Canon 70-200 focus issue

So I'm trying to see if anyone has had this issue before I bring the lens in for repair.
I have a 1996 lens, old, but was still lightning quick and sharp until the other week. At all distances BUT 200mm, it shudders while focusing, and takes , literally a couple of seconds. At 200mm, it's still fast as hell. I did take it in to get it repaired a few weeks ago from a drop from several years ago and it was fine from that drop. Any ideas?
Thanks, Merick

mrmerick wrote in post #17962145
I have a 1996 lens, old, but was still lightning quick and sharp until the other week... I did take it in to get it repaired a few weeks ago from a drop from several years ago and it was fine from that drop.

So timeline was:
- several years ago: dropped lens, but it was fine
- a few weeks ago: took it in get repaired (Why? If it was fine what repair did it need?)
- the other week: focusing started to shudder and go slow

Sounds like the "repair" messed something up?

The drop caused some internal damage, the top part of the body was loose, but it didn't affect IQ, but I gaffer taped it to keep it from wobbling just in case it did affect it. I finally was able to get it fixed, and bam, this new problem. I'm hoping it's something he may have inadvertently bumped or missed. I figured I'd check here to see if anybody has had this issue. It's still an amazing lens after 20 years, but I might just sell this after it's fixed and bump up to an IS model, maybe something within list last century ;P

Check the videos of my 85mm. Sounds kind of similar

https://photography-on-the.net …/showthread.php​?t=1456833

Not that I'm any help it was like that when I got it.

1. AF slow = faulty USM motor, needs rebuilding or adjustments.
2. AF hunting back and forth, sometimes misses focus = problems with AF optical encoder (or zoom encoder). Encoder ring might be dirty, scratched or misadjusted.
3. No AF (or hesitating AF), slippery MF = Loose spring pressure against USM stator or AF lens mechanism jammed.

travisvwright: Your 85mm seems to have option 2: faulty encoder

I dropped mine, and it wouldn't focus, had to take it in to a local guy and he set it right. I'd say the repair didn't quiet repair it all. JMHO.

ksbal wrote in post #17965112
I dropped mine, and it wouldn't focus, had to take it in to a local guy and he set it right. I'd say the repair didn't quiet repair it all. JMHO.

He repaired the part that was broken for sure. The whole front end of the lens was moving about 1mm.

Owl_79 wrote in post #17965046
1. AF slow = faulty USM motor, needs rebuilding or adjustments.
2. AF hunting back and forth, sometimes misses focus = problems with AF optical encoder (or zoom encoder). Encoder ring might be dirty, scratched or misadjusted.
3. No AF (or hesitating AF), slippery MF = Loose spring pressure against USM stator or AF lens mechanism jammed.

travisvwright: Your 85mm seems to have option 2: faulty encoder

That's the weird thing with this, it's none of those. It's in the shop right now, hopefully not too expensive