Transgo shift kit issues w/billet servo

[jpwalt1987]

Hey guys I am still working (20 hours of upgrades and unf#%*ing hack job installs) on a local guys GN and the final issue the car seems to have is a funky 1-2 shift. I talked to the previous owner and he told me a trans go shift kit was installed by the owner before him. (This car has changed hands alot) It also has a billet servo by PATC (I believe that's what it said) The 1-2 shift sucks. It's like it will hold first gear just a tad too long then when it does shift it's not the usual crisp shift that it should be when just cruising along It's kinda like a bump and push all at the same time. I know that doesn't really make sense but its hard to describe. I had to install a new TV cable because the old one was some Mickey Mouse POS. Got it in and adjusted properly. Still shifts stupid. While the pan was off I pulled the 1-2 accumulator to see if it was blocked. It wasn't. I remember blocking it when installing the original Art Carr shift kits back in the late 90s. (Still have the install manual). I am thinking that the servo cushion spring is not installed. I will check that in the morning. Would there be any downsides to blocking the 1-2 accumulator even though the rest of the "shift kit" isn't an Art Carr or whatever other brand that blocks it? There is not slippage and 2-3 shift is good. Thanks.

 

[TexasT]

Might need a new band. Drum could be warped. Have you measured the pin clearance? This patc servo, is it similar to one of the other aftermarket units?

 

[jpwalt1987]

Not sure how similar the PATC servo is to others. I have an Art Carr servo in my extra transmission that I can compare it to. Before I drop the pan again I am going to swap out the billet servo for a stock GN servo and see how that does. I will also check the pin length.

 

[jpwalt1987]

Just what I thought. No cushion spring. Hmmmm

 

[jpwalt1987]

Reinstalled a stock GN servo with cushion spring. Second gear is much better. Tomorrow I may tap the 1-2 accumulator for a set screw to see how it affects the 1-2 shift. I also have to do something with the wot shift rpm. It shifts way too soon.

 

[SSedan64]

The PATC Servo is the Superior/Fairbanks Super Servo. Just has engraving. They also sell Sonnax Servo.
http://www.200raptor.com/200-4r_servo.jpg
http://200raptor.com/HPIM1241.JPG
1/5th way down Pg. >> http://www.transmissioncenter.net/200-4r.htm

TV Cable adjusted correctly?

 

[jpwalt1987]

Yes the TV cable is adjusted properly. It's a new one from G-Body parts. The owner just brought me a box of parts so I am going to see what is what. The car does have 3.73 gears in it for some reason. This car has been a cluster f$&% of hack jobs from the start. Looking at the convertor also it's supposed to be a 2600 stall but its stamped "6" and painted black. No idea who made it either. Gotta love playing the guessing game!! I also need to look at the governor. There is one in the box of parts that has a green gear on it. The car shifts wayyy to early at wot and lugs the motor.

 

[Ttype6]

Reinstalled a stock GN servo with cushion spring. Second gear is much better. Tomorrow I may tap the 1-2 accumulator for a set screw to see how it affects the 1-2 shift. I also have to do something with the wot shift rpm. It shifts way too soon.

Did you install the correct GN return spring? It's much heavier than the one in your picture. If you install a larger servo,you need an even stronger return spring than the stock GN. CK performance sells one.

 

[jpwalt1987]

I installed a complete servo from another Gn that i have just to see how it would perform. The guy brought me a box of parts and there was a stock servo in it also. But it wasn't a GN servo. After much searching and reading I reinstalled his PATC servo along with the proper small spring and the big cushion spring. I also blocked the 1-2 accumulator with a set screw. Shift quality is sooo much better.

The only thing now is that it still shifts 2-3 too soon at part throttle take off/just driving. And it also shifts too soon at wot and still lugs the motor. If you hold it in gear till 5000 the car will fly pretty good for a stock car. I inspected the governor and it looks like the Gn governor with the small weight on one side and only one spring, but the small spring looks kinda heavy. I have another governor I am going to compare it to in a minute.

 

[TexasT]

Have you considered replacing the spring?

http://m.summitracing.com/search/pr...ent-governor-springs/transmission-type/200-4r

 

[jpwalt1987]

Yes I have. In fact, I took apart my extra 2004R trans today. I compared the true GN governor to the extra one he had in the box. It was definitely not from a turbobuick. But one of the springs in the extra governor looks real close to the GN spring. I ground it down to match the weight of the GN governor weight. I will try that next week. Is the governor weights the only thing that control wot shift points? What controls part throttle shift timing? If nothing else I will swap my known good BRF valve body that has an Art Carr shift kit into his car to see what it does.

 

[jpwalt1987]

Anyone else have suggestions?

 

[jpwalt1987]

A bit of an update:


I pulled the stock governor and replaced it with another that I modded to be the exact same weight as a GN governor. I also stole the stock governor spring from my BRF trans that is torn apart and used it. While I had the pan off I went ahead and removed the valvebody to compare the springs used with the transgo kit vs. the Art Carr kit I have in another BRF valvebody. I was not going to just give my BRF VB away on this car. I found it had a TCI seperator plate installed. The other glaring issues I found were the lack of enough check balls and the line bias valve spring was not installed. The TG kit called for a white spring. There were a couple extra springs in the kit from the previous owner but none were white. I pulled the line bias spring from my VB to compare and found the correct spring that used to be white in the box. I checked several other valves to see if they were installed the right way and all seemed ok. As for the check balls, there were only a total of six in the whole trans and VB. Three in the VB and three in the case. I installed them according to the Art Carr instructions adding the missing ones. However with the TCI plate the "reverse third" #6 is plugged with a rivet. I adjusted the TV cable with the pan off to verify proper engagement to the throttle valve when at idle position. I did have to secure the tv cable with a section of rubber hose and a clamp to keep it from moving forward. It's a brand new piece from G-body too.

Now the trans shifts from 1-2 at 1500 rpm when just driving normal whereas before it would shift at 2000rpm very abruptly. 2-3 still happens a bit too soon but it's not terrible. Also, 1-2 used to be stupid harsh. Now it feels just right.

At WOT, 1-2 happens at 5200 rpm and is quick and firm. However, 2-3 happens at about 4200-4300 rpm.
Does anyone one know what I can do to get the 2-3 shift to happen 700 rpm later? The owner was impressed with the results so far but it can still be better. It's a CZ core with what appears to be a BRF VB.( pinkish/purple on side)
Thanks for any advice.

 

[77 cruiser]

What the 3-4 shift at? Compare the 2-3 shift valve spring with your known BR vb.

 

[jpwalt1987]

What the 3-4 shift at? Compare the 2-3 shift valve spring with your known BR vb.

Would a stiffer 2-3 shift valve spring make it shift at a higher rpm?

 

[77 cruiser]

Yes it would raise PT & WOT but it's going to hard to gain the 1000 rpm's I think.

 

[jpwalt1987]

Yes it would raise PT & WOT but it's going to hard to gain the 1000 rpm's I think.

Any idea how I would be able to get that rpm then? I have studied all my manuals and scoured the net for info. I will pull the 2-3 spring and compare it to the other one I have. I am getting tired of dropping this pan!!

Donnie, what do you think?

 

[Alky V6]

Any idea how I would be able to get that rpm then? I have studied all my manuals and scoured the net for info. I will pull the 2-3 spring and compare it to the other one I have. I am getting tired of dropping this pan!!

Donnie, what do you think?

If it's truly a BRF VB and you are using a matching governor (or one made to match), then it has to be the 2-3 shift spring. Commonly, even with an unmodified VB, the 1-2 and the 2-3 don't always have the exact same shift point. If you wanted to raise all WOT shift points together, you can shim up the TV limit spring. Careful. It's very sensitive.

 

[jpwalt1987]

The only indication I have that it's a BRF vb is the trace amount of paint on the side of it. Is there any other way to tell?

 

[Alky V6]

The only indication I have that it's a BRF vb is the trace amount of paint on the side of it. Is there any other way to tell?

Measure the TV valve lands. The small, inner valve, not the plunger. The size of the smaller land is unique to the BRF VB.