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Help me identify mysterious part that appeared after removing oil pan!?!
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
so how di the hole in the center of the U-joint trunnions get there in the first place?
at the factory... So serviceable ones have holes all the way through them, so you can grease them, but non serviceable ones still have a "reserve" of grease in that hole so they last longer, but not a hole all the way through.
Yeah I'd call it a grease reservoir. I'm sure it gets hot enough in the u joint that the grease melts all the time and it is constantly remixing all of itself into the needle bearings.... Sounds like a good idea to me anyway... Haha.
So if I understand....a U-Joint that is not serviceable is, for lack of better terms, hollow..with no apparent evidence of external drilling to make it that way, no zerk fitting...and is cast in such a way they fill it with grease?
So if I understand....a U-Joint that is not serviceable is, for lack of better terms, hollow..with no apparent evidence of external drilling to make it that way, no zerk fitting...and is cast in such a way they fill it with grease?
Kind of but not quite. Take a look at Randy's photo again. The center cross is a single part with four "arms" that are the trunnions. There is a shallow hole drilled into the end of every trunnion and grease is packed into them. The bearing caps fit over the trunnions and it is centrifugal action that pushes grease from the reservoir hole into the needle bearings. The center of the cross is not hollow; it's solid.
Kind of but not quite. Take a look at Randy's photo again. The center cross is a single part with four "arms" that are the trunnions. There is a shallow hole drilled into the end of every trunnion and grease is packed into them. The bearing caps fit over the trunnions and it is centrifugal action that pushes grease from the reservoir hole into the needle bearings. The center of the cross is not hollow; it's solid.
and just to add, as the grease heats up, it expands a little, so it's also to give it some space to expand without coming out of the cap.
So the part in the picture which is the trunnion of a universal joint is what was cut off and was in the undercarriage some where long enough for the cut end to gather all the grease and grime.
better than the guys with the 2021 rubicon that left it in 4lo and 1st gear, towed behind his motorhome. you could see the valves in the head, from underneath.
Oh man I saw that video. That thing grenaded. I cant believe the people towing it couldnt tell it was a little more difficult to accelerate the RV....
Must have been some people that had no clue and just wanted to have an RV with a cool jeep behind it...
Or they kept it in gear for another reason and forgot about it...... Maybe they went to sleep and then woke up to keep driving down the road and forgot to take it out of gear...
But it seems like we have decided on u-joint trunnion as the mystery part..............................
So the part in the picture which is the trunnion of a universal joint is what was cut off and was in the undercarriage some where long enough for the cut end to gather all the grease and grime.
Alright you guys are wizards. Thank you. I'm going to go check everything in the front end to make sure something wack didn't happen to the u joints (front driveshaft is wiggly where it has the zerk on end that connects to front diff).
BUT what almost certainly happened is that I did the rear driveshaft ujoints and ended up taking an angle grinder to one. It probably rolled under somewhere and I missed it in the clean up. Still odd that there would be rust at the end of it though since the caps were on all the ones I took off... I'll report back if there's anything crazy but this gives me a good jumping point. Thanks guys.
Rust is just probably because the outer area of the trunnion could have been coated with something to prevent rust, where as the inside of the metal doesnt have the "coating", so it rusted....
Rust is just probably because the outer area of the trunnion could have been coated with something to prevent rust, where as the inside of the metal doesnt have the "coating", so it rusted....
Why rust only on the cut end?
cut end was fresh exposed metal, other surfaces had grease on them? or the part had an anticorrosion finish on the uncut surfaces.
03-18-2021, 05:06 PM
