Mornin everybody.

I have a TH350 lock-up transmission. It was re-built about 3 years ago and had new clutches, a few hardened parts, and a transgo shift kit installed.

About 10 months ago I put in a 2500 stall lock-up converter in it and lately, for the last 2 months I've been experiencing the lock-up clutch shuddering at about 2600-2800 RPM, depending on how much throttle I have in it.

If I'm real easy on the throttle everything is great. If I hammer on the throttle everything is great. If I'm mid range on the throttle it'll hit that rpm and start shaking real bad.

What can I do to try and prevent the shudder? Are there any springs in the valve body I can tighten up to increase the lock-up clutch pressure?

Thanks,

-HD

 

What makes it lock? I just installed a lock-up kit in my 700R4 (disabling ECM) and I noticed in the instructions that, since the kit locks the T/C with a vacuum switch, that some shuddering may occur given the vacuum. My kit is preset at 8-10 for the vacuum switch, and adjustable, and they say to adjust if you have more or less vacuum given your set-up. Since yours occurs at a mid-accelleration point, maybe it's a vacuum issue? Just taking a guess here, I'm no expert.