Clunk on Acceleration (1 Viewer)

[RFB]

A slight clunk on starting from a stop. I have new OEM DC up front and in rear. I grease it religiously even when on the road these have like 10K on them. using red and tacky for u joints all OEM u joints. what am I missing. its not a junky clunk but its not smooth like it was.

 

[leonard_nemoy]

My control arm bushings, (frame side) made a clunk on acceleration

 

[chap79]

And you are greasing the CV joint in between the u-joints? Are you sure it is coming from the front end? How’s the rear upper and lower control arm bushings?

 

[RFB]

And you are greasing the CV joint in between the u-joints? Are you sure it is coming from the front end? How’s the rear upper and lower control arm bushings?

I grease everything I pull front DC way too much actually and its OEM so the ball has a zerk not a needle fitting. and my rear upper and lowers are new blackhakws and landtanks respectivly.

 

[chap79]

And no movement at the u-joints? When did this start, after the new driveshafts?
IIRC you had Valley Hybrids replace your TC output bearings last year, how’s your pinion backlash? Drive flanges?

 

[RFB]

And no movement at the u-joints? When did this start, after the new driveshafts?
IIRC you had Valley Hybrids replace your TC output bearings last year, how’s your pinion backlash? Drive flanges?

OTRAMM DID MY BEARINGS, It started after last trip out west. its not HUGE but I would rather it wasnt there, pulled front rear greased checked all flanges for play nothing one u joint is sticky on rear DS but other wise all is well. I checked everything BEFORE posting here. and only thing i have is a ujoint that isnt silky smooth.

 

[chap79]

OTRAMM DID MY BEARINGS, It started after last trip out west. its not HUGE but I would rather it wasnt there, pulled front rear greased checked all flanges for play nothing one u joint is sticky on rear DS but other wise all is well. I checked everything BEFORE posting here. and only thing i have is a ujoint that isnt silky smooth.

I feel your frustration, I went though 4 drive shafts last year. Playing in the big rocks can get expensive. When chasing my clunks I replaced all the bushings, drove with just front or rear shafts, disconnected sway bars, new panhards... I know you’ve thrown a lot of money at that rig getting it dialed in and it’s been interesting watching it transform over the years (I remember when it got lined by PO).

Have you tried running Moly in the u-joints? Maybe they’re just too sticky

 

[MaTm]

Check your engine and transmission mounts?

 

[RFB]

Check your engine and transmission mounts?

ok nice, Ive been thinking they could be culprits I just dont know how to check for play or how much they should have I was going to replace anyway after 330K with 37s and supercharger I assumed it wouldnt be wasting money.

 

[RFB]

I feel your frustration, I went though 4 drive shafts last year. Playing in the big rocks can get expensive. When chasing my clunks I replaced all the bushings, drove with just front or rear shafts, disconnected sway bars, new panhards... I know you’ve thrown a lot of money at that rig getting it dialed in and it’s been interesting watching it transform over the years (I remember when it got lined by PO).

Have you tried running Moly in the u-joints? Maybe they’re just too sticky

i had been using moly for a year or so, then saw one of the "elders" here mention red and tacky. I use redline for birfs moly, red and tacky for u joints.

 

[RFB]

I feel your frustration, I went though 4 drive shafts last year. Playing in the big rocks can get expensive. When chasing my clunks I replaced all the bushings, drove with just front or rear shafts, disconnected sway bars, new panhards... I know you’ve thrown a lot of money at that rig getting it dialed in and it’s been interesting watching it transform over the years (I remember when it got lined by PO).

Have you tried running Moly in the u-joints? Maybe they’re just too sticky

i have read the PO posts over and over for the last 2 years and yea white with 20in chrome rims lol

 

[bryson]

Rear driveshaft slip yoke can cause a clunk as it binds and unloads on start/stop. It's a fairly common (but seldom mentioned here) issue. Mr T. even has a TSB on this exact issue for at least the early 200 series Cruisers. I know for a fact that my 80 rear has this exact issue.

This video explains the issue even though it is on a F-150 with the slip joint on the output shaft, the principle is the same. They call it "Slip bump" or Slip Lock".

 

[RFB]

Rear driveshaft slip yoke can cause a clunk as it binds and unloads on start/stop. It's a fairly common (but seldom mentioned here) issue. Mr T. even has a TSB on this exact issue for at least the early 200 series Cruisers. I know for a fact that my 80 rear has this exact issue.

This video explains the issue even though it is on a F-150 with the slip joint on the output shaft, the principle is the same. They call it "Slip bump" or Slip Lock".

ok but it wasnt happening when DS was new 10K ago and its not a thing to worry about? because I worry. lol

 

[bryson]

ok but it wasnt happening when DS was new 10K ago and its not a thing to worry about? because I worry. lol

I'd guess it wasn't happening when new because the slip yoke was probably (lightly) lubed during initial assembly. I never said it wasn't a thing to worry about (and I don't recall hearing that in the video) - I'd disassemble the slip, clean it out, reapply a good, thick (probably moly) grease inside the splines and reassemble the shaft. I think disassembly is key though - make sure you get the grease inside ALL the splines. I had a Ford Excursion with this exact issue, and the solution was to pull the slip apart every 10k or so and apply grease to the splines. It was required that often because the grease doesn't stay put forever, and the clunk would come back. I assume that the duration of the repair is directly related to the quality of the grease used. It did have a grease zerk on the slip, but the grease wouldn't get where it needed to when pumped in, hence the disassembly.

Toyota's TSB for the same issue in the 200 series is a full replacement rear driveshaft. I don't know what they changed, but it certainly fixed the issue in my 2008. I suspect it's a different slip yoke with more spline surface area to spread the load. Maybe a different factory-applied grease as well?

 

[RFB]

Cool because I did all that last night, Thanks for the info brother. I always worry about greasing the splines too much or too little. Ive gone through some driveshafts over the last couple years and a lot of miles. so my DS are always something im concerned about.

 

[BILT4ME]

Cool because I did all that last night, Thanks for the info brother. I always worry about greasing the splines too much or too little. Ive gone through some driveshafts over the last couple years and a lot of miles. so my DS are always something im concerned about.

You can also drill and tap a new hole in the side of the yoke to install a new zerk so you can grease more areas.

 

[RFB]

You can also drill and tap a new hole in the side of the yoke to install a new zerk so you can grease more areas.

you do realize Im still trying t figure out f your breaking my balls. If I could tap the shaft where splines are Im thinking all would be well. But it wont throw off balance( i know its a tiny item) but I keep this girl running smooth, hence the OP

 

[BILT4ME]

you do realize Im still trying t figure out f your breaking my balls. If I could tap the shaft where splines are Im thinking all would be well. But it wont throw off balance( i know its a tiny item) but I keep this girl running smooth, hence the OP

No, I'm not busting your balls.

Totally serious if you find there is a dry area in the splines.

You will be removing material to replace it with similar amounts of new material so your balance would only be affected by a tiny amount.

 

[RFB]

No, I'm not busting your balls.

Totally serious if you find there is a dry area in the splines.

You will be removing material to replace it with similar amounts of new material so your balance would only be affected by a tiny amount.

I didnt think so , but as youve seen its happened to me b4, lol thanks man

 

[nukegoat]

Live with it IMO