OE Cushion Spring Needed


May 24, 2016
I am in need of an OE Servo Cushion spring. It seems they are no longer available from GM and none of the GM Internet Parts places seem to carry them. Does anyone know where can I get one?

It is for a 1986 Monte Carlo TH200-4r if that helps. (CZF Code). It seems when they put in the billet servo, they left it out.
Are you taking out the billet servo? Might not be able to use the spring with a billet servo if it wasn't designed for it.
Are you taking out the billet servo? Might not be able to use the spring with a billet servo if it wasn't designed for it.

Good point that I hadn't considered, but I have a Sonnax Super Hold servo kit on the shelf I can use if it won't work with the billet. The Sonnax unit will allow the OE cushion spring.
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I pulled the tranny today. I couldn't remove the servo without pulling it since the tunnel clearance was too close. Anyhow, as suspected, NO CUSHION SPRING. So thats my problem. I am going to install the Sonnax Super Hold Servo,...but...

I need a stock cushion spring. I tried the link that TexasT sent me, but that was for the return spring which I have in the kit, so I am still searching for the cushion spring.

I found a thread from a site vendor, Chris718, and he says he has these, ( http://www.turbobuick.com/threads/servo-cushion-springs.431374/ ) but I don't see a way to message him...can anyone tell me how to sent him a message? OR, does anyone have a stock cushion spring to sell?
Thanks a bunch 626gn. I called Dave and he was working tonight. He hooked me up with the cushion spring so I bought some other stuff from him to finish the job. Great guy to deal with. Took the time to walk me through setting the servo pin clearance too!
No problem. Glad it worked out. Dave is one of the best vendors we have here and is more than just one of the best transmission guys around. True asset to our little community.
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From a prior thread, you may have read I had a nasty 3-2 downshift clunk in my 200-4r. I suspected it was because I had the Superior servo...no cushion spring.

Well, I swapped out the Superior and completed the installation of the Sonnax Super Hold Servo (K65703). Dave Husek supplied me with a new cushion spring and other parts and he recommended a much shorter servo pin travel than what Sonnax recommends. He said to shoot for .025 - .050. Sonnax says .110. Dave suggested I stay on the mid to higher end of that since my band is not being replaced. When Googling, I found it interesting that recommendations for travel are all over the board. For example, TCI's servo looks like a rebranded Sonnax and they recommend .070 to .100. Googling showed others like .060, some with the cushion spring installed, others without. Before I pulled the Superior servo, I checked the pin travel and it was .040 which had been that way for two years . For piece of mind, once the old servo was out, I used an inch pound torgue wrench to measure the effort to turn the output shaft each way. That was my baseline. Once the new servo was in, and while I was trying to come up with the best travel, I measured again. There was still some band drag showing on the torque wrench at about .030 pin travel. It was within the next .010 that the torque wrench showed no more drag. I ended up at .040 pin travel which is right around where Dave suggested, and right where my old one was set.

Problem solved! The 3-2 dowshift clunk is completely gone. The upshifts remain unchanged, nice and firm, but the 3-2 downshift is great now. I am very pleased with the results. Thanks to everyone who gave input and special thanks to Dave for helping me solve this problem....GREAT customer service!

Is it this spring?