For fleets running routes across Central and South Texas, from San Antonio and New Braunfels to Corpus Christi and the oilfield corridors near Pleasanton, unplanned downtime is never an option. Proper transmission service at the right interval extends component life, protects your drivetrain investment, and keeps your trucks moving reliably mile after mile. At H&H Diesel Services, we diagnose the root cause — not just the symptom — so you get a repair that lasts.
Allison Automatics
Allison transmissions require specific TES 295 or TES 668 fluid and precise service intervals. We perform fluid and filter changes, solenoid replacement, and full rebuilds on Allison units.
Eaton Fuller Manual
The Eaton Fuller 10 and 18-speed are the backbone of the trucking industry. We rebuild worn synchronizers, replace shift forks, and restore proper shift feel and engagement.
Clutch Service
Clutch slippage, chatter, and hard engagement are diagnosed and corrected. We replace clutch packs, pressure plates, and release bearings and adjust linkage to spec.
Fluid Analysis
Transmission fluid tells a story. Metal particles, burnt smell, and discoloration all indicate internal wear. We use fluid analysis to catch problems before they become failures.
TCM Diagnostics
Automatic transmission control modules can cause shift problems that look mechanical but are actually electronic. We diagnose and reprogram TCMs as needed.
Driveline Inspection
Vibration and noise often originate in the driveline, not the transmission. We inspect U-joints, slip yokes, and carrier bearings as part of any transmission diagnosis.
Ready to Get Started?
Let's Get Your
Truck Back on the Road
Call us or send a message and we'll get you scheduled fast. No runaround, no upsell — just straight answers and solid work.