trans question. shifting too soon

[sleepycutlasscruzer]

ok so my trans seems too be shifting to early which is making it seem like the car is a dog taking off from a light. it shifts from 1st to 2nd really quick and the other two gears seam fine. it does go threw all the gears and down shifts when its supposed to but the take off is bothering me. any ideas. the car is a 88 old w/ a 307 and a od trans. let me know what you think or tell me if im just looking into it to much. thanks guys

 

[richp85elco]

do you have your TV cable set right?

 

[DoubleV]

What are the RPM's it's shifting at? Is this problem on part throttle or full throttle shifts?

 

[sleepycutlasscruzer]

i can teel the rpms because i dont have a tach but i would guess 1500 rpm under normal acceleration and i havent messed with the tv cable because it looks as if it hasent been touched. but in case im wrong how do you adjust the tv cable? thanks guys

 

[Longroof79]

Here's a start. There's several different sites to get info on adjusting a TV cable. Just Google it. http://www.cpttransmission.com/tech_tvcable.htm

 

[pontiacgp]

this is what I think is a good explanation of the system and how it works. I liked it cause it gave me an understand of the purpose of the cable adjustment. Now I just shift the stick when I want to

http://www.tvmadeez.com/article/index.html

 

[azmalibuwagon]

I hope adjusting the cable works for you.

My 2004r transmission started doing the exact same thing after I switched the rear end from a 2.56 to a 3.73. It shifts through all the gears, but gets to 4th gear way too soon. Adjusting the cable didn't help it at all.

I haven't figured it out yet, don't know much about auto transmissions and haven't really worked on it all that much. But my guess is that the higher reving caused by the rear end makes the transmission think I'm going faster than I really am - like maybe the shift points were set up for the 2.56, and now needs to be changed to match the 3.73... Maybe some internal valve/pressure adjustments???

Anhow, right now, I just shift manually in traffic, it's more fun anyhow. And like you I don't have a problem once I'm up to highway speed.

 

[pontiacgp]

if it's shifting too soon in all gears it's the governor that needs to be changed or modified. You can look for a governor out of a Monte SS, Olds 442 or hurst and the GN or you adjust it yourself by trimming the weight of the smaller spring in the governor. There are two weights in the governor, a primary and a secondary and you have to remove the large primary spring to get to the small one. You trim the weight just a little at a time till it shifts like you want it..

I had the same problem when I went from 2.41 to 3.08 but I fixed with installing a manual...I'm lazy..

 

[DoubleV]

I hope adjusting the cable works for you.

My 2004r transmission started doing the exact same thing after I switched the rear end from a 2.56 to a 3.73. It shifts through all the gears, but gets to 4th gear way too soon. Adjusting the cable didn't help it at all.

I haven't figured it out yet, don't know much about auto transmissions and haven't really worked on it all that much. But my guess is that the higher reving caused by the rear end makes the transmission think I'm going faster than I really am - like maybe the shift points were set up for the 2.56, and now needs to be changed to match the 3.73... Maybe some internal valve/pressure adjustments???

Anhow, right now, I just shift manually in traffic, it's more fun anyhow. And like you I don't have a problem once I'm up to highway speed.

In your case it just sounds like you're suffering from the typical low shift points of the stock transmission. Your better gearing allows your engine to rev up faster so you hit those low shift points alot quicker. As stated, you need to shave some weight off the governor but depending on where you want your shift points to be ( full and part throttle ), you may have to change the valve body too. It's usually easier to get a valve body/governor combo from a better transmission ( Monte SS,442/HO, GN ) that already has ( or is closest to ) the shift points you desire, then tweak from there.

Some combos of valve bodys and ( non matching ) governors can give you some crazy shift points so you gotta be carefull.

 

[Longroof79]

Check CK Performance http://ckperformance.com/resources/GM2004RCATALOG.html for governors, valve bodies, etc.
A stock low performance transmission will shift sooner than a performance model, and at lower RPM's.