# Transmission Seal Replacement in Upland > Route 66 Auto Repair in Upland replaces leaking transmission seals, from axle seals to the front pump seal, and explains which ones need the unit removed. Source: https://route66autorepairshop.com/transmission-services/transmission-seal-replacement Updated: 2026-09-17 Business: Route 66 Auto Repair, 1775 W Foothill Blvd, Upland, CA 91786, (909) 608-7699 Hours: Monday to Friday 8 AM–5 PM, Saturday 8 AM–2 PM, Sunday closed **TLDR:** Seals range from **quick axle seals** to a **front pump seal** that needs the transmission out. We name the exact seal before quoting. Transmission seals keep fluid inside where shafts pass through the case, and Route 66 Auto Repair in Upland replaces them when they harden, crack or wear. There are several seals, and they differ a lot in effort. An axle seal can be a quick job. A front pump seal means removing the transmission. Our ASE-certified technicians identify which seal is leaking and explain the work before you approve it. ## Which transmission seals leak most often? - **Axle seals** on front-wheel-drive cars, where the drive axles enter the transmission - **Output shaft seal** at the rear on rear-wheel-drive trucks - **Front pump seal** between the engine and transmission - **Shift shaft seal** where the linkage enters the case - **Sensor O-rings** on speed and range sensors ## Why does seal location change the job so much? Axle seals are replaced after pulling the axle, which often needs a [wheel bearing](https://route66autorepairshop.com/drivetrain-and-additional-mechanical-services/wheel-bearing-replacement) and suspension check anyway. Shift shaft and sensor seals are reachable from outside. The front pump seal sits behind the torque converter, so the transmission must come out, and we often inspect the converter and pump bushing at the same time. We also ask why the seal failed. A worn bushing or bearing lets the shaft wobble and will ruin a new seal quickly. Those checks are part of the job. Rear seals on trucks are covered on [output shaft seal replacement](https://route66autorepairshop.com/transmission-services/output-shaft-seal-replacement). If you are not sure where your leak is, start with [transmission fluid leak repair](https://route66autorepairshop.com/transmission-services/transmission-fluid-leak-repair). ## Our seal replacement process 1. **Confirm the seal:** We trace the leak to a specific seal and photograph it. 2. **Check for shaft play:** The shaft, bushing or bearing behind the seal is checked for wear. 3. **Replace the seal:** The old seal is removed without scoring the bore and the new one is installed straight. 4. **Refill and verify:** Fluid is topped off and the seal is checked after a road test. ## What's included in seal replacement - Leak source identification with photo - Shaft and bushing play check - New seal of the correct type - Related parts removed and reinstalled as needed - Fluid top-off to the specified level - Road test and leak recheck ## Which seal leaks need attention now? **Need now:** - A front pump seal leak that is getting worse - An axle seal dripping on a brake or CV boot - Any seal leak dropping the fluid level **Need later:** - A shift shaft seal that is only damp - A sensor O-ring seep with a steady level ## How seal pricing works The seal part is usually small. Labor is the difference, and it depends on what must come off to reach it. The written estimate names the seal, the parts removed and the fluid. If we find worn bushings, we stop and call before adding them. Outside seals often finish the same day when the board allows. ## After seal replacement A little residue may drip for a day. Fresh spots after that are worth a return visit. If the transmission came out for a front seal, we check mounts and connections again at your next oil change. ## Frequently asked questions ### Can a seal leak cause transmission damage? Yes, if it drops the fluid level. Low fluid means slipping and heat. That is why we treat level-dropping leaks as need-now. ### Why replace the front seal with the transmission out? There is no other way to reach it. When it is out, we check the converter hub and pump bushing too, so the new seal lasts. ### Do axle seals come with a new axle? No. Seals are separate parts. If an axle is being replaced for a torn boot, replacing the seal at the same time is smart, and we will quote it. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.