Fluctuating and inconsistent rpm's at shift points...

[J Banning]

I could use some trans advice here. I just put in a fresh tranny and Precision 9.5" lockup convertor the other week. I also just got Directscan installed and running over the weekend so I recorded some runs.

Something is funny with HOW and WHERE my trans shifts. The shift points are not consistent, and the rpm fluctuates up and down before each shift - It'll go something like: 4800, 4850, 4875, 4800, 4900, then make the 2/3 shift. In addition, when viewing my recorded runs I don't see the 3rd gear switch light up in Directscan (maybe that's a software problem?).

Here's a brief rundown of three runs I recorded Sunday...

Note:
- All runs were with the trans in Drive.
- The TV cable is tight.
- Fluid level is fresh and normal.

1/2 shift:
Run 1) 5350 @ 37mph
Run 2) 5550(!) @ 38
Run 3) 4850 @ 29

2/3 shift:
Run 1) 5100 @ 61mph
Run 2) 5225 @ 65
Run 3) 4900 @ 59

3/4 shift:
Run 1) 4950 @ 97mph
Run 2) 4950 @ 98
Run 3) 4900 @ 94

I can email my Directscan files if anyone is interested.

Thanks,
-Banning.

 

[WE4]

What is trans temp? I'll bet trans temp plays a part. Fluid is thinner and with the gov/valvetrain these have, thinner fluid would tend to effect it. Do you have a trans temp gauge on it? I would be curious......


Bruce
WE4
www.ptsnctb.com

 

[J Banning]

Sorry, no trans temp gauge... though I should get one. I don't think the temp was very high though. The three runs I did yesterday were right after the car sat for quite a long time. I'm running the stock cooler in addition to an external B&M. Outside temp was cool as well... probably right around 60 degrees.

Thoughts?

-Banning.

 

[J Banning]

Why the high RPM's for the 1/2 and 2/3 shifts? Should I back off on the TV cable adjustment?

-Banning.

 

[WE4]

You could try...I think you got something else wrong though. If not add a gram of weight to secondary side of gov.

Bruce
WE4
www.ptsnctb.com

 

[J Banning]

Thanks Bruce, I'll ask my trans guy.
-Banning.