Shift Kit Effects on TH350, Need Guidance

[pontiac guy]

Do not remove the modulator. Just remove the vacuum line and cap it at the motor. But that's not the right way to do it. The governor is the way shift points are controlled. Change the weights and leave the modulator for fine tuning. That's what it's actual job is. The detent cable for down shift, modulator for fine tuning and governor for global control. In reality, the detent and modulator act as redundant controls, but just keep them both and do it right.

 

[G_RIDE_81]

Makes sense. Will keep this in mind. My calibration kit won't arrive for a few more days. Hope to work on it weekend after this.

Update:
So, the kit came in over the weekend and been doing some wrenching. Kit came with 6 weights and 6 springs, all different. Had never worked on a transmission before. Felt intimidating but turned out to be childs play, ha ha!!

First adjustment: The two springs in the trans were of equal spring rate, felt firm for sure. I swapped out springs only for the 2 lightest springs in the kit and went for a drive. The 1-2 shift didn't move, stayed at about 10mph, but 2-3 shift rose from 18mph to 35. Much better than before however the rpms were too high here

Second adjustment: I swapped only one of the weights for a -2 grams weight from the kit. Also, I went down a spring (from #5/6 to #4/5). From the drive the 1-2 shift went up to about 12mph and 2-3 shift dropped to about 25mph. I know the 1-2 shift change wasn't much but the shift kit is suppose to move you through the gears more quickly/efficiently right?! Rpms at this shift could probably be higher, maybe removing the other stock weight for a lighter one would bring it near 15mph, more optimal.

Overall: I've been cruising around town and it just feels right now!! Went on the highway, around 55mph you can tell the deeper 3.42 rear-end is begging for an overdrive gear. I'll postpone that swap for the moment and stick to street cruising.

Thanks all for your advice. Hope this helps others with a similar problem.

 

[JerRol79ElCam]

What I did is what I believe to be the easiest DIY for improving the shifts on a TH350: a B&M Shift improver kit, a new adjustable vacuum modulator, a new filter, added an inline cooler, a new pan with a drain plug and B&M Trick Shift fluid. Since I already had my transmission pulled, I also added a new SFI approved flex-plate and 1800 stall converter. It's still on jack stands as I'm about to complete my new dual exhaust set-up. I'll post the results of my test drive and possible adjustments in a week or so.

 

[CopperNick]

For your new pan, did you go steel or aluminum? I am currently running B&M TRick Shift in my 700R4 and the first one or two times it shifts during the course of a drive, the 1-2 shift can be felt. After that either the plates warm up or the oil warms up and the shifts become slick as glass and mostly un-notice-able. Thinking here that the stock clutch plate friction material may not "like" the B&M formula when cold and they may need heat in them more quickly to make the shifts smoother sooner. The change to a pan with a drain would allow me to dump and replace oil far easier than having to drop the pan. The existing unit is aluminum and heavy.

This is not a TV issue for anyone thinking in that direction; did get that sorted out. The gearing in the R4 might just be that little closer than it was in the old 350E. The spacing and timing between the gears is still about where it ought to be and under even half throttle the van will get up and boogie. The only roadblock in that regard is that local commuter traffic is the definitive picture that can be found beside the definition of mob stupidity.



Nick

 

[pontiac guy]

For your new pan, did you go steel or aluminum? I am currently running B&M TRick Shift in my 700R4 and the first one or two times it shifts during the course of a drive, the 1-2 shift can be felt. After that either the plates warm up or the oil warms up and the shifts become slick as glass and mostly un-notice-able. Thinking here that the stock clutch plate friction material may not "like" the B&M formula when cold and they may need heat in them more quickly to make the shifts smoother sooner. The change to a pan with a drain would allow me to dump and replace oil far easier than having to drop the pan. The existing unit is aluminum and heavy.

This is not a TV issue for anyone thinking in that direction; did get that sorted out. The gearing in the R4 might just be that little closer than it was in the old 350E. The spacing and timing between the gears is still about where it ought to be and under even half throttle the van will get up and boogie. The only roadblock in that regard is that local commuter traffic is the definitive picture that can be found beside the definition of mob stupidity.



Nick

The 700 R4 was known to shift hard from day 1. It actually drew complaints when new. GM teck would use a bar on the band servo to manually apply it and glaze it up a bit when they can in with complaints. My 700 shifts so hard with the trans go kit in it that it barks second on part throttle and in slippery conditions the car is almost unmanageable on the 1-2. Which was exactly what I wanted 20 years ago. Now I don't drive automatics and I'm thinking of replacing it with a proper manual trans when I put it back together

 

[L92 OLDS]

For your new pan, did you go steel or aluminum? I am currently running B&M TRick Shift in my 700R4 and the first one or two times it shifts during the course of a drive, the 1-2 shift can be felt. After that either the plates warm up or the oil warms up and the shifts become slick as glass and mostly un-notice-able.


Nick

I had that issue and it was related to line pressure. As the transmission heated up my pressures were reduced which affected shift firmness. Have you put a gauge on it?