new gears, bad vibs and whine?? (1 Viewer)

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TexasD90

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Ok, I have been searching for a few days, and I have tried a few different things that have been recommended on the forum. I am still having issues. Here is the situation:

I'm running 850J's up front with 30mm spacers and 863's in the rear with 30mm spacers. I am running caster correction from Man-a-fre (they are mounted on the frame side). Stock front shaft. I know my caster is off slightly since I added the spacer, but has not been an issue.....

I rebuilt my front axle and while I had it apart went ahead and had my Nitro 5.29's installed in both thirds. Upon re-installing the thirds I noticed some noise. There is a whine coming from what I think is the front third member. It is constant, gets louder with speed, and never goes away. Also on deceleration I am getting a bad vibe/rattle/grinding noise.

So, I started searching around and after reading decided it must be my front drive shaft making more noise due to rotating faster with new gears. I pulled the drive shaft, locked the cdl and went for a drive. The whine seems to be gone, but I'm not sure if that is because the gears are not under load. The same vibe/rattle/grinding noise on deceleration is still there.

This leads me to believe that it is not the shaft. Maybe the diff is not set up properly? I had it done by a very well known Toyota and 4x4 specialist over in the dallas area. He was highly recommended and has done a ton of these. He tells me everything is in spec... I don't know. On top of all of this I have a leak at the pinion seal on the rear.

What are your thoughts and ideas???
 
sure sounds like a bad setup job. specially if the rear pinion seal is leaking in a brand new setup. did you go all the way and install new bearings and everything?

grinding/rattling noise from the back on deceleration sounds a lot like broken/bad outer pinion bearing and/or loose pinion bearing nut behind the driveshaft flange (edit, i mean behind the u-joint plate. the nut holds the flange in place and controls the pinion bearing preload).
this is backed up by your pinion seal leaking. can you feel any play (up, down, left, right) if you try to move the flange around? make this with the car in neutral on a flat, level ground. e-brake applied :)

also give the u-joints a good inspection.
 
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That is about where I am right now... I feel like possibly the preload is off on both thirds causing the whine in the front and the leak in the rear. Anything else it could be?

Yes, all new Toyota install kits from slee (bearings, seals, etc.)
 
I did a 5.29 setup for a club member and there was a bad bearing in the kit. Tore everything down and one bearing was definitely not running right. I ordered a whole new kit and rebuilt it and it's been perfectly fine.

it happens.
 
a whine that changes with road speed, and changes sound from accel to decel sounds like a bad gearset. There may be a problem with the installation or one of the many parts inside.

Next step is to take it out and check gear contact.
 
So.... I guess I need to pull the thirds again and have them redone
 
I have had them in for 2 weeks. As per my installers direction I took 4 trips to start. 2 at 2 miles each and then 2 at 3 miles each staying under 45mph. Then I started driving about 10 miles per trip and allowing complete cool down. When I would stop I put my hand on the rear third member to make sure it was not too hot to leave my hand on. It never did get too hot to touch. Then we started driving it to town for church (40 miles) staying under 55 mph. Still the diff housing never seemed to get that hot. The truck would cool completely as we sat in church for 2 hours. The diffs now have roughly 150 miles on them and they have not been over 55 mph.
 
Just throwing this out there, based on my experience.

Before regearing, had an OE front shaft installed that was refreshed (new U-joints, lengthened, and balanced) and worked perfect. No noticeable vibes or whines.

After regearing, (by Robbie Antonson, to establish credentials) Robbie drove, called me and said he was concerned that something was wrong (transport is waiting on his lot, at this time) and was going to check gear pattern pics to rule out.

Calls me back, said they're perfect, as he knew they were, and that he was pulling his front DS (16 year old, DC jointed, in very used condition, showing signs of sway bar contact at the slip yoke) and driving again.

This fixed all issues. (Edited: in retrospect, it corrected due to the slip yoke being crushed. Pressure between output flanges and reason why a new DC shaft didn't)

So, I get 80 back, put on a new DC DS that's the same length as Robbie's 16 year old shaft, and it whined, growled, vibrated so badly I was concerned about damage after three miles.

Problem solved with newest shaft, but my point is, it may be a good idea to further investigate DS solutions before pulling thirds again.

Check the TC output bearings, as well, since previous slack may no longer be present and the varying speeds may be causing the noises.

A pro's first though upon experiencing similar was the gear pattern being incorrect, and all wound up being attributed to DS, so the potential exist that's your issue too.
 
I have pulled the shaft and driven without it. the issues still were present.
 
that is possible. the whine was for sure less noticeable, but the grinding/vibe was still there. you think possibly 2 different problems? could be shaft up front and something else in the rear?
 
You mention touching the rear third for temp, you did this also for the front?

I personally think you have a couple of things going on. I would take the truck over to the installer and have him listen to it. To me, ithe whine sounds just like the time I had a bad bearing which was the inner pinion on the front diff.

As for the vib, while the shaft is definitely spinning faster the load on it is reduced as the gears reduce the effort to turn the tires. I think it's that drop in load that brought out the vib.
 
But the vibe stays the same with or without the shaft.? Is the vibe in the third??
 
How about taking the drive flanges off the front hubs and front DS to isolate the front third?
 
just the front one. I haven't heard of people having trouble with rear shaft. could that be a possibility? guess i could try it just to eliminate the question. removing the drive flanges is also a good idea. supposed to take it to the installer on friday if i haven't figured it out by then.

i did also check heat in the front diff, but it was never hot. was always significantly cooler than the rear.
 
Throw this in the mix. I know how bad this sucks and I know I'm offering little.

Rock caressed my shaft in Clayton ( I know, Rick. I know) but wasn't able to isolate it for several days. Felt like a tire out of balance and could feel vibrations (can't hear chit in mine, due to exhaust).

When I pulled and took for repair, drove front only for 4 miles ( Tulsa block ) and vibe was gone.

Another local's rear output bearings mysteriously went after regearing, too. Said it was fine but in last 100 miles, heard/felt something. Thought gears but wound up being TC bearings.

Not sure how to diagnose bearing play.
 
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