Troubleshoot slipping issue.

[corsair231]

I have a problem starting that I need help narrowing down. My car is a pretty mild build. Te-60, 42's, 3" thdp, pac alky, stock suspension, stock d-5 and a stock 2004r that has a B&M transpak shift improver kit.

Normally when I roll on to the throttle fairly agressively from a second gear start the car will break traction and then grab and start pulling thru the top of the rpm range. You can tell by the rear end twitch and the speedometer bounce. :smile: Lately though, especially on cold mornings when it feels like the car is making good power, the car has started acting differently sometimes. It feels like the car is not pulling like it should. The car starts off just like it has broken traction but the speedometer doesn't jump like it would with tire spin. The rpms jump to redline almost immediately and hold. Ease off of the throttle a little bit, rpms drop and everything returns to normal. I guess something is starting to go but I'm not sure what it is. How do you determine if the slippage is in the trans or in the converter?

TIA

 

[turbojimmy]

I have a problem starting that I need help narrowing down. My car is a pretty mild build. Te-60, 42's, 3" thdp, pac alky, stock suspension, stock d-5 and a stock 2004r that has a B&M transpak shift improver kit.

Normally when I roll on to the throttle fairly agressively from a second gear start the car will break traction and then grab and start pulling thru the top of the rpm range. You can tell by the rear end twitch and the speedometer bounce. :smile: Lately though, especially on cold mornings when it feels like the car is making good power, the car has started acting differently sometimes. It feels like the car is not pulling like it should. The car starts off just like it has broken traction but the speedometer doesn't jump like it would with tire spin. The rpms jump to redline almost immediately and hold. Ease off of the throttle a little bit, rpms drop and everything returns to normal. I guess something is starting to go but I'm not sure what it is. How do you determine if the slippage is in the trans or in the converter?

TIA

Is it only doing it on the 2-3 shift? Get some scan data that shows the 3rd gear switch, MPH relative to RPM and throttle position. That will tell you whether you really have a problem or not. Does the fluid smell like something electrical burning?

Mine was doing something similar. It was slipping between 2 and 3 during moderate-to-hard acceleration. A check of the line pressures revealed that the pressures were very low. A second transmission did the same thing. Turns out overfilling it by 1.5 quarts 'fixed' it. Still don't know what the problem really is/was but the fluid smells bad on this 'new' trans as well.

Jim

 

[gnxtc2]

Time for a quality re-build and a quality converter. You made upgrades to the motor but left a 20 year old trans alone.

Billy T.
gnxtc2@aol.com

 

[corsair231]

Time for a quality re-build and a quality converter. You made upgrades to the motor but left a 20 year old trans alone.

Billy T.
gnxtc2@aol.com

First off, this seems to be a lot of people's general answer to any problem. Throw money at it. The 20 year old transmission has worked fine for say...um... 20 years and to repair or replace something that was not broken does not make sense to the average working Joe that uses cars for one of the basics that they were made for, transportation. The car, with the exception of the PAC, has been running fine in the current configuration for over 5 years (alky has only been on it for about 18 months). It is a street car and not a dedicated weekend warrior that I'm trying to squeeze the last tenth out of it. The car is a dd with maybe a twice a year track excursion. That's why I kept the stock stuff. It fit into the performance goals that I had and it was not broken so I did not need to replace it. I have a problem starting now and I am sure it is due to wear from mileage, not just because they were stock pieces.

Now, with the confusion hopefully cleared up, on to addressing the problem.

JIm, the fluid smells fine and is still a good, clear red. The problem is also not in the 2-3 shift. It shifts fine. The problems is when the power first hits. This is from a low mph second gear pull, if anything it would be a 2-1 downshift. It all hits at one time. Boost comes up, it downshifts??, the rpms climb, and like when it breaks traction, you get the sensation that the car is not picking up speed. It seems just like a clutch slipping in a manual trans car. Once I lift throttle the car starts pulling again. I haven't launched the car so I don't know if it would do it from a good leave. It still powerbrakes fine and overpowers the brakes at about the same boost and rpm that it always did. In drive it downshifts and pulls normally. I think that just at that particular point in the rpm range the car is making enough torque while the resistance to accelleration is great enough for something to slip. I just don't know if it is my converter going or if it might be the clutches or bands in the trans. I will have to farm out a trans build but basic labor is cheap (I supply that) so saving on the labor cost of doing them both at once is not a factor.
I don't have the funds to r&r both so I will have to fix just what is broken which is why I need to be relativley sure which one it is. So, how do you determine which one is slipping?

And before someone comes up with one of the, "If you can't afford it then you shouldn't own it" comments please note that I have owned and daily driven this car for 20 years. It was never purchased as a luxury/toy/race/collecter car. When I got it it was just another car to get me back and forth to work and whatever else. Granted, I knew what it was and I was glad that I was able to get it but it was only about this far......from being a Mustang parked in my yard. After I got the car I realized just how special it was so while other cars have come and gone, it has hung around through good times and bad and even though it has never been babied, it has been a very dependable car. When it does break, I fix it and keep driving. That's what I bought it for, to drive. :smile: