Four problems related to differential unit have been reported for the 2003 Toyota Tacoma. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Toyota Tacoma based on all problems reported for the 2003 Tacoma.
Rust out of the differential cover. All of the oil in the differential leaked out. No parts are available from Toyota. The complete differential must be replaced at a cost of over $ 1,000. 00. This is a major problem as per many Toyota forums on the net. Toyota will not stand by this repair and will not admit to any problem about rust.
Differential made a bad noise at 21,221 miles checked gear lube only to find it empty. Took it to Toyota city where they said it was fine. Took it to independent repair shop, said obvious leak on pass. Side end of diff, axle. I had 15,000 mile service done at Toyota city ($165. 00), they never checked the diff, gear lube even though the owners maintenance book says to inspect diff, gear lube. (no repairs were even attempted at Toyota city). Brought the missed diff. Fluid check to cust. Service reps attention, said she will talk to service department, a month later, and still no reply .
Truck always pulled to the left since new, took it in to Toyota dealer 4 times, they said nothing is wrong with it. At 21,000 miles I heard a bad noise coming from the differential, I pulled over and removed the fill plug only to find no oil in it. So I put in 4 oz. Short of a quart of 80w90 gear oil. (pulled to left because a wheel bearing wasn't getting and lubrication). Returned to dealer, they said we can't find a leak, 50 miles later I pulled the fill plug and found the oil to be black as can be with metal in it. Dealers answer is to come back when it breaks. So now I am stuck with a 2003 Tacoma with a 200,000 mile differential. (what a shame).
At 21,000 miles heard loud noise for differential, and bad glunk when leaving stop light, Toyota never put in gear lube to cover up the bad welds on right end of differential (that would have leaked if they did put in gear lube), no reply from e-mails, phone calls, talking to cust. Rep, (requested arbitration forms by phone and e-mail 6 times, never received them even though Toyota lied and said they will send them. ) .