Alright, Ive posted this problem before, and basically was told to grease my rear slip yoke. I did, despite not wanting to. It fixed it for a little while, but has since returned.

ONLY from a complete dead stop, and only when given enough throttle it will "clunk" really hard, and loud. It is fairly violent and has me concerned. I ease into the throttle, nothing. I park on a hill, or am towing, the clunk is much louder.

Yes, I could regrease the slip yoke, but thats putting that grease into T-case thats not needed in there, and not wanted. (where else would it magically be disapearing to ?)

What is the actual fix ? What is it that makes the clunk ?

I'll be diving deeper into this issue later this week, its just came to my mind, thought I'd ask yall again. I don't want to regrease all the time, to me, thats just not right. I have owned many vehicles of all shapes and sizes, I work on them for a living, and have NEVER heard of this as "normal procedure".

Any ideas at all ?

Thanks

 

when I was hearing adn feeling a clunk on my truck it was because the rear differential had shattered and I was trying to figure it out for about a week before I desided to take the differential cover off to take a look and I saw that the rings teeth were gone and some other components cracked in half

not sure if it is that for sure with your truck but just a thought

 

Maybe the truck misses the crazy kid that used to be in your sig. Bring him back, and see what happens.




Needed the post count, but you know this already


Hope you get it figured out. That sucks.

 

-Yea, where's the kid man? Reminded me of my x's step brother.

Anyway - You have to really clean male/female ends up well and then make sure it's dry. Carb Cleaner/Brake Cleaner -Something like that. The TSB calls for Ford Teflon grease. I used Amsoil Teflon/Tacky (Red) and haven't heard that clunk again.

That was 3 or 4 years ago.

BTW- It may help to change out the rear gear oil - New 100% Syn and 8 Oz's of friction modifier does wonders. That's prolly all you can do without getting to extreme. I would try that first and give it a couple 100 miles to cure. Sounds funny, but it takes a little time for the rear end to heal if the oil was insufficient/broke down.

"Clunk's" caused from binding. - Good question tho, I'm not sure. I guess it could be from the rear or the Yoke. Maybe both - I know those Yokes have wore out in the past in Higher Mileage trucks.

 

i found a moderate amount of gear lash in my t-case. i dont know whats within spec but it sure seems like quite a bit. i hear the clunk when it downshifts sometimes, or from going from rev to d.

 

..."not a normal maintenance procedure".

The two '78 Broncos I owned had a grease zerk at the slip-joint and I wish our current trucks did also.
Question: The slip-joint has a rubber accordian boot clamped in place with a crimp style metal ring. If the crimp portion of the metal ring is not in the same position as before re-greasing, will the driveshaft be out of balance?

 

MT- It probably depends on what kind of grease you used. I know there is a certain kind of grease Ford uses on them now which usually solves the problem for good... If that doesn't fix it then I guess you would need a new driveshaft

 

To go along with what Klitch has mentioned about the transfer case.. I also have the "clunk"..I atributed it to my worn out rear assembly witch I am posting about in this forum.
I did find the same amount of gear lash in the transfer case at the output to driveshaft.
also lateral movement..
I'd say check it all out, in my particular case, everything is excesive from the output shaft of the transfer case to the worn out rear end..enough combination slop to make for a super duper "clunk".
For now I can only try to repair the rear, it will be intersting to see if the "clunk" goes away with the rear fixed and the sloppy transfer case...
btw ...180K on my trans, x-fer, and rear..
Chris

 

yeah i have high miles on my t-case too. i just cant seem to find any specs on it, although i didnt have any lateral movement that u spoke of.

 

Thanks for the replies.

I'll try bringing the kid back in the sig, but I happened to come across the actual story behind that kid... and it just lost its "funny factor". Some poor fat little girl, at age 7 she weighed like 400+ pounds or something.

Anyways, I do check my oils regularly, and I do peak inside on a regular basis to see if anything is FUBAR. Its not, teeth or clean, straight and the oil looks good. There is no extra play in anything underneath and this is what leaves me stumped. I tried putting high heat SWEPCO grease in the slip yoke, and the clunk is back.

I think i may try Brew's idea. Swap in some full synthetic. Probably go with Royal Purple. Then run next door to Ford and grab some of their "special high heat grease".

Guess I'll have to letcha all know how it goes. Thanks again

 

That wasnt trimble in your signature?


Anyway MT, good luck with your rear end...

sorry man, gotta bust ya

 

This may sound like a really weird idea but give it a shot...

Take one those little rubber bouncy ***** (super ***** or whatever you want to call them) and put it inside the yoke of the driveshaft so it is on the end of the output shaft of the T case but also still inside the yoke. I would bet dollars to donuts that it works for most of you

 

problem - too many sizes of *****... which size?

question : theory behind this? the drive shaft on my lifted truck is not bottoming out the slip yoke.

 

Hmmm, I have a question now lol.

This is a old and common problem with the half tons - Ford has had a TSB for a long time about this - Always happens coming to a stop.

I wonder if this happens with 3/4 tons ? The half ton springs are junk. They tweak and squeak after awhile. - Don't put to much in her all at once, she'll never be the same

 

Teflon

That's what you want and what Ford uses - An "Extreme Pressure" mixture w/low deflection.

IMO - There isn't any grease that lasts forever - The ONLY grease that's worth a sh^t is AMSOIL - Specially in sub-zero temps. AMSOIL doesn't freeze + hangs around the longest - Good ****!! Best I've ever seen and used myself. It's prolly expensive - I wouldn't know "PERK"