Really Strange Tranny Problem

[Crand]

I wanted to tell this story about what happened with my transmission because I tried Googling for an hour and couldn't find a single case where the symptoms I experienced were the same as anyone else, probably because it was a VERY strange problem. At least I thought it was.

(sorry for the length, I tend to use too many words, but this is interesting!)

I took my car apart and took the longblock to a local engine builder to have it gone through and a new rotating assembly installed as well as new heads and seals and the whole 9 yards. That was about 2 or 3 months ago and the first month I felt like something was off. The old engine that blew up averaged 20.5mpg but this new one started off at 19 and was working its way down. It was at 16.8 when I started to work the problem. It was subtle at first, almost like a transparent figure is behind you with a rope, holding you back as you accelerate. Over time it became more pronounced, especially when you took your foot off the gas and let it coast in gear. The only way I know how to describe it is it felt like I was in one of those cars that driving teachers use with a second set of pedals on the passenger side and occasionally someone was kicking the brake pedal. Over a period of two weeks it got REALLY bad where when the car was hot I was giving it twice as many beans just to go forward at a normal pace. Another thing happening is that when these "brake kicks" happened, the speedometer would drop to 0 and then pop back up, eventually staying down at 0 if I drove for longer than 20 minutes. As you drove down the road, you'd keep feeling these jolts and the speedometer would be bouncing all over the place. Those speedometer drop-outs of would also disengage the reverse lockout and if you weren't paying attention you could shift into reverse at speed! Danger!! When it was at its absolute worst, the reverse lockout solenoid would NOT disengage and I had to use both hands to overpower it to get it into the reverse gate! The whole time I never once had a problem shifting, it went into gear as smooth as melted butter.

I knew it was the transmission because I just had the engine rebuilt by a professional shop. It was also not the differential because those brake kicks would cease if I pushed in the clutch. It had to be in the transmission and the only thing I did to it when it was out of the car was change the fluid since I had 250k miles on it without ever changing the fluid. I Googled which fluid to use and people all over the place said the correct fluid is old school ATF, Dexron/Mercon Type III, so that's what I used. I remember I couldn't find it on the day I drained the transmission so I ended up using something like WalMart's in-house brand. Then when this problem first cropped up, I noticed a small leak from the transmission so I decided to top it up and the night I did that I could only find Dexron Type IV, so I figured what the hell and brought it up to full using that. That fixed it for one night but it started to get MUCH worse over that week.

Since I couldn't find any information at all about these symptoms, I decided that I'd do what I always do with my car, use the official ACDelco/GM part regardless of cost or difficulty to obtain. I ordered up the Delco 75w90 gear oil and limited slip additive to change the fluid in my differential. I didn't think that was the answer, I just knew it would be easy to do while I had the car up on stands and it has been running the same fluid since the second month I owned it. For the transmission, I came to the forums here to find the official Delco transmission oil part number, then I ordered it up from Amazon. The car was at the absolute worst on the evening of the 4th and since I live in Phoenix, the LAST thing I wanted to do that night was get under my car and swim in transmission fluid but I was getting scared to drive it so I drained it and refilled it with the proper Delco fluid. I was a little surprised when I inspected the drain pan and drain plug and found no metal or sparkles whatsoever. I was expecting an entire bearing race or some bearing balls to fall out of the drain hole but it was as clean as an unused whistle.

Ladies and Gentlemen, that fixed it. If you told me that the solution to my problem was to simply use the correct Delco manual gear fluid, I'd have told you to go take your meds. I still am in disbelief but I did it and it friggin works FLAWLESSLY now. Anybody ever heard of such a thing before? It's not like I filled the transmission with motor oil or bearing grease, I filled it with Dexron type III but it was just a crap brand! My average MPG started to increase on the very first test drive on the night I changed the fluid. No more brake kicks, no more speedometer hops. The second day, there was just the tiniest bit when I first left the house but by the time I got to the end of my street, it was solid. Who'd have thought the dang fluid mattered that much?! I was ready to purchase a new transmission. One benefit of rebuilding or purchasing a new LS3 and installing it yourself is that no repair job on your car, NOTHING will ever be that expensive or difficult so no matter what you do, it feels easy by comparison.

It's been a week now and it's still 100%. Have you ever heard of such a thing?

[0stones0]

Using correct fluids isn’t anything to take a chance with. Firm believer in that!