trans shifting a little too firm

[bluecollar]

Anybody got any advice on what's causing my tranny to shift a little too hard? I've replaced the tach sensor and just installed a new FIPL and got it set to 1.07 volts closed and 3.92 wot. It's changing gears at about 2500 rpms and shifts a little too hard and worries me that it may damage something else. If I go kinda easy on take-off the shifts will occur at lower rpms and don't seem as firm.

 

[reklund]

Done a line pressure check? What kind of shape is the fluid in? Maybe a broken accumulator spring in the valve body?

Ryan

 

[Mr_Roboto]

Is your OD light flashing? Does your OD light work?

 

[bluecollar]

Thanks for the replies. The od light has never blinked, but I've had erratic shifting patterns in the past. The fluid appears ok but has a bit of a burned smell to it. Think that may be causing some problems? After replacing tach sensor and FIPL I did notice it is shifting a lot firmer in all gears. On a side note though, they are not erratic anymore and it goes directly in the next gear and not just sliding in.

 

[reklund]

I'd start with a good basic trans service. Drop the pan, and replace the filter. Maybe look into installing a drainplug on your pan with a universal kit from summit, or get a mag-hytec pan or the like with added capactity and a drain plug.

Refill it with good old regular (non-synthetic) ATF and run it for a few hundred miles. Then drain and refill every few hundred miles until the burned smell is eliminated. (Draining the pan only drops about 40% of the trans fluid capacity) Try this before you condemn the whole thing. You'd be surprised at what some good clean fluid will do for a transmission...

Ryan

 

[argve]

I always dialed my FIPL so that I would get firm shifts - a firm shift is a sign of no slippage between gear shifts, slippage generates heat and heat is the number one killer of autos. You can move the FIPL around a little and effect how it shifts and when it shifts, no you don't have a ton of movement but just a little adjustment will change the attitude of the trans.

 

[Mr_Roboto]

But does the OD light work when you push the button? It's not uncommon for the light to quit working...... I'm just worried that you may be in "failsafe" mode and not know it.

 

[bluecollar]

Yea, the light is working. I've read that there is also a speed sensor either on the tranny or the rear axle that could cause hard shifting. The tach is working fine, but the speedo has some bounce untill it gets to about 30 or 40 mph. I also think it's reading about 5mph slower than I'm actually going.