Finally got around to greasing the slip-yoke in my 2002 F150. Long story short after doing this, the transmission seems to be slipping in first gear. After a few miles of driving the truck first gear seemed weak, didn't really want to creep like usual. And the moment the engines starts revving the trans kicks in harder and the truck sort of lurches forward. Only really happens form a standstill. Seems to shift ok after that.

What I believe happened was that I gobbed too much grease into the slip yoke, and when I put it in, a bunch of grease squeezed out into the transmission fluid.

So do you think the transmission is screwed? I drove it maybe 20 miles like this. I was thinking I could maybe flush the transmission fluid and see if that fixes it. Although the truck does already have 180,000 miles so the tranny may be due for a rebuild anyway.

Driveshaft clunk is gone lol!

 

have you checked the trans fluid level ? How would you get grease into the transmission by putting grease on the splines ?

 

 

The only way it would slip is if you used moly grease Nd put a ton of it on there. Is this truck 2wd?

 

 

Well I would immediately try to drain and refill the transmission. Lucky the 2001 trucks have a torque converter drain. So if you drop the pan and drain the torque converter you will get most of it out and then you can inspect for physical debris in the pan.

 

 

Well coming from someone who did screw up one of these 10 years ago putting too much moly grease I know the consequences well. But PTFE grease is safer and it could be coincidental but you should do a drain an fill.

 

Drove the truck again today. Felt completely normal and never felt like it was clunking into 1st gear like it did yesterday.

So I think it was the 20 miles of bumper to bumper traffic that probably overheated the trans. Still not happy with the way it felt. But the transmission probably isn’t in top shape after 180,000 miles.

Still think it’s worth it to change the fluid? It actually looks really good, not burnt and has a nice red tint.

 

how old is the fluid..?. could be lots of CRUD floating around inside that can stick valves, etc... COLOR is not all that is important.

 

 

yes replace the filter along with the fresh tranny fluid....just stay away from Fram....better off with OEM or wix filters

 

 

UPDATE:

So this is what it looked like when I changed the trans filter and fluid. little to no debris, but as pictured the fluid was pretty dark. Turns out my truck didn't have the converter drain so I only ended up replacing a little over 4 quarts of fluid. Still seems to act the same when the trans is hot. Seems ever so slightly better, but that may be my imagination.

So my big question is whether I should get all the fluid flushed? Talked to a few transmission rebuilders and they said a flush would be wasting my money, that the clutches are probably worn down to the metal, one even said a flush could make it worse since the transmission wouldn't be used to thinner fluid. Although they sort of trailed off when I asked why it acted normal 99% of the time.

Anyway what do you think? Would a transmission flush be a waste of money and trash the transmission, or are the rebuilders just wanting another customer?

 

Your report that the engine revs and then the trans takes hold suggest the A solenoid opens, the pressure rises, then the Servo 'fast' engages the clutch pak..
This suggests the valve in the valve body is either sticking or it's spring is broken.
The spring is there to soften the fluid flow to the SERVO and prevent harsh sudden engagements.
Good luck.
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