GMC Sierra owners have reported 4 problems related to transmission fluid leaking (under the power train category). The most recently reported issues are listed below.
This truck is a 3500 hd. I was pulling a camper on a 1100 mile trip. With 50 miles left I noticed that the truck was leaking transmission fluid from under the transmission cooler. Upon further investigation I found that the return hose from the trans cooler was positioned so the it rubbed on a frame component which caused a hole to rub in the aluminum trans coolant return line. I noticed this when the truck was parked running at a rest area for an hour but it was obviously an ongoing issue. Had I not noticed it when I did this condition could have caused catastrophic failure of the transmission. The dealer says there is no recall and it is not under warranty. I consider this to be a serious design flaw and a major safety issue. I was able to get to my delivery stop and get the line patched. It is at the dealer for repairs right now.
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all problems of the 2017 GMC Sierra
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Brake fluid leaking all over bottom of truck spraying out I took to a mechanic and had 1000 dollar brake line job done got truck back and abs brakes worked like manual brakes had a sensor and 2 ball joints replaced im being ripped of from a GMC loyal customer I was I guess back to Ford or Toyota for my next new trucks I had warranty issues you cheap [xxx] wouldnt pay for a waterpump that was leaking only a 7 dollar gasket also had a transmission on my work van repair and then replaced after a month of run around. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
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all problems of the 1999 GMC Sierra
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Automatic transmission is leaking fluid, dealer replaced clutch slave, cylinder assembly seal and found that the fluid was leaking at the shifter on top of the transmission, transmission mount is also weak which is causing problems shifting. Nlm.
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all problems of the 1996 GMC Sierra
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Vehicle jerks and violently vibrates when shifting up and down, increasing and decreasing speeds. Also, noticed greasy spots from fluid leaking. First time vehicle was sent for repairs problem was never done. It was taken taking back a second time. Dealer's service technician pointed out that it leaked while it was still up on the lift. Please provide more information.