8 Causes of Transmission Fluid Leaks (and Repair Costs)

If you notice a small puddle of red fluid underneath your vehicle, this is not a good sign and likely indicates a transmission fluid leak. It will form stains on your driveway or garage floor but more importantly, it can cost you a lot of money in repairing the leak and replacing the fluid.

To understand the reasons behind leaking transmission fluid and the cost to repair it, keep reading.

transmission fluid leak

Common Causes of Transmission Fluid Leaks

Your transmission may leak because of minor issues or critical ones. Despite the type of problem that it is, you should never let a leaky transmission wait. Get it checked right away.

If you continue to delay a minor repair, the problem will only get worse and cost you more money to fix. Here are some of the most common causes of transmission fluid leaks.

#1 – Loose or Stripped Drain Plug

If your transmission’s drain plug or bolts aren’t tightened properly, it could lead to a leak. This often happens right after a transmission fluid change.

Sometimes, over-tightening can strip the plug or bolt, also causing a leak. This also can happen when you start with a slightly loose plug/bolt (an easy fix) and you end up over-tightening and stripping the plug bolt (a more difficult fix).

In either case, under-tightened or over-tightened, fluid can escape through the drain plug area.

Read Also: Transmission Fluid Flush vs Change (What’s the Difference?)

#2 – Damaged Transmission Pan

transmission pan leaking

Transmission pans can develop leaks over time. This usually happens due to corrosion, especially in older vehicles or those driven in areas where roads are salted.

Manufacturing defects, though uncommon (especially with OEM parts), can also lead to weak spots that eventually leak. In some cases, impact damage from road hazards (such as running over a curb or very large rock) or improper jacking of the vehicle might dent or crack the pan.

#3 – Worn or Cracked Transmission Seals

An automatic transmission relies on various seals to maintain hydraulic pressure. However, over time, these seals can crack and deteriorate over time, especially when being frequently exposed to high temperatures or using the wrong transmission fluid.

Common locations for seal failure include the input shaft seal, output shaft seal, shifter housing seal, tail housing seal, speedometer input seal, and valve body.

In addition, overfilling your transmission fluid can cause excessive pressure in the system and force fluid past the seals, mimicking a seal leak.

Related: 4 Symptoms of a Rear Main Seal Leak

#4 – Faulty Transmission Pan Gasket

transmission gasket leaking

The gasket on your transmission pan can leak due to damage, manufacturing defect, bad gasket alignment during the previous install, or simply long-term wear from constant exposure to hot temperatures.

Fortunately, the pan gasket is relatively cheap to replace and DIY replacement is possible. It’s best to get a new one put in ASAP as more serious problems will likely soon follow.

#5 – Damaged Transmission Fluid Lines

The fluid lines of a transmission are typically made of either steel or aluminum and carry fluid between the transmission and the cooler. While generally durable, these lines can develop problems from:

  • Corrosion (if you drive where road salt is used or near the ocean)
  • Damage from large road debris
  • Repeated exposure to extreme heat cycles
  • Wear at the connection points (to transmission or cooler)

#6 – Faulty Transmission Pump

The transmission pump circulates fluid throughout the system. If it fails, it can cause fluid leaks. Worn pump gears, damaged seals, or a cracked pump housing are common issues. In addition to fluid leaking, signs of a faulty pump include smelling burnt fluid, transmission slipping, and unusual noises.

Like many transmission related issues, replacing a transmission pump is complex and usually requires removing the transmission, so it’s best to leave this job to the professionals.

#7 – Damaged Torque Converter

torque converter failure

The torque converter is responsible for propelling transmission fluid throughout the system. If the torque converter develops a crack in its housing or has damaged internal components (such as needle bearings), it can leak transmission fluid.

Torque converter issues are typically complex and require specialized tools and expertise to diagnose and repair. Due to the converter’s location within the transmission system, replacing it usually involves removing the transmission from the vehicle. For these reasons, torque converter repairs are generally best left to the pros.

#8 – Cracked Transmission Case

Transmission cases, while quite durable, can develop cracks that lead to fluid leaks. This might happen due to severe impacts, extreme overheating, or rarely, manufacturing defects. Very old transmissions may also develop stress cracks after years of use.

With a cracked case, significant, visible leaks and rapidly dropping fluid levels are the norm. Repairing a cracked transmission case is a major job, and in a lot of cases, it makes more sense to replace the entire transmission.

Typical Cost to Fix a Transmission Fluid Leak

Because of the variety of different causes and severities, the cost to repair a transmission fluid leak varies widely. Simple fixes like replacing a drain plug, pan gasket, or transmission seal might cost between $200 and $450, including parts and labor.

But more complex issues can be significantly more expensive:

  • Repairing damaged fluid lines: $300 to $800
  • Replacing a failed transmission pump: $800 to $1,500
  • Fixing/replacing a cracked torque converter: $600 to $1,200

If the transmission case is cracked or there’s severe internal damage, a full transmission replacement might be necessary. This can cost anywhere from $1,500 to $3,500 for a rebuilt transmission, or $3,000 to $8,000 (or more) for a new one, depending on your vehicle make and model.

Keep in mind that these are estimated ranges. The actual cost can vary based on your location, the shop you choose, and the specific requirements of your vehicle. Always get a detailed quote from a reputable mechanic before proceeding with repairs.

See Also: Average Cost of Transmission Filter Replacement

Locating the Leak

When you bring your vehicle to a mechanic for a suspected transmission fluid leak, they’ll typically follow a systematic approach to diagnose and locate the source of the leak:

  1. Visual Inspection – The mechanic will first look for signs of leaks around the transmission, checking for red or brown fluid stains or wet spots. They’ll examine the transmission pan, seals, gaskets, and surrounding areas.
  2. Fluid Level Check – They’ll check the transmission fluid level and condition. Low fluid levels can indicate a leak, while dirty or burnt-smelling fluid may indicate a different transmission issue.
  3. Dye Test – If the leak isn’t obvious, the mechanic may add a fluorescent dye to the transmission fluid. After running the engine and driving the vehicle, they’ll use a UV light to trace the dye’s path and pinpoint the leak’s origin.
  4. Pressure Test – For hard-to-find leaks, the mechanic might perform a pressure test. This involves pressurizing the transmission system to reveal leaks that only occur under specific conditions.
  5. Component-Specific Checks – Based on initial findings, the mechanic may focus on specific components like the torque converter, seals, or fluid lines for closer examination.
Mark Stevens

82 Comments

  1. Hi,I am driving a jeep grand Cherokee, now it shows transmission leak when driving, when car stop there is no leak in the garage but when car moving it shows smoke and oily in the exhaust system,and when I drive it takes time to change from one gear to the other.
    Please help,what can be the cause and how to fix.

    1. You’ll have to determine the source of the leak, then replace the leaking seal. Seals are cheap to replace, but sometimes require a bit of labor.

  2. My Pontiac Bonneville was snatching and hesitating changing gears after I had to stop at red lights! I checked the fluid while motor was hot and ran it through all gears then added 1guart of fluid! It was still not full but I drove it maybe 150 miles before it again started snatching and not wanting to change gears! The fluid also was down again. What does that sound like as far as repairing?

    1. Can you tell if you have a transmission fluid leak? Repair cost depends on how early you caught the issue, I think. Best case, it’ll be pretty cheap to refill the transmission fluid (and patch whatever transmission leak they find while they’re in there). Worst case, you might need a transmission rebuild or a new transmission.

  3. My Paljero has autotransmission fluid leak and is now overheating dipstick shows empty
    Elizabeth

  4. I have a 2004 ford taurus. I just noticed a huge puddle of transmission fluid underneath my car. I didn’t notice any leaking like a week ago. My car is shifting fine. Would you happen to know where it sounds like it’s leaking from?

    1. No idea from just that description. You’ll have to get under the car and look at where the leak is coming from or hire a mechanic to do it. Check the transmission fluid level to make sure you aren’t low.

      If you have hydraulic power steering, you should also check the power steering fluid reservoir. Many power steering systems use automatic transmission fluid (ATF).

  5. I’m having my f250, 5.8 cub 351/W
    Rebuild, the mileage is 240k , I was told the torque converter should be replaced I removed it and the only seal is on the transmission shaft at the very back of casing. I do see a leak somewhere , how do you remove it or adding a seal on top .

  6. My car is leaking transmission oil I just don’t know where from.. there’s oil on the floor and inside

  7. My farm truck has a heck of a issue… WHEN THE TRUCKS RUNNING and I add tranny fluid, the fluid runs out as quick as it goes in.

    WHEN ITS OFF…it doesn’t begin leaking until I start it up.

    Tranny still has its gears, I don’t drive it now for obvious reasons…but, I am not sure what the problem is.

    Leak comes from the front of the tranny.

  8. I was told that they would have to remove the transmission, because the leak was in two places. I have a 2014 Charger, about how much should that cost?

    1. Wild guess, probably around $1,000. You are better off getting a quote from the shop that told you they would have to remove the transmission. If it sounds high, call a couple more shops in the area and ask how much it would cost to drop the transmission to replace a few seals.

      You will get a more accurate estimate if you know which seals need to be replaced.

  9. how much damage will be done to a transmission if it leaks out fluid? for example, if the plug isnt put back on will the transmission be okay to still keep or will it be badly effected if the car was driven about 55km without the plug and was running pretty dry (making noises and stuff) but it still had a little fluid left in it before being topped up fully and putting the plug back on.

    1. Automatic or manual? That’s really not great. Hard to say how much damage was done, but I would start budgeting for a new or rebuilt transmission.

      If you have an auto, there may have been a little fluid left in the valve body (because you never really can drain it fully yourself). That’s probably better than nothing, but still way too little fluid for proper operation.

      1. it is automatic. It was flushed by a mechanic about 3 times to remove any bad stuff and then filled back up. they took a look at it and did the whole testing thing by driving it and checking the transmission pan/clutches but they said it looks good and passed the tests. there was about 1.2ls OA of fluid left in the transmission (takes about 3.6ls) when i brought it to them with the problem.

        im just worried that because it was leaking out for about 10 hours and was driven over 55km that there could be some big damage on the inside of the transmission. how long do you think before it starts showing any noticeable issues? and what issues or signs should i look out for?

        1. Oh, 1.2L is much different than an empty transmission, which is what I was picturing. While it’s still not ideal, I think it’s fine to run it if your transmission seems to be working OK with a fresh fill.

          If you notice any hard shifts that jerk the car, transmission slipping, or difficulty going into any gears that may be a time to bring the car back in again.

          I would keep a close eye on the transmission fluid level to verify the vehicle isn’t leaking anymore. If there is a leak, it needs to be fixed as soon as possible.

  10. Our 2009 Toyota Tacoma had a transmission leak and the local garage replaced the lines in June. We started having trouble in November with delayed shifting and went back to the same garage and they said it was very low in transmission fluid and that a seal had failed. Should a new leak have happened 6 months after the first repair?

  11. I have a 1995 Ford Ranger stx 4.0L V6 4 wheel drive. It leaks from the bell housing a slow drip, i replaced the front pump seal and it is still leaking anyone know why it is i cant seem to figure it out. Also, it developed a new problem where I will stop at a stop sign and go to go and it feels as if it is in a high gear in first gear and then roughly shifts into second then shifts fine threw out the other gears

    1. Are you sure it’s leaking transmission fluid? It could also be oil from the rear main seal.

      Sounds like the transmission is having a hard time grabbing first from a stop. This could be an issue internal to the transmission. It may be best to bring the vehicle to a trusted transmission shop for an inspection.

  12. I have a 2001 dodge stratus rt and it leaks trans oil.i checked the front trans pan and put a new seal on and it still leaks.when I’m driving at a decent speed no leak really.when I’m idle or slow movement it pours.i dont want to drop trans but if need be I will.i need help plz!!!!

    1. Do you have an idea where the transmission is leaking from?

      I would clean the transmission really, really good so it’s easier to tell where the fresh fluid is coming from. If it’s an external leak, it shouldn’t take too long to pinpoint if you’re starting with a clean transmission.

  13. Some venting from automatic transmissions went thru a vent acually made IN the dip stick and you could use carb cleaner to clear the blockage simply. A one dollar repair. If your transmission leaks after it starts, CHECK this out.

  14. I have a 2002 Honda Accord that I just bought a few days ago and noticed the day after that it was leaking. I took it to several mechanics and found that it was the transmission fluid leaking because of the reddish color. Two mechanics said they would have to remove the transmission to work on it and had one give me a quote at $680 and another for $800+. Is this reasonable?

    1. If they really do need to remove the transmission, then it will in fact be several hundred dollars since that’s a fairly labor-intensive job.

  15. I have a 1 ton 454ci chevy RV. Fluid has been leaking from a 1/4 inch rubber hose on the drivers side of the trans. I keep adding fluid and it takes about a 1/2 pint per thousand miles. Why is this happening? The fluid blows back on the driveline when traveling. Thanks!

    1. Perhaps the hose is just old and gave up. I would have that hose replaced. While you’re in there, check to see if any other hoses are old and will need replacing soon.

  16. I have a 2006 GMC Envoy Denali. I recently bought this SUV. It ran great all fluids were fine. Come last week the transmission was slipping. My husband checked the fluids and it was almost dry. We filled it and and about 3-4 days later it was down a quart. We have no puddles and see no dripping. However we have noticed about 2 days ago that some fluid was on my back hatch door. I took the car to a mechanic (who doesn’t work on transmissions) he said it was wet where the dopstick underneath is. He said there is a seal there, he tightened the bolts to the pan. Im hoping this all works. I have an appointment with someone who does work on transmissions next week but I just wanted some sort of answer today. The mechanic today said the problem is probably my transmission. I was more hoping it was just the pan or a seal or something a little less expensive. Any thoughts?

    1. I’m not sure. Perhaps it’s leaking from the axle seals, but only when the vehicle is in motion. Just a guess though.

  17. I have a 2009 sts Cadillac I’m finding small drops of transmission fluid coming from the front driver side.

    1. If you’re comfortable doing this, you could probably crawl underneath and spot the source of the leak. Otherwise, you could take it to a shop and have them throw it up on a lift. I bet they will be able to spot the source pretty quickly.

  18. I have a 2003 Jeep Liberty it has transmission fluid leaking and bubbling out from under the cap? Is it my cap or is the pump going bad or just low on fluid?

    1. Fluid should not be bubbling out from under any cap. You should probably bring your Jeep by a local mechanic for a look.

  19. I have a 2008 Chevy Silverado 1500 4×4 it just started leaking transmission fluid in the front of the transmission what could it be

  20. How much is starter motor, ignition switch, and automatic transmission pan,for Toyota sprinter Lx saloon 1995 model.

    1. Call autozone pep boys and advance auto for prices on parts by year make and model of your car and have a mechanic replace it if you can’t DIY. It’s less expensive

  21. I didn’t know that your transmission may be leaking if the fluid line has been cracked by debris on the road. My uncle has recently mentioned that his driveway has been getting stained by red fluids that are coming out of his car, and he needs to fix the problem before he goes on a business trip. Maybe he should consider finding a transmission service to help him repair his leak.

  22. Toyota dealership mechanic said they cannot fix the transmission leak because there are too many leaks. What can I do so the mechanic can find the leak(s)

  23. Hi – I Recently had my 2013 Honda Odyssey at the dealer for a transmission fluid flush (120k miles) They said I had a ‘small leak’ which I never noticed before and wanted to charge $850 to replace the lines. I said no. Took the car home and next day a huge puddle of fluid in the garage. Took the car back – they said the lines are rusted and disintegrating and falling off, the flush likely accelerated the leak. $850 to fix. This seems way too expensive. Any advice?

    1. You need to DIY. Find the line buy it. And have a mechanic replace that line. If you know it’s a line go to another mechanic. He is ripping you off

      1. My 2009 Chevy traverse has been idle for two days, I noticed a 12”x12” puddle of transmission fluid today dripping off the frame at a slow rate, half the pan is white on the bottom! Please help

  24. I have a 2004 ford expedition and have fluid problems. I tried to add fluid and it all went on the floor. I can also see the transmission fluid dipstick sticking out under my car what can be the problem

    1. Just a guess. I would check the tube that the dipstick gets guided down and make sure it goes all the way into the transmission. There’s a bolt that holds it in place about halfway down on most engines. It may simply be that the tube is not connected. I hope that’s all it is.

  25. I have 1997 Chrysler Sebring convertible thats leaking transmission fluid .i had the transmission pan replaced and gasket dune already and its still leaking transmission fluid can you tellz whats seriously going on please .and im tried of putting transmission fluid in it bout 7 to 8 times a day and thays Very costly.

  26. My Pontiac Grand Am is leaking transmission fluid at a high rate. I put about three to four quarts in to move across the street due street cleaning. It runs great, but just can’t keep the fluid in. Can you help with some advice.

    1. You’ll have to get under the vehicle to locate the source of the leak. See above for common areas to check. If leaking at a high rate, it’s likely a pressurized line.

  27. My 1995 F150 automatic transmission is getting rid of fluid at the rate of 1 qt. Per week . Not leaking on carport.Dont know where it’s going.

    1. If there’s no fluid on the ground, it’s likely a leak coming from the lines. They’re pressurized only when the engine is running, otherwise the fluid goes back in the pan. Check for cracks or punctures. Even if it’s a tiny hole, you can lose a lot of fluid due to it being pressurized.

    1. First thoughts are the transmission fluid was overfilled or it’s coming out of a vent tube or breather hose or the like.

  28. hAVE A 1994 fORD RANGER TRUCK. 200,000 MILES. CHECK ENGINE LIGHT COMES ON AND STAYS ON. TRUCK WILL NOT GO FORWARD IN ANY GEAR. WORKS IN REVERSE. SHADE TREE MECHANIC TELLS ME IT IS THE AUTOMATIC TRANSMISSION SUPPLY LINE. WHAT’S YOUR THOUGHT. HOW MUCH SHOULD IT COST ME TO REPAIR?

  29. My 04 F150 was hesitant at first in drive but picked up the pace but it was missing in an out finally catching I checked transmission fluid it was reading little low I put a quart an a half in but it went straight on the ground I just had it rebuilt but at low speed going in 3rd gear it would miss then catch but going at a high rate of speed it didn’t miss now when adding fluid it goes on the ground an their was a winding noise

    1. Take it back to those crooks. Poor job or take them to small claims court. Get your money back!

  30. I noticed that I have a transmission leak. when it is hot and full and I back up from an parking space it leaves a trail oil one the ground or pavement. it seems to be doing it also when I drive away from parking space as well. trying to determine if it is a front seal, converter or pan gasket problem?
    have a cost estimate for changing the pan with new filter etc at @ 178.00.
    WHAT IS YOU BEST GUESS AS TO WHY AND WHERE THIS LEAK IS COMING FROM????

    1. I was driving my 2003 dodge stratus on interstate when I noticed a cloud of smoke coming from what appeared behind me. I pulled over and opened the hood and transmission fluid was everywhere. It looked like the fluid was coming out from the pan and seal I’m assuming. However, what would make it go under the good like that? Could this be more than one issue? I just bought this car from an individual days ago who is not willing to help me please tell me this isn’t serious

    2. Dry the area and remove pan yourself much cheaper to DIY! I did mine and YouTube helped me step by step! Voila! Didn’t cost me a dime! Save your money

    3. My car mazda 2008 , mechanician said the seal gear box broken. How much does it cost for repair? Thanks

  31. William No I would check around your line should run about 130$ at most and fluid 30$ at most on top of the 180$ for the part. Labor is seeming a bit steep.

  32. i noticed transmission fluid drops on my garage flooring .
    my car is a 2006 Jaguar S type sedan with 77 thousand miles on it ..
    I have an AAMCO Transmission repair near me in Del ray beach FL
    that im thinking of taking my car to .. do you think they are a
    decent reliable honest outfit ?

    1. Some AAMCOs are hit or miss but that particular location has a good amount of positive reviews on Google so yes, I’d have them check it out.

      1. Ammco tore part my transmission completely apart then tried to charge me 1000 to put it back together. I drove it there and towed it home. I went there to have it put on the diagnostic FREE…. to tell me what the problem was.

        1. Diagnostics are often the hardest part of vehicle repair. They require in-depth knowledge of each vehicle, how the components work, and advanced troubleshooting that is often difficult, especially with intermittent problems. It is fair for shops to charge a small diagnostic fee for their time.

  33. Just did my 2013 VF Commodore. Converter was cracked, so the gearbox was pulled out, converter sent away for a test and repair, refitted, with full new tranny oil, had the new seal put in also as well as a rear engine seal at the same time, changed the oil and filter at the time.
    $1600 all up.
    Holden quoted me $5300

  34. I have a 2003 Chevy Malibu that is leaking transmission fluide and I cant see where its leaking from or how. Do you think it will cost a lot to repair

    1. I have a 2007 volkswag jetta and noticed the rubber tubing that connects ro the transmission fluid bowl is disconnected and caused all the fluids to spill out under the hood. Is something I can easily fix?

    2. Find the leak yourself and remove the line leaking or part and learn to do it yourself I save a lot of money this way and I don’t get ripped off by these mechanics!

      1. I think that’s great but I need to see under the car in order to be able to know what to look for I used to work on cars but I’m a senior now and yes I’m a female can you tell me how I can find pictures to show me the underneath of the vehicle I have a 2007 Ford Taurus SE if you can help please let me know

    3. I have a Cadillac Deville and I have a leak on the front driver side. I replaced the seal twice what else can it be

  35. THE MOST EXPENSIVE TRANS LINE BRILE ON MY 2009 VOLVO C30 THE PART COST AROUND 180.00 THE GARAGE IS CHARGING ME TOTAL600.00 THIS INCLUDES LINE,TRANS FLUID AND LABOUR. IS THIS A FAIR PRICE.

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