I recent got a 2006 G35x Sedan project car with a few known issues that I need to fix.

Short question: Is the tranny bad if it doesn't go in reverse til I rev it to 3000rpm?

Details: When driving the project car home, the tranny fluid leaked out and the gears weren't engaging due to lack of pressure. I had to get it off the highway to get it towed so I had to pump the accelerator to 7000rpm to get it moving and off the highway. I need to change the tranny cooler pipes (where the leak is coming from) but in the mean time, when I fill the tranny oil up, I would "expect" it to drive/engage as normal. Driving forward seems ok, though no engaging that quickly. Going reverse it definitely not normal.

Since I did not drive this project car much since I got it, did I damage the tranny when I rev-ed it too high trying to get it off the highway? The car definitely smelled like burnt oil and when I drained the tranny fluid it was definitely "roasted".

If the tranny is slipping, not sure if this can be my project car anymore given the low budget I originally planned on. Swapping out a tranny isn't cheap

 

Yes that's not normal. Definitely sounds damage .

 

I've had a tranny leak out and loose drive gears before. Never kept reving it to try and keep moving so I don't know what that would do to the brake band and clutches when it looses hydraulic pressure. I would guess it would be about as bad as riding a clutch at 7000 rpm. If the valve body gets air in the channels it will shift and act funny. When we put shift kits in they sometimes act weird for the first 20-30 miles. It also takes several warm up cool down cycles to get the fluid topped off and air out of the system.

 

Thanks - this makes me feel a little better and hopeful. Riding the tranny at 7000rpm wouldn't be that bad, but will it being 2-3 quarts low, I was concerned about the high temp causing harm

 

I'm also planning to put Lucas Transmission Fix oil in to help for now, til I have time to get the cooler pipes replaced (have to take off the Y pipe)

 

Do 3 back to back fluid changes, then get out on a good road and mash it full throttle while you closely watch the rpm.

They should jump about 500rpm and sort of "hang there" for a second until the car catches up in speed. This is close to your "stall speed" and it should sit somewhere between 1000-1500 until the car catches up, if it jumps to 2k or higher you probably smoked something on the low gear.

Next you're going to need to do a few full throttle pulls and watch the shift points closely, they should snap to the next gear, drop rpm, and then rise proportionally to speed. If the rpm kind of flutters and hangs similar to the stall launch test then you are slipping higher gear clutches or brake bands.

It's really important to get all that burned fluid out before doing this, I think it holds something like 11 quarts and a drain/fill will get 4 quarts out per change, first change you will have 30% new fluid, second change you will have 50% new fluid, third change you will have 65% new fluid (or thereabouts, math is hard). After you've done 3 changes you will have exchanged enough that you could safely go out and do the launch and shift tests without a reasonable risk of causing more problems from burned hydraulic fluid. If it passes the tests I would do two MORE fluid changes just to get up to about 80% new fluid.

Alternatively you could just pull the tranny and drain it and the torque converter.