When I replaced the Radiator about a month ago. I noticed the trans fluid looked more like engine oil.... Today I had the trans flushed (more like drained and replaced) I noticed the other day I had a bit of a slippage when it shifted into high. Hopefully the fluid change will make a difference. Mostly staying on the roads with this truck, next will be new tires...

 

Please post your assessment once you've given it a go. Did they replace the filer or just dump out everything they could and then re-fill? I feel like my tranny slips some but it's overfull and I need to do something here soon. Was thinking of just draining everything I can and adding in the new.

 

They extracted out the dipstick tube, so I am guessing they got as much as they could. They used some cleaner and conditioner added afterwards, no filter change as everything was done from the top. Fluid is a red coor like it should be so I feel good about that. Went about 100 miles yesterday driving to work and back with no problems. It wasn't cheap, about $170 and took about an hour.

 

When I changed my fluid I added a bottle of Lucas Transmission Fix, because that's what Disco Mike said to do. Thousands of miles and I haven't had any problems with my transmissions.

 

What can happen when transmission fluid is changed, is new fluid doesn't have enough anti-shudder agent for your transmission. There are different additive pkgs. II went through this yrs ago on a GM pickup. About 25 miles after changing the fluid, yeah, I had all kinds of shifting issues in OD. Thought it was toast. But I came across some posts describing how Penzoil Dextron III had more anti-shudder agent in it for older vehicles. I exchanged fluid again with the Dextron and yeah, it went away after about 25-40 miles. That was probably 16 years ago and still runs great.

What JohnZo described above is, adding the Lucus Trans Fix probably added more anti-shudder agent. You might want to consider it. Or change your fluid with another fluid, like the Penzoil.

 

Been about 600 miles and no problems so far...

 

Great to hear. Happy motoring!

For others reading this, the below product is kind of an anti-shudder additive that often resolves shudder. Or replace the fluid with different tranny fluid with good anti-shudder additive (like Penzoil). Or add the below to your tranny fluid if you sense shudder. It's not an uncommon condition at all across most makes of vehicles. Doesn't necessarily mean yer tranny's failing, just that the fluid friction properties aren't quite 'correct'.
https://www.lubegard.com/products/isf/

 

My 99 Expedition would do that if I didn't change trans fluid about every 30K miles. Had over 300K miles when I finally gave up on it. At 50K miles the dealer said it needed a new trans because of the shudder at 57 mph. Lucas makes a good product!