Baaahhhh Trans!

[SourTooth307]

Hey everyone. Something seems to be up with my trans, maybe you can help me diagnose it....

Took a 300 mile round trip yesterday in my 84 K/10 and noticed what I would call a rare problem. Aside from the afore mentioned clunking into Drive or Reverse my trans is a perfect shifter. I happened to notice there is a minor slip going from 1st to 2nd ONLY when moving along at a crawling pace with very light throttle. I saw this happen when sitting in bumper to bumper traffic driving past Philadelphia. If you're taking off from a dead stop and have enough room to give it a normal amount of throttle, even in a 25mph zone there is no noticeable problem. I also noticed if you do this exact kind of driving while not in the Overdrive position (regular "D" on the shifter) the problem disappears completely. I had it do this once before while sitting in traffic near Queens, NY so I pulled over and checked the trans fluid which was a quart low. The problem seemed to disappear after topping off the fluid with a fresh bottle of Dex/Merc from Advance Auto and driving for a little while. The trans fluid level is currently fine, but the fluid itself looks a little on the dark side. My head is thinking it might be time for a trans service with filter change, but I'm unsure if this is the beginning of an internal failure. Anyone have any ideas what kind of trouble I'm looking at?

[imjeff]

If your fluid isn't bright and clean, change it. The clunk isn't your transmission, it's the slack in the rest of your drivetrain. Heat and dirt is what kills transmissions. Slipping generates heat. Transmissions are made to slip for comfort. That's why shift kits reduce heat...less time with clutches slipping equals less heat. Its not possible to tell you if your transmission is terminal by what you wrote. I would change the fluid and filter, fix any leaks and see how it runs. You may want to take a look at your u-joints as well.

Jeff

[SourTooth307]

Originally Posted by imjeff

If your fluid isn't bright and clean, change it. The clunk isn't your transmission, it's the slack in the rest of your drivetrain. Heat and dirt is what kills transmissions. Slipping generates heat. Transmissions are made to slip for comfort. That's why shift kits reduce heat...less time with clutches slipping equals less heat. Its not possible to tell you if your transmission is terminal by what you wrote. I would change the fluid and filter, fix any leaks and see how it runs. You may want to take a look at your u-joints as well.

Jeff

Overheating was something I was thinking of too. I wonder if my performance headers are generating too much heat by the bell housing. My custom dual exhaust runs right alongside the trans. Might be time for some heat shielding......

[imjeff]

Originally Posted by SourTooth307

Overheating was something I was thinking of too. I wonder if my performance headers are generating too much heat by the bell housing. My custom dual exhaust runs right alongside the trans. Might be time for some heat shielding......

I doubt it. It probably overheated from being low on fluid, sitting in traffic, etc. when you sit in traffic your TC is still generating heat. When was the last time the fluid was changed?

[SourTooth307]

Originally Posted by imjeff

I doubt it. It probably overheated from being low on fluid, sitting in traffic, etc. when you sit in traffic your TC is still generating heat. When was the last time the fluid was changed?

Anytime between 1984 and when I bought it back in February. Sadly I didn't notice the condition of the fluid until recently so it could be a fair assumption that it needs changing. The fluid might not be low, but if it's thin I would assume that's just as bad......

[imjeff]

Originally Posted by SourTooth307

Anytime between 1984 and when I bought it back in February. Sadly I didn't notice the condition of the fluid until recently so it could be a fair assumption that it needs changing. The fluid might not be low, but if it's thin I would assume that's just as bad......

You said it was a quart low which increases heat. It's supposed to be thin.