Transmission clunk when downshifting to 1st

[zonianbrat]

I did a search and read a couple of other posts regarding this issue but would still like to ask for some "fresh" advice. My 98 XLT will occasionally downshift into 1st when coming to a stop with a kinda harsh clunk. I say occasionally because it seems like when I slow down "easy" it clunks. But if I have to stop kinda abruptly it downshifts really smooth. I read in a previous post that greasing the driveshaft where it goes into the T-case might help. Has anybody else tried this and if so what kinda grease did you use. Would putting in an additive like Lucas help? Aside from the clunk the tranny shifts great. My X has 100,000 miles on it and I really dont want to think about rebuilding any time soon if possible. I just bought the truck like 2 months ago and have big plans for it "if" I dont have to start off spending like 1-2 G's on the transmission. I plan on switching to full synthetic in the transmission soon as I can get some time off. Thanks for any advice.

Bri

 

[storlied]

Do you have the 4.0L or 5.0L?

 

[zonianbrat]

Yeah guess I should have specified that. My bad it's been a long day and I am still at work! I have the 4.0 SOHC with the 5R55E (I believe) Automatic.

 

[IZwack]

I read in a previous post that greasing the driveshaft where it goes into the T-case might help. Has anybody else tried this and if so what kinda grease did you use. Would putting in an additive like Lucas help?

Yeah thats the usual cheap first fix -- regrease the splines of the driveshaft. Dont use Lucas on them though, use something thicker like lithium grease (or "bearing grease")-- its almost like Vaseline in viscosity.

 

[IZwack]

Oh and make some alignment marks on both driveshaft halves (tape works, or a marker) because the entire driveshaft is "phased" and balanced as a whole unit and must be reassembled back to the same configuration.

 

[zonianbrat]

Oh and make some alignment marks on both driveshaft halves (tape works, or a marker) because the entire driveshaft is "phased" and balanced as a whole unit and must be reassembled back to the same configuration.

Thanks for the tip. I have never taken out a driveshaft before so it should be an experience. I wasnt planning on using Lucas on teh splines but as an additive in the transmission. Thanks for the tips!