75 mph vibrations.

[Ozymandias]

Buy a digital angle meter, from Amazon they are in the 20$ range and accurate.

Something like this >> Amazon product ASIN B00T6YZ0K6

 

[okiemoto]

Gotcha. Also, I just called 2 alignment shops. They told me there was no way caster was causing that vibration. I probably shouldnt have mentioned anything about it and just had them align it to see what happens.

Regardless I have a friend that's at a dealer and I'm going to try to get it to him. Hes about 1.5 hour drive away.

 

[sag2]

You posted as I was typing my previous response. I will get a dial indicator and check runout. If I'm not mistaken thiugh you can not "phase" the front driveshaft. It makes up to the companion flange in only one orientation I'm pretty sure. Will definitely check and advise as I have time.

I't been a while, but I believe they were all able to go 180°.

 

[okiemoto]

Ozyman has me thinking. After quick bits of research I'm seeing that the 2 alignment shops have no idea what they're talking about when it comes to caster. After a few minutes of research online it has a very direct affect on pinion angle.

Jeep forums have quite a bit of good information on this. Hopefully we are on to something. Fingers crossed!

 

[Ozymandias]

Yeah, they are not used to have front live axle vehicles around.
Aside from the Wrangler i think our trucks are the last vehicles with that still in production.
They know IFS with a fixed to the body differential.

 

[Ozymandias]

I get the same vibration at about the same speed but mine kinda pulsates. I very rarely go on the highway so I haven’t personally looked at it yet. Interested in seeing what you ultimately find

Is the center ball of the double u-joint properly greased?

 

[okiemoto]

Just to update this thread. I called a non chain store alignment shop this morning and spoke with a guy and he said it would be awesome if it was just caster out. He said if not at least you have concrete numbers to go off of. I'm going to hold off on doing anything else to the truck until I have that info.

I found thuren fabs alignment specs for these trucks. Something along the lines of 0 total toe and 3.8 to 4.2 degrees caster. I'm going to recommend he go by these specs however, I need to double check the truck has the "t" style steering not the factory y setup.

Anyone used the thuren specs? Truck drives great and doesnt wear tires unevenly at all I dont want to start an issue that isnt there.

 

[Ozymandias]

Yes I run this specs, fantastic.
If you still have the Y-Steering I recommend you upgrade to the T. It's somewhere around 300$. Truck drives wonderful with it, no more fighting to keep the lane going down the road.

 

[cerberusiam]

If caster is causing it you have a problem in the axle somewhere, there is no way the amount of caster change that is available in the eccentrics will have any effect on vibes UNLESS a component is bad. Predominantly on the front end if you have not changed the unit bearings I would be pulling brakes and spending time check them for issues.

 

[AEdelheit]

If caster is causing it you have a problem in the axle somewhere, there is no way the amount of caster change that is available in the eccentrics will have any effect on vibes UNLESS a component is bad. Predominantly on the front end if you have not changed the unit bearings I would be pulling brakes and spending time check them for issues.

I have personally seen people max out the caster cams running 6.5deg plus of caster causing front driveline vibrations, even more so if the truck if lifted at all.

 

[okiemoto]

The truck is stone stock as was stated. Also the vibrations are gone in the truck with the front driveshaft out. Outside of the vibration I have no issues. That being said I have a brand new unit bearing awaiting the inevitable failure. The drivers side i will admit I have not checked for play. However, the passenger side just got a brand new axle u joint. I thoroughly checked everything over on that side and everything seems fine. No play in the wheel and again no uneven tire wearing.

I have an appointment scheduled for next monday at 1230 to have it aligned. Fingers crossed.

 

[GCroyle]

Popcorn is ready.

 

[Jasonmm]

Hello everyone so about 10 years ago I built a CJ7 Jeep and it had a small lift in it while I was building it I put in a double cardan shaft just like the ones that are in the front of these trucks. So by referring to the caster being out of alignment it’s not the caster itself that would cause the vibrations is the angle that the U joint is put into at the pinion flange. You can’t change one without the other because the inner c flanges are welded to the tube. With a 3 joint double cardan shaft you want the drive shaft going straight into the pinion or 1-2 degrees down so when the drive forces are applied the pinion angle deflects and pulls it straight. Maybe over time the suspension has settled and the angle is off now. Also I would check the slip yoke for side to side wear unless it was replaced when you had it rebuilt. With a 2 joint standard drive shaft you want the pinion to be parallel with the slip yoke that comes out of the transfer case. I hope some of this might help.

 

[okiemoto]

Hey sorry havent updated this thread. A few weeks back I took some vacation time with one of the goals being to figure this truck out. Unfortunately other things came up and I wasnt able to do that. I ended up having to cancel my alignment appointment.

Hopefully in a few weeks I'll be able to get it on an alignment rack and have some numbers. I do intend to keep this thread updated but no news yet.

 

[nibroc]

patiently awaiting the outcome

 

[okiemoto]

Update to the thread. Sorry I have been super busy with work and kids getting back to school I havent had any time to mess with the truck.

I have called and scheduled an alignment tomorrow morning and I will be updating the findings when I get the truck back.

However. I am afraid this may not be the issue. Last weekend I had to put the t case in to 4 low and I heard the chain skip. Also a few times it sounded like it bound up and released. So the "rebuilt" transfer case could possibly be the culprit. Gotta call the dealer and see if I can get info on who supposedly rebuilt it and get with them to see if theyll stand behind their work or tell me to kick rocks.

If not looks like a learning experience for me...


I'm editing this post because I dont believe it was the chain skipping. I dont have anyone to help me determine where the noise is coming from but I just tried to recreate it in the driveway and think it may be the axle u joint. I'm going to bring it up to the alignment shop in the morning and see if they can help me pinpoint the noise. Fingers crossed it's not the t case.

 

[okiemoto]

Went to my alignment appointment this morning and I TRIED TO BY-PASS THE CUSSING FILTER chatted with the tech. We pulled it up on the 4 post and crawled under it. No accurate measurements but noticed a little slop in the front output bearing of the transfer case.

If I had to guess by feel there's probably .003 play in the bearing and he said that is more than likely the issue. We didn't even check alignment. He said there was no sense in it. Everything was tight and no uneven wear.

Got a quote of 3k to rebuild transfer case today and 2500 if I r&r it but if I r&r there is no warranty. So for time being I am going to drop the front driveshaft and drive in 2wd until I have some down time and can spend a couple of evenings attempting to repair the case myself.

 

[cerberusiam]

Rebuilt doesn't mean new with all new parts. The rebuild kits are bearings, chain, and seals. Lots of other meshing parts in there that can wear and induce vibrations with the front DS on and nothing with it off.

 

[okiemoto]

Well the front output is the culprit. I intend to replace bearings, seals, oil pump, drive and driven gears. See what happens. If all else fails ill have to buy a professionally reman'd t case.

 

[Ozymandias]

Okay, we wanted you to check the alignment to learn if your driveline angle is out of spec and not if the tires wear even.
And you skipped on that because someone talked you into that .003 play is a problem... .003 is nothing.
Okay, go for it, spend big $$$$ on your TC, it will still vibrate.

You better buy a 20$ angle finder and check your self .